Ulipristal acetate versus levonorgestrel-releasing intrauterine system for heavy menstrual bleeding: the UCON randomised controlled trial and mechanism of action study

Article history

The research reported in this issue of the journal was funded by the EME programme as project number EME 12/206/52. The contractual start date was in October 2014. The final report began editorial review in October 2021 and was accepted for publication in August 2022. The authors have been wholly responsible for all data collection, analysis and interpretation, and for writing up their work. The EME editors and production house have tried to ensure the accuracy of the authors’ report and would like to thank the reviewers for their constructive comments on the final report document. However, they do not accept liability for damages or losses arising from material published in this report.

Copyright statement

Copyright © 2023 Whitaker et al. This work was produced by Whitaker et al. under the terms of a commissioning contract issued by the Secretary of State for Health and Social Care. This is an Open Access publication distributed under the terms of the Creative Commons Attribution CC BY 4.0 licence, which permits unrestricted use, distribution, reproduction and adaptation in any medium and for any purpose provided that it is properly attributed. See: https://creativecommons.org/licenses/by/4.0/. For attribution the title, original author(s), the publication source – NIHR Journals Library, and the DOI of the publication must be cited.

2023 Whitaker et al.

The clinical problem

Heavy menstrual bleeding (HMB) affects one in four women of reproductive age and has a profound effect on quality of life. 1 The burden of HMB is significant2,3 and prompts 1 million women in the UK to seek help for their symptoms annually. 4 HMB is responsible for the loss of 5 million workdays in the UK,5 while globally, direct and indirect treatment costs amount to US$1 billion and $12 billion annually. 6

The previous objective measurement definition of HMB as > 80 ml of blood per menses has been superseded by the more patient centred ‘excessive menstrual blood loss which interferes with a woman’s physical, social, emotional, and/or material quality of life’ proposed by National Institute for Health and Care Excellence (NICE) and adopted by the Menstrual Disorders Group of the International Federation of Gynecology and Obstetrics. 7 The underlying mechanism of HMB is multifactorial and is broadly classified into structural (including uterine fibroids) and non-structural causes. 7 However, rather than a classification-driven, precision-based approach, present-day management of HMB is driven by other factors, including age, desire for fertility preservation, clinician and patient preference. 8

Treatment for heavy menstrual bleeding

Current management options include conservative treatment (wait and watch), medical or surgical (endometrial ablation and hysterectomy) approaches. Medical treatments for HMB predominantly target the progesterone receptor (PR). The levonorgestrel-releasing intrauterine system (LNG-IUS) is recommended by NICE as the first-line medical treatment; alternatives include other progestin-containing pharmacological agents, gonadotrophin-releasing analogues (GnRHa), or non-hormonal options such as cyclooxygenase inhibitors and anti-fibrinolytic therapy. 9

Existing medical treatments for HMB are not effective in, or acceptable to, all women. While first-line treatment with the LNG-IUS substantially reduces menstrual blood loss, often resulting in amenorrhoea, unscheduled bleeding may be problematic, with up to one-third ceasing use within 2 years. 10 The invasive nature of the insertion of the device also limits its acceptability11 and, while not a contradiction per se (unless distorting the endometrial cavity), the presence of fibroids may increase expulsion rates. 12 Other hormonal treatments incur the risk of irregular unpredictable spotting/bleeding, mood swings, hot flushes and weight gain, which may impact compliance. 13,14

GnRHa induce oestrogen deficiency, which reduces bone density and causes vasomotor symptoms. These side effects limit long-term use of GnRHa. Non-hormonal treatments may also be discontinued due to side effects as well as lack of efficacy. 15 Overall, of those women accessing medical treatments, up to 77% of women on oral drugs and 20–42% of those using the LNG-IUS will undergo surgery within five years. 16 In the absence of fibroids, surgery for HMB is limited to endometrial ablation or hysterectomy. While both surgical modalities are effective at delivering bleeding control and improving quality of life,17 neither is compatible with future fertility. For many women with HMB, fertility conserving treatment is growing in importance, in keeping with the rising age of first childbirth in the UK and elsewhere.

Selective progesterone receptor modulators: utility and mechanism

A group of pharmacological agents, the selective progesterone receptor modulators (SPRMs), have potential utility to provide an effective oral treatment for HMB. SPRMs bind with PRs, resulting in tissue-specific effects in both myometrial and overlying endometrial tissue as well as direct effects on uterine fibroids. 18 In addition, SPRM administration results in anovulation in up to 80% of women despite maintenance of circulating estradiol concentrations in the mid-follicular range. 19,20

Though the degree of progesterone receptor antagonism varies depending on the specific class member,21 treatment with the SPRMs mifepristone, asoprisnil and ulipristal acetate (UPA) has shown efficacy in reducing fibroid size and affording control of bleeding compared with a placebo. 22 Although no single agent is more effective than another,22 UPA is the only SPRM to have been licensed for clinical use, albeit prescription has been restricted to women with symptomatic fibroids. 9 In women with uterine fibroids ranging from 3 to 10 cm in size treated with UPA, control of HMB was achieved in over 90% of women treated with UPA and amenorrhoea reported in 70%, although the mechanism through which the bleeding control is achieved remains poorly understood. 23,24 Reported side effects were limited to minor complaints such as headache and breast tenderness. 23,24

UPA has the potential to be an effective, fertility-sparing, convenient oral treatment for HMB. However, there are uncertainties regarding the mechanism and location of action of UPA, as well as longer-term safety and effectiveness. SPRMs induce distinctive, non-physiological endometrial changes, which can be confused with endometrial hyperplasia. 25 This specific histological phenotype is termed progesterone receptor modulator-associated endometrial change (PAEC) and is present in 41–79% of women treated with SPRMs. 26,27 Despite mid-follicular range circulating estradiol concentrations and relative progesterone antagonism within the endometrium,28 these morphological changes do not appear to be associated with endometrial hyperplasia or malignant change. 29 Indeed UPA administration is associated with reduction in endometrial cell proliferation,28 and histology returns to normal after discontinuation of treatment. 25,26 However, the mechanisms underlying these changes and their clinical significance remains unclear.

Recently there has been concern regarding the potential for UPA to cause liver injury (i.e. drug-induced liver injury or DILI). Post marketing surveillance reports to the European Medicines Authority (EMA) Pharmacovigilance Risk Assessment Committee resulted in a temporary halt in UPA use in 201830 and 2020. 31 Use of UPA has been reinstated since January 2021, albeit in a restricted context,9 reflecting the paucity of existing alternatives for HMB. 32

Rationale for study

HMB remains a clinical area of unmet need, with high prevalence, marked adverse impacts on quality of life and a significant socioeconomic burden. There is an urgent need to develop effective, safe, acceptable and affordable fertility-sparing medical treatments for HMB that can be taken orally, whether associated with fibroids or not. SPRMs may provide a solution in light of the mounting evidence that progesterone and the PR play a pivotal role in both menstruation and fibroid growth and development. Studies in women with larger fibroids have demonstrated that UPA is well tolerated and can deliver effective control of bleeding in most women. However, despite its therapeutic potential, robust data on the long-term effectiveness and the mechanisms of action of SPRMs in women with HMB remained unknown. There was an urgent need to evaluate the use of UPA against current best medical treatment for all women with HMB. Further understanding of the impact of UPA on the endometrium and liver was also required to inform the role of SPRMs to treat HMB in context of existing medical treatments.

Study objectives

The objectives of the UCON study were specified in the trial protocol, available at https://www.fundingawards.nihr.ac.uk/award/12/206/52.

Trial oversight

Study oversight was provided by a trial steering committee (TSC) and a data monitoring committee (DMC). The TSC provided independent supervision for the trial, providing advice to the chief investigator and sponsor on all aspects of the trial throughout the study. The DMC adopted the DAMOCLES charter34 to define its terms of reference and operation in relation to oversight of the trial.

The trial had a favourable ethical opinion from the London (Bloomsbury) National Research Ethics Service Committee (REC No 14/LO/1602, 25 September 2014) and clinical trial authorisation from the MHRA. Amendments to the protocol, required as a consequence of the two USMs, were based on the MHRA guidance to monitor the safety of existing and new participants.

Patient and public involvement

The idea for the UCON trial was initially reviewed by a clinical studies group, including non-clinical members representing women’s health support groups, although none exist specifically for menstrual problems. A woman with lived experience and a professional understanding of the impact of HMB on women’s working lives, was invited to join the co-applicant team, to provide an independent lay perspective on the treatment options, the outcome measures and the approaches to recruitment. We also had another lay representative on the TSC, who responded to an invite via the Royal College of Obstetricians and Gynaecologists (RCOG) Women’s Voices panel.

At the time of first USM, when we were planning to reopen the trial to recruitment, we once again went via RCOG Women’s Voices. We conducted a small survey to elicit women’s concerns about the use of ulipristal, the addition of the blood tests for safety monitoring and the resumption of recruitment. The respondents were overwhelmingly in favour of the continuation of the trial and supportive of the information to be provided to existing and prospective participants and the safety measures.

Trial design

The UCON trial was a randomised, open-label, parallel-group, multicentre trial of UPA compared with LNG-IUS in women presenting to primary and/or secondary care with HMB. An embedded mechanism of action (MoA) study was also included (see Chapter 4 for the methods and results of studies pertaining to mode of action of UPA).

Recruitment

UCON participants were recruited from gynaecology outpatient departments in ten NHS participating sites across the UK (see Figure 2). Patients with HMB were identified either from general practice (via screening of HMB related codes) or by research nurses in secondary care who screened patient referral letters. Invitation letters (including the participant information sheet) were sent to potentially eligible patients who were then given opportunity to speak to the research nurse about the study by telephone. If the patient expressed an interest, they were invited to a screening visit where they were assessed for eligibility and written informed consent obtained. The gynaecologist providing clinical care discussed treatment options and established potential eligibility based on clinical history and treatment preferences. Potential participants at the Edinburgh site were offered the option to contribute to the MoA study in addition to the main study.

FIGURE 2.

Identification and screening of participants for the UCON trial.* Following first USM (February 2018).

At the screening visit, a transvaginal and/or abdominal ultrasound scan was conducted (unless the patient had an adequate ultrasound scan within the 3 months prior to randomisation) and an endometrial biopsy taken (unless an adequate endometrial biopsy had been taken within the previous 6 months). Blood samples [haemoglobin, serum estradiol, with addition of liver function tests (LFTs) from 20 March 2018], were taken, clinical history was elicited, and a menstrual blood loss diary was provided to the participant.

The next appointment was at least one menstrual cycle after the screening visit. The results of the ultrasound scan, endometrial biopsy and later, the LFTs, were reviewed and eligibility for the trial determined. The menstrual blood loss diary was collected and the other patient questionnaires (see Outcomes) were completed. If eligible, the woman had a urinary pregnancy test and ongoing consent was confirmed before randomisation. Where ultrasound scan, endometrial biopsy or LFTs rendered the patient ineligible, appropriate treatment was offered. Reasons why screened women were not randomised were noted.

Eligibility criteria

Women were eligible for the randomised trial if they met all the inclusion criteria and had none of the exclusion criteria, which were determined at the screening and baseline visits by scans, tests and review of medical history.

Randomisation

Once final eligibility was established, women were randomised to the UCON trial (see Figure 3). Randomisation was performed using a secure online randomisation service provided by the Birmingham Clinical Trials Unit (BCTU). Participants were allocated in an equal (1 : 1) ratio to UPA or LNG-IUS using a minimisation procedure via computer-based algorithm (based upon the method described by Taves35) to avoid chance imbalances in important prognostic variables. Strata used in the minimisation were:

• age: ≤ 35 years or > 35 years

• body mass index (BMI): ≤ 25 kg/m² or > 25 kg/m²

• presence of any fibroid > 2 cm, as determined by the ultrasound scans

• duration of symptoms: < 1 year or ≥ 1 year

• individual site.

FIGURE 3.

Patient pathway.* Following first USM (February 2018), LFTs performed once a month during each 12-week course of treatment. If the test was abnormal (liver enzyme levels more than three times the upper limit of normal), treatment stopped and participant closely monitored.** LFTs performed week 17 or 18 following USM.*** LFTs performed week 33 or 34 following USM.**** LFTs performed week 49 or 50 following USM.

For Edinburgh participants only, a further minimisation variable was included for those agreeing to participate in the MoA study. Participants not randomised at Edinburgh were designated ‘not applicable’ in the minimisation algorithm for the purposes of trial entry. To avoid any possibility of the treatment allocation becoming too predictable a random element was incorporated into the algorithm; participants were allocated to the minimised allocation with probability 0.8 and otherwise to the opposite intervention.

Investigational medicinal product information

UPA and the LNG-IUS are both investigational medicinal products under MHRA definitions.

Blinding

As the treatments are so different in route of administration, the participants, investigators, research nurses and other attending clinicians were not blinded to the treatment allocation.

Adherence monitoring

Participants randomised to UPA were provided with their prescription immediately. In the UPA group, women received a reminder to collect their repeat prescriptions from the hospital pharmacy. Self-reported adherence with treatment was evaluated by participants using the follow-up questionnaires (see Secondary outcome measures). For UPA, participants were given categorical choices that best represented their adherence with study medication: took medication not very often (once per week or less); took medication some days (2 to 3 days per week on average); took medication most days (5 to 6 days per week on average); took medication every day. Women who were considered adherent if medication was taken every day or most days. Pill counting was considered unfeasible due to the duration of treatment.

Those women randomised to LNG-IUS were encouraged to have it fitted promptly by the gynaecologist at the baseline visit. Women were counselled to expect some disturbance to their menstrual cycle but encouraged to persist with this treatment option. Retention of the LNG-IUS was captured by self-report; participants were considered adherent provided they did not report removal of the device.

Withdrawal from treatment

A participant could be told to cease the trial treatment if, in the opinion of the gynaecologist or GP, it was medically necessary to do so. Participants could also voluntarily stop UPA or request to have the LNG-IUS removed at any time; however, women were encouraged to continue follow-up following cessation or change of trial treatment to minimise attrition bias. If a participant did not return for a scheduled visit (or attend a telephone clinic appointment, once face-to-face visits were restricted due to the COVID-19 pandemic), attempts were made to contact her and, where possible, review adherence and safety data. All attempts were made to capture reasons for cessation or change of treatment.

Following the first USM, those participants prescribed UPA were allowed to complete their current course of treatment but not start any subsequent course. The second USM required participants taking UPA to cease treatment immediately and not take any further courses. The trial continued with follow-up of all participants, regardless of adherence (enforced or non-enforced) to 12-months post randomisation.

Withdrawal from the trial

Participants could voluntarily withdraw their consent to study participation at any time. If a participant did not return for a scheduled visit, attempts were made to contact her and where possible, review adherence and safety data. Reasons for withdrawal were captured where possible. If a participant explicitly withdrew consent to have any further data recorded their decision was respected and recorded on the electronic data capture system. All communication surrounding the withdrawal was noted in the patient’s medical notes and no further data collected for that participant.

Outcomes

Study assessments

Assessment times were at approximately 3, 6 and 12 months post randomisation and at other time points (see Table 1). Additional assessments related to the mechanism of action study are detailed in Chapter 4. Owing to the nature of the UPA treatment, with three courses taken over a 48-week period and the restrictions imposed by the USMs, women in the UPA had a specific assessment schedule for collection of outcomes, as follows:

1. The participant-completed questionnaires (MMAS, UFS-QoL, SAQ, EQ-5D-5L) were to be completed in the final week of each on-treatment cycle.

2. The menstrual blood loss diary while on treatment was to be completed over the final four weeks of each treatment cycle in the UPA group. The UPA group were also asked to complete the diary during the first four weeks off treatment before the start of the next treatment cycle.

3. The post treatment endometrial biopsy was to be completed after four weeks off treatment, which would be at around 48 weeks after UPA was commenced. If UPA treatment finished early, a biopsy was taken four weeks after cessation, or as soon as was feasible if access to gynaecology clinics was affected by the COVID-19 pandemic.

4. If PAEC was observed in the post treatment biopsy specimen, a repeat endometrial biopsy was taken around 13 weeks (15 months) after the completion of treatment, and then again around 26 weeks (18 months) post treatment if PAEC persisted. If UPA was ended prematurely, if PAEC was observed in the post treatment biopsy, repeat biopsies were performed 3 and 6 months thereafter if necessary, or when access to clinics was feasible.

5. With effect from 20 March 2018, blood samples were collected from women for LFTs each month while on UPA treatment and two to four weeks after each UPA course, including after the third course. After the second USM, when all participants were told to stop UPA treatment, blood samples were delayed or not performed due to restrictions on gynaecology services.

6. LFTs were also indicated for women who presented with signs or symptoms suggestive of liver injury (such as nausea, vomiting, malaise, right hypochondrial pain, anorexia, asthenia, jaundice) and UPA treatment was stopped. Such participants were closely monitored and referred for specialist hepatology evaluation as clinically indicated. During the period after the second USM, participants who had had to cease UPA treatment were telephoned to determine if they were exhibiting symptoms suggestive of liver injury.

Assessments were scheduled for an equivalent time, at 3, 6 and 12 months post randomisation in the LNG-IUS group.

The schedule for outcome assessment is summarised in Table 1.

The BCTU collected participant reported outcomes (e.g. MMAS, menstrual blood loss diary) postally at 3 and 6 months and then transcribed them to a secure web-based database. Twelve-month outcomes required clinic assessment, including an ultrasound assessment, blood sample (for haemoglobin and serum estradiol) and for those allocated to UPA, an endometrial biopsy. This final assessment was delayed for those participants whose 12-month clinical assessment fell during the period when non-COVID-19 research or face-to-face clinical assessment was suspended.

Adverse events and serious adverse events

The adverse event profile for LNG-IUS is well defined, as the system has been licenced for over a decade, and hence the collection of expected adverse events is not required. For example, elective admission for LNG-IUS insertion or elective admission for hysterectomy would not need to be classified as a serious adverse event. The focus for safety reporting of UPA was on changes to the endometrium, with repeat endometrial biopsies scheduled for those women where PAEC were observed (see Study assessments).

Reasons for change or cessation of treatment were collected, including decisions driven by perceived side effects of treatment such as weight gain. Postal questionnaires collected information on admission to hospital, gynaecological investigations or treatments (e.g. hysteroscopy or endometrial ablation), relevant diagnoses (e.g. endometrial thickening), or used any new medications. Pregnancy was considered an adverse event if the woman was compliant with either trial treatment, but not if she intentionally stopped treatment.

UPA treatment was stopped if any woman developed liver enzyme levels (ALT or AST) more than three times the upper limit of normal and participants were closely monitored and referred for specialist hepatology evaluation if clinically indicated.

A serious adverse event was defined as any event or reaction that was life-threatening, required emergency hospitalisation, resulted in death or persistent or significant disability or if the woman became pregnant, when a congenital anomaly was diagnosed in her baby. All diagnoses of endometrial cancer, ovarian cancer, cervical cancer, breast cancer or ductal carcinoma were defined as serious adverse events. The local investigator had to assign seriousness, severity, causality and expectedness (if deemed related) to the serious adverse event before reporting. Those categorised by the local investigator as both suspected to be related to the trial drugs and unexpected were subject to expedited reporting.

Impact of urgent safety measures on trial populations

The enforced non-compliance because of the temporary (and subsequently permanent) withdrawal of UPA had substantial implications for the sample size and validity of the data reported by participants. It was therefore necessary to redefine the analysis populations, considering the restrictions that prevented women taking their courses of UPA might influence their responses as well as any other new biases that may be apparent in either group due to, for example, knowledge of the safety concerns around UPA. The general principle was that a revised primary analysis population would be agreed – free from as much confounding and bias as possible – and supplemented with a number of additional planned sensitivity analyses, which may be more exploratory in nature. All changes were documented in a revised statistical analysis plan. Revisions were reviewed and approved by a statistician independent to the trial to ensure that they were necessary and appropriate from a methodological perspective and not because of observing accumulating interim data.

The original planned primary analysis population comprised all participants, regardless of adherence to treatment, in keeping with the principles of intention to treat. Following the urgent safety measures, the primary analysis population (population A; Figure 4) would now comprise participants with questionnaire responses received prior to the first USM (12 February 2018), along with questionnaire responses from participants recruited following the study restart (phase 2; from 18 October 2018) provided that these were returned before the second USM (17 March 2020). There was considered to be no additional risk of bias with these participants as a result of the urgent safety measures. However, there remained some concerns about whether those participants randomised in phase 2 were completely comparable with the earlier population, given that they were informed of the risk of liver damage by UPA and had to return to hospital for monthly LFTs. We planned to investigate any potential impact of this through examination of interaction of treatment effect by recruitment period. The same approach would be used for all assessment times (3, 6 and 12 months), provided that a previously agreed threshold for late returns was not breached. Participant responses would be still included, regardless of adherence to treatment, in keeping with principles of intention to treat, to limit any potential for confounding biases.

FIGURE 4.

Revised analysis populations. ¹ UPA participants could finish current course of treatment (up to 12 weeks); LNG-IUS participants unaffected² UPA participants were advised to cease treatment immediately; LNG-IUS participants unaffected³ Defined as taking treatment ‘Every day’ or ‘Most days (5–6 per week on average)’ in the UPA group and having the device inserted and not removed in the LNG-IUS group. This figure is reproduced from Whitaker et al. 33 This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.

Copyright © 2023 Whitaker et al.

The first exploratory sensitivity analysis (population B1; Figure 4) would extend the primary analysis population to include participants who chose to complete their current course of UPA (for up to 12 weeks of treatment) following the first USM. To allow for courses to be completed and questionnaires to be returned, a date 15 weeks after the first USM was considered an appropriate cut-off date for responses to be included. The equivalent group of participants in the LNG-IUS group completing assessments in this time window would also be incorporated. Only adherent participants in both groups were to be included in this population to ensure consistency with this ‘per protocol’ approach; those who had ceased taking UPA (or took it sporadically) for any reason or had LNG-IUS removed were also excluded. A second sensitivity analysis (population B2; Figure 4) would extend the first exploratory sensitivity analysis further by including responses from adherent LNG-IUS participants, who were unaffected by the USM in terms of being instructed to stop treatment but accepting there may be some further confounding biases accrued.

Any responses from participants randomised to UPA but received after enforced cessation of treatment would contribute to an observational cohort (population C; Figure 4), giving some valuable indication of the impact of stopping UPA. All sensitivity analyses would be limited to the condition-specific quality of life score as measured by the MMAS and some the other most important secondary outcomes (see Statistical principles) to reduce the possibility of overinterpretation of data.

Sample size, including impact of urgent safety measures

The trial was designed to be able to detect a clinically useful difference in MMAS score between the two groups at 12 months with high power. The ECLIPSE trial,10 which evaluated the effectiveness of LNG-IUS against standard treatment for HMB using MMAS as the primary outcome, demonstrated a difference of 13 points between the groups with a SD of 24 points. This size of difference is equivalent to approximately 0.5 SDs, which is often considered a medium-sized effect and likely to be at least minimally important. 46 To detect a difference of 0.5 SDs with 90% power (p = 0.05) required 86 women in each group (172 in total). To allow for a 20% loss to follow-up or pregnancy, the sample size was inflated to 220 women.

Prior to the first halt of recruitment on 12 February 2018, the trial had recruited 198 participants. At this stage, it was anticipated that recruitment would restart and therefore plans were made for recruiting new participants with a revised sample size. The aim was to recruit to the original target but in such manner that enough participants would be unaffected by enforced non-compliance or knowledge of the USM during the follow-up period (i.e. to gain 172 quality of life MMAS responses at 12 months in population A; Figure 4). This would mean an inflation from 220 participants to a target of 302 participants. This figure was derived from the number of participants who had completed 12-month assessment prior to the first USM (89), taking into account the total number who had been randomised up to this point (198). An additional 104 participants, gaining data on 83, would be required to reach 172 responses. The trial ultimately recruited 236 participants before recruitment was terminated after the second USM.

Statistical principles

A comprehensive statistical analysis plan was drawn up prior to any analysis and provided to the independent data monitoring and trial steering committees for review. The baseline characteristics of the trial population were tabulated for all randomised participants as well as for those participants in the primary analysis population A (those providing the primary outcome at 12 months were used for this purpose). Categorical data were summarised with frequencies and percentages. Normally distributed continuous variables were summarised with means with SDs, otherwise medians with interquartile ranges were presented.

The general analytical approach for all outcomes employed suitable regression models, dependent on the underlying data type and incorporating repeated responses at all assessment times where possible. Estimates were adjusted for the minimisation parameters and baseline response (where available). If repeated responses were made, models included variables for participant and assessment time (categorical) and to allow for varying treatment effect over time, a time by treatment interaction parameter. All estimates of differences between groups (mean differences or odds ratios) were presented with two-sided confidence intervals (CIs). Analysis was conducted for all outcomes for population A, along with the following for populations B1 and B2: quality of life MMAS scores; amenorrhoea and heavy menstrual bleeding; surgical interventions; the clinical measurements from pelvic ultrasound; and haemoglobin and estradiol. Plots of MMAS and PBAC bleeding score responses over time were presented for the exploratory population C (UPA group only).

For the primary outcome, the initial analytic approach incorporated a linear regression model estimating mean differences in quality of life MMAS responses between the two groups. Upon inspection of pooled data as part of data validation processes, a high degree of skew in the responses was thought likely. A reserve method for analysis was specified a priori should the regression residuals indicate skewed data, and this was ultimately the analysis performed. A generalised estimating equation (GEE) model47 was used with a cumulative logit link for ordered MMAS scores, categorised as ≤ 50, 51 75, 76–99, = 100. These categories have been used previously in similar trials of HMB with MMAS as the primary outcome. 17 The GEE model took into account correlated longitudinal data; a general unstructured covariance matrix was assumed. Cumulative odds ratios and 95% CIs for the treatment group parameter were produced and the statistical significance (p-value) of the treatment group variable determined by an associated chi-squared test. Questionnaire responses were considered valid provided that they had been completed before the subsequent time point (out to 18 months post randomisation for the 12-month assessment); if responses were late they were not included in the analysis but sensitivity analysis was performed with their inclusion.

MMAS scores at three’ and six months’ follow-up were analysed as part of the aforementioned model. Bleeding scores from the PBAC were converted into the following categories: (1) the proportion with amenorrhoea (= 0) and ‘any bleeding’ (score > 0) as well as (2) non-heavy (score ≤ 100) and heavy (score > 100) bleeding. These outcomes, along with cycle regularity, were analysed in a similar manner to the dichotomised MMAS scores. Duration of period was another ordinal response and was analysed in a similar manner to the MMAS categorised scores. Data from patient-reported outcomes (UFS-QoL, EQ-5D, VAS and SAQ) returning continuous scores were analysed using linear regression models for repeated measures to estimated mean differences between the two groups at each time point.

Continuous outcomes assessed by pelvic ultrasound or blood samples, such as uterine volume, largest fibroid volume, haemoglobin and serum estradiol, were analysed using linear regression models. Satisfaction and participant rating of treatment were analysed using ordinal logistic regression. Binary clinical observations from the pelvic ultrasound and willing to recommend to a friend was analysed using logistic regression. There were too few events to analyse the number of surgical interventions formally, so only summary statistics are presented. The number of serious adverse events was analysed using a chi-squared test. Observations from the endometrial biopsies taken after the end of UPA treatment and LFTs taken during UPA courses were tabulated.

Interim analyses

Interim assessment of effectiveness and safety outcomes were performed on behalf of the DMC (see Acknowledgments) on an annual basis throughout the study. These analyses were performed with the use of the Haybittle–Peto approach,48 therefore no adjustment was made in the final p-values to determine significance.

Recruitment and follow-up

The complete flow of participants through the trial is shown in Figure 5; 4471 women were approached for participation, of whom 1750 women were initially considered eligible based on clinical criteria. Of these women, 236 were randomised. Reasons for ineligibility and non-randomisation are provided in Table 2. MMAS questionnaires were completed at 12 months by 181/236 (77%) participants. Of the remainder, 17 were formally withdrawn from the trial (the majority at patient request) and 38 were lost to follow-up.

FIGURE 5.

CONSORT diagram. This figure is reproduced from Whitaker et al. 33 This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.

Copyright © 2023 Whitaker et al.

Participant characteristics

In all randomised participants, the minimisation algorithm ensured balance between groups in terms of age (mean 42.5 years overall), BMI (mean 30.8 kg/m² overall) and the proportion of women with fibroids (66% did not have any fibroids, 10% having a fibroid ≤ 2 cm with the remainder having a fibroid > 2 cm). Duration of symptoms was also balanced across groups in terms of being greater or less than one year, but the former characteristic dominated with 88% having a symptom length over one year. Overall, the median length of symptoms was 36 months, and this did vary from one group to the other (24 months for UPA vs. 48 months for LNG-IUS). Otherwise, the groups were well balanced for all other baseline characteristics (see Table 3). Women were overwhelmingly white in ethnicity (92%), which is likely to be reflective of typical populations at Scottish centres, where the majority of participants were recruited (31% Edinburgh, 20% Aberdeen, 15% Glasgow). Participants contributing to the main analysis (population A) were similar in nature to the full randomised population (see Table 4). Here, apart from the difference in symptom length, the groups appeared well balanced.

Adherence to treatment

The urgent safety measures had a substantial impact on adherence to treatment in the UPA group, with a total of 29 participants ending treatment as a result (Figure 6). A further 13 participants in this group chose to end treatment for other reasons, which were a mixture of side effects or dissatisfaction with the effect of treatment (see Table 5). Seventeen participants in the LNG-IUS group had the coil removed prior to 12 months; reasons here were frequently reported as lack of effective control of bleeding.

FIGURE 6.

Adherence to allocated intervention. This figure is reproduced from Whitaker et al. 33 This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.

Copyright © 2023 Whitaker et al.

Primary outcome: quality of life menorrhagia multi-attribute scale scores at 12 months

No evidence of a difference between groups was observed [median score category: 76–99, interquartile range (IQR) (51–75 to 100), n = 53 vs. 76–99, IQR (51–75 to 100), n = 50; adjusted OR 0.55, 95% CI 0.26 to 1.17; p = 0.12] (Table 6); estimates of treatment effect were very similar in both of the secondary populations and were robust to sensitivity analysis (see Appendix, Tables 18–20).

Secondary outcomes: quality of life menorrhagia multi-attribute scale scores at other assessment times and associated analyses

Scores in both groups were substantially improved from baseline [median score category: ≤ 50, IQR (≤ 50 to 51–75) for both groups] by 3 months, but more so with UPA, where the odds of being in a higher MMAS score category were higher than in the LNG-IUS group [median score category: 76-99, IQR (51–75 to 100) vs. 51–75, IQR (≤ 50 to 76-99); adjusted OR 2.22, 95% CI 1.24 to 3.96]. This was not apparent by six months [median score category: 76–99, IQR (≤ 50 to 100); vs. 76–99, IQR (61–75 to 100); adjusted OR 0.64, 95% CI 0.33 to 1.24] as participants in the LNG-IUS group continued to improve (see Appendix, Figure 24).

There was no evidence of varying treatment effect (p = 0.46) in the recruitment periods separated by the study suspension (see Appendix, Table 21), but power for this analysis was limited by lack of observations, particularly in the post USM1 recruitment period.

Other secondary outcomes

The proportion of women experiencing amenorrhoea was much higher in the UPA group compared with those in the LNG-IUS group across all time points (3 months: 56% vs. 5%, adjusted OR 29.3, 95% CI 7.37 to 116; 6 months: 53% vs. 10%, adjusted OR 11.7, 95% CI 3.78 to 36.0; 12 months: 64% vs. 25%, adjusted OR 7.12, 95% CI 2.29 to 22.2; Table 7). Results were similar in both secondary analysis populations (see Appendix, Tables 22 and 23). The proportion of women experiencing heavy bleeding was not noticeably different between groups.

There was no consistent evidence that the proportion of women reporting irregular or on-off bleeding menstrual cycles was different between the groups (see Table 8); similarly, cycle duration was not consistently different between groups across the assessment times (see Table 9).

There was no evidence of a difference in the other patient-reported outcomes (see Table 10); the uncertainty around the treatment effect estimates was either too large to rule out no effect or there was lack of consistency across the assessment times.

The number of women reporting a surgical intervention was low at the 12-month follow-up in all those randomised. Two hysterectomies were reported in the UPA group. One participant in the LNG-IUS group reported a ureteric stenting, sigmoidoscopy and biopsy, another having a cystectomy and another a prophylactic bilateral salpingo-oophorectomy.

A greater reduction in endometrial thickness with LNG-IUS was observed compared with UPA (adjusted mean difference 2.6 mm, 95% CI 0.8 to 4.4), along with more of an increase in haemoglobin (adjusted mean difference 5 g/l, 95% CI 1 to 10; Table 11). There was no evidence of a consistent difference in the other clinical measurements in any of the analysis populations (see Appendix, Tables 24–25).

No participants treated with UPA had evidence of malignancy following endometrial biopsy out to a maximum of 12 months (timing of biopsy was earlier in those who ceased treatment earlier; Figure 7). Seven participants (8%) had evidence of PAEC in their initial biopsy, reducing to one at subsequent biopsy after a further 3 months and none at a further following 3 months.

FIGURE 7.

Endometrial biopsy result. ¹Timing dependent on when participant stopped UPA in some cases; if prior to 12-month follow-up, the first assessment was at first opportunity thereafter; repeat assessment (if required) would be after a further 3 and 6 months. ²Does not include 3 participants missing diagnosis, 4 with insufficient sample and 22 participants who withdrew or were lost to follow-up prior to 12 months assessment. This figure is reproduced from Whitaker et al. 33 This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.

Copyright © 2023 Whitaker et al.

Two participants in the UPA group (5%) had a clinically significant LFT result while on treatment; this increased to five (9%) in the post treatment period. When considered in conjunction with whether transaminase levels were greater than three times the upper level of normal in any of the tests, these numbers reduced to one (3%) and three (5%), respectively (see Table 12).

There were six SAE reports in the UPA group and five in the LNG-IUS group (p = 0.76). SAEs in the UPA group were predominantly related to hospital admissions, typically for elective surgery or management of unrelated conditions. One participant developed breast cancer but had only a short period on UPA treatment due the early termination of the study. A further participant in the UPA arm was admitted for pain control in the context of expulsion of an endometrial cast but had previously discontinued UPA and had an IUS inserted prior to the SAE. There was only one directly related SAE, where the participant was diagnosed with complex endometrial hyperplasia with atypia at the end of study biopsy.

In the LNG-IUS group there were more directly related SAEs: one participant was admitted for pelvic pain control and had their IUS removed, and one underwent risk-reducing surgery in view of a family history of breast cancer. A further participant was recommended hysterectomy for identification of a mitotic active cervical fibroid, excised at the time of LNG-IUS insertion. One patient with previous multiple myomectomies developed hydronephrosis with associated hypertension from an undiagnosed desmoid tumour, thought to be related to her previous fibroid surgery. She required admission for examination under anaesthesia, including biopsy of the lesion and insertion of ureteric stent. As part of her clinical management, despite achieving bleeding control, her IUS was removed and complete ovarian suppression with a GnRH agonist and letrozole was commenced. A final SAE in the IUS group was related to an elective admission for excision of a symptomatic sesamoid bone and ganglion.

There was one suspected unexpected serious adverse reaction (SUSAR), development of an acute hepatitis during the final course of UPA. This occurred prior to the initial USM. At initial presentation there was concern that this could represent a DILI and was thus reported as a SUSAR. However, the strong family history of autoimmune hepatitis led to her hepatology clinicians to conclude that this was the likely aetiology, and liver biopsy demonstrated widespread lymphoplastic hepatitis. The diagnosis of autoimmune hepatitis was not adjusted following the USM. Her symptoms resolved with high-dose steroids and the participant continues on long-term azathioprine with normal liver function.

Adverse events categorised using MedDRA coding were varied, with no obvious evidence of a difference between groups (see Appendix, Table 26).

Follow-up of participants in the UPA group who ceased treatment early due to the urgent safety measure was analysed separately (population C).

These participants had inconsistent MMAS scores treatment with UPA (Figure 8). A number of women had returned to PBAC scores associated with heavy menstrual bleeding by 12 months (Figure 9).

FIGURE 8.

Individual participant plot of menorrhagia multi-attribute scale scores over time for those women who ceased treatment early due to the urgent safety measure.

FIGURE 9.

Individual participant plot of pictorial blood loss assessment chart bleeding diary scores over time for those women who ceased treatment early due to the urgent safety measure.

Summary of findings for mechanism of action embedded study

Mechanism of action study introduction

HMB affects up to one in four women of reproductive age1 and causes significant morbidity,2 and there is an unmet clinical need for new treatments for this debilitating and life-altering symptom. The causes of the symptom of abnormal uterine bleeding (AUB), including HMB, may be categorised using the acronym ‘PALM-COEIN’; and adenomyosis, fibroids (leiomyoma) and endometrial factors are identified as important causes. 7 By using SPRMs to study the effect of targeting the PR on steroid receptor/enzyme/steroid availability, it may be possible to obtain increased understanding of endometrial and uterine physiology and the regulation of menstrual bleeding.

The steroid hormone progesterone (P4) plays a pivotal role in the structure, function and regulation of the female reproductive tract and, most notably, the uterus/endometrium. The binding site for progesterone, the PR, is expressed in the endometrium, myometrium and uterine fibroids. Progesterone is responsible for endometrial differentiation in an oestrogen-primed endometrium,51 and withdrawal of progesterone (and oestrogen) following regression of the corpus luteum (in the absence of a pregnancy) is the trigger for menstruation and endometrial shedding. Any dysregulation of progesterone-based pathways is thus highly likely to contribute to HMB. 52

SPRMs are a class of compounds with varying molecular structures that interact with the PR, and exert agonist, antagonist or mixed responses. 53 SPRMs have been reported to provide an effective therapy for management of the symptom of HMB in women with uterine fibroids. 18,22

The SPRM UPA has been reported in the PEARL clinical trials to reduce menstrual bleeding in 98% of women with uterine fibroids23,24 and to induce amenorrhoea in 90% of women after four treatment courses of UPA. 55 SPRMs in current clinical use include mifepristone (licensed for pregnancy interruption in conjunction with a prostaglandin analogue) and UPA when licensed as an emergency contraceptive and (with restrictions) for the management of women with symptomatic uterine fibroids and HMB. 21

The therapeutic benefits of SPRMs are thus recognised; however, much remains to be discovered about the mechanisms of action of SPRMs on the endometrium and the uterus. We therefore aimed to address three linked hypothesis-driven investigations: studies described herein as study parts A, B and C. As SPRMs (and in these studies UPA) modulate (i.e. exert agonist, antagonist or mixed response depending upon the pharmacological structure of the compound) alteration of the local endometrial availability of the steroid hormone progesterone and location and presence of its binding site, the PR, along with other steroid hormones and their receptors, will likely affect the (a) ‘structure’ (Part A: cellular markers for location and presence of endometrial steroid hormone receptors and their metabolising enzymes; or Part B: volume of uterus and fibroids) and (b) ‘function’ (Study A: markers of endometrial cell function, i.e. cell proliferation; and Part C: physiological parameters of the microcirculation) of the SPRM (UPA) target tissues (i.e. endometrium, uterine muscle, fibroids).

Mechanism of action study objectives

To provide further insight into how UPA may cause a reduction in menstrual bleeding and to explore action upon the uterus, including uterine/fibroid volume in women with HMB, we determined whether:

1. A: administration of UPA alters cellular markers that reflect endometrial cell function, (e.g., and not limited to: cell proliferation, apoptosis, expression of steroid receptors, tumour suppressors and inflammatory mediators)

2. B: UPA reduces uterine and fibroid volume

3. C: UPA reduces (microvascular) blood flow in the endometrium, uterine myometrium and fibroid tissue.

Mechanism of action study outcomes

1. A: Effects on cellular markers of endometrial steroid receptors and metabolising enzymes (governing local endometrial steroid (ligand) availability), cell proliferation, cell survival (apoptosis); detection of genes implicated in control of proliferation in endometrium.

2. B: Effects on uterine/fibroid structure addressed by obtaining volume measurements for the whole uterus, and for the total volume of fibroids when present, by using high resolution structural MRI and stereology.

3. C: Uterine vascularity using DCE-MRI.

The background, methods, results and a short commentary on each of these three objective/outcome areas are presented herein as:

• MoA participants and study time points.

• Part A: Study of the impact of UPA administration on selected cellular markers that reflect cell function of the endometrium.

• Part B: Study of the impact of UPA administration on uterine/fibroid volume as determined with high resolution structural magnetic resonance imaging (MRI).

• Part C: Study of the impact of UPA administration on uterine vascularity as determined with DCE-MRI.

Mechanism of action participant and study time points

Mechanism of action participant recruitment

Participants with symptomatic HMB were drawn from those who were recruited to the UCON trial from the Edinburgh region and consented to participation in the MoA study at the time of consent to the main trial. Approval for the MoA study was part of the wider UCON approval obtained from the London (Bloomsbury) Research Ethics Committee (REC14/LO/1602). Participants of the MoA study could opt to be included in both the endometrial biopsy and MRI studies or opt to a single part of the MoA study. In addition to the inclusion and exclusion criteria for the main trial, further exclusion criteria applied to those undergoing MRI, including the presence of non-magnetic resonance-compatible implants such as pacemaker and cochlear implants, claustrophobia and, additionally, contraindication to intravenous hyoscine butylbromide for the DCE-MRI component. Following consent and completion of pre-randomisation screening process for the main study, randomisation in a 1 : 1 allocation to UPA or LNG-IUS was performed using a minimisation procedure via computer-based algorithm, as described in Chapter 2. If allocated to UPA, participants received treatment with UPA, 5 mg once daily for three 12-week courses, each separated by 4 weeks without UPA treatment (Figure 10).

FIGURE 10.

Patient pathway of mechanism of action participants.* End of study biopsy obtained after withdrawal bleed. MoA: mechanism of action study; UPA: ulipristal acetate.

The intended sample size was 20 participants in each study part. All participants opted to participate in all components of the MoA study. One participant withdrew after the first treatment cycle of UPA to undergo surgical management of HMB, so an additional participant was randomised to UPA. A further participant was lost to follow-up during the second treatment cycle and was not replaced (Figure 11). Patient characteristics are summarised in Table 13.

FIGURE 11.

Consort diagram of participants recruited to UCON mechanism of action study.

TABLE 13 - Included participant characteristics

AUB-A, abnormal uterine bleeding due to adenomyosis; AUB-E, abnormal uterine bleeding due to endometrial dysfunction; AUB-L, abnormal uterine bleeding due to leiomyoma (fibroids).

Serial number	PALM-COEIN classification	Age (years)	Ethnicity	Body mass index (kg/m2)	Parity (n)	Mechanism of action study part participation
						Endometrial	Stereology	DCE
1	AUB-E	41	Other mixed ethnicity	23.9	3	Yes	Yes	Yes
2	AUB-A	43	White British	30.8	5	Yes	Yes	Yes
3	AUB-E	38	White British	37.6	0	Yes	Yes	Yes
4	AUB-E	40	White British	27.5	2	Yes	Yes	Yes
5	AUB-L	51	White British	21.9	1	Yes	Yes	Yes
6	AUB-L	42	White British	22.9	0	Yes	Yes	No
7	AUB-L & AUB-A	49	White British	35.2	1	Yes	Yes	No
8	AUB-A	46	White British	48.9	6	Yes	Yes	No
9	AUB-L	44	White British	30.4	0	Yes	Yes	Yes
10	AUB-E	39	White British	26.8	3	Yes	Yes	Yes
11	AUB-E	44	White British	34.6	3	Yes	Yes	Yes
12	AUB-E	41	White British	25.5	1	Yes	Yes	Yes
13	AUB-L	46	White European	23.6	3	Yes	Yes	Yes
14	AUB-A	41	White British	39.5	2	Yes	Yes	Yes
15	AUB-L & AUB-A	44	White British	29.0	2	Yes	Yes	Yes
16	AUB-L	46	White British	23.1	2	Yes	Yes	No
17	AUB-L	47	White British	23.0	2	No	Yes	Yes
18	AUB-A	52	White British	29.0	3	No	Yes	Yes
19	AUB-E	42	White British	44.2	3	No	Yes	Yes

Part A: studies of impact of ulipristal acetate administration on selected cellular markers that reflect cell function of the endometrium

Results

The data presented herein on the endometrial cell impacts of UPA administration have provided evidence that targeting the PR with UPA treatment causes: (1) altered localisation of local endometrial steroid receptor (oestrogen, progesterone, androgen, glucocorticoid) and metabolising enzyme expression, thus changing local endometrial steroid/ligand availability; and (2) confirmation of previous reports of reduction in endometrial cell proliferation. 28,49 All temporal and spatial cellular alterations of cell marker localisation are reversible on discontinuation of UPA administration. These data have already been reported (no comparator arm) by Chodankar et al. (2021). 49

Key outcomes

Key outcomes from our laboratory-based studies described in Part A are thus as follows:49

1. Endometrial mRNA levels and protein localisation of steroid receptors were altered and returned to pretreatment expression patterns upon cessation of UPA treatment.

2. Endometrial mRNA levels and protein localisation of steroid metabolising enzymes were altered and returned to pretreatment expression patterns upon cessation of UPA treatment.

3. Endometrial expression of progesterone regulated genes was altered and returned to pretreatment expression patterns upon cessation of UPA treatment.

4. Endometrial cell proliferation was reduced and the effect was reversed upon cessation of UPA treatment.

5. There is a suggestion of reduced endometrial apoptosis.

UPA treatment was found to alter endometrial mRNA levels and protein localisation of steroid receptors which returned to pretreatment expression patterns after cessation of UPA administration

As described in publication by Chodankar et al.,49 Steroid receptor (ESR1 (ERα), PR, AR and PRB) mRNA levels were significantly greater in the pretreatment proliferative endometrium versus the secretory phase endometrium; ESR1 (p = 0.0028, Figure 12, A-i), PR (p = 0.0008, Figure 12, C-i), AR (p = 0.0016, Figure 12, E-i) and PRB (p = 0.0008, Figure 13, A-i). There were no differences in ESR1, PR, AR and PRB mRNA levels with UPA treatment versus pretreatment proliferative phase endometrial samples (Figure 12; A-ii, C-ii, E-ii and A-ii). There was a significant increase in ESR1 (p = 0.0012, Figure 12, A-iii), PR (p = 0.0089, Figure 12, C-iii), AR (p = 0.0010, Figure 12, E-iii) and PRB (p = 0.0010, Figure 13, A-iii), mRNA levels with exposure to UPA treatment when compared with pretreatment secretory phase endometrial samples. GR mRNA levels did not differ between pretreatment proliferative and secretory phase endometrium (see Figure 12, G-i). UPA treatment resulted in increased GR mRNA levels when compared with pretreatment secretory phase endometrium (p = 0.05, Figure 12, G-iii) and pretreatment proliferative phase endometrium (p = 0.06, Figure 12, G-ii). It was notable that the modulation of mRNA levels of all steroid receptors returned to pretreatment levels following cessation of UPA administration and the occurrence of a menstrual withdrawal bleed.

FIGURE 12.

Administration of SPRM (UPA) altered the mRNA levels and protein expression of the endometrial steroid receptors; these effects are reversed upon cessation of treatment. Administration of SPRM (UPA) altered the mRNA levels and protein expression of the endometrial steroid receptors; these effects are reversed upon cessation of treatment. SPRM (UPA) treatment resulted in an increase in the mRNA levels of the steroid receptors ESR1 (A-iii), PR (C-iii), AR (E-iii), and GR (G-iii) compared with the pretreatment secretory endometrium determined by RTqPCR. All the altered mRNA levels returned to a pretreatment state following cessation of UPA treatment and withdrawal bleed. *p < 0.05, **p < 0.01, ***p < 0.001. Error bars: median with 95% CI. Representative images demonstrating the IHC staining of the steroid receptors ER (B), PR (D), AR (F), and GR (H). Each panel demonstrates representative IHC staining in the pretreatment proliferative endometrium (i), pretreatment secretory endometrium (ii), UPA-treated endometrium (iii), post-treatment proliferative endometrium (iv), post-treatment secretory endometrium (v), and a negative control (vi). The impact of UPA on the protein expression of the candidate genes is detailed in the results section. Most importantly, the protein expression of the candidate genes showed no differences between the pretreatment and post-treatment endometrium. Scale bar = 20 μm; negative control scale bar = 100 μm. AR = androgen receptor; CI = confidence interval; ER = oestrogen receptor; G = glands; GR = glucocorticoid receptor; IHC = immunohistochemistry; mRNA = messenger ribonucleic acid; PR = progesterone receptor; SPRM = selective progesterone receptor modulator; RTqPCR = real-time quantitative reverse transcription polymerase chain reaction; S = stroma; UPA = ulipristal acetate. Reproduced from Fertil Steril. 2021;116(3): 882–895. Chodankar RR, Murray A, Nicol M, Whitaker LHR, Williams ARW, Critchley HOD. The endometrial response to modulation of ligand-progesterone receptor pathways is reversible. Copyright (2021), with permission from Elsevier. This is an Open Access article distributed in accordance with the terms of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0) license, copy and redistribute the material in any medium or format for commercial use, provided the original work is properly cited. See https://creativecommons.org/licenses/by-nc-nd/4.0/. This text includes minor additions and formatting changes to the original text.

Copyright © 2023 Whitaker et al.

FIGURE 13.

Administration of SPRM (UPA) modulates the PRB mRNA levels and protein localisation, which are reversed upon cessation of treatment. (A) SPRM (UPA) treatment results in a statistically significant increase in the mRNA levels of the PRB vs. the pretreatment secretory endometrium determined by RTqPCR (A-iii). The altered mRNA results returned to pretreatment levels after cessation of UPA exposure. *p < 0.05, ** p < 0.01, *** p < 0.001. Error bars: median with 95% CI. (B) Representative images demonstrating the immunohistochemical staining of the PRB in the pretreatment proliferative endometrium (B-i) and pretreatment secretory endometrium (B-ii), UPA-treated endometrium (B-iii), post-treatment proliferative endometrium (B-iv) and post-treatment secretory endometrium (B-v). The protein expression of the PRB showed no differences between the pretreatment and post-treatment endometrium. Scale bar = 20 μm; G: Glands, S: Stroma. Negative control (B-vi, scale bar = 100 μm). (C) DIA results of the PRB between the pretreatment proliferative vs. secretory endometrium (C-i), UPA treatment vs. the pretreatment and post-treatment proliferative endometrium (C-ii) and UPA treatment vs. the pretreatment and post-treatment secretory endometrium (C-iii). There was an impressive consistency between the RTqPCR data (A) and the DIA data. (C) Reproduced from Fertil Steril. 2021;116(3): 882–895. Chodankar RR, Murray A, Nicol M, Whitaker LHR, Williams ARW, Critchley HOD. The endometrial response to modulation of ligand-progesterone receptor pathways is reversible. Copyright (2021), with permission from Elsevier. This is an Open Access article distributed in accordance with the terms of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0) license, copy and redistribute the material in any medium or format for commercial use, provided the original work is properly cited. See https://creativecommons.org/licenses/by-nc-nd/4.0/. This text includes minor additions and formatting changes to the original text.

Copyright © 2023 Whitaker et al.

The IHC data described below have already been reported (no comparator arm). 49

As described in publication by Chodankar et al. ,49 ER-α protein immunolocalisation in proliferative phase endometrium was observed to be intense in cellular nuclei of both glands and stroma when compared with pretreatment secretory phase endometrium (see Figure 12, B-i and B-ii). ER-α immunoreactivity in UPA-treated endometrium resembled proliferative phase endometrium (see Figure 12, B-iii). The localisation of PR and isoform PRB protein differed in pretreatment proliferative and secretory endometrium with intense immunoreactivity observed in the proliferative phase in both glandular and stromal cells. Reduced immunoreactivity was limited to endometrial stromal cells in pretreatment secretory phase endometrium (PR Figure 12, D-i and D-ii; PRB Figure 13, B-i and B-ii). 49 PR and PRB immunoreactivity in UPA-treated endometrium was altered (intense immunoreactivity) in glands with negligible immunoreactivity in stroma cells in some endometrial biopsies (PR Figure 12, D-iii; PRB Figure 13, B-iii). Other endometrial samples displayed patterns of PR and PRB immunoreactivity with the features of proliferative phase endometrium. 49 Endometrial AR protein localisation was intense in pretreatment proliferative phase stromal cells when compared with the pretreatment secretory endometrium (see Figure 12, F-i and F-ii). AR immunoreactivity in UPA-treated endometrium displayed positive immunoreactivity in stromal and gland cells (see Figure 12, F-iii). 49 Expression of endometrial GR protein was similar in proliferative and secretory phases and was localised to cell nuclei of stromal and endothelial cells. GR immunoreactivity was absent in endometrial glandular cells (see Figure 12, H-i and H-ii). GR immunoreactivity in UPA-treated endometrium was intense in stromal cells when compared with proliferative and secretory phase endometrium (see Figure 12, H-iii). 49

DIA results indicated a strong agreement with gene expression (RTqPCR) data. The DIA of the IHC data for the steroid receptors ER (A), PR (B), AR (C), GR (D), and steroid metabolising enzymes 17βHSD-2 (E), 17βHSD-5 (F), and 11βHSD-2 (G) showed an impressive consistency with the RTqPCR data indicating a strong temporal and spatial agreement in the expression of the candidate genes. All the alterations assessed by DIA returned to a pretreatment morphology on cessation of SPRM (UPA) exposure. * p < 0.05. 11βHSD-2 = 11beta-hydroxysteroid dehydrogenase type 2; 17βHSD-2 = 17beta-hydroxysteroid dehydrogenase type 2; 17βHSD-5 = 17beta-hydroxysteroid dehydrogenase type 5; AR = androgen receptor; DIA = digital image analysis; ER = oestrogen receptor; GR = glucocorticoid receptor; PR = progesterone receptor; SPRM = selective progesterone receptor modulator; RTqPCR = real-time quantitative reverse transcription polymerase chain reaction; UPA = ulipristal acetate.

The DIA of IHC data for ER-α (see Figure 14, A), PR (see Figure 14, B), AR (see Figure 14, C), GR (see Figure 14, D), and PRB (see Figure 13, C), revealed consistency with the RTqPCR data. The lack of statistical significance is attributable to small sample size and clear trends are visible. 49

FIGURE 14.

DIA of endometrial steroid receptors and steroid metabolising ensymes. Reproduced from Fertil Steril. 2021;116(3): 882–895. Chodankar RR, Murray A, Nicol M, Whitaker LHR, Williams ARW, Critchley HOD. The endometrial response to modulation of ligand-progesterone receptor pathways is reversible. Copyright (2021), with permission from Elsevier. This is an Open Access article distributed in accordance with the terms of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0) license, copy and redistribute the material in any medium or format for commercial use, provided the original work is properly cited. See https://creativecommons.org/licenses/by-nc-nd/4.0/. This text includes minor additions and formatting changes to the original text.

Copyright © 2023 Whitaker et al.

In sum, all steroid receptors, assessed by IHC and measurement with DIA, returned to pretreatment patterns following cessation of UPA treatment.

UPA alters endometrial mRNA levels and protein localisation of steroid metabolising enzymes, with a return to pretreatment expression patterns following cessation of UPA administration

Our studies, and as published,49 show that endometrial 17βHSD-2 mRNA levels were significantly higher in secretory than proliferative phase endometrium (p = 0.0076, Figure 15, A-i). A significant decrease in mRNA levels was observed with UPA treatment when compared with pretreatment proliferative (p = 0.0043, Figure 15, A-ii) and secretory phase endometrium (p = 0.0035, Figure 15, A-iii). 49

FIGURE 15.

Administration of a SPRM (UPA) altered the mRNA levels and protein expression of the endometrial steroid metabolising enzymes; these changes were reversed upon cessation of treatment. UPA treatment resulted in a decrease in the mRNA levels of the steroid metabolising enzymes vs. the pretreatment proliferative and secretory endometrium; 17βHSD-2 (A-ii and A-iii), 17βHSD-5 (C-ii and C-iii), and 11βHSD-2 (E-ii and E-iii). No changes in the mRNA level of 11βHSD-1 were noted with UPA treatment (G-ii and G-iii). *p < 0.05, ** p < 0.01, ***p < 0.001. Error bars: median with 95% CI. Representative images demonstrating the IHC of the steroid metabolising enzymes 17βHSD-2 (B), 17βHSD-5 (D), 11βHSD-2 (F), and 11βHSD-1 (H). Each panel demonstrates representative IHC staining in the pretreatment proliferative endometrium (i), pretreatment secretory endometrium (ii), UPA-treated endometrium (iii), post-treatment proliferative endometrium (iv), post-treatment secretory endometrium (v), and a negative control (vi). The impact of UPA on the protein expression of the candidate genes is detailed in the results section. Most importantly, the protein expression of the candidate genes showed no differences between the pretreatment and post-treatment endometrium. Scale bar = 20 μm; Negative control scale bar = 100 μm. 11βHSD-1 = 11beta-hydroxysteroid dehydrogenase type 1; 11βHSD-2 = 11beta-hydroxysteroid dehydrogenase type 2; 17βHSD-2 = 17beta-hydroxysteroid dehydrogenase type 2; 17βHSD-5 = 17beta-hydroxysteroid dehydrogenase type 5; CI = confidence interval; G = glands; IHC = immunohistochemistry; mRNA = messenger ribonucleic acid; SPRM = selective progesterone receptor modulator; S = stroma; UPA = ulipristal acetate. Reproduced from Fertil Steril. 2021;116(3):882–895. Chodankar RR, Murray A, Nicol M, Whitaker LHR, Williams ARW, Critchley HOD. The endometrial response to modulation of ligand-progesterone receptor pathways is reversible. Copyright (2021), with permission from Elsevier. This is an Open Access article distributed in accordance with the terms of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0) license, copy and redistribute the material in any medium or format for commercial use, provided the original work is properly cited. See https://creativecommons.org/licenses/by-nc-nd/4.0/. This text includes minor additions and formatting changes to the original text.

Copyright © 2023 Whitaker et al.

Endometrial 17βHSD-5 mRNA levels did not differ between baseline proliferative and secretory phases (see Figure 15, C-i). A decrease with UPA administration was observed between pretreatment proliferative (p = 0.0069, Figure 15, C-ii) and secretory phase endometrium (p = 0.09, Figure 15, C-iii). Endometrial mRNA levels returned to pretreatment levels once UPA treatment ceased, and a menstrual bleed had occurred.

Endometrial aromatase mRNA was undetectable in our sample set as determined by RTqPCR. 49

Endometrial 11βHSD-2 and 11βHSD-1 (both glucocorticoid metabolising enzymes) mRNA levels did not differ significantly between pretreatment proliferative and secretory phase samples (see Figure 15, 11βHSD-2, E-i; 11βHSD-1, G-i). 49 Treatment with UPA resulted in reduced 11βHSD-2 mRNA levels when compared with pretreatment proliferative (p = 0.0003, Figure 15, E-ii) and secretory endometrium (p = 0.06, Figure 15, E-iii). 49 All altered mRNA levels returned to pretreatment status with treatment completion and a menstrual bleed. There were no differences in 11βHSD-1 mRNA levels with UPA treatment (see Figure 15, G-ii and iii). 49

Cellular immunohistochemical localisation of endometrial 17βHSD-2 protein differed between pretreatment proliferative and secretory phases with intense positive immunoreactivity in the secretory phase where it was confined to the cytoplasm of glands (see Figure 15, B-i and ii). 49 UPA-treated endometrium displayed an almost complete absence of immunoreactivity for 17βHSD-2 protein (see Figure 15, B-iii). 49

Endometrial expression of 17βHSD-5 protein was confined to glandular cytoplasm and endothelium with no differences in immunoreactivity between proliferative and secretory phase endometrium (see Figure 15, D-i and ii). 49 Endometrial 17βHSD-5 enzyme immunoreactivity from UPA-treated subjects revealed reduced immunostaining when compared with pretreatment proliferative and secretory endometrium (see Figure 15, D-iii).

Endometrial aromatase enzyme was not detectable in proliferative, secretory and UPA-treated endometrium. 49

11βHSD-2 and 11βHSD-1 enzymes were localised to the cytoplasm of endometrial glands and stromal cells. Endometrial 11βHSD-2 immunoreactivity did not differ between pretreatment secretory and proliferative phase samples (see Figure 15, F-i and ii). 49 UPA treatment resulted in reduction in positive immunostaining when compared with pretreatment endometrium (see Figure 15, F-iii). Endometrial 11βHSD-1 protein expression did not vary between pretreatment, UPA treated or post UPA treatment samples (see Figure 15, H). 49

DIA data for the immunolocalisation of endometrial 17βHSD-2 (see Figure 14, E), 17βHSD-5 (see Figure 14, F) and 11βHSD-2 (see Figure 14, G) demonstrated a strong correlation with RTqPCR data. 49 The lack of statistical significance is likely attributable to small sample size; however, clear trends were evident.

UPA alters endometrial expression of progesterone (P)-regulated genes, with return to pretreatment levels of gene expression following completion of UPA administration

We have studied and published our findings of the effects of UPA on known progesterone (P)-regulated genes; that is, Homeobox A10 (HOXA10), Forkhead Box M1 (FOXM1), Indian hedgehog (IHH) and Heart- and neural crest derivatives protein 2 (HAND2) mRNA levels. 49 UPA treatment increased mRNA levels of endometrial IHH (p = 0.0015, Figure 16, C) and HOXA10 (p = 0.0183, Figure 16, L) compared with the pretreatment secretory phase. There was a significant reduction in mRNA levels of endometrial FOXM1 (p < 0.0001, Figure 16, E) compared with the pretreatment proliferative phase. 49 These alterations of mRNA levels returned to the pretreatment state with completion of UPA treatment. No differences in endometrial HAND2 mRNA levels were observed with UPA treatment (see Figure 16, H-I).

FIGURE 16.

Selective progesterone receptor modulator (UPA) treatment alters mRNA levels of progesterone-regulated genes which are reversed on cessation of treatment. SPRM (UPA) treatment resulted in an increase in the mRNA levels of IHH vs. pretreatment proliferative (B) and secretory endometrium (C). A significant reduction in mRNA levels of FOXM1 was noted vs. baseline proliferative endometrium (E). A significant increase in HOXA10 mRNA was observed when compared with pretreatment secretory endometrium (L). All the altered mRNA concentrations returned to pretreatment levels following cessation of UPA treatment and after a withdrawal bleed. No differences in the HAND2 mRNA levels were noted with UPA treatment (H-I). * p < 0.05, ** p < 0.01, *** p < 0.001, **** p < 0.0001. Bars: median with 95% CI. Reproduced from Fertil Steril. 2021;116(3):882–895. Chodankar RR, Murray A, Nicol M, Whitaker LHR, Williams ARW, Critchley HOD. The endometrial response to modulation of ligand-progesterone receptor pathways is reversible. Copyright (2021), with permission from Elsevier. This is an Open Access article distributed in accordance with the terms of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0) license, copy and redistribute the material in any medium or format for commercial use, provided the original work is properly cited. See https://creativecommons.org/licenses/by-nc-nd/4.0/. This text includes minor additions and formatting changes to the original text.

Copyright © 2023 Whitaker et al.

Treatment with UPA reduces endometrial cell proliferation with reversal of effect upon completion of UPA administration49

The cell proliferation marker, Ki67, mRNA levels were found to be significantly greater in the pretreatment proliferative phase when compared with secretory phase endometrium (p = 0.0016, Figure 17, A-i). UPA treatment significantly reduced endometrial Ki67 mRNA levels compared with the pretreatment proliferative phase (p = 0.0003, Figure 17, A-ii). Endometrial Ki67 mRNA levels returned to the pretreatment state upon cessation of UPA treatment. 49

FIGURE 17.

The SPRM (UPA) treatment reduced endometrial cell proliferation; this effect was reversed upon cessation of treatment. (A) The SPRM (UPA) treatment resulted in a statistically significant decrease in the Ki67 mRNA levels determined by RTqPCR compared with the pretreatment proliferative endometrium (A-ii). The altered mRNA results returned to pretreatment levels after cessation of UPA exposure. * p < 0.05, ** p < 0.01, *** p < 0.001. Error bars: median with 95% CI. (B) Representative images demonstrating the immunohistochemical staining of Ki67 in the pretreatment proliferative endometrium (B-i) and pretreatment secretory endometrium (B-ii), the UPA-treated endometrium (B-iii), post treatment proliferative endometrium (B-iv), and post treatment secretory endometrium (B-v). Reduced immunopositivity staining for Ki67 was noted with the UPA-treated compared with the pretreatment proliferative endometrium with reversal of this effect in the post treatment proliferative endometrium. Scale bar = 20 μm; negative control (B-vi) scale bar = 100 μm. (C) The DIA results of the cell proliferation marker Ki67 for the pretreatment proliferative vs. pretreatment secretory endometrium (C-i), UPA-treated vs. the pre- and post-treatment proliferative endometrium (C-ii), and UPA-treated vs. the pre- and post-treatment secretory endometrium (C-iii) displayed as a percentage of positively stained cells. There was an impressive consistency between the RTqPCR data (A) and the DIA data. CI = confidence interval; DIA = digital image analysis; G = glands; mRNA = messenger ribonucleic acid; SPRM = selective progesterone receptor modulator; RTqPCR = real-time quantitative reverse transcription polymerase chain reaction; S = stroma; UPA = ulipristal acetate. Reproduced from Fertil Steril. 2021;116(3): 882–895. Chodankar RR, Murray A, Nicol M, Whitaker LHR, Williams ARW, Critchley HOD. The endometrial response to modulation of ligand-progesterone receptor pathways is reversible. Copyright (2021), with permission from Elsevier. This is an Open Access article distributed in accordance with the terms of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0) license, copy and redistribute the material in any medium or format for commercial use, provided the original work is properly cited. See https://creativecommons.org/licenses/by-nc-nd/4.0/. This text includes minor additions and formatting changes to the original text.

Copyright © 2023 Whitaker et al.

Positive immunostaining for the cell proliferation marker, Ki67, was observed in the nuclei of endometrial stromal cells and the glandular epithelium during the pretreatment proliferative phase. Ki67 immunostaining was greater when compared with secretory phase endometrium (see Figure 17, B-i & ii). 49 Ki67 immunostaining in UPA treated endometrium was negligible in endometrial glands and stromal cells (see Figure 17, B-iii). 49

DIA and quantification studies of positive Ki67 immunostaining (displayed as positive percentage) were performed and have been published. 49 A high level of agreement of data was obtained between RTqPCR and DIA. There was reduced cell proliferation as assessed by Ki67 immunoreactivity in UPA-treated endometrium when compared with pretreatment proliferative phase endometrium. (see Figure 17 C). 49

Effects of UPA administration upon cellular markers of apoptosis in the human endometrium

Study of endometrial biopsies collected before UPA treatment and, after six months of UPA treatment, investigated expression of markers of apoptosis (relative mRNA expression of apoptotic markers: Cleaved caspase-3, BAX and BCL-2 using RT-qPCR) (see Figure 18). Our data suggest reduced endometrial apoptosis following UPA exposure, though results were not statistically conclusive. Cleaved caspase-3 and BAX (pro-apoptotic markers) expression decreased following UPA treatment while BCL-2 (anti-apoptotic marker) expression increased.

FIGURE 18.

Relative mRNA expression of apoptotic markers: Cleaved caspase-3 (CC3), BAX and BCL-2.

Part B: Studies of impact of UPA administration on the uterus as determined with high resolution structural MRI

Results

Key outcomes

Our key outcomes from our MRI stereology studies described in Part B are thus as follows:

1. - No significant reduction in the volume of fibroids.

2. - No significant reduction in the volume of the uterus, irrespective of whether or not fibroids are present.

Intra-rater Repeatability and Inter-rater Reproducibility

Results of the intra-rater repeatability and the inter-rater reproducibility studies for uterine body (i.e. analysis of 49 MR images referring to 19 patients at one or more of three time points) and for three largest fibroids (i.e. analysis of 19 MR images referring to 8 patients at one or more of three time points) are presented using Bland–Altman plots, which indicate both limits of agreement (LoA) (see Figure 19) and summarised in Table 17. The solid black horizontal line at 0 point on the vertical axis illustrated in Figure 19 indicates where the mean value would be plotted if there was no difference between the two measurements. Therefore, when the mean difference between the two measurements lies outside the boundary of the 95% CIs (i.e. the region shaded blue in Figure 19) the bias is considered to be significant with p < 0.05.

FIGURE 19.

Bland–Altman plot for repeatability and reproducibility of uterine and fibroid volume. Results of intra-rater (top row) and inter-rater (bottom row) studies performed to determine repeatability and reproducibility for estimating the volume of the body of the uterus (left column) and of the three largest fibroids (right column). The dotted black lines within the light blue area and the dotted black line within the blue area indicate LoA and bias with 95% CI, respectively. The solid black horizontal line corresponds to no mean difference between the two measurement results. The written values refer to the mean difference and 95% CI for the estimated upper and lower bound of LoA and bias. This figure is reproduced from Yin et al. 50 This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.

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TABLE 17 - Bland–Altman analysis repeatability and reproducibility studies

LoA, limits of agreement; * p < 0.05.

This table is reproduced from Yin et al. 50 This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.

Copyright © 2023 Whitaker et al.

		Intra-rater		Inter-rater
		Uterine body	Uterine fibroids	Uterine body	Uterine fibroids
Bias (95% CI)		5.53* (3.34 to 7.72)	0.42 (−5.3 to 6.14)	−6.9* (−10.1 to, −3.65)	1.86 (−3.62 to 7.34)
LoA (95% CI)	Lower	−9.45 (−13.23 to −5.67)	−22.83 (−32.78 to −12.88)	−29.06 (−34.65 to −23.47)	−20.43 (−29.96 to −10.90)
	Upper	20.5 (16.72 to 24.28)	23.68 (13.73 to 33.63)	15.26 (9.67 to 20.85)	24.14 (14.61 to 33.67)

Analysis of the results plotted in Figure 19 revealed a small but significant (p < 0.05) measurement bias between repeat estimates for the volume of the body of the uterus obtained using the Cavalieri method in combination with MRI in both intra-rater [5.53 ml (95% CI 3.34 ml to 7.72 ml)] repeatability and inter-rater [6.9 ml (95% CI −3.65 ml to −10.15 ml)] reproducibility studies, and which is in both cases of the order 5%. The repeated measurement of the three largest fibroids showed no bias, either on two occasions with one observer or by two different observers.

Results of intra-rater (top row), and inter-rater (bottom), studies performed to determine repeatability and reproducibility for estimating the volume of the uterus (left column) and of the three largest fibroids (right column).

Change in the total volume of fibroids

The total volume of uterine fibroids in the group of eight patients in whom fibroids are present are plotted at baseline and after two and three 12-week courses of treatment with SPRM-UPA in Figure 20(C). Prior to performing the one-way repeated measures ANOVA to test the null hypothesis that, on average, there was no significant reduction in the total volume of fibroids in the group of eight patients in whom they were present, application of the Shapiro test indicated that the volumes obtained at the three time points were not normally distributed. Accordingly, the fibroid volumes were converted to logarithms, after which the same test confirmed that the resulting data were normally distributed, and sphericity of the data was confirmed by application of Mauchly’s test. Subsequent application of the one-way ANOVA confirmed the null hypothesis that there was no significant reduction in the volume of fibroids, after either two or three courses of treatment with the SPRM UPA (p = 0.1666213).

FIGURE 20.

Total uterine and fibroid volume. This figure is reproduced from Yin et al. 50 This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.

Copyright © 2023 Whitaker et al.

Individual data points and mean values of the volume of the uterus (A) with and (B) without the inclusion of total volume of fibroids are plotted at baseline and after 6 and 12 months of treatment with SPRM-UPA. Open circles refer to patients with fibroids and closed circles to patients without fibroids. Corresponding values are plotted in (C) for total fibroid volume in the group of patients with fibroids and in (D) for the volume of the uterus, excluding the volume of fibroids when present, in the combined cohort of patients.

Change in the volume of the uterus

The total volume of the uterus plus fibroids in the group of 8 patients in whom fibroids are present, and of the uterus in the group of 11 patients without fibroids, are plotted as open and closed symbols, respectively, at baseline and after two and three 12-week courses of treatment with SPRM-UPA in Figure 20(A). The same data are plotted in Figure 20(B), except that, for the patients with fibroids, total fibroid volume is subtracted from the volume of the uterus, and the volume of the uterus, excluding the total volume of fibroids when present, is plotted for the combined cohort of 19 patients in Figure 20(D). As was the case for the study of the change in fibroid volume, application of the Shapiro test again indicated that the measures of the volume of the uterus obtained at the three time points were not normally distributed. Accordingly, the volumes were converted to logarithms, after which the same test confirmed that the resulting data were normally distributed, and sphericity of the data was confirmed by application of Mauchly’s test. Subsequent application of the two-way ANOVA confirmed the null hypotheses that that there was no significant reduction in the volume of the uterus in the total patient cohort (p = 0.50652544), and no significant difference between the behaviour of the two groups (p = 0.62602183), after either two or three courses of treatment with the SPRM UPA (p > 0.05).

Power calculations to assist in the design of future studies

As above, the volumes of fibroids and uterus were converted to logarithms for performing the simulations proposed by Kerns78 to establish the number of subjects to be recruited for future studies to be appropriately powered to obtain particular levels of significance. Based on the data obtained in the present study, and performing 1000 simulations, for three time points and a group size of up to 50, with alpha (type I error) and beta (type II error) set to 0.05 and 0.2, respectively, indicated that a total of at least 35 patients would need to be recruited for the null hypothesis that there is no significant reduction in total fibroid volume to potentially be rejected.

Part C: Studies of impact of UPA administration on uterine vascularity as determined with DCE-MRI

Results

Key outcomes

Our key outcomes from our DCE-MRI studies described in section C are thus as follows:

1. Treatment with UPA did not alter plasma flow in the myometrium or endometrium, but significantly increased plasma volume in fibroid tissue.

2. UPA treatment did not alter permeability-surface area product in the myometrium, endometrium or uterine fibroids.

3. UPA significantly increased initial rate of enhancement in uterine fibroids.

Among the 15 participants with HMB (with and without fibroids) studied with DCE-MRI, three courses of UPA treatment significantly increased plasma volume in uterine fibroids but not in the myometrium or endometrium (p = 0.03). There were no significant changes in plasma flow in the myometrium, endometrium or fibroids. A sub-group analysis of patients revealed that treatment with UPA significantly decreased plasma flow in the endometrium of women with adenomyosis from baseline to third course of UPA treatment (p = 0.01, n = 5 women) but not in women with a normal uterus or fibroids. UPA did not significant modify plasma volume in any regions of interest (ROIs) for the sub-group analysis of women with and without fibroids or adenomyosis.

Treatment with UPA did not alter plasma flow in the myometrium or endometrium and significantly increased plasma volume in fibroid tissue

UPA administration did not significantly alter plasma flow in myometrium or endometrium for the 15 women studied throughout the three courses of UPA treatment. There was a non-significant trend that UPA administration increased plasma flow in fibroid tissues from baseline to second UPA course to third UPA course (see Figure 21, A; see Appendix, Tables 27–29). UPA treatment did not alter plasma volume in myometrium or endometrium, but significantly increased plasma volume in fibroids from baseline to third UPA course (p = 0.03, n = 11 fibroids; Figure 21, B; see Appendix, Tables 27–29).

FIGURE 21.

Changes in tissue parameters prior to SPRM (UPA) administration and after treatment cycle 2 and treatment cycle 3. (A) There were no significant changes in plasma flow in myometrium, endometrium and uterine fibroids over a period of 11 months of treatment. (B) Plasma 2 volume increased significantly from MRI 1 (baseline, pretreatment) to MRI 3 after 11 months of exposure to SPRM (UPA) in uterine fibroids (p = 0.03; n = 11 fibroids across 5 women). There were no changes in plasma volume in myometrium and endometrium across 11 months of UPA administration. (C) There were no significant changes in permeability-surface area product in myometrium, endometrium and uterine fibroids over 11 months of UPA treatment. (D, F, G) There were no significant changes in relaxation time T1, maximum enhancement and area under the curve in myometrium, endometrium and uterine fibroids over 11 months of UPA treatment. (E) Initial rate of enhancement increased significantly from baseline to 11 months of UPA treatment (p = 0.03) in uterine fibroids, but not in the myometrium or endometrium. The horizontal lines represent median and interquartile range. *p < 0.05.

UPA treatment did not alter permeability-surface area product in the myometrium, endometrium or uterine fibroids

UPA administration did not significantly alter permeability-surface area product in myometrium, endometrium or uterine fibroids for 15 women after three courses of UPA treatment (see Figure 21, C; see Appendix, Tables 27–29).

UPA significantly increased initial rate of enhancement in uterine fibroids

UPA treatment did not significantly impact upon relaxation time T1, which is reflective of tissue structure of the myometrium, endometrium or fibroid ROIs (see Figure 21, D; see Appendix, Tables 27–29). UPA administration significantly increased initial rate of enhancement in fibroids, which is the gradient of initial enhancement of the contrast agent concentration-time curve, from baseline to third UPA course (p = 0.03, n = 11 fibroids; Figure 21, E; see Appendix, Tables 29). There was a non-significant trend that UPA administration increased the maximum enhancement of the contrast agent concentration-time curve and area under the contrast agent concentration-time curve for uterine fibroids (see Figure 21, F; see Appendix, Tables 29). UPA treatment did not alter initial rate of enhancement, maximum enhancement, or the area under the curve for myometrium or endometrium (see Figure 21, E-G; see Appendix, Tables 27 and 28). The area under the curve is a mixed parameter that has correlation with plasma, extraction fraction and plasma volume. 91

Sub-group analyses revealed that UPA treatment significantly decreased plasma flow in the endometrium of women with adenomyosis, but not in women with a normal uterus or with the presence of uterine fibroids.

The women were separated into sub-groups for analysis, these being women with a normal uterus (n = 6), women with uterine fibroids (n = 5) and women with adenomyosis (n = 5). One woman had both uterine fibroids and adenomyosis and she was included in both the uterine fibroid and adenomyosis sub-groups. When the women were separated into sub-groups, those exposed to UPA treatment displayed a significantly decreased plasma flow in the endometrium of those with adenomyosis from baseline to third UPA course (p = 0.0133, n = 5 women; Figure 22, A). UPA administration did not significantly alter plasma flow in the endometrium of women with a normal uterus or uterine fibroids (see Figure 22, A). In addition, UPA treatment did not significantly alter plasma volume or permeability surface-area product in the endometrium of women with normal uterus, with uterine fibroids or adenomyosis (see Figure 22, B&C).

FIGURE 22.

Sub-group analysis of changes in endometrial parameters from baseline (before SPRM; UPA treatment) to after two courses (7 months) and three courses (11 months) of SPRM, ulipristal acetate (UPA) treatment, n = 6 in patient group without uterine fibroids or adenomyosis, n = 5 in patient group with uterine fibroids, n = 5 in patient group with adenomyosis. One patient had both uterine fibroids and adenomyosis, and was included in both the fibroid and adenomyosis groups. (A) UPA significantly decreased plasma flow from baseline to after three courses (11 months) in patients with adenomyosis (n = 5; p = 0.01), but not in normal uterus or uterus with fibroids. (B, C) UPA did not significantly alter plasma volume or permeability-surface area product in the endometrium of sub-group analyses. (D, E, F, G) UPA did not significantly alter relaxation time, initial rate of enhancement, maximum enhancement and area under the curve in endometrium of sub-group analyses. *p < 0.05.

In the sub-group analysis, UPA exposure did not have any significant impact on relaxation time T1, initial rate of enhancement, maximum enhancement and area under the curve in the endometrium of women with normal uterus, with uterine fibroids or adenomyosis (see Figure 23, D–G). UPA treatment did not alter any quantitative or semi-quantitative parameters in myometrium in our sub-group analyses (see Figure 23, A–G).

FIGURE 23.

Sub-group analysis of changes in myometrial MRI-DCE parameters from baseline (prior to SPRM; UPA) treatment to after two courses (7 months of UPA treatment) and three courses (11 months) of SPRM, ulipristal acetate (UPA) treatment, n = 6 in patient group without uterine fibroids or adenomyosis, n = 5 in patient group with uterine fibroids, n = 5 in patient group with adenomyosis. One patient had both uterine fibroids and adenomyosis, and was included in both the fibroid and adenomyosis groups. No significant changes were seen across all patient groups. The p-value was set at 0.05.

Overview conclusions

Consistent with our objectives, we have described (1) how UPA administration alters selected markers of endometrial cellular function (markers of cell proliferation, apoptosis, expression of steroid receptors, progesterone-dependent genes); (2) how UPA treatment impacts upon uterine and fibroid volume as determined with high resolution structural MRI; and (3) how UPA treatment effects blood flow and blood volume in the endometrium, myometrium and fibroid tissue, along with study of other parameters with DCE-MRI.

Analysis of selected markers of endometrial cellular function demonstrated UPA modulation of the PR resulting in molecular and cellular alteration in steroid receptors (including cellular location) and steroid metabolising enzymes within the endometrium, consistent with the development of a local (endometrial) oestrogenic microenvironment. Yet, despite this, there is no evidence of pathological endometrial changes. We demonstrated that alteration in the microenvironment reverses on cessation of UPA treatment, a key factor for a medical treatment of HMB, particularly for those who wish to preserve fertility. In contrast to previous published literature examining the effects of SPRM we observed no significant reduction in the volume of the uterus, whether or not fibroids were present and furthermore there was no significant change in the volume of fibroids themselves.

In the first study to assess how targeting the PR impacts upon the uterine microcirculation, as measured with DCE-MRI, we observed no significant changes in plasma flow or plasma volume in the normal endometrium or myometrium. The absence of changes in plasma flow, especially, suggests that there are no changes in blood flow in arterial and venous micro-vessels. However, we did observe a significant increase in plasma volume within uterine fibroids and this may be interpreted as reflecting a reduction in the proportion of extracellular matrix components. Furthermore, plasma flow was significantly reduced in the endometrium of women with adenomyosis but not in the myometrium of women with a normal uterus or fibroids. The role of UPA in the alteration of plasma volume remains uncertain in those with fibroids, and endometrial plasma flow in those with adenomyosis and the complaint, and subsequent control, of HMB. The modulation of the endometrial microenvironment by targeting the PR, irrespective of underlying aetiology of HMB, and the reversibility of these changes on cessation of UPA provide novel insights into the use of SPRMs for control of HMB, irrespective of underlying aetiology.

Clinical studies to date with SPRMs have addressed their use in uterine specific conditions (i.e. uterine fibroids) rather than as in the UCON study the symptom patients experience HMB whether or not uterine fibroids were present in participants. HMB remains an underreported debilitating symptom with unmet need for new medical options for treatment. Given the success of SPRMs with achieving amenorrhoea/reduced menstrual bleeding, the quest for an SPRM class member, without risk of the very rare risk of liver toxicity, may well be revisited.

Principal findings of randomised trial

This randomised controlled trial compared the LNG-IUS and UPA in a population of women with self-reported HMB, with either small or no fibroids. At 12 months after randomisation, the impact of HMB, measured with the MMAS, was improved substantially from baseline in both groups. There was no evidence of a statistically significant difference in MMAS scores between treatments, though those allocated UPA exhibited a more rapid rate of improvement in MMAS scores. Those allocated to UPA had a greater magnitude of improvement in overall menstrual bleeding scores (as measured by PBAC) and were more likely to achieve amenorrhoea at 12 months (64% vs. 25%), yet this was not reflected in greater improvement in quality of life or sexual functioning. In those with uterine fibroids, there were no changes in fibroid or uterine volume in either treatment group.

Principal findings of mechanism of action study

Safety findings of UPA

There were no malignant changes in the endometrium of either patient group although one participant allocated to UPA administration developed endometrial hyperplasia with atypia. The MoA studies further support the absence of pathological changes despite a local oestrogenic microenvironment following treatment with UPA. Rates of PAEC following treatment were low and all had resolved within six months of treatment cessation. Two participants developed liver transaminase levels over three times the upper limit of normal, rising to three in the post-treatment period; none required hospital admission for management thereof. SAEs were infrequent and typically unrelated to treatment. There was one SUSAR, development of an acute hepatitis during the final course of UPA. This occurred prior to the initial USM. At initial presentation there was concern that this could represent a DILI, given the previous hepatoxic effects of other SPRMs such as onapristone109 and was thus reported as a SUSAR. However, the strong family history of autoimmune hepatitis led her hepatology team to conclude that this was the likely aetiology, and liver biopsy demonstrated widespread lymphoplastic hepatitis. The diagnosis of autoimmune hepatitis was not adjusted following the USM. The participant continues on long-term azathioprine with normal liver function. Following the USM, LFT eligibility and monitoring criteria were instigated in line with MHRA recommendations and it is likely that this participant would not have been eligible to participate.

Generalisability, equality, diversity and inclusion

In contrast to previous studies of SPRMs, typically limited to those with large fibroids only, the UCON trial has reflected a more ‘real-world’ participant population affected by the symptom of HMB, particularly given two-thirds of study participants had structurally normal uteri and those with small fibroids were evenly distributed between the two treatment regimens. Among the individuals recruited to the UCON trial, the mechanism of heavy bleeding is likely different to those with large uterine fibroids, and fewer therapeutic options are available. The average age of the participant population was 42.5 years and the duration of their symptom of HMB was considerable, with a median duration of symptoms of 3 years. This participant population reflects one with a high burden of symptoms, further reflected in a median MMAS score at entry of 37 in the UPA arm and 33 in the LNG-IUS arm out of a possible 100 (0 worst possible health, 100 best possible health state). This underscores the burden of HMB, reflecting a large and underserved patient population with unmet therapeutic needs.

The study population was predominantly white, with relative underrepresentation of other ethnicities, particularly black women, who represented only 2% of study participants. This may contribute to the relatively low rates of uterine fibroids. This lack of ethnic diversity is likely as a result of the majority study participants being recruited from Scotland, and that those with large fibroids were excluded. The potential impact of this lack of diversity is unclear. We did not collect data regarding social deprivation and level of education and so are unable to comment on diversity within these areas.

The UCON clinical trial recruited participants both from primary care and secondary care; however, the relative proportions of these differing populations were not recorded. Those presenting to secondary care may reflect a more refractory subset of women with HMB, having likely failed initial medical management in the community. As such they may have held differing views of acceptability of treatment strategy, which may in part explain why 40% of those eligible for, but declining participation to UCON, was due to a strong preference either for or against LNG-IUS. Furthermore, those who were relatively treatment naive may have had differencing expectations of what would constitute treatment success.

Adenomyosis may cause HMB,7 and although its presence was not an exclusion criterion, the incidence of adenomyosis within the UCON trial may have been underestimated. Rates of adenomyosis vary in the literature, reflecting both the impact of coexisting pathology and the challenge of diagnosis using non-invasive techniques, but a background rate of 20–30% is frequently reported,110 even in younger women. 111 The sensitivity of ultrasound for detecting adenomyosis is less than MRI, but remains the first-line image tool of choice. 112 In the MoA study, described in Chapter 4, participants taking UPA underwent MRI. In the 19 participants of the MoA study, 6 (32%) had adenomyosis on MRI imaging. However, an overall incidence of adenomyosis in those recruited to the main clinical trial, as determined by ultrasound scan, was 8.5%, and was evenly distributed between the two treatment groups. Given the findings of the MoA study, and background rates of adenomyosis it is possible that there may have been unrecognised cases of abnormal bleeding due to adenomyosis. As such, it is difficult to ascertain the impact of this coexisting pathology may have had upon treatment efficacy.

Limitations of the randomised trial

Interpretation in context of other literature

Implications for decision makers

On the basis of recruited participants, our study has shown that UPA treatment achieves amenorrhoea, improves quality of life and has a high rate of patient satisfaction. However, the risk of DILI has meant that UPA is no longer recommended as a therapeutic option for those with small (< 3 cm) fibroids in the UK, and UPA unlikely to proceed to be licensed as a treatment for those patients with structurally normal uterus with the symptom of HMB. While surgical intervention for HMB, particularly hysterectomy, is associated with greater improved quality of life, it is typically fertility ending, has a risk of serious complications, and higher associated mortality risk compared with that of fatal liver injury following UPA treatment (> 1 : 100 vs. 0.1 : 100,000). 32 At present, given very low rates of DILI, and that multiple studies have demonstrated improvement in quality of life, there remains a role for UPA treatment as a therapeutic option for symptomatic uterine fibroids as outlined by NICE,9 particularly given the medical alternative with GnRH analogues is associated with more deleterious impact on bone density and other unwanted side effects such as vasomotor symptoms24. However, in those with small uteri, the risk–benefit may be less, given the equivalent impact on quality of life compared with existing alternative option of LNG-IUS, a treatment strategy typically less successful or inappropriate in those with large fibroids. While LNG-IUS remains a popular choice for many women with HMB, and in some countries use has increased exponentially over the last two decades,130 data from previous studies are consistent with our finding that the LNG-IUS is not effective for all women, and for many is unacceptable for an initial trial of treatment. There remains a pressing need for effective oral medical treatments for HMB with an acceptable side effect profile.

Recommendations for future research

SPRMs remain an attractive class of compounds, given their oral route of administration, high rates of amenorrhoea, preservation of bone density and lack of long-term endometrial effects. While UPA is now unlikely to be licensed for use in the patient population reflected in the UCON study, in the future, other SPRMs may be developed that do not have the reactive metabolite formation131 and thereby should be considered as new therapeutic options, given the demonstrable efficacy and acceptability to patients. Until these are available a promising class of compounds are the oral GnRH receptor antagonists, explored as a therapy for endometriosis associated pain,132 which are well tolerated, and have minimal impact on long-term risk of fracture. 133 When used for HMB in association with fibroids, control of bleeding was achieved in up to 84.1% of participants compared with placebo,90 and is again associated with preserved bone mineral density when used with HRT combination therapy. 134

Our view is that a study in a similar population as that in our UCON clinical trial, namely those with HMB in conjunction with small or no uterine fibroids, is a comparison between an oral GnRH receptor antagonist compared with a progestin. Ideally this would be large enough to permit differential analysis between those with HMB resultant from AUB due to adenomyosis, leiomyoma and endometrial dysfunction,7 informing both precision-based care but also reflecting a population where the primary complaint is HMB. Whether the underlying mechanism between these three pathologies is significant in the context of medical treatment strategy is unknown.

The optimal condition-specific patient-reported outcome measures remain uncertain, with a multitude of measures previously reported. 135 Development of a core outcome set for HMB by Cooper et al. 136, under the CROWN/COMET initiative,137 will aid potential to draw insights from pooled data. Additional learning points from the UCON trial include the need for inclusion of an embedded qualitative study, to explore the disconnect between achieving amenorrhoea and improvement in quality of life. Finally, our experience with not one but two urgent safety measures, and in particular the resultant complexity for statistical analysis, we hope will aid other clinical trialists in the future.

Given our findings from the UCON study, our recommendations for future research include:

1. Further studies of medical treatments for HMB

   1. a. Developing and utilising other SPRMs, not associated with DILI

   2. b. Other hormonal/non-hormonal medical treatments for HMB

2. Patient populations that encompass both the symptoms of HMB, and underlying aetiologies, including structurally normal uteri, adenomyosis and small fibroids

3. Study design with outcome measures including impact on bleeding pattern, pain and impact on haemoglobin and iron-deficiency, as well as quality of life

4. Qualitative studies to determine what are the most important outcomes to women who suffer HMB.

Conclusion

Both UPA and LNG-IUS improve bleeding symptoms and alleviate the adverse impact of heavy menstrual bleeding on quality of life. UPA is now only available for intermittent treatment of moderate to severe uterine fibroid symptoms before menopause and when surgical procedures (including uterine fibroid embolisation) are not suitable or have failed. New, effective and acceptable oral medical treatment options are needed to address an important unmet clinical need.

Contributions of authors

Lucy H.R. Whitaker (https://orcid.org/0000-0002-7678-6551) (clinical lecturer in obstetrics and gynaecology) contributed to methodology, and investigation including mechanism of action studies and led writing of the final monograph report.

Lee J. Middleton (https://orcid.org/0000-0003-4621-1922) (reader in clinical trials, senior statistician) contributed to conceptualisation, funding acquisition, methodology, supervision, formal analysis, visualisation and data curation, writing of the original draft and review/editing of the final report.

Lee Priest (https://orcid.org/0000-0002-0070-2294) (trial manager) contributed to methodology, project administration, visualisation, writing of the original draft and review/editing of the final report.

Smita Odedra (https://orcid.org/0000-0001-6495-7782) (trial manager) contributed to project administration and review/editing of the final report.

Versha Cheed (https://orcid.org/0000-0002-6713-0913) (statistician) contributed to formal analysis, visualisation, data curation and writing of the original draft.

Elaine P. Nicholls (https://orcid.org/0000-0001-5643-616X) (human resources consultant, management and development) contributed to conceptualisation, funding acquisition, methodology and review/editing of the final report.

Alistair R.W. Williams (https://orcid.org/0000-0002-7085-4525) (professor of pathology) contributed to conceptualisation, funding acquisition, investigation, methodology, formal analysis, validation, writing of the original draft and review/editing of the final draft.

Neil Roberts (https://orcid.org/0000-0001-5538-8653) (professor of medical physics and imaging science) contributed to conceptualisation, funding acquisition, investigation, methodology, formal analysis, validation, writing of the original draft and review/editing of the final draft.

Clive E. Stubbs (https://orcid.org/0000-0003-2690-6583) (trial management team leader, clinical trials) contributed to project administration, resources, supervision and review/editing of the final draft.

Konstantinos Tryposkiadis (https://orcid.org/0000-0002-2516-1180) (statistician) contributed to formal analysis, visualisation, data curation and writing of the original draft.

Hannah Bensoussane (https://orcid.org/0000-0002-6266-8204) (statistician) contributed to formal analysis, visualisation, data curation and writing of the original draft.

Rohan Chodankar (https://orcid.org/0000-0001-8881-1681) (clinical research fellow, obstetrics and gynaecology) contributed to the investigation, data analysis and visualisation (endometrial Part A, mechanism of action study) and writing of the final report.

Alison A. Murray (https://orcid.org/0000-0003-3719-3291) (postdoctoral researcher, reproductive sciences) contributed to the investigation, data analysis and visualisation (endometrial Part A, mechanism of action study) and review/editing of the final report.

Moira Nicol (https://orcid.org/0000-0002-5503-5281) (postdoctoral researcher, reproductive sciences) contributed to the investigation, formal analysis (endometrial Part A, mechanism of action study), project administration and review/editing of the final report.

Aleksandra O. Tsolova (https://orcid.org/0000-0002-0273-5815) (PhD student, reproductive sciences) contributed to investigation, formal analysis (endometrial Part A, mechanism of action study) and review/editing of the final report.

Kaiming Yin (https://orcid.org/0000-0002-8069-1117) (academic researcher, medical physics) contributed to investigation, formal analysis and visualisation (MRI stereology Part B, mechanism of action study) and writing of the final report.

Marcos Cruz (https://orcid.org/0000-0002-4767-530X) (professor of medical physics) contributed to formal analysis (MRI stereology Part B, mechanism of action study) and review/editing of the final report.

Hui Wei Leow (https://orcid.org/0000-0002-4341-7610) (medical student) contributed to investigation formal analysis and visualisation (MRI DCE Part C, mechanism of action study) and writing of the original draft.

Lucy E. Kershaw (https://orcid.org/0000-0001-9510-7940) (senior research fellow, clinical sciences) contributed to methodology, investigation, formal analysis and visualisation (MRI DCE Part C, mechanism of action study), writing of the original draft and review/editing of the final report.

Suzanne L. McLenachan (https://orcid.org/0000-0002-0263-9559) (consultant, clinical radiology) contributed to formal analysis and validation (MRI stereology Part B, mechanism of action study) and review/editing of the final draft.

Graham McKillop (https://orcid.org/0000-0002-9326-0076) (consultant, clinical radiology) contributed to formal analysis and validation (MRI stereology Part B, mechanism of action study) and review/editing of the final draft.

Jane Walker (https://orcid.org/0000-0003-1119-291X) (consultant, clinical radiology) contributed to resources and investigation and review/editing of the final draft.

Scott I. Semple (https://orcid.org/0000-0002-4008-7564) (professor of medical imaging and physics) contributed to conceptualisation, funding acquisition and methodology, and review/editing of the final draft.

T. Justin Clark (https://orcid.org/0000-0002-5943-1062) (professor of obstetrics and gynaecology) contributed to conceptualisation, funding acquisition, investigation, and methodology, supervision of research activities in Birmingham Women’s Hospital and review/editing of the final draft.

Mary Ann Lumsden (https://orcid.org/0000-0003-2998-9185) (professor of obstetrics and gynaecology) contributed to conceptualisation, funding acquisition, investigation and methodology, supervision of research activities in Glasgow Royal Infirmary and review/editing of the final draft.

Dharani Hapangama (https://orcid.org/0000-0003-0270-0150) (professor of gynaecology) contributed to conceptualisation, funding acquisition, investigation and methodology, supervision of research activities in Liverpool Women’s Hospital and review/editing of the final draft.

Lucky Saraswat (https://orcid.org/0000-0002-5434-7750) (senior clinical lecturer, obstetrics and gynaecology) contributed to supervision of research activities in Aberdeen Royal Infirmary and review/editing of the final draft.

Siladitya Bhattacharya (https://orcid.org/0000-0002-4588-356X) (professor of obstetrics and gynaecology) contributed to conceptualisation, funding acquisition, investigation, methodology and review/editing of the final draft.

Paul Smith (https://orcid.org/0000-0002-1430-5732) (clinical lecturer, obstetrics and gynaecology) contributed to conceptualisation, funding acquisition, investigation, methodology and review/editing of the final draft.

Jane Daniels (https://orcid.org/0000-0003-3324-6771) (professor of clinical trials) contributed to conceptualisation, funding acquisition, investigation and methodology, supervision, writing of the original draft and review/editing of the final report.

Hilary Critchley (https://orcid.org/0000-0003-1913-4044) (professor of reproductive medicine and chief investigator) contributed to conceptualisation, funding acquisition, investigation and methodology, supervision of research activities, writing of the original draft and review/editing of the final report.

Members of the UCON Collaborative Group

Chief investigator – Hilary Critchley, University of Edinburgh

Co-investigators

Siladitya Bhattacharya, University of Aberdeen

Justin Clark, University of Birmingham

Jane Daniels, University of Nottingham

Dharani Hapangama, University of Liverpool

Mary Ann Lumsden, University of Glasgow

Lee Middleton, University of Birmingham

Elaine Nicholls (PPI representative)

Neil Roberts, University of Edinburgh

Scott Semple, University of Edinburgh

Paul Smith, University of Birmingham

Alistair Williams, University of Edinburgh

Trial management group

Emma Barlow, University of Birmingham

Versha Cheed, University of Birmingham

Hilary Critchley, University of Edinburgh

Jane Daniels, University of Nottingham

Max Feltham, University of Birmingham

Arshad Mahmood, University of Birmingham

Lee Middleton, University of Birmingham

Smita Odedra, University of Birmingham

Lee Priest, University of Birmingham

Neil Roberts, University of Edinburgh

Clive Stubbs, University of Birmingham

Konstantionos Tryoskiadis, University of Birmingham

Lucy Whitaker, University of Edinburgh

Alistair Williams, University of Edinburgh

Additional Birmingham Clinical Trials Unit staff

Julia Seely, BCTU Programmer and data manager

Recruiting site principal investigators and support staff

Aberdeen Royal Infirmary, Aberdeen: Lucky Sarawat,* Siladitya Bhattacharya, Sandra Cant, Pat Cooper, Diane Crowe, Diane Ledingham, Minimol Paulose, Fiona Payne, Judith Wilson.

Birmingham Women’s Hospital, Birmingham: Justin Clark,* Faye Andrews, Fiona Beale, Prathiba de Silva, Raji Ganesan, Virginia Iqbal, Shanteela McCooty, Clare McPake, Siobhan O’Connor, Hammara Sattar, Paul Smith, Helen Stevenson, Jennifer Taylor.

Burnley General Hospital and Royal Blackburn Hospital, East Lancashire Hospitals NHS Trust: Kalsang Bhatia,* Bev Hammond, Santhi Kumar, Rebekah Mcrimmon, Cathie Melvin, Matthew Milner, Pam Sikora, Victoria Taylor.

Glasgow Royal Infirmary, Glasgow: Mary Ann Lumsden,* Joan Blevings, Isobel Crawford, Cecelia Lyons Lorna McKay, Therese McSorley, David Millan, Anne Marie Munro, Kirsten Paterson, Carol Ruth.

Liverpool Women’s Hospital, Liverpool: Dharani Hapangama,* Kathie Cooke, Pat Cooper, Pam Corlett, Howida Shawki, Gillian Smith, Elaine Willis.

Royal Gwent Hospital, Newport: Leena Gokhale,* Joanne Carter, Jane Gray, Patricia James, Tracy James, Emma Mills, Victoria Richards-Green.

North Manchester General Hospital and the Royal Oldham Hospital, Pennine Acute Trust: Sachchidananda Maiti,* Shabaz Hussein, Rachel Newport, Grainne O’Connor, Jennifer Philbin, Mfon Sam, Zainab Sarwar.

Prince Charles Hospital, Gurnos: Sanjay Chawathe,* Sean Dodington, David McRae, Lisa Mellish, Jamie Tucker, Joanna Wilson.

Royal Infirmary of Edinburgh, Edinburgh: Hilary Critchley,* Ruaridh Buchan, Rohan Chodankar, Catherine Hall, Barbara Hamilton, Sharon McPherson, Catherine Murray, Jane Reavey, Jane Walker, Lucy Whitaker, Tatiana White, Alistair Williams.

University Hospital, Crosshouse: Inna Sokolova,* Danielle Gilmour, Margo Henry, Lynne McNeil.

Wrexham Maelor Hospital, Wrexham: Geeta Kumar,* Huyam Abdelsalam, Sarah Davies, Emma Hall, Rachel Hughes, Sue Lord, Vicki Saul, Jane Stockport.

* principal investigator.

Trial steering committee (independent members)

Christian Becker, University of Oxford

Ying Cheong (chair from 7 June 2017), University of Southampton

Emma Crosbie, University of Manchester

Emily O’Toole (PPI representative)

Lesley Regan, Imperial College London

Jim Thornton (chair until 6 June 2017), University of Nottingham

Sanjay Vyas, University of Bristol

Data monitoring committee

Patrick Chien, University of Dundee

Lelia Duley, Nottingham Clinical Trials Unit, Nottingham

Richard Gray (chair), Clinical Trials Service Unit and Epidemiological Studies unit (CTSU), Oxford

Glenn McGluggage, Queen’s University of Belfast

Mechanistic study team

Sponsor

ACCORD: NHS Lothian and University of Edinburgh

Monitoring and audit teams led by Elizabeth Craig and Lorn McKenzie

Authors wish to thank Tatiana White, MRC Centre for Reproductive Health, University of Edinburgh for assistance with finalisation of manuscript preparation and submission.

Publications

Whitaker LHR, Middleton LJ, Daniels JP, Williams ARW, Priest L, Odedra S, et al. Ulipristal acetate versus levonorgestrel-releasing intrauterine system for heavy menstrual bleeding (UCON): A randomised controlled phase III trial. EClinicalMedicine 2023;60:101995. https://doi.org/10.1016/j.eclinm.2023.101995

Yin K, Whitaker L, Hojo E, McLenachan S, Walker J, McKillop G, et al. Measurement of changes in uterine and fibroid volume during treatment of heavy menstrual bleeding (HMB). Human Reproduction Open 2023;3:hoad021. https://doi.org/10.1093/hropen/hoad021

Chodankar, RR, Murray A, Nicol M, Whitaker LHR, Williams ARW and Critchley HOD. The endometrial response to modulation of ligand-progesterone receptor pathways is reversible. Fertil Steril 2021;116(3):882–95.

Patient data

This work uses data provided by patients and collected by the NHS as part of their care and support. Using patient data is vital to improve health and care for everyone. There is huge potential to make better use of information from people’s patient records, to understand more about disease, develop new treatments, monitor safety and plan NHS services. Patient data should be kept safe and secure, to protect everyone’s privacy, and it is important that there are safeguards to make sure that it is stored and used responsibly. Everyone should be able to find out about how patient data are used. (#datasaveslives). You can find out more about the background to this citation here: https://understandingpatientdata.org.UK/data-citation.

Ethics statement

The trial had a favourable ethical opinion from the London (Bloomsbury) National Research Ethics Service Committee (REC No 14/LO/1602) and clinical trial authorisation from the Medicines and Healthcare products Regulatory Agency (MHRA; EudraCT No: 2014-003408-65). Amendments to the protocol, required as a consequence of the two urgent safety measures, were based on the MHRA guidance to monitor the safety of existing and new participants.

Data-sharing statement

All data requests should be submitted to the corresponding author for consideration. Access to anonymised data may be granted after review.

Disclaimers

This report presents independent research. The views and opinions expressed by authors in this publication are those of the authors and do not necessarily reflect those of the NHS, the NIHR, the MRC, the EME programme or the Department of Health and Social Care. If there are verbatim quotations included in this publication the views and opinions expressed by the interviewees are those of the interviewees and do not necessarily reflect those of the authors, those of the NHS, the NIHR, the EME programme or the Department of Health and Social Care.