Condition category
Date applied
Date assigned
Last edited
Prospectively registered
Overall trial status
Recruitment status
No longer recruiting
Publication status
Results overdue

Contact information



Primary contact

Ms Faiza Idries


Contact details

Nightingale & Genesis Prevention Centre
Wythenshawe Hospital
Southmoor Road
M23 9LT
United Kingdom
0161 291 4408

Additional identifiers

EudraCT number number


Protocol/serial number


Study information

Scientific title

A pilot prevention study of the effects of the anti-progestin Ulipristal acetate (UA) on surrogate markers of breast cancer risk


Study hypothesis

1.4 million women worldwide are diagnosed with invasive breast cancer (BC) each year and over a third die from their disease. Uptake and adherence to licensed chemo-preventative agents, tamoxifen and raloxifene, is low due in part to their adverse toxicity profiles. There is an urgent need for effective, well tolerated and safe breast cancer chemo-preventative agents. Endogenous progesterone induces proliferation of the normal mammary stem/progenitor cell population and exogenous progesterone is well known to increases the risk of postmenopausal breast cancer. Taken together these data suggest antagonism of PgR signaling may be a fruitful approach in the prevention of BC. Ulipristal acetate (UA) is a well-tolerated anti-progestin already licensed for the treatment of benign uterine fibroids. This project will, for the first time, determine the effects of the PgR antagonist UA on the normal breast in women at increased risk of BC and correlate molecular with imaging (MRI) effects.

Ethics approval

UK National Research Ethics Service: North West – Greater Manchester South Committee, provisional approval 18/06/2015, ref: 15/NW/0478

Study design

Non-randomised; Interventional; Design type: Prevention

Primary study design


Secondary study design

Non randomised study

Trial setting


Trial type


Patient information sheet

Not available in web format, please use contact details to request a participant information sheet


Malignant neoplasm of breast


1. Treatment: Ulipristal acetate 5mg daily for 12 weeks
2. Vacuum assisted breast biopsies before and on treatment
3. Imaging, MRI and USS elastography before and on treatment

Intervention type



Phase II

Drug names

Ulipristal acetate

Primary outcome measure

The change in the proliferation of normal breast epithelium, assessed by Ki67, from baseline to 3 months on treatment with ulipristal acetate

Secondary outcome measures

1. The changes in expression of individual genes and key pathways induced by UA therapy at baseline and after 3 months of therapy
2. The change in tissue stiffness and collagen organisation induced by UA therapy at baseline and after 3 months of therapy
3. The changes in key stem cell and PgR target proteins induced by UA therapy at baseline and after 3 months of therapy
4. The proportion and type of clonogenic cells in the breast following treatment with UA at baseline and after 3 months of therapy
5. MRI imaging biomarkers of anti-progestin (UA) activity at baseline and after 3 months of therapy
6. The side effect profile of UA in this patient population at baseline and then monthly to 4 months

Overall trial start date


Overall trial end date


Reason abandoned (if study stopped)


Participant inclusion criteria

1. Premenopausal females aged between 25 and 45 years
2. Regular menses defined as date of onset of last menstrual period +/­ 3 days of expected
3. Known BRCA1 or BRCA2 mutation or moderate to high risk of developing BC defined as >17% lifetime risk from age 20 or >3% risk between 40­50 years
4. Ovulatory menstrual cycles defined as serum progesterone =15nmol 7 days prior to expected onset of menses
5. eGFR = 40mls/min/1.73m2 in view of requirement for gadolinium contrast MRI scans
6. Willing and able to provide informed consent to undergo all trial procedures

Participant type

Healthy volunteer

Age group




Target number of participants

Planned Sample Size: 30; UK Sample Size: 30

Participant exclusion criteria

1. Personal history of breast, uterine, cervical or ovarian cancer
2. Breast feeding within the last 3 months
3. Pregnant or planning for pregnancy in the next 6 months. Pregnancy must be excluded with serum ßhCG <5nmol during screening.
4. Known hypersensitivity to radiological contrast media or to ulipristal acetate or any of its excipients (microcrystalline cellulose, mannitol, croscarmellose sodium, talc, magnesium stearate)
5. Current treatment with:
5.1. Anti­estrogens (e.g. tamoxifen or raloxifene), GnRH analogue therapy (e.g. goserelin or buserelin) or hormonal contraceptives including androgens such as cyproterone acetate. Such treatments must have been stopped for at least6 months and regular menstrual cycles resumed
5.2. Corticosteroids at any dose, these must have been stopped for at least 1 month with low likelihood that retreatment will be required
5.3. Antiplatelet or anticoagulant therapy – must have been stopped for at least 7 days and clotting be at satisfactory levels
5.4. Moderate or potent inhibitors of CYP3A4
5.5. Potent inducers of CYP3A4
6. APTT and PT outside the normal institutional ranges. Hb <100g/l and platelet count <150x109/l
7. Serum creatinine, bilirubin, ALT, ALP or LDH >1,5xULN
8. Contraindications to MRI, such as intracranial aneurysm clips, implanted electrical devices and intra­ocular metallic foreign bodies
9. Co­morbidity that would put the patient at increased risk such as recognised bleeding diathesis, moderate to severe hepatic impairment, moderate or severe renal impairment (eGFR <40 ml/min/1.73m2), severe asthma not adequately controlled with corticosteroids (note steroid usage precludes trial entry)
10. Prior breast enhancement/augmentation surgery
11. Genital bleeding of unknown aetiology

Recruitment start date


Recruitment end date



Countries of recruitment

United Kingdom

Trial participating centre

University Hospital of South Manchester
Genesis Prevention Centre Wythenshawe Hospital Southmoor Road
M23 9LT
United Kingdom

Sponsor information


University Hospital of South Manchester

Sponsor details

Wythenshawe Hospital
Southmoor Road
M23 9LT
United Kingdom

Sponsor type

Hospital/treatment centre



Funder type


Funder name

Breast Cancer Campaign

Alternative name(s)

Funding Body Type


Funding Body Subtype


Results and Publications

Publication and dissemination plan

To be confirmed at a later date

Intention to publish date

Participant level data

Stored in repository

Basic results (scientific)

Publication list

Publication citations

Additional files

Editorial Notes

23/10/2018: The main contact was updated from Donna Watterson to Faiza Idries 22/10/2018: The overall trial end date has been changed from 30/09/2017 to 30/06/2019 02/06/2016: Cancer Help UK lay summary link added.