Blocking Mifepristone Action With Progesterone

University of California (UC) Davis

Status and phase: Terminated; Phase 2; Phase 1

Conditions: Pregnancy, Unwanted

Treatments: Drug: micronized Progesterone; Drug: Mifepristone 200 MG; Drug: Placebo oral capsule

Study type: Interventional

Funder types: Other

Identifiers

NCT03774745

1353650

Details and patient eligibility

About

Double-blind randomized trial to evaluate the potential impact of progesterone treatment on early pregnancies exposed to mifepristone.

Full description

Medical abortion commonly refers to early pregnancy termination (usually before 10 weeks' gestation) performed without primary surgical intervention and resulting from the use of abortion-inducing medications. The use of medications to cause abortion has been around for almost 70 years but the modern era of medical abortion treatment evolved with the development of mifepristone, a progesterone-receptor blocker with an affinity for the receptor greater than progesterone itself.

Medical abortion with mifepristone and misoprostol is highly effective; however, the risk of continuing pregnancy is still present, especially as gestation advances. While most women opt for further treatment in these scenarios, such as surgical aspiration, there are some who decide to continue the pregnancy. Thus, even following treatment, some women do change their mind.

No well-done study has evaluated whether such treatment works. Poorly controlled case series are not evidence and systematic reviews of continuing pregnancy rates after mifepristone/prostaglandin analogue treatment failure do not reflect real life outcomes. This study is also a first step to understanding if large studies evaluating mifepristone antagonization with high-dose progesterone are indicated and if placebo-controlled randomized trials can be successfully completed when evaluating this question.

Enrollment: 12 patients

Sex: Female

Ages: 18+ years old

Volunteers: Accepts Healthy Volunteers

Inclusion criteria

1. Pregnant females 18 years and older at enrollment.
2. Seeking surgical abortion at 44-63 days' gestation on Study day 1.
3. Have received counseling and signed informed consent per UCD standard procedures for surgical abortion.
4. Presence of embryonic gestational cardiac activity on transvaginal ultrasonography.
5. English-speaking
6. Willing to sign informed consent and follow study protocol.
7. Willing to experience potential expulsion of the pregnancy with mifepristone treatment.

Exclusion criteria

1. Medical contraindications to medical abortion.

   1. Poorly controlled hypertension (systolic BP >160 or diastolic BP >95)
   2. Significant anemia - known recent hemoglobin <9.5 gm/dL
   3. Clinically significant cardiovascular disease (angina, valvular disease, arrhythmia, or congestive heart failure)
   4. Breastfeeding
   5. Coagulopathy or therapeutic coagulation
   6. Ultrasound evidence of molar or ectopic pregnancy
   7. Chronic systemic corticosteroid use
   8. Adrenal disease
   9. Sickle cell anemia with frequent/recent crises
   10. Glaucoma

2. IUD in place during conception, even if removed.

3. Peanut allergy.

4. Known intolerance of mifepristone or progesterone.

5. Any other condition, that in the opinion of the clinician, would contraindicate mifepristone, progesterone or medical abortion.

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Quadruple Blind

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12 participants in 2 patient groups, including a placebo group

Progesterone

Experimental group

Description:

Micronized progesterone 200mg oral capsules starting 24 hours after mifepristone 200mg ingestion (day 1). Progesterone treatment days 2-4: two capsules twice daily orally. Progesterone treatment days 5-15, 16 or 17: two capsules once daily orally.

Treatment:

Drug: Mifepristone 200 MG

Drug: micronized Progesterone

Placebo oral capsule

Placebo Comparator group

Description:

Placebo capsules starting 24 hours after mifepristone 200mg ingestion (day 1). Placebo treatment days 2-4: two capsules twice daily orally. Placebo treatment days 5-15, 16 or 17: two capsules once daily orally.

Treatment:

Drug: Placebo oral capsule

Drug: Mifepristone 200 MG