Safety and Efficacy of CDB-2914 in Comparison to Levonorgestrel for Emergency Contraception

Study Overview
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Brief Summary
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The purpose of this study is to assess the safety and efficacy of CDB-2914 in comparison to levonorgestrel for preventing pregnancy up to 5 days after unprotected sexual intercourse.

Conditions
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Contraception

Intervention / Treatment
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* Drug: CDB-2914
* Drug: Levonorgestrel


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: women 16 or older in UK(except Northern Ireland) sites, 17 years or more in Northern Ireland (UK) and 18 years or more in Ireland and US present within 120 hours of unprotected intercourse regular menstrual cycles No current use of hormonal contraception Willing to not use hormonal methods of contraception until study completion At least one complete menstrual cycle (2 menses) post miscarriage, delivery or abortion For women who present more than 72 hours after intercourse, decline the insertion of an Intra Uterine Device for emergency contraception Able to provide informed consent Willing to abstain from further acts of unprotected intercourse until study completion Exclusion Criteria: One or more acts of unprotected intercourse more than 120 hours current or recent use of hormonal methods of contraception currently pregnant or breastfeeding tubal ligation or current use of IUD Use of hormonal emergency contraception since last menstrual period Current use of IUD Tubal ligation Partner with a vasectomy Unsure about the date of the last menstrual period Severe asthma insufficiently controlled by oral glucocorticoid Hypersensitivity to the active substance levonorgestrel or any of the excipients of the drug products used in the study

Ages Eligible for Study
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Minimum Age: 16 Years

Sexes Eligible for Study
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Female

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: CDB-2914<br> | Drug: CDB-2914<br>* Single dose<br>|
| Active Comparator: Levonorgestrel<br> | Drug: Levonorgestrel<br>* Single dose<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Number of Participants With Pregnancy | The rate of pregnancy in women who received emergency contraception within 72 h of unprotected sexual intercourse. | Within 72 hours of unprotected Intercourse | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Actual Pregnancy Rate Compared to Expected Pregnancy Rate | Conditional probabilities of pregnancy from the time of unprotected sex intercourse to treatment were estimated for up to 120 hours using Spline Cubic Estimation (Stone & Koo, 1985) Pregnancy rate expected in the absence of emergency contraception is based on Trussell J, Rodriguez G, Ellertson C. New estimates of the effectiveness of the Yuzpe regimen of emergency contraception. Contraception. 1998;57(6):363-9. | Within 120 hours of unprotected Intercourse | 
| Menstrual Bleeding Patterns | Onset of next menses after emergency contraception compared to usual date. | within the menstrual cycle of the unprotected Intercourse |