Sponsor decision to stop the study early and complete all required study close-out activities. This decision was made for business reasons unrelated to safety. None of the pre-specified efficacy endpoints were analyzed.

The purpose of this study is evaluating Contraceptive Efficacy and Safety of NOMAC-E2 Combined Oral Contraceptive in Premenopausal Females Aged 14 to 35 Years (Inclusive).

This is a Phase 3, Open-label, Multi-center, Single-arm Study to Assess Contraceptive Efficacy and Safety of the Nomegestrol Acetate + 17β-estradiol Combined Oral Contraceptive (OG-8175A) in Premenopausal Females Aged 14 to 35 Years (Inclusive). Potential participants must be sexually active and engage in heterosexual vaginal intercourse at least once per month with a partner who is not known to be subfertile, sterilized, or infertile, and should not routinely use any other form of contraception.

A total of 2,680 fertile premenopausal women aged 14 to 35 years (inclusive) will be screened to achieve about 1,878 (with at least 657 participants with BMI ≥30 kg/m2) being allocated to study treatment. Over 1,000 total participants are expected to complete 1 year of treatment (13 cycles).

The total duration of study participation will be up to 60 weeks, which includes a Pre-treatment Period of approximately 6 weeks, a Treatment Period of 52 weeks, and a Follow-up Period of 2 weeks after the last intake of study drug.

Inclusion Criteria:

• Postmenarcheal, premenopausal female aged 14 to 35 years (inclusive)
• At risk for pregnancy (including heterosexual vaginal intercourse at least once a month and not sterilized).
• No desire for pregnancy within 1 year following screening and is not intending to use any other form of contraception
• Good physical and mental health
• History of regular menstrual cycles prior to the use of any hormonal contraceptive.
• Able and willing to adhere study procedures

Exclusion Criteria:

• Current known or expected pregnancy
• History of subfertility or infertility
• Less than 2 normal menstrual cycles following recent pregnancy of gestational age
• Breastfeeding within 2 months of study drug start
• Known HIV infection
• Untreated gonorrhea, chlamydia, or trichomonas
• abnormal PAP within timeline of standard of care guidelines
• Unexplained/unresolved abnormal vaginal bleeding
• Presence/history of VTE, ATE, transient ischemic attack, angina pectoris, or claudication
• Higher risk for VTE
• Uncontrolled or severe hypertension
• Severe dyslipoproteinemia
• History of migraine with aura or focal neurological symptoms
• Diabetes mellitus (with either end-organ involvement or >20 years duration)
• Multiple cardiovascular risk factors
• History of pancreatitis associated with severe hypertriglyceridemia
• Presence/history of clinically significant liver disease
• History of malabsorptive surgical procedures
• History of malignancy in last 5 years
• Presence/history of meningioma
• Disease that may worsen under hormonal treatment
• Presence/history of severe depression (unless currently stable and asymptomatic)
• Known allergy/sensitivity to NOMAC-E2
• Drug or alcohol abuse/dependence in last 2 years
• Clinically relevant abnormal lab result at screening
• Expected use of other contraceptive medications or medications that induce liver enzymes during study
• Used another investigational drug within 2 months of study drug start