LPRI-421

**LPRI-421** is an investigational prolonged-release combined oral contraceptive developed by Exeltis. It contains the synthetic progestogen dienogest and the synthetic estrogen ethinyl estradiol in an extended-release oral tablet formulation. A completed single-center, open-label, randomized Phase II trial evaluated three prolonged-release dienogest/ethinyl estradiol formulations against flexible-regimen drospirenone plus ethinyl estradiol in 100 healthy women, using ovulation inhibition assessments. ([clinicaltrialsregister.eu](https://www.clinicaltrialsregister.eu/ctr-search/trial/2016-003830-26/DE)) The contraceptive effect is mediated through estrogen- and progesterone-receptor signaling, which suppresses ovulation and contributes to cervical-mucus changes that impede conception. ([ema.europa.eu](https://www.ema.europa.eu/en/documents/referral/dienogest-ethinylestradiol-article-31-referral-annex-ii_en.pdf))