FDA Approves Gwyn Lo (norelgestromin and ethinyl estradiol transdermal system), a Once-Weekly Contraceptive Patch – Viatris

Viatris Inc. announced that the FDA has approved Gwyn Lo (norelgestromin and ethinyl estradiol transdermal system).
Gwyn Lo is a new combined hormonal contraceptive  patch with low-dose estrogen.

The patch has demonstrated contraceptive efficacy for women of childbearing potential with a body mass index (BMI) below 30 kg/m² who are appropriate candidates for CHC. The Gwyn Lo dosage is norelgestromin 220 mcg/day and ethinyl estradiol 20 mcg/day.

“Gwyn Lo will provide a discreet option for women seeking a reversible, non-invasive, once-weekly contraception patch with a low dose of estrogen,” said Philippe Martin, Viatris Chief R&D Officer. “Building on our expertise in transdermal drug delivery systems and legacy in women’s health, we are pleased that the approved label for this new patch reflects the strength of our clinical program. This includes demonstrated efficacy in women with a BMI of 25 to less than 30 kg/m², with no BMI-based limitation of use in this population.”

The approval was granted under the FDA’s 505(b)(2) regulatory pathway and was supported by results from the Phase 3 Luminous Study (NCT05139121), which demonstrated contraceptive efficacy, a well-characterized safety profile and robust patch adhesion performance. Key outcomes of the Phase 3 study included:

i) The primary efficacy endpoint was the Pearl Index (PI), defined as the number of pregnancies per 100 woman-years of exposure in the efficacy evaluable population (women aged 18 to 35 years), which was 4.14 (95% CI: 2.77 to 5.95).

ii) The study demonstrated robust patch adhesion under real-world conditions, with only 1.3% of the 39,790 transdermal systems applied during the year-long trial fully detaching.

iii) The most common adverse reactions (2% or greater) reported during the study were application site irritation (4.8%), application site erythema (3.7%), application site pruritus (3.7%), intercycle bleeding (3.9%), heavy withdrawal bleeding (2.0%), and nausea (2.0%).

iv) Cycle control improved over time, as rates and duration of unscheduled bleeding or spotting decreased from 34.5% and a mean of 3.2 days in Cycle 1 to 20.0% and 2.4 days by Cycle 13.

Data from four Phase 1 studies investigating various application sites and conditions demonstrated consistent drug delivery under conditions including sauna, whirlpool, treadmill exercise and cold-water bath.

Unintended pregnancy remains a significant public health issue in the United States, accounting for 41.6% of pregnancies in 2019. Women’s contraceptive needs and preferences also vary: in a 2023 CDC survey, 18.1% of women who had used a contraceptive method changed or stopped a method within the previous 12 months. Among those women, 42.8% reported that they did not like the method they had been using. These findings underscore the continued need for a range of contraceptive options that can align with individual needs and preferences. Gwyn Lo helps address this need by offering a non-invasive, reversible, low-estrogen-dose CHC option for women who prefer once-weekly administration.

The Company expects Gwyn Lo to be commercially available later this year and will provide additional information during its upcoming financial results call.