WASHINGTON — Seasonale Lo, the 91-day extended-regimen low-dose oral contraceptive, was effective and well tolerated compared with a 28-day low-dose oral contraceptive, after both 1 year and 3 years of use.
The Seasonale Lo data from a randomized, multicenter study were presented in two posters at the annual meeting of the American College of Obstetricians and Gynecologists.
Dr. Andrew M. Kaunitz of the University of Florida Health Science Center in Jacksonville, Fla., monitored women aged 18–35 years who could potentially become pregnant. After 1 year, the overall cumulative failure rate of Seasonale Lo was 2.23% among 463 patients, compared with a 2.83% failure rate among 231 patients who took a traditional 28-day oral contraceptive (Levlite).
Compliance rates were high—98.1% in the Seasonale Lo group and 96.5% in the Levlite group. Among compliant patients, the Seasonale Lo failure rate was only 0.65%, compared with 4.14% among compliant Levlite patients. Although more Seasonale patients reported unscheduled bleeding days than the Levlite patients (6.1% vs. 3.3%), the number of scheduled bleeding or spotting days per cycle was approximately the same in both groups.
Breakthrough bleeding episodes were reported more frequently by the Seasonale Lo group than the Levlite group (13.8% vs. 1.3%), but the incidence of other adverse events was similar between the two groups. For example, headaches, the most common adverse event, were reported by 22% of the Seasonale Lo group and 21% of the Levlite group.
Each Seasonale Lo pill includes 0.02 mg of ethinyl estradiol and 0.1 mg of levonorgestrel. The regimen includes 84 days of active pills followed by 7 days of placebo pills. Dr. Kaunitz serves as a consultant to Barr Pharmaceuticals, the manufacturer of Seasonale, which also supported the study.
Seasonale continued to be safe and well tolerated in a subset of 161 women who participated in a 2-year extension of the study, reported Dr. David Portman of the Columbus Center for Women's Health Research in Columbus, Ohio.
Notably, the median number of unscheduled bleeding or spotting days decreased over the course of the study, from 2 days during the first cycle to 0 days by the eighth cycle. Patient exposure to the drug included 937 complete 91-day cycles. Patients reported their pill-taking, bleeding, and spotting data in electronic diaries, and they underwent clinical evaluation during quarterly visits. The overall discontinuation rates were similar to those for Seasonale Lo and Levlite in the original study, which were about 44% and 32%, respectively.
Dr. Portman serves on the speakers' bureau of Barr Pharmaceuticals.