By Tony Carpasso
NEW YORK, Jul 21 (Reuters Health) - Investigators in Virginia are
spearheading research on a birth control pill that could cut the annual number
of a woman's menstrual periods to four. It could also reduce the number of
unintended pregnancies in women on long-term birth control.
The year-long study at Eastern Virginia Medical School in Norfolk, and at 49
other sites in the US will test Seasonale, a combination of ethinyl estradiol
and levonorgestrel--two commonly used hormones already available in various
dosages in conventional oral contraceptives.
If the phase III study proves successful, the Food and Drug Administration
(FDA) could approve sales of Seasonale by 2003, according to Dr. Gary D. Hodgen,
professor of obstetrics and gynecology at Eastern Virginia Medical School and
president of the Jones Institute Foundation.
Physicians have been prescribing this combination of hormones for women "off
label"--meaning for indications not approved by the FDA--for years, with
excellent results, explained principal investigator Dr. Freedolph Anderson of
the Jones Institute. More than 900 women have taken the hormones in the
combination present in Seasonale with an excellent safety profile, he said.
"At least seven or eight studies have looked at a regimen with them,"
Anderson told Reuters Health. "The biggest problem has been spotting and
breakthrough bleeding in the first and second month of administration. As they
go on longer, they have less spotting and breakthrough bleeding," he said.
The 1-year study will enroll 1,350 women in 50 US cities. One of the biggest
advantages of Seasonale is that it is taken continuously on a cycle of 84 days,
Anderson said. The routine regimen in birth control pills is 21 days on and 9
days off, which means users have 13 pill-free intervals per year, he pointed
out.
"Starting and remembering to start birth control pills is when errors get
introduced that can lead to unintended pregnancies," Anderson noted. "Seasonale
cuts the 'stop and start' cycle from 13 times yearly to 4 times per year," he
said.
Phase I studies done at Barr Laboratories, Eastern Virginia's partner in
developing Seasonale, demonstrated the safety and efficacy of the hormone
combination, Anderson said.
The wealth of experience with this combination of hormones for contraception
documented in the medical literature together with Barr's phase I results
convinced the FDA to approve skipping phase II testing and moving directly to
phase III, he said.
Anderson predicted it would take about 18 months for all the women in the
study to complete the year's regimen. Writing the final paper on the study
results will take an additional 6 months, he said. Typically, the FDA requires
about a year to decide on approval, Anderson said.
"Seasonale could be on the market in about 3 years," he predicted.
