Gel Alternative To Contraceptive Pill Shows Promising Results In Small Trial
A gel alternative to the contraceptive pill that women may only have to rub into the skin every day to prevent ovulation has shown promising results in a small phase 2 clinical trial reported at a conference in the US this week.
The birth control gel, which the trial investigators referred to as Nestorone®-Estradiol (NES/E2), is being developed by the drug firm Antares Pharma Inc, with corporate offices in New Jersey, in partnership with the not-for-profit Population Council research center in New York, both in the US.
Dr. Ruth Merkatz, director of clinical development of reproductive health at the Population Council presented the findings of the trial in an oral session of the 66th Annual Meeting of the American Society for Reproductive Medicine (ASRM) in Denver, Colorado, on Monday.
According to information on the Antares website, Nesterone is a “pipeline product” currently completing Phase 2 trials and about to enter Phase 3.
The NES/E2 transdermal gel, which is is rubbed into the skin of the arms, thighs, shoulders or abdomen, contains two hormones, a potent progestin close to progesterone, and natural estrogen (Estradiol), and has the same effect as the combined oral pill, but without causing weight gain, nausea and reduced sexual desire.
For the study, the researchers recruited 18 healthy ovulating women in their 20s and 30s in Chile, the Dominican Republic and the US. Over 7 months, the women tested three doses of NES/E2: a high dose (4.5mg Nesterone NES and 1.5 mg Estradiol E2), a medium (3.0 mg NES, 1.0 mg E2), and a low (1.5 mg NES, 0.5 mg E2).
The results showed that the medium dose demonstrated “good ovarian suppression” and the researchers selected it for further study.
There was also minimal breakthrough bleeding during 3 weeks of use, and the participants reported that the gel was easy to use and remember, and had few side effects. Their partners also reported no negative effects.
Merkatz and colleagues concluded that NES/E2 showed “promising results and may represent a safe, effective, acceptable hormonal method of contraception”.
They said more studies in larger groups should now be done.
The idea of a gel is thought to be more appealing to women than a skin patch, which can fall off and is visible.
Family planning experts said that while it is still early days, they welcomed the news because it gives women more choice.