Antares Pharma, Inc. (NYSE Amex: AIS) and the Population Council today
announced successful results from a dose-finding Phase 2 trial for a
novel contraceptive gel containing the progestin Nestorone and estradiol
(NES/E2) utilizing the Antares ATD (advanced transdermal delivery) gel
system. Based on this successful data, the two parties continue to
expect to partner with a worldwide or regional pharmaceutical company in
order to commercialize this novel contraceptive gel.
This first of its kind contraceptive gel may offer an attractive option
for women. The combination of Nestorone, a highly potent and versatile
synthetic progestin, and the natural estrogen estradiol, was chosen due
to the potential for superior safety profiles when compared to other
commonly used hormones in contraceptives. The ATD system is currently
utilized in Elestrin® a marketed product for hormone replacement therapy
(HRT) in postmenopausal women. The gel is easy to apply, crystal clear,
fast drying and cosmetically appealing.
The trial was a dose-finding, open-label, cross-over study to evaluate
the effect of NES/E2 transdermal gel on ovulation suppression in normal
women of fertile age. Eighteen women participated in the trial, which
took place in three sites: Los Angeles, California; Santo Domingo,
Dominican Republic; and Santiago, Chile. Each woman completing the study
received each of the three separate doses of the gel for 21 days,
separated by a washout month in which no products were administered when
they recovered normal ovulation. The primary objective of the study was
to find the lowest acceptable dose of the NES/E2 gel to achieve
appropriate therapeutic levels for effective contraception (ovulation
suppression), as measured by progesterone levels and ultrasound
evaluation of follicular development. Secondary objectives included
determining the plasma profile of estradiol and the evaluation of
bleeding patterns. General safety and tolerability of the NES/E2 gel,
including any local skin irritation, was also assessed.
Active treatment concluded in October 2009. Safety and efficacy
objectives were met and no serious adverse events or instances of skin
irritation were recorded.
Régine Sitruk-Ware, executive director for research and development in
the Reproductive Health program of the Population Council, said, “We
have demonstrated that the transdermal gel combining Nestorone and
estradiol is able to suppress ovulation at all doses tested and we
determined the dose that gave the most stable levels of hormones to the
subjects. Most women who participated in the study found the gel very
easy to use and convenient. We believe this new formulation is likely to
be a safe and effective contraceptive that offers a new option for women
who may be unable to use alternative forms of contraception.”