The FDA approved a topical estrogen product for hot flashes, Bio-E-Gel (estradiol), boosting shares in BioSante Pharmaceuticals Inc. by about 25 percent Monday. BioSante's stock (AMEX:BPA) gained 62 cents to close at $3.14.
Two doses of the hormone drug, to be marketed as Elestrin, received clearance to treat moderate-to-severe vasomotor symptoms associated with menopause, 0.87 grams per day and 1.7 grams per day. Importantly, the former represents the lowest dose of estradiol approved in this indication, which could mean a nice competitive advantage in a U.S. estrogen therapy market that's estimated to be worth about $1.3 billion annually. About a fifth of it comprises transdermal products.
"In medicine, lower is better, the lowest dose possible, to avoid potential side effects," said BioSante President and CEO Stephen Simes. When it comes to hormone therapy such as this, he told BioWorld Today that physician and patient groups, as well as the FDA, recommend using the lowest possible dose to avoid breast cancer, cardiovascular risks, bloating and breast tenderness.
He said new patients should start at the low end and move up, if necessary. Elestrin is applied to the skin on a patient's upper arm through a metered dose bottle that delivers 0.87 grams per actuation, meaning it's easily titrated to dose changes.
Its approval was largely based on Phase III data from a double-blinded study of 484 symptomatic menopausal women in which more than 80 percent of those who used Elestrin reported great or moderate results, a highly significant improvement over placebo treatment (p<0.0001). Additional findings showed a clear dose response in the reduction in the number and severity of hot flashes in the doses tested, and the lowest dose produced very low estradiol blood levels and exhibited a safety profile similar to that observed in the placebo group.
The product will be marketed by Bradley Pharmaceuticals Inc., per terms of an agreement signed last month, and its launch is scheduled for next year. Women "typically" use such estrogen products for a year to two, Simes said, when they're dealing with hot flashes.
Its approval triggered a milestone payment of almost $8 million for BioSante, of Lincolnshire, Ill., with sales-based milestone payments and royalties still to come from Bradley. That amount is net of BioSante's obligations to Antares Pharma Inc., from which BioSante licensed the transdermal estradiol gel formulation in Elestrin.
In the commercialization arrangement, which could be worth more than $40 million, Fairfield, N.J.-based Bradley will employ at least 49 sales representatives to market Elestrin to estrogen-prescribing physicians in the U.S., a group mostly made of gynecologists. Antares, of Exton, Pa., stands to receive a share of BioSante's sales-based milestone payments and royalties. (See BioWorld Today, Nov. 9, 2006.)