A topical testosterone gel designed to be applied to the upper leg has won FDA approval for use by testosterone-deficient men, its manufacturer said.
The 2% testosterone gel will be sold under the name Fortesta by Endo Pharmaceuticals of Chadds Ford, Pa.
Applying the product to the thigh is intended to reduce the risk of inadvertently transferring testosterone gel to other people, especially children.
Cases of children with premature puberty have been reported in association with testosterone gels intended for application to the arm or abdomen. The FDA mandated a boxed warning on such products in May 2009.
The warning -- which will also be included in Fortesta's label -- highlights the risk and instructs users to take precautions against accidentally exposing other people to the gel.
Patients should wash their hands after applying the gel and keep children and others from touching the application site, which should be covered with clothing after the gel has dried.
A spray-on estradiol product for women has also been linked to accidental exposures in children and pets. The reports prompted the FDA to issue a drug safety alert earlier this year.
In November, the FDA approved another topical testosterone product called Axiron that is applied to the armpit, also intended for men with hypogonadism.
According to Endo, some 14 million men in the U.S. are testosterone deficient, but only 9% are receiving treatment.
Fortesta comes in a metered-dose pump that dispenses the correct amount of gel. The label calls for patients to use one finger to rub the gel on the front and inner thighs.
In the product's pivotal clinical trial, 78% of men using the gel achieved serum testosterone levels in the normal range within three months. The most common adverse effects were application-site reactions.
The drugmaker indicated that Fortesta gel would be available in pharmacies early in 2011.