Pfizer has received good news on the regulatory front after the US Food and Drug Administration gave its approval for one of the company’s contraceptives to be used as a treatment for the gynaecological condition, endometriosis.

Depo-subQ provera 104 is a long-acting injectable, which was approved as a contraceptive by the FDA at the end of last year. It contains the same active ingredient as the contraceptive Depo-Provera (medroxyprogesterone), but the new treatment comes in a new formulation with 30% less hormone. Pfizer notes that the medicine is the first new treatment for endometriosis pain in 15 years, adding that the condition affects one in 10 women of reproductive age and is one of the top three causes of infertility.

The approval has been given on the back of clinical data which showed that depo-subQ provera 104 is equally as effective for treating pain caused by endometriosis as TAP’s Lupron Depot (leuprolide), with significantly less decline in bone mineral density, and lower incidence and severity of menopausal symptoms, such as hot flashes.

Getting this new indication is particularly good news for Pfizer given that Depo-Provera’s start as a contraceptive was fairly inauspicious. It was forced into a label change warning of a risk of bone loss with extended use [[22/11/04e]], though a recent trial suggested that the latter side effect is reversible [[10/02/05f]].