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Pfizer To Withdraw Fablyn NDAs

(RTTNews) - Pfizer Inc. (PFE), in a SEC filing on May 13, revealed that it is in the process of withdrawing its New Drug Applications with the U.S. Food and Drug Administration relating to Fablyn, for the treatment of osteoporosis in postmenopausal women at increased risk of fracture and for the treatment of vulvar and vaginal atrophy.

Pfizer submitted an NDA to the FDA for Fablyn for the treatment of osteoporosis in December 2007. In January 2009, Fablyn was issued a complete response letter by the FDA, which sought additional information.

In September 2005, Fablyn was rejected by the FDA as a preventive therapy for osteoporosis in post-menopausal women on concerns that the drug might cause cancer in the lining of the uterus.

Fablyn is a product candidate that resulted from a collaboration between Pfizer and Ligand Pharmaceuticals Inc. (LGND). Under the terms of the agreement with Pfizer, Ligand is entitled to receive royalty payments on worldwide net sales of Fablyn for any indication. Pfizer said that it is exploring strategic options for Fablyn, including out-licensing or sale.

Viviant and Aprela are the other experimental drugs for the treatment of post-menopausal osteoporosis developed in collaboration between Pfizer and Ligand.

In April 2007 and December 2007, Viviant was issued "approvable letters", which sought additional information for approval, for the prevention of post-menopausal osteoporosis. In May 2008, Viviant was again handed out an "approvable letter" by the FDA for the treatment of post-menopausal osteoporosis.

However, in the EU, Fablyn received approval from the European Commission in February 2009, and Viviant under the trade name Conbriza, received approval for the treatment of post-menopausal osteoporosis in women at increased risk of fracture in April 2009.

Pfizer is also developing Aprela for the treatment of menopausal vasometer symptoms and an NDA is planned in the second half of 2010.

PFE closed Monday's trading session at $16.11 on a volume of 98.8 million shares. LGND closed the day's session at $1.62 on a volume of 344 thousand shares.