PFIZER'S OSTEOPOROSIS TREATMENT NOT APPROVABLE, SAYS FDA

Pfizer's highly anticipated osteoporosis treatment Oporia has been deemed "non-approvable" by the FDA. The New York-based drugmaker didn't disclose why its new drug application (NDA) for Oporia (lasofoxifene) was rejected, saying only that it recently received a non-approvable letter from the FDA regarding the drug, a second-generation selective estrogen receptor modulator (SERM). The company added "it will be reviewing its submission with the FDA and considering various courses of action."

Pfizer submitted its NDA for Oporia in August 2004. The FDA was originally supposed to rule on the application in June, but the deadline was extended for three months after the agency determined it needed more time to review the NDA, which sought an indication for the prevention of osteoporosis.

Oporia has been in development since the early 1990s when Pfizer partnered with specialty pharmaceutical firm Ligand Pharmaceuticals to use Ligand's intracellular receptor technology. Although this collaboration ended in 1993, Ligand is entitled to royalties dependent upon achievement of regulatory milestones.

Pfizer was hoping Oporia could challenge Eli Lilly's Evista (raloxifene HCl), which currently dominates the SERM market. Evista generated worldwide revenues of $261 million in the second quarter.