In a brief announcement, Pfizer Inc disclosed that it has received a nonapprovable letter from the US FDA for lasofoxifene (Oporia), a selective estrogen receptor modulator (SERM) for the prevention of osteoporosis. Oporia is the first of three late-stage SERM products under development by Ligand Pharmaceuticals to be submitted for regulatory approval in the US. Pfizer stated that it will meet with the FDA to discuss the nonapprovable designation of the NDA for lasofoxifene, and will chart a course of action following these discussions.