NASTECH RESPONDS TO FDA LETTER FOR NASAL SPRAY ANDA

Nastech Pharmaceutical announced it has submitted a complete response to the not approvable letter from the FDA for its abbreviated new drug application (ANDA) for a generic nasal treatment for osteoporosis. The response addresses the potential for immunogenicity that might result from a possible interaction between calcitonin-salmon and chlorobutanol, the preservative in Nastech's calcitonin-salmon nasal spray formulation.

Nastech's response consists of an extensive comparison of Nastech's product with the innovator drug, Novartis' Miacalcin, using multiple analytical and bio-analytical methods. Neither peptide-preservative interactions nor peptide-peptide aggregation were affected by a change in preservative by any method evaluated. Data obtained using numerous measurement techniques indicate that there is no evidence of a structural or conformational change in the peptide, and no increase in the potential to aggregate as a result of the preservative change. Finally, both immunoassay and bioassay studies indicate no difference associated with either preservative or an absence of preservative in the formulation.