SAVIENT FILES CITIZEN PETITION TO BLOCK GENERIC VERSIONS OF ITS OXANDRIN

Savient Pharmaceuticals has filed its second citizen petition with the FDA in two years to block generic versions of its anti-weight-loss drug Oxandrin.

Both petitions followed submissions of new clinical data and labeling changes to the FDA by Savient for Oxandrin (oxandrolone), according to the firm.

In its latest petition, the New Jersey-based drugmaker asked the FDA not to approve any abbreviated new drug applications for generic oral products containing oxandrolone until Savient's geriatric labeling market exclusivity expires in June 2008. In June of this year, the FDA approved Savient's supplemental new drug application and new labeling that recommends a lower starting dose of Oxandrin for elderly patients.

Generic Oxandrin would cut into market share of Savient's best-selling product, which generated 41 percent of Savient's net sales in 2004. Several drugmakers have submitted drug master files for generic Oxandrin, and Oxandrin "could experience competition from an FDA-approved generic at any time," Savient said in its 2004 annual report.

Savient's earlier petition, filed in February 2004, asked the FDA to require bioequivalency evidence for generic oral oxandralone products, to show that they interact with anticoagulants containing warfarin in the same way that Savient's brand version of oxandralone does. Results from Savient's clinical study showed Oxandrin increases the therapeutic effect of warfarin and that patients' warfarin doses should generally be decreased by 80 to 85 percent when taken with Oxandrin.