Barr Pharmaceuticals, Inc. announced that its wholly-owned subsidiary, Barr Laboratories, Inc., has received tentative approval from the US FDA for its generic version of Ortho-McNeil's Topamax Tablets (Topiramate Tablets), 25 mg, 100 mg and 200 mg. The company anticipates receiving final approval and launching its generic product following the expiration of Ortho-McNeil's patent on September 26, 2004, or at a later date as Ortho-McNeil is currently seeking a patent term adjustment of up to 5 years that would, if granted, expire on September 26, 2008.

Barr's tentatively approved Topiramate Tablets are indicated as adjunctive therapy for adults and pediatric patients ages 2-16 years with partial onset seizures, or primary generalized tonic-clonic seizures. Ortho-McNeil has been granted Orphan Drug Exclusivity through August 28, 2008 for Topiramate's indication in patients 2 years of age and older with seizures associated with Lennox-Gastaut syndrome. Topiramate Tablets had annual sales of approximately $904 million, based on IMS data for the twelve months ended October 2003.

Barr filed its Abbreviated New Drug Application (ANDA) containing a Paragraph III certification for Topiramate Tablets, 25 mg, 100 mg and 200 mg, with the FDA in December 2001 and received notice of the application's acceptance for filing in December 2001. The patent currently covering Topamax Tablets was due to expire on September 26, 2003. On February 24, 1997, Ortho-McNeil filed for an application for patent term adjustment seeking up to 5 years of extension under Hatch-Waxman Act. On March 11, 2003, Ortho-McNeil was granted an interim 1-year patent term extension that extended the patent covering Topamax Tablets to September 26, 2004. If Ortho-McNeil's original application for adjustment is granted, the patent term could be extended until September 26, 2008.

A tentative approval reflects FDA's preliminary determination that a generic product satisfies the substantive requirements for approval, subject to the expiration of all statutorily imposed non-approval periods. A tentative approval does not allow the applicant to market the generic drug product.