Momenta Pharmaceuticals Inc. placed a high stakes wager in September 2005 when it decided to submit its application for FDA approval of M-Enoxaparin as a generic drug, rather than use the regulatory pathway that other manufacturers have used to gain approvals of follow-on versions of biologics that are marketed under NDAs.
MNTA and partner Sandoz, the generics unit of Novartis AG (NVS; SWX:NOVN, Basel, Switzerland) are dangerously close to losing that bet, as FDA's Office of Generic Drugs last week issued a not approvable letter for M-Enoxaparin citing immunogenicity concerns.
Although agency officials have not closed the door, it remains to be seen if the companies will have to abandon the generic route, which could leave submission of an NDA as the only option for approval.
And because there are no set FDA timelines under the generic rules, MNTA doesn't even know when it will learn more from the agency about the path forward.
There were good reasons for MNTA to attempt to get M-Enoxaparin approved as a generic under an ANDA, which is governed by the 505(j) section of the Food, Drug and Cosmetic (FD&C) Act.
MNTA chose that route because approval under section 505(b)(2) - which other sponsors have used to gain approval of follow-on versions of biologics that are regulated as drugs, such as human growth hormone - does not usually confer a therapeutic equivalence rating, according to President