Another nasty lobbying battle has broken out over biosimilars. And the latest involves a group of generic drugmakers, insurers and pharmacy benefit managers, which are pushing back against a recent effort by brand-name drugmakers to weaken a part of healthcare reform that is supposed to create competition for expensive biologics.

The provision says generics can enter the market after a brand-name biologic has had exclusivity for 12 years. But earlier this month, a bipartisan group of four US Senators - including Orrin Hatch, Kay Hagan, Michael Enzi and John Kerry - wrote FDA commish Margaret Hamburg to urge a different interpretation that would favor brand-name drugmakers and biotechs. Their letter was circulated on and beyond Capitol Hill by, among others, the BIO trade group.

At issue is exclusivity. The senators maintain brand-name drugmakers and biotechs should get an extra 12 years if their existing meds are changed in a way that would bolster safety or effectiveness. They also want the FDA to define exclusivity in a way that could further delay generic drugmakers from filing applications for approval to market biosimilars.

However, the AARP, Humana, Medco, Aetna, Watson Pharmaceuticals, Mylan Labs, Teva Pharmaceuticals and Express Scripts, among others, have now written Hamburg to note that the law says the FDA can’t accept a biosimilar appplication until four years after a Biologics License Application was approved and that approval can occur after a 12-year period of exclusivity (read the letter). Moreover, they maintain there is no specific mention of data or market exclusivity (see this interpretation).

Gordon Johnston, VP of Regulatory Affairs for GPhA: “GPHA supports an abbreviated process that provides accesss and affordability. The statute clearly provides biosimilar applications can be submitted after four years and approved upon expiration of the 12-year exclusivity. But the statute makes no reference to data exclusivity.”

The skirmish, of course, reflects heightened concern over the cost of biologics, while drugmakers and biotechs see these expensive meds as not only the next frontier in science, but a salve to their patent woes in which more big-selling treatments are about to face low-cost generic competition. (You can read some recent background in The Wall Street Journal).