CAMBRIDGE, Mass. (AP) — Momenta Pharmaceuticals Inc. said late Wednesday it is suing three generic drugmakers for allegedly infringing patents used to produce its generic version of Lovenox, a popular blood thinning drug.
On Monday, Momenta won federal approval to market its generic version of the blockbuster drug after years of legal battles with French drugmaker Sanofi-Aventis, which made more than $4 billion from the drug last year.
On Wednesday, generic drugmakers Watson Pharmaceuticals Inc. and Amphastar Pharmaceuticals said they received approval for their own low-cost version of Lovenox.
Momenta said it filed suit against those companies and International Medical Systems in the U.S. District Court for the District of Massachusetts for infringement of two Momenta patents.
Drugmakers routinely sue each other for patent infringement to try and delay the launch of competing products.
Momenta shares rose 17 cents, or 1.6 percent, to $10.79 in afterhours trading Wednesday. Shares fell 98 cents, or 8.5 percent, to close at $10.62 in regular trading before the suit was announced.