Catalyst Pharmaceuticals (NASDAQ:CPRX) said Teva Pharmaceuticals (NYSE:TEVA) submitted an application to the U.S. Food and Drug Administration (FDA) seeking approval to make and sell a generic version of Catalyst’s medicine Firdapse in the U.S.

Coral Gables, Fla.-based Catalyst noted that Teva sent a notice letter to company informing that the Israeli company filed an abbreviated new drug application (ANDA) to the FDA for generic version of Firdapse.

The drug is used to treat Lambert-Eaton myasthenic syndrome (LEMS) a neuromuscular disorder in which the immune system attacks the body’s own tissues at the connection between nerve and muscle (neuromuscular junction) leading to muscle weakness.

In the notice, Teva said that it plans to market a generic version of Firdapse before Catalyst’s patents expire.

Teva alleges that these patents are not valid, not enforceable, and/or will not be infringed by the commercial manufacture or sale of the proposed generic, Catalyst added.

Catalyst noted that it has 45 days to start a patent infringement lawsuit against Teva to trigger a stay precluding FDA from approving Teva’s ANDA until May 2026 or entry of judgment holding the patents invalid or unenforceable, whichever happens first.

Catalyst added that it is assessing the notice and intends to enforce its intellectual property rights related to Firdapse.

CPRX -19.23% to $16.80 premarket Jan. 23