Fresenius Sues Zydus Over Patents for Rare Thyroid Disease Drug

Fresenius SE & Co. filed a new federal complaint alleging Zydus Lifesciences Ltd.’s proposed generic version of an injectable treatment for myxedema coma, a rare and life-threatening condition in patients with chronic severe untreated hypothyroidism, infringes three Fresenius patents for its levothyroxine sodium powder for injection.

Fresenius on March 3 received a letter from Zydus saying the generic-drug maker had amended its application for U.S. Food and Drug Administration approval of its copycat to add a dosage that wasn’t among the strengths included in Zydus’ first notice on Feb. 7, according to a complaint filed March 25 in the U.S. ...