Astra Sues Alembic, Natco to Block Copies of Calquence Drug

AstraZeneca PLC’s Acerta unit and a subsidiary of Merck & Co. filed lawsuits alleging that copycat versions of the blood-cancer treatment Calquence proposed by two generic-drug companies infringe as many as six patents.

In complaints filed Wednesday in the U.S. District Court for the District of Delaware, Astra said Natco Pharma Ltd.’s proposed copy infringes six patents and Alembic Pharm. Ltd.’s proposed generic version infringes five of those.

Calquence, whose active ingredient is acalabrutinib, is a kinase inhibitor used to treat adults with mantle cell lymphoma who’ve received at least one prior therapy, and as a first-line treatment ...