The US-based biotech Bioverativ has alleged patent infringements by Australian blood products giant CSL.
Bioverativ has filed complaints in the US District Court for the District of Delaware and with the International Trade Commission.
The company specialising in the treatment of haemophilia alleges that Idelvion, developed by CSL Behring, infringes three patents.
However, CSL says it is highly confident of its intellectual property position for Idelvion, a product the subject of more than a decade of innovative research and a major advance for patients suffering hemophilia B.
The action will be vigorously defended.
A short time ago, shares in CSL were up 0.3% to $134.65.