The University of Minnesota has filed a lawsuit against Gilead Sciences claiming that the drugmaker's hepatitis C drugs violate its intellectual property.

The university believes that Gilead's sofosbuvir-containing hepatitis C treatments, which include the multi-billion-dollar selling therapies Sovaldi and Harvoni, infringe its patent.

"Patent rights assigned to the University by Dr Carston R. Wagner, Endowed Chair in Medicinal Chemistry in the University's College of Pharmacy, cover Gilead's drugs, and Gilead has reaped tens of billions of dollars in sales of those drugs, without the University's authorisation and without compensating the University," the lawsuit states.

The University is asking for "damages adequate to compensate it for Gilead's infringement, in no event less than a reasonable royalty," and that the damages are determined by a jury.

Gilead, however, has rejected the claim. In a media statement, it said it "strongly believes that it has the sole right" to sell sofosbuvir in the US. "We believe the University of Minnesota's patent is invalid and is not infringed by the sale of Gilead's medicines for chronic Hepatitis C."