AnaptysBio (ANAB) said Friday it filed a complaint in Delaware Chancery Court seeking a declaration that GSK (GSK) unit Tesaro has "materially breached" the companies' collaboration deal covering cancer drug Jemperli.

The company is also seeking a court declaration that GSK has "tortiously interfered" with the deal, AnaptysBio said. The company has requested that the court declare that AnaptysBio is entitled to all rights and remedies under the agreement.

AnaptysBio said that despite its efforts to engage in good faith discussions to potentially resolve the claims, Tesaro launched its own lawsuit against AnaptysBio.

"Anaptys contends that Tesaro's claims are entirely without merit and intends to pursue all appropriate legal remedies against Tesaro, including dismissal of such claims at the earliest opportunity and the potential for additional litigation," AnaptysBio said.

The parties have agreed to request an expedited schedule, with trial expected in July.

GSK didn't immediately respond to MT Newswires' request for comment.