03:05 AM EDT, 04/27/2026 (MT Newswires) -- GSK (GSK.L) unit Tesaro said Monday the Delaware Chancery Court in the US dismissed its claim for anticipatory breach of contract against AnaptysBio.

In November 2025, Tesaro sued AnaptysBio in the Delaware Chancery Court over the alleged breach of their March 2014 license deal for cancer drug Jemperli, or dostarlimab. AnaptysBio lodged a counterclaim in the same month and, in January 2026, filed a partial motion to dismiss against Tesaro's anticipatory breach of contract claim.

Tesaro noted that the dismissal does not affect its remaining claim against AnaptysBio for declaratory judgment, saying the ruling does not address the parties'principal contract dispute. The company and its parent GSK plan to pursue the claim at a trial scheduled for July 14-17.