By Christopher Kuo

AnaptysBio shares rose after a Delaware court dismissed Tesaro's anticipatory breach of contract claim against the company.

Shares of the San Diego-based biotechnology company climbed 14% to $67.28. Its shares reached a five-year high of $70.22 on Monday.

The company's legal dispute with Tesaro, which is a subsidiary of biopharmaceutical company GSK, stems from a collaboration agreement that Tesaro and AnaptysBio formed in 2014.

In October, AnaptysBio alleged that Tesaro had violated the agreement by helping to develop a competitor drug. That claim resulted in dueling lawsuits between the two companies.

In November, Tesaro filed a lawsuit alleging that AnaptysBio repudiated the collaboration agreement and committed anticipatory breach of contract. That anticipatory breach of contract claim was dismissed by the Delaware Chancery Court on April 24.

GSK said Monday the court's ruling has no impact on Tesaro's remaining claim against AnaptysBio for declaratory judgment.

AnaptysBio's suit against Tesaro, which alleges breach of their collaboration agreement, remains ongoing, with a trial scheduled for July.

Write to Christopher Kuo at chris.kuo@wsj.com

(END) Dow Jones Newswires

April 27, 2026 13:05 ET (17:05 GMT)

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