GSK (Tesaro) and AnaptysBio traded lawsuits over a decade‑old license tied to the cancer immunotherapy Jemperli, with GSK seeking termination or modification of the agreement and Anaptys counterclaiming material breaches and tortious interference. The litigation centers on testing and commercialization rights that affect milestone and royalty streams tied to Jemperli sales. Anaptys also announced a $100 million stock repurchase plan amid the dispute and noted anticipated royalties and a $75 million milestone if Jemperli reaches $1 billion in sales. The court will decide contractual interpretation and revenue rights—outcomes that could materially affect Anaptys’ near‑term financials and strategic plans.