Overview
- AnaptysBio filed a partial motion on Dec. 30, 2025 to dismiss Tesaro's anticipatory‑breach claim, and the motion was unsealed on Jan. 8, 2026.
- The court is expected to hear the motion by early March under Delaware's anti‑SLAPP procedures.
- Tesaro and GSK assert the motion stays discovery, a position Anaptys opposes as both sides gear up for trial set for July 14–17, 2026.
- The litigation stems from a 2014 license granting Tesaro rights to develop and sell Jemperli, with Anaptys eligible for tiered royalties of 8%–25% continuing at least to patent expirations in 2035 in the U.S. and 2036 in the EU.
- Tesaro sued on Nov. 20, 2025 seeking declarations that could cut or end payments, while Anaptys countersued on Nov. 21 alleging exclusivity breaches and tortious interference by GSK.