Anaptys and Tesaro/GSK dispute will go to trial on July 14-17, 2026. AnaptysBio filed a motion to dismiss Tesaro’s anticipatory breach of contract claim. Tesaro initiated a lawsuit against Anaptys in November 2025 without notice. Anaptys filed its own complaint against Tesaro and GSK in response. Anaptys filed a motion to dismiss Tesaro’s claim on December 30, 2025. The court is expected to hear the motion by early March. Anaptys and Tesaro/GSK are working towards the trial date while facing contention over discovery. The Collaboration Agreement entitles Anaptys to receive royalties from sales of Jemperli. Anaptys is focused on delivering immunology therapeutics for autoimmune and inflammatory diseases.

In March 2014, Anaptys entered a Collaboration Agreement with Tesaro, now part of GSK. Under the agreement, Anaptys is entitled to royalties from Jemperli sales. The royalty term extends at least through the molecule’s composition of matter coverage expiration in 2035 in the U.S. and 2036 in the EU. Anaptys is developing various therapeutics, including rosnilimab, ANB033, and ANB101. The company has also out-licensed therapeutic antibodies to GSK and Vanda Pharmaceuticals. Anaptys plans to separate its biopharma operations from its royalty assets by year-end 2026.

Read more at GlobeNewswire: Anaptys Files Motion to Dismiss Tesaro’s Claim of