Pharma BD Deal Intelligence
In June 2021 GSK paid iTeos Therapeutics $625M upfront (deal value up to ~$2.075B with $550M development/regulatory and $900M commercial milestones, plus equal US profit share and ex-US royalties) to co-develop and co-commercialize belrestotug (EOS-448), an Fc-active anti-TIGIT monoclonal antibody, for next-generation immuno-oncology combinations. On 13 May 2025 GSK and iTeos terminated the belrestotug program and ended the collaboration after the Phase 2 GALAXIES Lung-201 interim analysis (belrestotug + dostarlimab in first-line PD-L1-high NSCLC) failed to show clinically meaningful progression-free survival despite an improved objective response rate, and the GALAXIES H&N-202 head-and-neck cohort trended below the ORR threshold. All belrestotug-containing cohorts ended and new enrollment in the Phase 3 GALAXIES Lung-301 trial stopped; iTeos subsequently announced a corporate wind-down. The deal joins a long list of TIGIT-class clinical failures, with GSK's $625M upfront unrecovered.