iTeos Therapeutics is a clinical-stage biopharmaceutical company focused entirely on immuno-oncology — developing drugs that help the immune system attack tumors by blocking the suppression mechanisms cancer cells use. iTeos has three drug candidates in clinical development, none of which are approved or generating product revenue. The lead program, belrestotug, is an anti-TIGIT antibody being developed in partnership with GSK, primarily in non-small cell lung cancer and head and neck squamous cell carcinoma, mostly in combination with GSK's anti-PD-1 antibody dostarlimab. The second candidate, EOS-984, is a first-in-class small molecule that blocks ENT1, a transporter that allows immunosuppressive adenosine into T cells, and is in Phase 1. The third, EOS-215, is an anti-TREM2 antibody targeting tumor-resident macrophages that is still completing preclinical studies. iTeos' business model is to discover and develop novel immunotherapy candidates and partner with large pharma for funding and commercialization. The GSK collaboration is the financial backbone of the company: GSK paid $625M upfront in 2021, with up to $1.45B in additional milestones available. In the U.S., iTeos and GSK co-develop and will co-commercialize belrestotug on a 50/50 profit split; outside the U.S., iTeos receives tiered royalties of up to 20% on net sales. Until belrestotug is approved, iTeos has no product revenue, and near-term cash depends on GSK milestone payments and capital raises.