iTeos Therapeutics
The business, the turning points, and the decisions behind them.
01 / WHAT IT BUILT
What the company did
iTeos Therapeutics was a Belgian-American clinical-stage immuno-oncology biotech headquartered in Gosselies, Belgium (with offices in Watertown, Massachusetts), founded in 2011 as a spin-out of the Ludwig Institute for Cancer Research and the de Duve Institute at UCLouvain. It pioneered next-generation immuno-oncology drugs including the adenosine A2A antagonist EOS-850 and the anti-TIGIT antibody belrestotug. After its 2020 Nasdaq IPO, it partnered with GSK on belrestotug; when the drug failed in 2025, the company announced on May 28, 2025 that it would wind down operations and sell its assets, expecting to substantially complete the process by the third quarter of 2025.
02 / iTeos Therapeutics FAILURE REASONS
Failure reasons
In May 2025 the Phase 2 GALAXIES Lung-201 study of belrestotug + dostarlimab failed to meet criteria for clinically meaningful improvements in progression-free survival in NSCLC, and the GALAXIES H&N-202 head-and-neck study trended below the meaningful threshold — the latest casualty for the anti-TIGIT drug class. iTeos and partner GSK agreed to terminate the belrestotug development program, and the collaboration was ended. With no viable pipeline path, a review of strategic alternatives concluded that winding down operations and selling the assets — including experimental cancer treatments and an obesity drug — was the best way to maximize shareholder value.
03 / EVENT HISTORY
Events in the structured record
- Operations ended
summarizing company announcement + regulatory filing: iTeos plans to wind down operations, sell assets/IP, spend on severance and clinical wind-down through 3Q2025 — after shelving TIGIT program with GSK. Later Concentra cash+CVR tender (Aug 2025) followed this wind-down path.
04 / CONTEMPORARY REBUILD ASSESSMENT
Difficulty of rebuilding this project today
Material for this section is being gathered and checked. It will appear here once ready.
Overall assessment: Not completed
05 / CAUSAL CHAIN
How the factors connect
- 01
iTeos raised €9 million in April 2012 (with Walloon Region support), a €64 million Series B in 2018 led by MPM Capital, $125 million in 2020, and completed a $151 million Nasdaq IPO in July 2020.
- 02
On May 13, 2025 iTeos and GSK terminated the belrestotug program after the GALAXIES trials failed.
- 03
On May 28, 2025 iTeos announced it would wind down operations and sell its assets, expecting $21.8–$24.7 million in severance costs plus $11.1 million to shut down clinical programs; the company held $624.3 million in cash at March 31, 2025 and expected to substantially complete the wind-down by Q3 2025.