ESMO 2024: iTeos shares tumble despite TIGIT:PD-1 doublet promise

Shares in Belgo-American immuno-oncology company iTeos Therapeutics (Nasdaq: ITOS) were down by more than 20% during Monday’s early trading.

This came despite the company’s apparently positive announcement of follow-up interim data from GALAXIES Lung-201, the Phase II platform study sponsored by iTeos’ development partner GSK (LSE: GSK), assessing the belrestotug and dostarlimab doublet in previously untreated, unresectable, locally advanced or metastatic PD-L1 high non-small cell lung cancer (NSCLC).

Belrestotug is iTeos’ Fc active human immunoglobulin G1, or IgG1, monoclonal antibody targeting T cell immunoglobulin and immunoreceptor tyrosine-based inhibitory motif domains (TIGIT), an important inhibitory receptor which contributes to the suppression of innate and adaptive immune responses against cancer.