GSK and iTeos Therapeutics’ Promising Phase 3 Lung Cancer Study: Market Implications

GlaxoSmithKline ((GSK)), GlaxoSmithKline plc (UK) ((GB:GSK)), Iteos Therapeutics, Inc. ((ITOS)) announced an update on their ongoing clinical study.

GlaxoSmithKline (GSK) and iTeos Therapeutics are conducting a Phase 3 clinical trial titled ‘GALAXIES Lung-301’ to assess the safety and efficacy of belrestotug combined with dostarlimab versus pembrolizumab with placebo in patients with high PD-L1 non-small-cell lung cancer (NSCLC). The study aims to determine if the new combination improves progression-free survival and overall survival compared to the current standard treatment.

The trial involves two main interventions: the experimental combination of biological agents dostarlimab and belrestotug, and the active comparator of pembrolizumab with a placebo. These treatments target the immune system to enhance cancer-fighting capabilities.

This randomized, double-blind study employs a parallel intervention model with quadruple masking, ensuring unbiased results. Its primary purpose is treatment-focused, aiming to provide new insights into NSCLC management.

The study began on June 10, 2024, and was last updated on August 7, 2025. These dates are crucial as they indicate the study’s progress and the latest developments in the trial.

For investors, this study could significantly impact GSK and iTeos Therapeutics’ market performance, especially if the results show a substantial improvement over existing treatments. This could enhance investor confidence and potentially affect stock prices positively, particularly in a competitive oncology market.

The study is ongoing, with further details available on the ClinicalTrials portal.