CAMBRIDGE, Mass.– EQRx, a new type of pharmaceutical company committed to developing and delivering important new medicines to patients at radically lower prices, today announced a late-breaking mini oral presentation of data from its partner CStone Pharmaceuticals’ Phase 3 GEMSTONE-301 study at the European Society for Medical Oncology (ESMO) Congress 2021. GEMSTONE-301 is a placebo-controlled Phase 3 trial evaluating the efficacy and safety of the anti-PD-L1 antibody sugemalimab as consolidation therapy in patients with locally advanced/unresectable Stage III non-small cell lung cancer (NSCLC) without disease progression after concurrent or sequential chemoradiotherapy. GEMSTONE-301 is the first positive Phase 3 trial of a PD-(L)1 agent in this broad Stage III NSCLC patient population setting.
In May 2021, EQRx, along with its partner CStone Pharmaceuticals, announced that the GEMSTONE-301 study met its primary endpoint of prolonged progression-free survival (PFS). Detailed results of the study to be presented at ESMO 2021 on Saturday, September 18, are as follows:
- Sugemalimab, as a consolidation therapy, demonstrated statistically significant and clinically meaningful improvement in PFS vs. placebo as assessed by blinded independent central review (BICR).
- Median PFS was 9.0 months vs. 5.8 months (HR=0.64, P=0.0026).
- Clinical benefits were observed in patients who received either concurrent or sequential chemoradiotherapy prior to sugemalimab.
- For patients who received prior concurrent chemoradiotherapy (cCRT), median PFS was 10.5 months vs. 6.4 months (HR=0.66).
- For patients who received prior sequential chemoradiotherapy (sCRT), median PFS was 8.1 months vs. 4.1 months (HR=0.59).
- Overall survival (OS) data were immature, but an encouraging trend for a survival benefit with sugemalimab vs. placebo was observed with follow-up of patients ongoing.
- Median OS was not reached for sugemalimab vs. 24.1 months for placebo (HR=0.44).
- Sugemalimab had a well-tolerated safety profile and no new safety signals were observed.
“GEMSTONE-301 is a unique trial in that it enrolled a highly heterogenous population of patients with Stage III NSCLC reflective of everyday practice across a range of tumor pathologic subtypes, performance status and those treated with either sequential or concurrent chemoradiotherapy,” said Vincent Miller, MD, physician-in-chief at EQRx. “Sequential chemoradiotherapy is a widely used alternative for those who cannot tolerate or access concurrent chemoradiotherapy and there remains a high unmet need to improve outcomes for these patients. These data suggest sugemalimab may have the potential to treat a broad population of patients with Stage III NSCLC.”
The upcoming presentation at ESMO 2021 in Stage III NSCLC builds upon the recent presentation of updated data from the GEMSTONE-302 study in Stage IV NSCLC at the IASLC 2021 World Conference on Lung Cancer, positioning sugemalimab as a potential treatment option to address both Stage III and IV NSCLC.
Separately, a poster is also being presented at ESMO 2021 on the final results of the Phase 2 APOLLO study, conducted by EQRx’s partner Hansoh Pharma, of EGFR inhibitor aumolertinib in second-line NSCLC. Data demonstrate an encouraging OS benefit with a median OS of 30.2 months in patients with EGFR T790M-positive advanced NSCLC after disease progression on first-/second-generation EGFR TKI therapies.
