Summit Therapeutics Inc. (NASDAQ: SMMT) reported a GAAP net loss of $215.7 million, or $0.28 per share, for the second quarter ended June 30, 2026, compared with a net loss of $565.7 million, or $0.76 per share, in the same period a year earlier. The year-over-year decrease was largely due to a $410.1 million reduction in stock-based compensation expense related to a modification of performance-based stock option awards in the second quarter of 2025.

Non-GAAP operating expenses rose to $151.8 million from $89.6 million in the prior-year quarter, driven by expansion of clinical studies and development costs for its lead drug candidate, ivonescimab. Cash and short-term investments stood at $690.7 million as of June 30, 2026, down from $713.4 million at December 31, 2025. During the quarter, the company raised $230.8 million in gross proceeds through its at-the-market equity facility.

The company provided updates on ivonescimab, an investigational bispecific antibody targeting PD-1 and VEGF. An updated overall survival analysis from the global Phase III HARMONi study showed a hazard ratio of 0.76 for the full intent-to-treat population, with the same ratio observed in both western and Asian patient subgroups. The FDA accepted a Biologics License Application for ivonescimab in January 2026, with a PDUFA goal date of November 14, 2026.

A separate Phase III study conducted in China by Akeso Inc. (HKEX: 9926.HK), HARMONi-6, showed ivonescimab plus chemotherapy achieved a statistically significant improvement in overall survival compared with tislelizumab plus chemotherapy in squamous non-small cell lung cancer, with a hazard ratio of 0.66 (95% CI: 0.50, 0.87; p=0.0017). The company said this represents the first Phase III trial in any tumor type to demonstrate superiority in overall survival over an anti-PD-(L)1 antibody-containing regimen, though this claim originates from the company's press release.

Enrollment in the HARMONi-3 global study is complete. PFS events in the squamous cohort are expected in the second half of 2026, with non-squamous cohort PFS events expected in the first half of 2027.

Summit also disclosed it sold ridinilazole, an antibiotic asset, to Biossil Inc. for $500,000 upfront and up to $104.5 million in milestone payments plus tiered royalties.