Summit Therapeutics Shares Surge on Positive Phase III Data From Chinese Partner Akeso

Summit Therapeutics Inc. (NASDAQ: SMMT) shares jumped nearly 8% on Wednesday, August 26, 2026, rising to around $14.40 after its Chinese partner, Akeso Inc., announced positive topline results from a Phase III cancer trial involving Summit’s key drug candidate, ivonescimab.

The rally was driven by news that Akeso’s HARMONi-GI1 study met its primary endpoint, showing that ivonescimab plus chemotherapy achieved a statistically significant and clinically meaningful overall survival benefit compared to durvalumab plus chemotherapy in patients with advanced biliary tract cancer.

The single-region Phase III trial, conducted in China, also hit key secondary endpoints of progression-free survival and objective response rate. Notably, this marks the first Phase III readout for ivonescimab outside of non-small cell lung cancer (NSCLC), broadening the drug’s potential therapeutic reach.

Ivonescimab, a bispecific antibody that simultaneously targets PD-1 and VEGF, is central to Summit’s pipeline. The company licenses rights to the drug in North America, Europe, and other territories, while Akeso develops it in China. Wednesday’s news adds to a string of positive catalysts, including Tuesday’s publication of HARMONi trial data in The Lancet Oncology and a recent analyst upgrade from Bernstein SocGen.

Investors are also watching the FDA’s pending decision on Summit’s Biologics License Application for ivonescimab in EGFR-mutated NSCLC, with a target action date of November 14, 2026. Despite Wednesday’s gains, shares remain well below their 52-week high, reflecting lingering concerns over cash burn and a recent $500 million stock offering that had pressured the price.