Summit Therapeutics Inc. (NASDAQ: SMMT) shares rose 7.75% on Wednesday after partner Akeso Inc. disclosed positive results from the HARMONi-GI1 study in advanced biliary tract cancer (BTC).
The 682-patient trial, conducted in China, met its primary endpoint, demonstrating that ivonescimab combined with chemotherapy provided statistically significant improvement in overall survival compared with durvalumab plus chemotherapy as a first-line treatment. The study also met key secondary endpoints, including progression-free survival and objective response rate.
Ivonescimab is already approved in China for certain non-small cell lung cancer indications but remains investigational in Summit’s licensed territories, which include the United States and Europe. Detailed trial results are expected to be presented at an upcoming medical congress.
Analysts offered cautious optimism. Mitchell S. Kapoor of H.C. Wainwright maintained a Neutral rating, noting the lack of overall survival hazard ratio data prevents a clear assessment of ivonescimab’s incremental benefit over durvalumab. The analyst also highlighted that Summit has not disclosed plans for a global BTC study, assigning no economic value to the BTC opportunity outside China. The next potential catalyst is the final progression-free survival and interim overall survival data from the HARMONi-3 study, expected in the second half of 2026.
Brad Canino of Guggenheim reiterated a Buy rating with a $38 price target, emphasizing that the BTC results reinforce the consistency of ivonescimab’s efficacy and support the generalizability of earlier first-line lung cancer findings. While BTC represents a smaller market, Canino noted the valuation reflects greater importance in the lung cancer read-through than the newly unlocked BTC opportunity.
