Summit Therapeutics Announces Updated Phase III HARMONi Overall Survival Results

What Happened
Summit Therapeutics Inc. announced on September 15, 2026 that updated overall survival (OS) results from its global Phase III HARMONi clinical trial were presented at the International Association for the Study of Lung Cancer 2026 World Conference on Lung Cancer (WCLC 2026). The 8-K notes a related presentation of data from the randomized, double-blind Phase III HARMONi-2 trial by Summit’s partner Akeso Inc. A press release describing these presentations was attached to the filing.

Key Details

• Date filed/published: September 15, 2026.
• Event: Updated overall survival results from the global Phase III HARMONi trial were presented at WCLC 2026.
• Partner data: Akeso Inc. presented randomized, double-blind Phase III HARMONi-2 trial data at the same conference.
• Documentation: Summit’s press release about the presentations is included as Exhibit 99.1 to the 8-K.

Why It Matters
Overall survival is a primary clinical endpoint in oncology and can materially affect regulatory decisions, commercialization potential, partner valuations and investor sentiment. This 8-K confirms Summit is publicly disclosing updated OS data and that related data from a partner-sponsored Phase III trial were also presented. Investors should review the attached press release and conference materials for the specific numerical results and any commentary on regulatory or next-step plans, since the 8-K itself summarizes the presentations rather than listing detailed outcomes.