Summit Therapeutics Inc. filed a Form 8-K on September 3, 2026, reporting that its partner Akeso Inc. announced positive overall survival results from the Phase III HARMONi-2 study evaluating ivonescimab monotherapy versus pembrolizumab monotherapy in patients with locally advanced or metastatic non-small cell lung cancer with positive PD-L1 expression.

Key Highlights

  • Partner announcement: Akeso Inc. disclosed positive overall survival results from the randomized, double-blind Phase III HARMONi-2 study.
  • Trial design: HARMONi-2 compared ivonescimab monotherapy against pembrolizumab monotherapy in patients with PD-L1-positive locally advanced or metastatic non-small cell lung cancer.
  • Statistically significant result: According to the filing, ivonescimab monotherapy demonstrated a statistically significant improvement in overall survival compared to pembrolizumab monotherapy in this preplanned analysis.
  • OS classification: Overall survival was a secondary endpoint in HARMONi-2, and the reported analysis was preplanned.
  • Study scope: HARMONi-2 is a single-region, multi-center study conducted in China, sponsored by Akeso, with all relevant data exclusively generated, managed, and analyzed by Akeso.
  • Conference presentation: Results from this analysis are scheduled to be presented at an upcoming medical conference, according to the filing.

HARMONi-2 Overall Survival Results and Summit Therapeutics' 8-K Disclosure

Summit Therapeutics Inc. (NASDAQ:SMMT) filed a current report disclosing that its partner Akeso Inc. announced positive overall survival data from the HARMONi-2 Phase III study on September 2, 2026. The study evaluated ivonescimab monotherapy head-to-head against pembrolizumab monotherapy in a patient population with locally advanced or metastatic non-small cell lung cancer whose tumors express PD-L1 positivity.

According to the filing, the overall survival analysis was a preplanned evaluation of a secondary endpoint in HARMONi-2. Akeso reported that ivonescimab monotherapy demonstrated a statistically significant improvement in overall survival compared to pembrolizumab monotherapy. The filing notes that HARMONi-2 is a single-region, multi-center study conducted in China, sponsored by Akeso, and that "all relevant data exclusively generated, managed, and analyzed by Akeso." Summit disclosed this information by attaching a press release as Exhibit 99.1 to the filing.

The filing does not include specific numerical survival data or hazard ratios, and notes that full results from this analysis are scheduled to be presented at an upcoming medical conference. The 8-K was signed by Manmeet S. Soni, identified as Chief Operating Officer, Chief Financial Officer and Director, on September 3, 2026.

What Was Disclosed

Summit Therapeutics filed an 8-K reporting partner Akeso's announcement of statistically significant overall survival improvement for ivonescimab versus pembrolizumab in the HARMONi-2 Phase III study, with full results to be presented at a future medical conference.