Akeso reported a China overall survival benefit for ivonescimab. It is not a U.S. approval.

Akeso reported an overall survival benefit for ivonescimab in a China lung-cancer study. Summit's licensed territories still treat the drug as investigational.

Summit Therapeutics Inc. (Nasdaq: SMMT) said on September 2, 2026, that its partner Akeso Inc. had announced positive overall survival results from HARMONi-2 (AK112-303). The disclosure is Form 8-K AccNo 0001599298-26-000076, Items 8.01 and 9.01, accepted September 3 at 09:21:44 ET, with the press note attached as Exhibit 99.1.

Akeso ran HARMONi-2 in China

HARMONi-2 is a randomized, double-blind Phase III study in locally advanced or metastatic non-small cell lung cancer whose tumors have positive PD-L1 expression. It compared ivonescimab monotherapy with pembrolizumab monotherapy. Summit's 8-K and exhibit describe it as a single-region, multi-center trial conducted in China and sponsored by Akeso, with all relevant data exclusively generated, managed, and analyzed by Akeso.

That ownership matters. A China readout is not a U.S. review. Ivonescimab, known as SMT112 in Summit's license territories — North America, South America, Europe, the Middle East, Africa, and Japan — and as AK112 outside those territories, remains investigational and is not approved by any regulatory authority in Summit's territories, including the United States and Europe.

China's National Medical Products Administration authorized ivonescimab based on HARMONi-2 in April 2025. The exhibit also notes an earlier China marketing authorization in May 2024. Those are China authorizations. They are not FDA approvals.

Survival is significant. The hazard ratio is not here.

In a preplanned analysis of overall survival, a secondary endpoint, Akeso reported that ivonescimab monotherapy demonstrated a statistically significant improvement compared with pembrolizumab monotherapy. Summit's note does not print an OS hazard ratio, median overall survival, or p-value. Those figures are scheduled for an upcoming medical conference.

What the exhibit does print is the study's primary analysis: progression-free survival by independent radiologic review. Ivonescimab monotherapy showed a statistically significant PFS improvement versus pembrolizumab monotherapy, with a hazard ratio of 0.51 (95% CI: 0.38, 0.69; p<0.0001). Summit says a clinically meaningful benefit was demonstrated across clinical subgroups, including PD-L1 low, PD-L1 high, squamous, and non-squamous histologies, citing the Lancet HARMONi-2 paper (Xiong et al., 2025). That PFS package is the prior primary endpoint, not the new OS table.

Akeso, as noted by Summit, says more than 4,000 patients have been treated with ivonescimab in clinical studies globally and more than 70,000 in a commercial setting in China. The exhibit counts 16 Phase III studies announced, ongoing, or completed — five Summit-sponsored global studies, one cooperative-group multiregional study, and 10 conducted in China by Akeso. Five Phase III trials have read out to date, all five with positive data as Summit defines a positive study.

Summit's U.S. file is a different trial

Summit is running its own global program. HARMONi-7 is a Phase III trial of ivonescimab monotherapy versus pembrolizumab monotherapy in first-line metastatic NSCLC with high PD-L1 expression. Enrollment began in 2025.

The U.S. marketing clock in this note is HARMONi, not HARMONi-2. HARMONi tests ivonescimab plus chemotherapy versus placebo plus chemotherapy in EGFR-mutated, locally advanced or metastatic non-squamous NSCLC after a third-generation EGFR TKI such as osimertinib. Summit submitted a Biologics License Application; the FDA accepted it for filing in January 2026. The goal PDUFA date is November 14, 2026.

The exhibit also lists HARMONi-3 in first-line metastatic NSCLC with chemotherapy, with squamous and non-squamous cohorts separately powered; HARMONi-GI3 in colorectal cancer; and HARMONi-GU1 in urothelial carcinoma. Those are program context. They are not this OS analysis.

Akeso, as summarized by Summit, has reported statistically significant overall survival benefits in three single-region China Phase III NSCLC studies — HARMONi-A, HARMONi-2, and HARMONi-6 — and in HARMONi-GI1 in advanced biliary tract cancer. Those are Akeso China readouts. They do not substitute for a U.S. label.

OS hazard ratio, PDUFA, and HARMONi-7 still pending

The OS hazard ratio, median, and p-value for HARMONi-2. The conference presentation. Whether FDA acts on the HARMONi BLA by the November 14, 2026 PDUFA date. HARMONi-7, which is still the PD-L1-high monotherapy comparison Summit is running itself.