In the long struggle against one of humanity's most lethal cancers, a new compound called ivonescimab has offered measurable hope — not through a single dramatic breakthrough, but through the patient accumulation of evidence across continents and populations. Presented at the 2025 World Conference on Lung Cancer, updated data from the HARMONi trial confirmed that patients with advanced non-small cell lung cancer who received ivonescimab alongside chemotherapy lived meaningfully longer than those who did not, with a 22 percent reduction in the risk of death. The finding, which required extended
Ivonescimab Shows Survival Benefit in Updated Lung Cancer Trial Data
The trial demonstrates potential to extend survival for non-small cell lung cancer patients, offering meaningful clinical benefit in a disease with high mortality.
The benefit became clear only after patients were followed longer than initially planned.
Mark
So the drug missed its primary endpoint initially—what changed?
Mimi
The trial wasn't finished. Western patients had only been followed for 9.2 months when they did the first analysis, but the median survival was 16.8 months. They needed more time to see the full picture.
Luke
Right, but that's important to flag. They extended follow-up for Western patients but locked the Asian cohort. So this improvement is driven by one population, not both.
Mimi
True, but the Asian trial—HARMONi-A—also hit its survival endpoint separately. The consistency across regions is what matters here.
Mark
What does a hazard ratio of 0.78 actually mean for a patient?
Mimi
It means the risk of death was reduced by 22 percent. In this trial, that translated to a median survival gain of 2.8 months—16.8 months versus 14.0 months.
Luke
Which is real but modest. And we should note: median survival is the midpoint. Some patients lived much longer, some much shorter. The hazard ratio tells us about the overall population trend.
Mark
Did the drug work faster than standard treatment?
Mimi
Yes. The progression-free survival—time before cancer worsened—showed a hazard ratio of 0.52. That's a much bigger effect. Tumors shrank in 45 percent of patients versus 34 percent on placebo.
Luke
And the response lasted longer with ivonescimab. But progression-free survival and overall survival are different things. A tumor can shrink and patients can still die at similar rates if the drug doesn't extend life.
Mimi
That's why the overall survival data matters. It shows the benefit extends beyond just slowing growth.
Mark
How confident should we be in these numbers?
Luke
The p-value is 0.0332, which is statistically significant. But it's a nominal p-value from an extended follow-up analysis, not the prespecified primary analysis. The original p-value was 0.057. That's a meaningful distinction for readers to understand.
Mimi
The consistency across subgroups and the parallel success in the China trial do strengthen confidence. But Luke's right—this is a post-hoc analysis of extended follow-up.
Mark
What happens next?
Mimi
Eight Phase III trials in lung cancer are ongoing, with four already meeting endpoints. The drug is also being tested in breast cancer, colorectal cancer, pancreatic cancer, and others.
The Pulse
- An earlier analysis had tantalized researchers with a near-miss — a hazard ratio of 0.79 and a p-value of 0.057 that fell just outside the threshold for significance, leaving the drug's promise unconfirmed.
- Extended follow-up of Western patients, stretched from 9.2 to 13.7 months, finally pushed the results across the line, with the hazard ratio tightening to 0.78 and a p-value of 0.0332 confirming the survival benefit is real.
- North American patients showed the strongest signal of all — a 30 percent reduction in death risk and a median survival in the ivonescimab arm that had not yet been reached at the time of analysis.
- The drug's dual mechanism, simultaneously blocking PD-1 and VEGF pathways, produced response rates of 45 percent versus 34 percent for placebo, with responses lasting nearly twice as long — 7.6 months compared to 4.2 months.
- Consistency across Western and Asian populations, across high and low PD-L1 expressers, and across predefined subgroups positions ivonescimab not as a niche solution but as a broadly applicable therapy.
- With eight Phase III lung cancer trials underway and expansion into five additional cancer types, ivonescimab is moving rapidly from promising candidate to potential pillar of next-generation immunotherapy.
In the long struggle against one of humanity's most lethal cancers, a new compound called ivonescimab has offered measurable hope — not through a single dramatic breakthrough, but through the patient accumulation of evidence across continents and populations. Presented at the 2025 World Conference on Lung Cancer, updated data from the HARMONi trial confirmed that patients with advanced non-small cell lung cancer who received ivonescimab alongside chemotherapy lived meaningfully longer than those who did not, with a 22 percent reduction in the risk of death. The finding, which required extended observation to reach statistical significance, reflects a truth familiar to medicine: some gifts reveal themselves only to those willing to wait.
When researchers gathered at the 2025 World Conference on Lung Cancer, they brought with them a story that had required patience to complete. Ivonescimab, a drug designed to block two cancer-enabling pathways at once, had previously shown encouraging but statistically inconclusive results in the HARMONi Phase III trial. The hazard ratio of 0.79 suggested a meaningful reduction in death risk, but the p-value of 0.057 fell just short of the study's required threshold — and Western patients had been followed for only 9.2 months, less time than the median survival itself.
Extending that follow-up to 13.7 months changed the picture. The hazard ratio improved to 0.78, the p-value dropped to 0.0332, and the survival benefit crossed into statistical significance. Median overall survival remained 16.8 months for patients on ivonescimab plus chemotherapy versus 14.0 months for those on placebo — but the additional data made clear the advantage was durable, not a statistical artifact. Among North American patients, the effect was even stronger: a hazard ratio of 0.70, and a median survival in the treatment arm that had not yet been reached at the time of analysis.
Beyond survival, the drug demonstrated speed and depth of effect. Progression-free survival showed a hazard ratio of 0.52 in the primary analysis, holding at 0.57 in extended follow-up. Tumor response rates reached 45 percent with ivonescimab compared to 34 percent with placebo, and those responses lasted nearly twice as long — 7.6 months versus 4.2 months. Crucially, benefits appeared consistently across both Western and Asian populations and regardless of PD-L1 expression levels, suggesting the drug's utility is not confined to a narrow patient profile.
Ivonescimab works by simultaneously targeting PD-1 and VEGF, two distinct mechanisms that tumors exploit to grow and evade immune detection. Akeso, the company behind the drug, argues this dual blockade produces a synergistic effect greater than either approach alone — and the safety profile, with no new signals identified in extended follow-up, supports continued development. Eight Phase III trials are now active in lung cancer, with four already meeting primary endpoints, and the program is expanding into biliary tract, head and neck, breast, colorectal, and pancreatic cancers. The HARMONi results mark not an endpoint, but a confirmation that ivonescimab is becoming a serious contender in the crowded and consequential field of cancer immunotherapy.
At the 2025 World Conference on Lung Cancer in September, researchers presented updated findings from a global trial testing ivonescimab, a drug that works by blocking two separate pathways in the immune system simultaneously. The results showed that patients with advanced lung cancer who received ivonescimab combined with chemotherapy lived longer than those given chemotherapy alone—a finding that emerged only after the trial had been running longer than initially planned.
The original analysis of the HARMONi trial, conducted across Western and Asian patient populations, had shown a promising trend but fell just short of statistical significance. The hazard ratio was 0.79, meaning the drug reduced the risk of death by roughly 21 percent, but the p-value of 0.057 exceeded the threshold of 0.0448 required by the study's statistical plan. Median overall survival was 16.8 months for patients receiving ivonescimab plus chemotherapy compared to 14.0 months for those on placebo plus chemotherapy. At that point, however, Western patients had only been followed for a median of 9.2 months—less time than the median survival itself, suggesting the picture might change with longer observation.
When researchers extended follow-up of Western patients to a median of 13.7 months in September 2025, the benefit became statistically significant. The hazard ratio improved to 0.78 with a nominal p-value of 0.0332, crossing the threshold for significance. The median survival times remained unchanged, but the additional months of data strengthened the evidence that the drug's advantage was real. Among North American patients specifically, the benefit was even more pronounced, with a hazard ratio of 0.70—meaning a 30 percent reduction in death risk. In that subgroup, median survival had not yet been reached in the ivonescimab arm at the time of analysis, compared to 14.0 months in the placebo group.
The trial also confirmed earlier findings about how quickly the drug worked. Progression-free survival—the time before cancer worsened—showed a hazard ratio of 0.52 in the primary analysis, a substantial improvement. In longer-term follow-up, this benefit held steady at a hazard ratio of 0.57. Response rates were higher with ivonescimab: 45 percent of patients saw their tumors shrink or disappear, compared to 34 percent on placebo. Among those who responded, the response lasted longer with ivonescimab—a median of 7.6 months versus 4.2 months.
What distinguished these results was their consistency across different populations. Benefits appeared in both Western and Asian patients, in those whose tumors expressed high levels of PD-L1 and those whose tumors did not, and across predefined subgroups. A separate trial conducted in China, called HARMONi-A, had also reached its overall survival endpoint and showed clinically meaningful benefit, with results to be presented at future conferences. This parallel success in different geographic regions suggested the drug's advantage was not limited to one population.
Ivonescimab works by simultaneously targeting PD-1 and VEGF, two distinct mechanisms involved in cancer growth and immune evasion. The drug combines the effects of blocking both pathways at once, which the developers argue produces a synergistic effect—the combination working better than either approach alone. The safety profile remained favorable, with no new safety signals identified in the extended follow-up.
The drug is advancing through an expansive development program. Eight Phase III trials are underway in lung cancer alone, with four already meeting their primary endpoints. Additional trials are testing ivonescimab in biliary tract cancer, head and neck cancer, triple-negative breast cancer, colorectal cancer, and pancreatic cancer. The company behind the drug, Akeso, is pursuing a dual strategy: accelerating commercialization and label expansion in China while advancing global development in partnership with Summit Therapeutics. The HARMONi results represent one piece of a broader effort to establish ivonescimab as a next-generation option in immunotherapy, competing against established drugs like pembrolizumab and tislelizumab.
Notable Quotes
Ivonescimab uniquely targets both PD-1 and VEGF, producing a synergistic anti-tumor effect that overcomes the efficacy and safety limitations of each target alone.— Akeso statement on drug mechanism
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