NextFin News - An experimental lung cancer therapy developed by Akeso and Summit Therapeutics reduced the risk of death by 34% in a late-stage trial, according to data presented Sunday at the American Society of Clinical Oncology (ASCO) annual meeting. The drug, ivonescimab, combined with chemotherapy, extended the lives of patients with squamous non-small-cell lung cancer by a median of four months compared to the current standard of care. While the results from the Harmoni-6 trial offer a potential challenge to Merck’s dominant immunotherapy Keytruda, the fact that the study was conducted exclusively in China has sparked a debate over whether these gains will translate to a global patient population.
The trial results showed that patients receiving the ivonescimab combination lived for a median of 27.9 months, compared to 23.7 months for those on a standard PD-1 inhibitor and chemotherapy regimen. Ivonescimab is a bispecific antibody designed to hit two targets simultaneously: PD-1, which helps the immune system recognize cancer, and VEGF, which blocks the blood vessel growth that tumors need to survive. This "two-in-one" approach is intended to simplify treatment and potentially increase efficacy over the sequential or separate administration of similar drugs.
Dr. Suresh Ramalingam, executive director of the Winship Cancer Institute of Emory University, described the improvement in overall survival as "very encouraging" for a difficult-to-treat patient group. However, Ramalingam cautioned that the exclusive use of Chinese participants raises questions about the drug's applicability in Western markets. Historically, certain patient populations in China have shown different response rates to VEGF-targeting therapies compared to those in Europe or the United States, a discrepancy that may only be resolved by the ongoing global Harmoni-3 trial.
The financial stakes are high for Summit Therapeutics, which licensed the rights to ivonescimab outside of China from Akeso. Summit’s stock has surged nearly 600% over the last two years on the back of early data, though it has faced recent volatility as investors weigh the "China-only" data risk. Robert Duggan, Summit’s co-CEO and chairman, maintained on Sunday that the data confirms the company has a "very valuable product" in its early stages. Despite this optimism, some analysts remain wary of the competitive landscape. Ethan Smith, oncology director at Norstella, noted that ivonescimab faces a more crowded market than Keytruda did a decade ago, particularly with the emergence of antibody-drug conjugates (ADCs) that are also showing significant survival benefits.
Safety remains a critical focal point for the PD-1/VEGF combination. Because VEGF inhibitors can interfere with blood vessel repair, there is a heightened risk of hemorrhaging, particularly in squamous lung cancer where tumors often sit near major pulmonary arteries. In the Harmoni-6 trial, bleeding of any severity occurred in nearly 25% of the ivonescimab group—double the rate of the control group—though severe cases remained low at less than 3%. This safety profile will be closely scrutinized by the U.S. Food and Drug Administration as Summit seeks to move toward a global filing.
Merck, the manufacturer of Keytruda, is also developing its own PD-1/VEGF candidate but has signaled a more conservative outlook on the class. Dr. Marjorie Green, Merck’s head of global oncology clinical development, stated that while the company is excited about the new therapies, it does not necessarily expect them to displace Keytruda as the universal cornerstone of treatment. Instead, the industry may be moving toward a more fragmented market where multiple specialized options coexist. Summit expects to report further data from its global trial in the second half of 2026, which will likely determine if ivonescimab can truly transition from a regional success to a global standard.
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