Lung Cancer Drug Reduces Death Risk by 34% in Chinese Trial

• Patients receiving ivonescimab plus chemotherapy lived a median of 27.9 months versus 23.7 months for those on standard PD-1 immunotherapy plus chemotherapy, a four-month survival improvement
• Bleeding complications occurred in nearly 25% of ivonescimab patients (twice the control group rate), raising safety concerns particularly for squamous lung cancer patients whose tumors are near major blood vessels
• Questions remain about whether results from the China-only trial will translate to Western populations, with a global Phase 3 study (Harmoni-3) expected to report results in the second half of this year

Summary: Lung Cancer Drug Shows 34% Death Risk Reduction in Chinese Trial

Key Trial Results:

Ivonescimab, an experimental lung cancer drug from Akeso and Summit Therapeutics, reduced death risk by 34% in the Phase 3 Harmoni-6 trial conducted in China. When combined with chemotherapy, the drug extended median survival to 27.9 months versus 23.7 months for standard treatment—a four-month improvement that was statistically significant.

Drug Mechanism:

Ivonescimab is a bispecific antibody targeting both PD-1 (similar to Merck's Keytruda) and VEGF (similar to Roche's Avastin). This combination represents an emerging drug class that has sparked intense debate in oncology and investment communities.

Market Context:

The drug is being positioned as a potential successor to Keytruda, which generated over $30 billion in sales for Merck last year across 44 indications. Licensing deals involving PD-1 drugs reached $30 billion in 2024, nearly doubling the 2017 peak of $16 billion. Both Merck and Bristol Myers Squibb have signed multibillion-dollar deals for similar PD-1/VEGF drugs.

Safety Concerns:

Bleeding events occurred in nearly 25% of ivonescimab patients—double the control group rate—though severe cases remained under 3%.

Limitations and Next Steps:

Experts question whether results from the China-only trial will translate to Western populations, as Chinese patients historically respond better to these therapies. Summit plans to report global Harmoni-3 trial results in the second half of this year. Analysts note that while promising, these drugs face more competition from antibody drug conjugates than Keytruda encountered at launch.