Akeso and Summit Therapeutics report phase 3 trial results for lung cancer drug ivonescimab

Ivonescimab Shows Promising Survival Benefit in Lung Cancer Trial

A new experimental lung cancer drug has shown a significant improvement in survival rates in a late-stage clinical trial, offering a potential new option for patients with a difficult-to-treat form of the disease.

• Developed by Akeso and licensed to Summit Therapeutics outside China, ivonescimab reduced the risk of death by 34% in a Phase 3 trial known as Harmoni-6.
• When combined with chemotherapy, ivonescimab extended median overall survival to 27.9 months, compared to 23.7 months for a standard PD-1 inhibitor plus chemotherapy—a statistically significant improvement of four months.
• The trial enrolled patients with squamous non-small-cell lung cancer, a particularly aggressive and hard-to-treat population.

“The four-month survival benefit is encouraging, but its meaningfulness varies by patient.” — Dr. Deborah Doroshow, Icahn School of Medicine

• The trial was conducted exclusively in China, raising questions about how well the results will translate to patient populations elsewhere.
• Notably, the control group receiving standard immunotherapy lived approximately six months longer than expected, suggesting the trial population may not be fully representative of broader patient groups.
• A global Phase 3 study (Harmoni-3) is already underway to address this question.

Ivonescimab is a bispecific antibody that simultaneously targets two key pathways:

• PD-1 (the same target as Merck's blockbuster drug Keytruda)
• VEGF (the same target as Roche's Avastin)

“Results are encouraging, but applicability outside China requires further investigation.” — Dr. Suresh Ramalingam, Winship Cancer Institute

Previous trials had already shown improved progression-free survival, but overall survival data—the gold standard for cancer treatments—had been eagerly awaited.

• Summit Therapeutics' stock surged approximately 600% following earlier positive results.
• However, the stock has declined over the past month due to lingering concerns about the drug's global efficacy.

• H2 2024: Summit plans to report progression-free survival results from squamous patients in the global Harmoni-3 trial.
• H1 2025: Results from non-squamous patients are expected.

Expert note: The four-month survival advantage for ivonescimab might actually be better than reported, due to potential issues with the trial's control group performance.