An experimental lung cancer drug developed by Akeso and Summit Therapeutics has demonstrated promising results in a late-stage trial, reducing the risk of death by 34% for patients with squamous non-small-cell lung cancer. The findings reveal that when combined with chemotherapy, the drug extended the median survival of patients by four months compared to the standard immunotherapy and chemotherapy regimen. These results were shared in an abstract ahead of the American Society of Clinical Oncology’s annual meeting.
The trial, conducted in China, observed that the bispecific antibody, known as ivonescimab, targets both PD-1 and VEGF, similar to existing treatments like Merck’s Keytruda and Roche’s Avastin. Experts in oncology are engaged in heated discussions regarding ivonescimab’s potential; while some view it as a contender to replace Keytruda, others express caution, noting previous disappointments with similar drugs.
Since Summit Therapeutics announced that ivonescimab had achieved better tumor control results than Keytruda in an earlier trial, its stock price has surged nearly 600%. However, concerns about its efficacy in broader populations have led to a dip in shares over the past month.
The key measure of success in drug approval is overall survival, and ivonescimab’s performance in the Harmoni-6 trial showed a median survival of 27.9 months for patients receiving the drug and chemotherapy, compared to 23.7 months for those receiving a standalone PD-1 treatment. Though this four-month difference is statistically significant, some experts, such as Dr. Deborah Doroshow from the Icahn School of Medicine at Mount Sinai, question its clinical relevance. They highlight that the patient demographics in the trial raise doubts about how these results might translate to other populations.
The trial’s background is notable as it was limited to China, where patients traditionally respond more favorably to PD-1 and VEGF therapies, leading experts like Dr. Suresh Ramalingam from Emory University to call for further trials in Western populations to fully understand the drug’s effectiveness.
Additionally, ivonescimab was associated with higher incidences of bleeding compared to the control group, although severe cases were infrequent. This has sparked conversations about the safety of PD-1/VEGF-targeting drugs, particularly for squamous lung cancer patients, who typically have tumors located near major blood vessels, posing significant risks.
As the oncology community anticipates further results from the global Harmoni-3 trial later this year, the competitive landscape for lung cancer therapies is rapidly evolving. Keytruda, which has transformed lung cancer treatment and netted more than $30 billion in sales last year, is facing inquiries about whether it will maintain its dominance amidst emerging options.
The ongoing rush in drug development has seen an increase in licensing deals for PD-1 drugs—reaching $30 billion last year—which reflects the potential market for effective therapies. However, industry experts caution that ivonescimab may not achieve the same level of widespread use as Keytruda, given the growing competition from other innovative treatments.
Overall, optimism persists as new therapies are developed, providing hope for patients diagnosed with lung cancer, who may soon have access to a range of treatment options. The coming months will likely clarify the role ivonescimab and similar drugs will play in the evolving landscape of cancer therapy.


