Summit's Lung Cancer Drug Ivonescimab Faces Setback in Phase 3 Trial

Summit Therapeutics and Akeso's experimental lung cancer drug ivonescimab has encountered a significant obstacle in its path to regulatory approval. The latest data from the global Phase 3 Harmoni trial, presented at the World Conference on Lung Cancer in Spain, revealed that the combination of ivonescimab and chemotherapy failed to extend overall survival compared to chemotherapy alone in patients with lung cancer.

Trial Results Cast Doubt on FDA Approval Prospects

The Harmoni trial, which tested ivonescimab in combination with chemotherapy in patients with EGFR mutations and PD-1 expression who had progressed on a VEGF inhibitor, initially showed promise. In May, Summit reported that the combination reduced the risk of death or disease progression by 48% compared to chemotherapy plus placebo. However, the trial was unable to demonstrate a statistically significant improvement in overall survival at that time.

The final analysis, released on Sunday, further clouded the drug's prospects. Data from North American and European participants showed only a 16% relative reduction in the risk of death when assessed together. North American patients, analyzed separately, demonstrated a 30% relative risk reduction.

Summit executives acknowledged that the timing and conflicting nature of the survival data might raise doubts about ivonescimab's effectiveness. Jack West, Summit's vice president of clinical development, stated during a call with analysts, "We knew this was going to be a problem."

Market Reaction and Analyst Perspectives

The disappointing trial results had an immediate impact on Summit Therapeutics' stock, with shares falling 24% in morning trading following the announcement.

Analysts have expressed skepticism about ivonescimab's future. Leerink Partners analyst Daina Graybosch suggested that the FDA is unlikely to approve the drug based on these results, and that Summit may struggle to secure a licensing deal "at the substantial valuation expected by investors."

Evercore ISI analyst Cory Kasimov proposed that while Summit might attempt to renegotiate with the FDA and file for approval based on the current data, it may be more prudent for the company to await results from first-line setting trials before proceeding.

Despite the setback, Summit executives remain optimistic, emphasizing the positive experiences of physicians who have used ivonescimab in clinical practice. Jack West urged critics to consider the perspectives of these clinicians, stating, "Some of the conversations I've had just in the last few hours are with people who have actually used ivonescimab, who are extremely committed to it, who have participated in this trial. They've seen what they've come to conclude are really good results as well."