Lilly Reports 62% Confirmed Response Rate for Experimental Drug in Advanced Lung Cancer
Key Facts
Lilly announced new results on October 25, 2026, for its experimental drug olomorasib as a first-line treatment for advanced non-small cell lung cancer with a KRAS G12C mutation, at the European Society for Medical Oncology Congress in Madrid. In an analysis of patients who received the drug with pembrolizumab, pemetrexed and platinum-based therapy, the confirmed tumor response rate was 62%, or 48 of 77 patients. The results came from a single-arm analysis, so they do not provide a randomized comparison establishing the extent of benefit attributable to the drug. The researcher presenting the results, Marcelo V. Negrao of MD Anderson Cancer Center, said responses lasting a median of more than a year among patients with different levels of PD-L1 expression represent needed progress in first-line treatment. Olomorasib remains an investigational drug not approved by the U.S. Food and Drug Administration or any regulatory authority.
Median duration of response was 14.5 months, with the 95% confidence interval ranging from 8.5 months to a value that could not be estimated. Median progression-free survival was 11.6 months, within a confidence interval of 9.5 to 21.5 months. These measures describe the duration of response and disease control in the combination-therapy group and do not represent a comparison with a control group. Median follow-up was 18.7 months at the analysis, defining the period during which patients' cases were observed. Those with PD-L1 expression below 50% made up 74% of participants in this analysis.
Lilly also presented a separate analysis of a chemotherapy-free treatment regimen combining olomorasib with pembrolizumab in 85 patients. PD-L1 expression was 50% or higher in 64% of them, while median follow-up was 20.7 months. Median duration of response and median progression-free survival had not been reached at this follow-up, so the analysis does not provide a median time measure that can be directly placed alongside the combination-therapy results. But the 18-month progression-free survival rate was 55% for the overall group and 65% for patients with PD-L1 expression of 50% or higher. Results from this regimen were scheduled to be presented in a poster at the congress on October 26, after the oral presentation of the combination-therapy results on October 25.
In the chemotherapy-free group, the most common treatment-related grade 3 or higher adverse events included elevated ALT at 15.3%, elevated AST at 12.9% and diarrhea at 8.2%. Lilly reported no treatment-related grade 5 adverse events. These figures provide one part of the safety profile observed in the analysis, alongside the progression-free survival results, without by themselves resolving the balance of benefits and risks. The company said the KRAS G12C mutation occurs in about 13% of people with non-small cell lung cancer. It added that there are no approved targeted treatments for this mutation in the first-line setting, where standard treatment includes immunotherapy with or without chemotherapy.
The U.S. Food and Drug Administration granted olomorasib with pembrolizumab Breakthrough Therapy designation on September 4, 2025, for first-line treatment of a group of patients with advanced or metastatic non-small cell lung cancer, a KRAS G12C mutation and PD-L1 expression of 50% or higher. The designation indicates a special regulatory pathway, but does not mean the drug has been approved. SUNRAY-01 was also listed as an active trial funded by Lilly, with no results posted on ClinicalTrials.gov in the latest update shown on May 19, 2026. Lilly expects the first randomized Phase 3 data in the first half of 2027; Part B, which has completed enrollment, compares olomorasib with chemoimmunotherapy against chemoimmunotherapy alone. This randomized comparison will be the next test of the early results presented by the company.