Eli Lilly Reports 79.3% Response Rate for Sofe-M in Platinum-Sensitive Ovarian Cancer at ESMO 2026
Eli Lilly shared phase 1 trial data at the European Society for Medical Oncology (ESMO) 2026 Congress revealing a 79.3% confirmed response rate for its antibody-drug conjugate sofetabart mipitecan (Sofe-M) combined with bevacizumab in platinum-sensitive ovarian cancer. The trial enrolled 33 patients whose disease progressed at least six months after their last platinum-based chemotherapy dose. Researchers recorded a 20.7% complete response rate in the cohort, with responses holding steady regardless of folate receptor alpha expression levels or prior exposure to PARP inhibitors.
The study evaluated Sofe-M, an FRα-directed antibody-drug conjugate carrying a topoisomerase I inhibitor payload, given alongside bevacizumab. Two-thirds of the participants had previously received a PARP inhibitor such as AstraZeneca’s Lynparza, while roughly 10% had received AbbVie’s competing FRα-directed antibody-drug conjugate Elahere. The trial achieved a 79% confirmed response rate from 29 evaluable patients, with every patient in the cohort achieving disease control as of the July 6, 2026, data cutoff.
Data Maturity and Progression-Free Survival in Phase 1
Median follow-up reached 10.2 months for progression-free survival and 6.2 months for duration of response, with the median progression-free survival yet to be reached. Nearly 80% of responding patients remained on treatment at the data cutoff, and almost 70% had received treatment for at least nine months. The data showed consistent efficacy among patients who had received prior PARP inhibitors and those who had not, a finding that addresses a clinical population where platinum re-challenge typically yields lower response rates.
Researchers described the combination regimen as well-tolerated in a heavily pretreated population that had received a median of three prior systemic therapies. Grade 3 or worse treatment-emergent adverse events included neutropenia at 42.4% and anemia at 24.2%. Any-grade nosebleeds and nausea each affected 72.7% of patients. Dose reductions occurred in 42% of patients, while only two patients discontinued treatment because of adverse events.
Competition for Ovarian Cancer Antibody-Drug Conjugates
“The standard of care for platinum-sensitive ovarian cancer has remained unchanged for a decade and demands new treatment options,” Jacob Van Naarden, President of Lilly Oncology, said in a release. Van Naarden added that the trial results give the company confidence as it continues studying the drug in the FRAmework-01 phase 3 program.
Lilly launched a phase 3 trial of Sofe-M in platinum-sensitive ovarian cancer one year ago, enrolling patients whose disease responded to platinum treatment and remained controlled for at least six months. Control cohorts in that study receive platinum-based doublet chemotherapy plus bevacizumab.
Rivals are advancing competing antibody-drug conjugates in the same patient population. AbbVie, which secured FDA approval for Elahere in platinum-resistant ovarian cancer in 2022, is running a phase 3 trial in platinum-sensitive ovarian cancer with an estimated primary completion date of April, based on federal trial database records. Genmab initiated a phase 3 trial for its FRα-directed antibody-drug conjugate rinatabart sesutecan, and AstraZeneca advanced its candidate torvutatug samrotecan into a phase 3 trial.