Eli Lilly’s folate receptor alpha antibody-drug conjugate sofetabart mipitecan, known as Sofe-M, combined with bevacizumab produced a confirmed objective response rate of 79.3 percent in platinum-sensitive ovarian cancer in Phase 1 data presented at ESMO on October 24. Among 29 patients with measurable disease, 23 responded, including a 20.7 percent complete response rate, and disease control was 100 percent at the July 6, 2026 data cutoff. Median duration of response and median progression-free survival had not been reached, at median follow-ups of 6.2 and 10.2 months respectively.
The cohort was heavily pretreated. Thirty-three patients received Sofe-M, with a median of three prior systemic regimens; two-thirds had received a PARP inhibitor such as AstraZeneca’s Lynparza, about 70 percent had received bevacizumab before, and about 10 percent had already received AbbVie’s Elahere, the first folate receptor alpha ADC on the market. Lilly said responses were consistent across folate receptor expression levels and regardless of prior PARP inhibitor exposure, which matters because Elahere’s label and trial history are tied more closely to high receptor expression and to platinum-resistant disease.
Safety was the cost visible in the data. The most common grade 3 or worse treatment-emergent adverse events were neutropenia, in 42.4 percent of patients, and anaemia, in 24.2 percent; nosebleed and nausea were the most common events of any grade, each in 72.7 percent. Dose reductions were needed in 42 percent of patients in the pharmaphorum summary, and two patients, 6 percent, discontinued for adverse events. Researchers described the treatment as well tolerated relative to that profile.
Sofe-M came to Lilly through its 2023 acquisition of France’s Mablink Bioscience and its masked-payload ADC platform, and Lilly is already running three global Phase 3 trials under the FRAmework-01 protocol across platinum-resistant and platinum-sensitive disease, at a lower 3 mg/kg Phase 3 dose than the 4 mg/kg used here. A 33-patient Phase 1 cohort cannot settle a standard of care that has stood for a decade, but it is enough to make the Phase 3 program the ovarian ADC race to watch.