Sofe-M combination shows 79% response rate in platinum-sensitive ovarian cancer

Eli Lilly has reported early clinical data showing that sofetabart mipitecan, also known as Sofe-M, combined with bevacizumab produced a high response rate in patients with platinum-sensitive ovarian cancer.

The findings come from a Phase I study and were presented at the 2026 European Society for Medical Oncology Congress in Madrid.

Among 29 patients with measurable disease, the combination achieved a confirmed objective response rate of 79.3%.

This included six complete responses, representing 20.7% of patients, and 17 partial responses, representing 58.6%.

The disease control rate was 100%.

Lilly said responses were observed regardless of folate receptor alpha expression levels and were maintained in patients who had previously received PARP inhibitor treatment.

The Phase I cohort included 33 women with platinum-sensitive ovarian cancer who received Sofe-M at 4 mg/kg in combination with bevacizumab at 15 mg/kg.

Patients had received a median of three previous systemic treatment regimens.

Around 67% had previously been treated with a PARP inhibitor, while 70% had received bevacizumab.

At the July 6, 2026 data cut-off, median duration of response had not been reached after a median follow-up of 6.2 months.

Median progression-free survival had also not been reached after a median follow-up of 10.2 months.

Sofe-M is an investigational antibody drug conjugate targeting folate receptor alpha, a protein expressed at high levels across many ovarian cancers.

The treatment consists of an FRα-specific humanised monoclonal antibody linked to exatecan, a topoisomerase I inhibitor.

It is designed to bind to FRα on tumour cells and deliver the cytotoxic payload directly into the cancer cell, where it interferes with DNA replication.

Chrisann Kyi, MD, Gynecologic Medical Oncologist and Early Drug Development Specialist at Memorial Sloan Kettering Cancer Center, said the responses were particularly notable among patients previously treated with PARP inhibitors.

She said the combination’s activity and safety profile support further investigation in platinum-sensitive ovarian cancer.

The safety profile was consistent with the known profiles of Sofe-M and bevacizumab, with no new safety signals identified.

The most common treatment-emergent adverse events included epistaxis and nausea, each reported in 73% of patients, followed by anaemia in 58%, neutropenia in 55% and fatigue in 52%.

The most common Grade 3 or higher adverse events were neutropenia in 42% of patients and anaemia in 24%.

Febrile neutropenia occurred in 3% of patients.

Any-grade neuropathy was reported in 9% of patients, with no Grade 3 or higher cases observed.

Dose reductions were required in 42% of patients, while 6% discontinued treatment because of an adverse event.

The findings support Lilly’s ongoing Phase III FRAmework-01 development programme.

Part A is evaluating Sofe-M as a monotherapy in platinum-resistant ovarian cancer.

Part B is testing Sofe-M plus bevacizumab in platinum-sensitive disease that progressed during or within six months of completing PARP inhibitor treatment.

Part C is evaluating the same combination in PARP inhibitor-naïve patients with platinum-sensitive disease.

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Related Topics and Keywords

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