Lilly Unveils Promising Phase 1 Results for Ovarian Cancer ADC Targeting FRα at ASCO 2025

Introduction

At the recent American Society of Clinical Oncology (ASCO) Annual Meeting, Eli Lilly and Company presented encouraging results from their Phase 1 clinical trial for an investigational antibody-drug conjugate (ADC) designed to target folate receptor alpha (FRα). This promising development targets women suffering from platinum-resistant ovarian cancer, offering a glimmer of hope for patients previously treated with limited success.

Background

Ovarian cancer remains one of the most challenging cancers to treat, particularly in cases where patients have become resistant to platinum-based therapies. The urgency for innovative treatments in this space is underscored by the current unmet medical needs. Lilly's investigational ADC, designated LY4170156, stands out due to its unique composition that allows it to target FRα across various expression levels, potentially expanding treatment options for a broader patient population.

Clinical Trial Details

The Phase 1 trial, which involved 95 women diagnosed with high-grade serous ovarian cancer, was designed to evaluate both safety and efficacy. Participants had previously undergone a median of five systemic treatment regimens, with some even treated with mirvetuximab soravtansine, another FRα-targeting therapy. Notably, the study reported an impressive preliminary overall objective response rate (ORR) of 55% at a promising dosage of 4 mg/kg.

Efficacy and Safety Findings

According to the data cutoff on March 9, 2025, results from the 58 efficacy-evaluable patients indicated an ORR of 45%, with a disease control rate of 74%. Furthermore, across all dose levels, efficacy was observed irrespective of the FRα expression levels present in tumors. For patients previously treated with other FRα-targeting treatments, the early data suggested that LY4170156 could provide meaningful therapeutic benefits.

Common side effects included nausea (64%), anemia (40%), and fatigue (32%), but notably, there was no maximum tolerated dose established yet, and concerning adverse effects, such as neuropathy and ocular toxicity, were not reported at this point.

Insights from Key Opinion Leaders

Dr. Isabelle Ray-Coquard, president of the ENGOT group, emphasized the critical need for such ADC therapies, stating, "ADCs have begun to change the treatment paradigm for some women with ovarian cancer, but a large proportion of patients still have significant unmet needs." Her insights echo the imperative for new therapies that can improve patient outcomes beyond existing options.

Looking Ahead

David Hyman, M.D., Lilly’s Chief Medical Officer, expressed enthusiasm about these results, highlighting the potential to broaden the patient base that could benefit from this innovative ADC. Moving forward, Lilly aims to expedite the transition of LY4170156 into Phase 3 clinical trials, focusing on determining its full therapeutic potential in the treatment of advanced ovarian cancer.

Conclusion

With each passing year, the landscape of treatment options for ovarian cancer expands, but the urgency for effective therapies remains high. Eli Lilly's novel FRα ADC represents a significant advancement, and as they prepare for forthcoming trials, both the medical community and patients will be watching closely. This promising development could herald a new era of hope for women battling resistant forms of ovarian cancer, reaffirming Lilly’s commitment to pioneering transformative medicine.