QLS5132, a CLDN6-Targeting ADC from Qilu Pharmaceutical, Demonstrates Promising Efficacy and Safety in Platinum-Resistant Ovarian Cancer at AACR 2026

On April 21, Qilu Pharmaceutical announced that the latest clinical research data of its innovative drug QLS5132 had been presented in an oral report at the 2026 American Association for Cancer Research (AACR) Annual Meeting.

As of January 21, 2026, this clinical study enrolled a total of 28 patients with advanced platinum-resistant ovarian cancer, including 26 cases of ovarian cancer and 2 cases of fallopian tube cancer, of which 23 patients had an ECOG performance status score of 1.

Efficacy data showed an objective response rate (ORR) of 50.0% and a disease control rate (DCR) of 94.4%, with 9 patients achieving partial response (PR). Notably, at the 4.8 mg/kg dose level, anti-tumor activity was more prominent, with ORR and DCR reaching 55.6% and 100%, respectively. Importantly, among the 9 patients who achieved PR, 5 maintained their responses for over 3 months, and in the 3.2 mg/kg dose group, all PR patients sustained their efficacy for more than 6 months. Additionally, PR was observed in 2 patients without detectable CLDN6 expression, offering potential directions for exploring the drug's application in broader populations.

In terms of safety, one case of dose-limiting toxicity (DLT) was reported in the 6.4mg/kg dose group; at the potential recommended Phase II doses (4.8mg/kg, 5.6mg/kg), the most common treatment-related adverse events were gastrointestinal and hematological toxicities, with an incidence rate ≥30%, mainly Grade 1/2, and no Grade 4/5 events occurred. No interstitial lung disease, ocular toxicity, or febrile neutropenia was reported, and no treatment-related adverse events led to treatment discontinuation or death.

QLS5132 for Injection is an antibody-drug conjugate (ADC) targeting CLDN6, combining the potent cytotoxic effects of traditional small-molecule drugs with the precise targeting of antibody drugs. At the 2025 AACR Annual Meeting, preclinical data of QLS5132 were presented in a poster, showing that QLS5132 significantly inhibited tumor growth.

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