Safety, Tolerability, and Pharmacokinetics of Mirvetuximab Soravtansine in Chinese Patients With Folate Receptor α‐Positive Advanced Ovarian Cancer

ABSTRACT Background Folate receptor α (FRα) is a glycosylphosphatidylinositol‐anchored protein that facilitates folate transport and has emerged as a promising therapeutic target for ovarian cancer, particularly due to its association with tumor progression. This Phase I study investigated the safety, tolerability, pharmacokinetics, and preliminary efficacy of mirvetuximab soravtansine (MIRV), an antibody‐drug conjugate targeting folate receptor α (FRα), in Chinese patients with FRα‐overexpressed platinum‐resistant ovarian cancer. Methods This study enrolled 19 Chinese patients with previously treated FRα‐overexpressed ovarian cancer in the dose escalation phase (5 mg/kg, n = 4; 6 mg/kg, n = 3) and dose expansion phase ( n = 12). MIRV was administered in escalating doses from 5 to 6 mg/kg (adjusted ideal body weight), following a 3 + 3 dose‐escalation design. The trial is registered with chinadrugtrials.org.cn (CTR20211876). Results Median treatment exposure were 9.9 weeks for the 5 mg/kg cohort ( n = 4) and 13.1 weeks for the 6 mg/kg cohort ( n = 15). The most common grade ≥ 3 adverse events were decreased platelet count (21.1%), decreased lymphocyte count (15.8%), and anemia (15.8%). The plasma concentration‐time and pharmacokinetic profiles of MIRV and the total antibody were generally comparable after the first and third doses. Pharmacokinetic analysis revealed a median time to maximum concentration ( T max ) of 3.33 h, mean terminal half‐life ( T 1/2 ) of 118 h, and geometric mean maximum concentration ( C max ) of 137.07 μg/mL. MIRV exposures were comparable to those reported in Caucasian patients. No anti‐drug antibodies were detected. Among 15 efficacy‐evaluable patients with high‐grade serous ovarian cancer, the objective response rate was 26.7%, with partial responses in four patients and stable disease in seven patients. Conclusions MIRV showed anticipated pharmacokinetics, safety, tolerability, and efficacy profiles in Chinese patients with FRα‐positive platinum‐resistant ovarian cancers, supporting its potential as a targeted therapeutic agent for this patient population. Trial Registration The trial is registered with chinadrugtrials.org.cn (CTR20211876)