Clinical trial of safety and antitumor activity of farletuzumab ecteribulin in patients with platinum-resistant ovarian cancer: Phase I expansion results.

objectiveIn the dose-escalation part of Study 101, which included multiple tumor types, objective responses were observed in 10 of 22 patients across multiple dose levels of farletuzumab ecteribulin (FZEC). We explored the safety/antitumor activity of FZEC in patients with platinum-resistant ovarian cancer (PROC) from the Study 101 expansion part.

methodsEligible patients were aged ≥20 years and received FZEC 0.9 or 1.2 mg/kg intravenously Q3W. Safety, objective response rate (ORR), duration of response (DOR), progression-free survival (PFS), and overall survival (OS) were evaluated. Tumor assessments were performed by investigators per Response Evaluation Criteria in Solid Tumors version 1.1, and folate receptor-alpha (FRα) status of tumor samples was assessed by central immunohistochemistry.

resultsA total of 45 patients from Japan were treated. Among these patients, 24 were treated with FZEC 0.9 mg/kg and 21 with 1.2 mg/kg; 70.8% and 85.7% had FRα expression in ≥75% of neoplastic cells, respectively. Grade (Gr) ≥3 treatment-emergent adverse events were observed in nine patients (37.5%) in the 0.9 mg/kg group and in six (28.6%) in the 1.2 mg/kg group. Interstitial lung disease (ILD)/pneumonitis occurred in 37.5% (Gr ≥3: 0%) of the 0.9 mg/kg group and 66.7% (Gr ≥3: 4.8%) of the 1.2 mg/kg group. In the 0.9 and 1.2 mg/kg groups, ORR was 25.0 and 52.4%, median (m)DOR was 10.6 and 7.6 months, mPFS was 6.7 and 8.2 months, and mOS was 10.5 and 20.5 months, respectively.

conclusionFZEC showed promising antitumor activity, and the observed adverse events were generally manageable, with the exception of ILD, in patients with PROC. CLINICALTRIALS: GOV REGISTRATION: NCT03386942. URL: https://clinicaltrials.gov/study/NCT03386942.