A phase II trial of irinotecan in patients with advanced or recurrent endometrial cancer and correlation with biomarker analysis.

Objective: Chemotherapy for advanced or recurrent endometrial cancer requires further development. Irinotecan hydrochloride (CPT-11) suppresses tumor growth in several endometrial cancer strains. The present study evaluated the anti-tumor activity and toxicity of CPT-11 in patients with advanced or recurrent endometrial cancer.

Methods: Enrolled patients had advanced endometrial cancer with measurable lesions and received 2 pretreatment regimens. A 90-minute intravenous infusion of CPT-11 (100 mg/m) was given on days 1, 8, and 15 of a 4-week cycle, aiming for an effect with ≤2 cycles. Treatment was continued until the primary disease worsened or severe toxicity occurred. The primary endpoint was response rate, and the secondary endpoints were progression-free survival, overall survival, and adverse events. Antitumor effect and adverse events were evaluated according to RECIST version 1.1 and NCI-CTC AE version 3.0, respectively.

Results: Twenty-two patients were registered (11 endometrioid carcinomas and 11 serous carcinomas). The median duration of the treatment-free interval (TFI) was 7.5 months, and the median number of administered cycles per patient was 4. Response rate was 36.4% (complete response: 1 patient, partial response: 7 patients). Clinical benefit rate, including stable disease, was 77.3%. Median progression-free and overall survival was 4.4 and 18.4 months, respectively. Observed adverse events included grade 4 hematotoxicity (neutropenia and thrombocytopenia), and grade 2 or 3 non-hematotoxicity (diarrhea). All adverse events were manageable. Biomarker predictors of therapeutic effectiveness were not observed.

Conclusion: As a single agent, CPT-11 has anti-tumor activity for advanced or recurrent endometrial cancer and has manageable adverse events.