Phase II Study of Biweekly Pemetrexed Plus Irinotecan as Second-Line Therapy for Metastatic Colorectal Cancer

Abstract EN

Background.

This open-label, single-arm, two-stage, Phase II study investigated the efficacy and safety of bi-weekly pemetrexed combined with irinotecan, in patients with metastatic colorectal cancer (mCRC), after first-line chemotherapy using FOLFOX regimen.

Patients and methods.

Patients received pemetrexed 400 mg/m² as a 10-minute intravenous infusion (with vitamin supplementation) followed by irinotecan 180 mg/m² as a 90-minute infusion on day 1 of a 14-day cycle, for a maximum of 12 cycles.

The primary endpoint was response rate (RR; H0≤ 5%, Ha≥ 20%, α=0.05, power = 90%).

Secondary endpoints were duration of response, progression-free survival (PFS), overall survival (OS), and toxicities.

Results.

Partial response was observed in six out of 44 patients enrolled in the study (RR = 13.6%).

The median PFS and OS were 4.0 and 13.9 months, respectively.

The most common grade 3-4 toxicities were fatigue: 20.5% of patients, neutropenia: 18.6%, diarrhea: 13.6%, elevated transaminases: 9.5%, anemia: 9.3%, and vomiting: 6.8%.

Conclusion.

Pemetrexed plus irinotecan administered every two weeks is an active and well-tolerated regimen in mCRC patients pretreated with FOLFOX regimen.

However, this regimen does not seem to provide clinically relevant advantage over historical data of a classical FOLFIRI regimen.