A phase I/II dose finding study evaluating the safety and tolerability of capecitabine and aflibercept in patients with unresectable metastatic colorectal cancer deemed unsuitable for doublet/triplet chemotherapy: results of the phase I study

MOMENTUM: A Phase I Trial Investigating 2 Schedules of Capecitabine With Aflibercept in Patients With Gastrointestinal and Breast Cancer

BACKGROUND

Although data from preclinical and clinical studies provide a strong rationale for combining capecitabine with anti-angiogenic agents, clinical development of this fluoropyrimidine in combination with aflibercept has lagged behind other treatments. We conducted a nonrandomized, noncomparative, 2-arm, phase I trial to address this unmet need.

PATIENTS AND METHODS

Patients with chemorefractory gastrointestinal and breast cancer were sequentially recruited into a continuous (Arm A, starting dose 1100 mg/m²/day) or intermittent (Arm B, 2 weeks on/1 week off, starting dose 1700 mg/m²/day) capecitabine dosing arm. Aflibercept was administered at a flat dose of 6 mg/kg every 3 weeks in both arms. A classical 3 + 3, dose-escalation design was used. The primary objective was to establish the maximum tolerated dose, dose-limiting toxicities (DLTs), and recommended dose for phase II trials.

RESULTS

Thirty-eight eligible patients were recruited of whom 33 were assessable for DLTs (15 in arm A and 18 in arm B). Fourteen had colorectal cancer, 8 gastric cancer, and 11 breast cancer. DLTs included grade 2 hand-foot syndrome, grade 2 anorexia considered unacceptable by the patient, and grade 3 hypertension. The recommended dose for phase II trials for capecitabine was established at 1300 mg/m²/day in Arm A and 2500 mg/m²/day in Arm B with treatment-related grade ≥ 3 adverse events occurring in 47% and 50% of patients, respectively. Among 26 assessable patients, the objective response rate was 15.4% in Arm A and 7.7% in Arm B.

CONCLUSION

Combining capecitabine with aflibercept is feasible and associated with a manageable safety profile and some anti-tumor activity in patients with chemorefractory gastrointestinal and breast cancer.