A phase II trial of carbetimer for the treatment of colorectal cancer. A trial of the Northern California Oncology Group.

Carbetimer (carboxyimamidate) was administered at a dose of 6,500 mg/m2/day intravenously for 5 consecutive days to 14 patients with measurable metastatic or recurrent colorectal cancer in a single institution phase II study of the Northern California Oncology Group. A total of 38 cycles of therapy were administered; nine patients completed at least three cycles of treatment. No partial or complete responses were observed. One patient did have a greater than 50% response in the liver while developing new retroperitoneal lymphadenopathy and is considered a nonresponder. Carbetimer was well tolerated with elevations of calcium from 10.2 to 12.5 mg/dl in nine patients, prolongation of prothrombin time and partial thromboplastin time in 14 patients, proteinuria in 10 patients, dizziness in six patients, nausea in two patients, and venous pain during infusion in three patients. Myelosuppression was not observed. Carbetimer at this dose and schedule is inactive in the treatment of colorectal cancer.