Phase II trial of fazarabine (ARA-AC, arabinosyl-5-azacytosine) in metastatic breast cancer.

Fourteen consecutive female patients with metastatic breast cancer received a total of 31 courses of fazarabine at a dose of 2 mg/m2/hour x 72 hours (48 mg/m2/day x 3) as a continuous infusion. There were no responses seen, although one patient achieved stability of her disease for five courses. Because of encouraging in vitro results and the primarily hematologic dose-limiting toxicity, further study in combination with colony stimulating growth factors might be of interest.