Phase II study of fazarabine in advanced head and neck cancer
Fazarabine is an analog of the antitumor nucleosides cytosine arabinoside and 5-azacytidine. In the cell, the drug is metabolized to the nucleotide level by deoxycytidine kinase, is incorporated into DNA, and inhibits DNA synthesis and methylation [1-3] . Fazarabine has demonstrated antitumor activity against a wider variety of human tumor xenografts than cytosine arabinoside [4]. In leukemia models, direct comparison revealed that the therapeutic margin of safety for fazarabine was double that for cytosine arabinoside [5]. This phase II trial was designed to study the response and toxicity of fazarabine in advanced head and neck cancer.