Bioenvision Inc announced that a phase II investigator sponsored trial of clofarabine as first line treatment in older adults with acute myeloid leukemia (AML) who are considered unfit for intensive chemotherapy will come to a premature end, due to results exceeding expectations, in order to accelerate enrollment in the pivotal study.

Bioenvision recently announced that nine out of 14 patients in the phase II study (64 per cent) have shown a complete response using clofarabine as a single agent. Based on these encouraging results, the study, which was originally anticipated to enroll a total of 37 patients, will now stop enrollment at 25 valuable patients. There are 21 patients enrolled to date. The study is expected to conclude in the next four weeks.

Lead investigator on the study, Professor Alan Burnett, M.D., chairman of the National Cancer Research Institute Hematological Oncology Study Group in the U.K., commented, "clofarabine has demonstrated promise as a new agent for the treatment of acute myeloid leukemia in this difficult subgroup of patients. Of all the new investigational compounds in clinical development, clofarabine represents a potentially important advance in this therapeutic area. The response rate seen in this phase II study has exceeded our expectations to the point that we have decided to accelerate enrollment in the pivotal study."

The open-label, non-randomized pivotal study is expected to enroll up to 65 patients age 65 or older with acute myeloid leukemia (AML) considered unsuitable for intensive chemotherapy. Each patient will receive at least one course of clofarabine.

Bioenvision's phase II study has been designed to meet Regulatory Authority requirements for marketing authorization approval for clofarabine as a first line treatment in older patients with AML who are considered unsuitable for intensive chemotherapy.