Non-aggressive therapy for chronic myeloid leukaemia in blastic transformation.

A total of 40 patients presenting with chronic myeloid leukaemia in blastic transformation were treated with a non-aggressive chemotherapy regimen consisting of vincristine, cytosine arabinoside and thioguanine. Remissions were achieved by 3/10 (30%) patients displaying lymphoid transformation (remission duration, 2, 3, and 5 months, respectively) and by 5/30 (17%) subjects exhibiting myeloid changes (duration 2+, 4, 4, 5 and 7 months, respectively). Myelosuppression was the major toxicity and non-haematological toxicities were mild and acceptable. The median survival of patients exhibiting lymphoid and myeloid blastic transformation as measured from the time of transformation was 6 and 3 months, respectively, but the difference was not statistically significant. Three subjects displaying lymphoid transformation and five showing myeloid changes survived for greater than 12 months after the time of transformation.