Comparison of in vitro and in vivo effects of vincristine and vindesine on leukemic cells from patients with chronic granulocytic leukemia in blast crisis.

We employed a liquid culture system to examine the in vitro effects of vincristine and vindesine on cellular incorporation of 35SO4 into leukemic cells obtained from 5 patients with chronic granulocytic leukemia in blast crisis. The per cent of 35SO4 into drug-treated as compared to saline-treated leukemic cells was compared to the clinical outcome of patients treated with these agents. A good or partial clinical response to vincristine or vindesine was seen in patients whose leukemic cells incorporated less than 50% 35SO4 when exposed to vincristine or vindesine in vitro, compared with control saline-treated cells. No clinical response was observed following treatment with vincristine or vindesine if the 35SO4 incorporation of drug treated leukemic cells was greater than 50% of saline-treated cells. These data suggest that the in vitro effects of vincristine or vindesine on 35SO4 incorporation into leukemic cells of patients in blast crisis may parallel the clinical outcome of patients treated with these agents in vivo.