Clofarabine: new drug. Children with acute lymphoblastic leukaemia: a last resort.

(1) Standard treatments fail in about 20% of children with acute lymphoblastic leukaemia. About half these children die within 10 weeks. (2) Clofarabine, a cytotoxic drug chemically related to fludarabine, is now marketed for use in this setting. (3) The decision to grant marketing authorization was based mainly on the results of a non comparative trial including 61 patients aged from 1 year to 20 years who had few if any other therapeutic options. The median survival time was 13 weeks overall, but about 70 weeks in the subgroup of children who had a full haematological response (20% of the study population). About half these latter patients were able to undergo potentially curative haematopoietic stem-cell transplantation. (4) Preliminary results from another non comparative trial suggest similar efficacy. (5) Short-term adverse effects are frequent and often serious, and include gastrointestinal disorders, infections, tumour lysis syndrome, and cardiac, renal and hepatobiliary disorders. The latter effects had also occurred in animal studies. (6) These results warrant further studies, especially to identify those children most likely to benefit from clofarabine. In the meantime, this last-chance treatment can sometimes create the conditions for potentially curative therapy.