Continuous-infusion cyclophosphamide plus vincristine, cytosine-arabinoside and prednisone for refractory acute lymphoblastic leukemia in adults.

BACKGROUND

Despite more aggressive salvage regimens, the prognosis of refractory acute lymphoblastic leukemia (ALL) is still poor. Hence, alternative approaches are warranted in heavily pretreated patients. Some studies suggest the enhancement of cyclophosphamide (CY) activity when given by continuous infusion.

METHODS

To evaluate the effectiveness of this scheduling in refractory ALL, we treated 15 adult patients (4 primary resistant, 11 relapsed and refractory to salvage regimens) with a seven-day course of CY 350 mg/m2/day by continuous i.v. infusion, associated with vincristine, cytosine-arabinoside and prednisone.

RESULTS

The median time for hematologic recovery was 18 days, with negligible extramedullary toxicity. Two patients died while aplastic, 3 were non responders, 10 (66%) achieved complete remission after the first cycle. The response duration ranged from 5 to 32 (median 14) weeks, and the median survival of responders was 23 weeks. It is noteworthy that half of the responding patients had been resistant to prior CY in different schedules and other drug combinations.

CONCLUSIONS

These data seem to confirm that CY exerts its best antineoplastic activity by continuous infusion.