Treatment of resistant/relapsing chronic lymphocytic leukemia with a combination regimen containing deoxycoformycin and rituximab.

BACKGROUND: Patients with chronic lymphocytic leukemia (CLL) are sometimes resistant to treatment or relapse soon after the administration of the currently available frontline therapy including chlorambucil-prednisolone CHOP and fludarabine. We report the beneficial effect of an alternative chemotherapeutic regimen containing 2'-deoxycoformycin (pentostatin) and the monoclonal antibody anti-CD20 (rituximab) in 5 patients with resistant/relapsing CLL. PATIENTS: Five patients (4 men and 1 woman) with CLL at stage C, according to Binet's classification, were included in the therapeutic protocol. The median age of the patients was 76 years (range 57-84 years). Previous treatment consisted of chlorambucil-prednisolone, fludarabine, and CHOP. The current regimen comprised six 2-week cycles of pentostatin, 4 mg/m(2) i.v., combined with four cycles of rituximab, in a dose of 375 mg/m(2), every other week. RESULTS: Three patients responded to therapy, 2 achieved complete remission and 1 a partial response. Two patients did not respond to treatment. Toxicity was mild and well tolerated. The median survival duration of the responders was 19 months. These promising results suggest that salvage therapy with a combination regimen including pentostatin and rituximab may have a beneficial effect in patients with resistant/relapsing CLL.