Treatment with a combination of zidovudine and alpha-interferon in naive and pretreated adult T-cell leukemia/lymphoma patients.

Adult T-cell leukemia-lymphoma (ATL) is an aggressive malignancy of mature activated T cells, associated with human T-cell lymphotropic virus type I (HTLV-1) infection. ATL has a poor prognosis, due mainly to its resistance to conventional chemotherapy. Recent important advances in the treatment of ATL were obtained in two independent phase II studies with the combination of an antiretroviral agent (zidovudine; AZT) and alpha-interferon (IFN). In our study, 10 previously untreated patients (8 acute ATL, 1 smoldering ATL, and 1 ATL lymphoma) received this combination. Eight responses were obtained, with two complete remissions, four very good partial remissions (PR) with a 95% reduction of the tumor burden, and two 50% PR. Six patients relapsed, with a median event-free survival of 12 months (range, 3-15 months). Seven patients are still alive, with a median follow-up of 15 months (range, 6 to 28 months). Toxicity was mild in all patients and was mainly hematological. In conclusion, the combination of AZT and IFN exhibits a high response rate in ATL patients and seems to prolong survival. However, a randomized international study versus the best induction polychemotherapy is warranted. The success of this potentially antiretroviral approach in the treatment of ATL suggests the existence of a possible late effect of HTLV-I replication in vivo.