Purpose: To evaluate the safety and efficacy of liposomal doxorubicin (Myocet; Medeus Pharma Ltd, Herts,UK) when substituted for doxorubicin in the CHOP regimen (cyclophosphamide, doxorubicin, vincristine, prednisone) in patients with newly diagnosed AIDS-related non-Hodgkin's lymphoma (AIDS-NHL). Secondary objectives were to assess the impact of HIV viral control on response and survival, and to correlate MDR-1 expression with outcome.
Patients and methods: Liposomal doxorubicin at doses of 40, 50, 60, and 80 mg/m(2) was given with fixed doses of cyclophosphamide, vincristine, and prednisone every 21 days. All patients received concurrent highly active antiretroviral therapy. NHL tissues were evaluated for multidrug resistance (MDR-1) expression.
Results: Twenty-four patients were accrued. 67% had high or high-intermediate International Prognostic Index scores; the median CD4 lymphocyte count was 112/mm(3) (range, 19/mm(3) to 791/mm(3)). No dose-limiting toxicities were observed at any level, with myelosuppression being the most frequent toxicity. Overall response rate was 88%, with 75% complete responses (CRs), and 13% partial responses. The median duration of CR was 15.6+ months (range, 1.7 to 43.5+ months). Effective HIV viral control during chemotherapy was associated with significantly improved survival (P =.027), but CRs were attained independent of HIV viral control. MDR-1 expression did not correlate with response, suggesting that the liposomal doxorubicin may evade this resistance mechanism.
Conclusion: Liposomal doxorubicin in combination with cyclophosphamide, vincristine, and prednisone is active in AIDS-NHL, with complete remissions achieved in 75% independent of HIV viral control or tissue MDR-1 expression. HIV viral control is associated with a significant improvement in survival. Additional studies are warranted.