Phase I/II trial of nonpegylated liposomal doxorubicin, cyclophosphamide, vincristine, and prednisone in the treatment of newly diagnosed aggressive non-Hodgkin's lymphoma.

BACKGROUND: The toxicity and efficacy of nonpegylated liposomal doxorubicin (TLC D-99) when substituted for conventional doxorubicin in the CHOP (doxorubicin/cyclophosphamide/vincristine/prednisone) regimen were evaluated in the treatment of newly diagnosed patients with aggressive non-Hodgkin's lymphoma. Liposomal doxorubicin at doses of 40 mg/m2, 50 mg/m2, 60 mg/m2, and 80 mg/m2 was given with fixed doses of cyclophosphamide, vincristine, and prednisone. Chemotherapy cycles were repeated every 21 days. PATIENTS AND METHODS: Forty-seven patients with a median age of 55 years (range, 25-83 years) were studied. RESULTS: No dose-limiting toxicities were observed at any level. Reversible grade 3/4 neutropenia was the most common toxicity (95.8%). Most nonhematologic side effects were grade 1/2 in severity. Complete remissions were documented in 31 of 46 evaluable patients (67.4%) and partial remissions in 7 (15.2%), for an overall major response rate of 82.6%. The median duration of complete remission is > or = 27.7 months (range, 2.4 months to > or = 59.8 months). An exploratory objective was to correlate multidrug resistance-1 (MDR-1) expression with outcome. Immunohistochemistry for MDR-1-related p-glycoprotein was assessed in lymphoma tissues from 27 patients. Of the 27 lymphoma tissues studied, 8 (30%) were MDR-1 positive at diagnosis. The complete response rate was 63% in MDR-1-positive lymphomas and 74% in the MDR-1-negative cases (P = 0.66). CONCLUSION: Nonpegylated liposomal doxorubicin in combination with cyclophosphamide, vincristine, and prednisone is an active regimen for patients with newly diagnosed, aggressive non-Hodgkin's lymphoma. The regimen is relatively well tolerated, with hematologic suppression as the major toxicity. Liposomal encapsulation might evade resistance caused by MDR-1 expression.

Multidrug resistance (MDR-1) expression in AIDS-related lymphomas.

P-glycoprotein is a product of the multidrug resistance (MDR-1) gene. In non-Hodgkin's lymphoma, less than 20% of untreated de novo lymphomas express MDR-1 compared with approximately 50% after failure of chemotherapy. We wished to study the expression of MDR-1 in AIDS-related non-Hodgkin's lymphoma (AIDS-NHL). Tissue biopsies from 50 patients with newly diagnosed AIDS-NHL were studied by immunohistochemical analysis using C494, a monoclonal antibody specific for the MDR-1 isoform of P-gp. MDR-1 expression was correlated with patient demographics, lymphoma characteristics, response to chemotherapy, and survival. Forty-six males and four females with a median age of 38 years (range 26-63) were studied. A prior AIDS-defining opportunistic infection was reported in 35 patients (70%). The median CD4+ lymphocyte count was 69/mm(3) (range 0-920). Thirty-two patients (63%) had received prior anti-HIV therapy, including a protease inhibitor in five (10%). Pathologic types consisted of diffuse large cell in 13 (26%), immunoblastic in 13 (26%), small non-cleaved in 22 (44%), and high grade not otherwise specified in two (4%). The majority of patients (76%) had stage III/IV disease. Pre-treatment lymphoma tissues from 33 patients (66%) stained positively for MDR-1. MDR-1 positive patients had a significantly lower complete remission rate compared to MDR-1 negative patients (33 versus 65%, P=0.042). Duration of complete response was significantly longer in MDR-1 negative patients compared with MDR-1 positive patients (not reached versus 9.9 months, P=0.003). Strategies to overcome MDR-1 expression may be important for initial treatment in patients with AIDS-NHL.