Perspectives in active specific immunotherapy with autologous immature dendritic cells combined with photodynamic therapy and cyclophosphamide in patients with disseminated melanoma resistant to standard therapy

Abstract

There are described the results of clinical and immunological efficacy assessment of active specific immunotherapy with autologous immature dendritic cells (DC) combined with photodynamic therapy (PDT) and cyclophosphamide (C) in disseminated melanoma patients, resistant to standard therapy. 27 patients treated in the N.N. Petrov Research Institute of Oncology were included in the study from 2007 till 2016. Immunotherapy was conducted in a 21-day cycles. Therapy included following steps: 1) preparation of individual vaccine preparation from bone-marrow derived DC with immune phenotype CD34-/CD14-/CDla+/CD83-/CD80-/+/CD861/+/HLA-DR+; 2) Intramuscular 300 mg C injection in day 1 of treatment cycle for elimination T-lymphocytes with immunosuppressing activity; 3) PDT with chlorin salts at day 4 six hours before start of vaccinotherapy; 4) Daily intralesional injections of DC vatccine in irradiated lesions in the dose 1×106 DC cells/kg. Clinical and immunological efficacy was assessed in 27 patients. Fourteen (52%) patients received 1-2 cycles of therapy, 13(48%) received 3 or more cycles. No complete response was seen. Partial response (RECIST 1.1) was found in 2 (7,4%) patients, stable disease in 8 (29,6%) patients. Seventeen (63%) patients progressed. Median time to progression (TTP) was 2.5 month, median overall survival (OS) 8.4 month. One-year survival was 5% and 37% for TTP and OS, respectively. No adverse events (AE) of grade 4-5 (CTC AE v4) were seen. Grade 3 fever was registered in 4% of patients. Grade 1-2 AE were found in 54% of patients. Immunologic assessment revealed significant decline of immunoregulatory index (CD/CD8) caused by prevalence of cytotoxic T-lymphocytes in peripheral blood of responding patients (patients with clinical benefit). Tendency for elevation of absolute number of activates T-helpers and cytotoxic T-lymphocytes together with low T-regulatory cells concentration was also found. Combination therapy using immunomodulatory effects of C, PDT and DC vaccine in 21-day treatment cycles produce promising activity and favorable toxicity profile in heavily pretreated disseminated melanoma patients.