Interim results of a phase II multicenter clinical trial evaluating the activity of a therapeutic allogeneic melanoma vaccine (theraccine) in the treatment of disseminated malignant melanoma.

A total of 139 patients with disseminated malignant melanoma were enrolled in an uncontrolled Phase II trial evaluating the activity of Melacine, allogeneic vaccine incorporating Detox, immunologic adjuvant. Nineteen patients, including 18 with progressive disease, dropped out of the study prior to receiving one full vaccination course of five injections over 6 weeks. Disease presentation among study participants included skin or lymph nodes (34%), pulmonary (24%), visceral (34%), and no evidence of disease (NED) (7%). One documented metastatic site was seen in 41%, two sites in 24%, and three or more sites in 27% of the patients studied. Objective clinical response rates for evaluable patients were CR 3%, PR 5%, minor response 4%, stable 23%, and progressive disease 65%. Median survival from time of diagnosis for patients treated with Melacine is presently estimated at 23 months (45/139 patients censored). Median date from diagnosis of metastatic disease to study entry was 3 months. Side effects were generally mild to moderate with pain at injection site (37%), granulomas (13%), erythema (6%), and flu-like symptoms (14-29%) predominating. Precursor antimelanoma cytotoxic T cell (pre-CTL) titers, in comparison with prestudy evaluations, clearly increased in 42% of the patients evaluated. Significantly extended survival characteristics were observed among patients who displayed an expansion of a population of CD57, CD8 co-positive lymphocytes during therapy in comparison with those patients not displaying this peripheral blood lymphocyte (PBL) population expansion (34 mo vs. 12 mo, respectively, p = 0.04) and among those patients displaying disease stabilization or better as a clinical response (p = 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)