A natural cytokine mixture (IRX-2) and interference with immune suppression induce immune mobilization and regression of head and neck cancer.

Prior studies indicate that combination immunotherapy of squamous cell cancer (SCC) of head and neck (H&N) with cytokines is feasible (Hadden et al., 1994). To induce immune regression of H&N SCC 20 stage II-IV patients received 3 weeks prior to surgery low dose cyclophosphamide (300 mg/M2), then 10 daily perilymphatic injections of a natural cytokine mixture (IRX-2)(150 units of IL-2 equivalence) and daily oral indomethacin and zinc. Tumor responses, T-lymphocyte and subset counts, and toxicity were monitored. Six patients had major clinical responses (both complete [CR] and partial [PR]) without major toxicity. Five of 20 patients were lymphocytopenic (1242 +/- 88 mm3) prior to treatment and the immunotherapy induced marked significant increases in total lymphocyte counts, CD3+ T-cells, and both CD4+ and CD8+ T-cells as well as a population of CD3+, CD4-, and CD8- lymphocytes. The post treatment specimen of 18/20 patients showed histologically tumor fragmentation, overall reduction and diffuse infiltration with lymphocytes and plasma cells. Histologic tumor reductions in these patients averaged 44% and the lymphoid infiltration increased 4.7 fold from 9-42%. The immune infiltration of the tumor reflects varying degrees of both T- and B-cells and indicates immunization to the tumor. The immunization achieved may improve clinical control of H&N SCC by improving the possibility that surgical resection of advanced loco-regional disease will leave no viable tumor.