Immunotherapy of cancer with "immune" RNA. A preliminary report

A phase I clinical trial of immunotherapy with "Immune" RNA was undertaken fifteen months ago. Twenty-six cancer patients were treated with RNA extracted from the lymphoid organs of sheep immunized with either autologous tumor cells or allogeneic tumor cells of the same histologic type. Eighteen patients had gross disease and eight had minimum residual disease. RNA was administered weekly, intradermally, at doses up to 9 mg/week without any significant local or systemic toxicity. Four patients improved, thirteen achieved stability of disease or possible improvement, seven were treatment failures, and two are indeterminate. Lymphocyte-mediated cytotoxicity to allogeneic tumor target cells of the same histologic type were monitored in eleven patients. In seven patients, cytotoxicity increased after "Immune" RNA therapy; no change was observed in three patients; a decrease was noted in one patient. There appeared to be a possible correlation between cytotoxicity assessed in vitro and clinical response. There is some evidence that these responses may be specific for the particular tumor used to immunize the RNA donor.