Pseudomonas vaccine: A phase I evaluation for cancer research

A heptavalent lipopolysaccharide vaccine of Pseudomonas aeruginosa (Pseudogen) was administered at four dose levels (0.1, 0.25, 0.5, and 0.75 mg/m²) to patients with advanced metastatic cancer that had proved refractory to chemotherapy. The vaccine was administered subcutaneously twice weekly. Local toxicity was seen in erythema, edema, pain and tenderness at the site of injection, and painful regional lymphadenopathy; manifestations of systemic toxicity included fever, chills, myalgias, nausea, and vomiting. Toxicity showed a clear-cut dose dependence. The maximally tolerated dose by this route and schedule was 0.5 mg/m². A significant rise of antibody titers was observed at all four dose levels. Evaluation of the delayed cutaneous hypersensitivity response to recall antigens and to the pseudomonas vaccine, and quantification of peripheral blood T and B cell levels and of in vitro lymphocyte blastogenic responses to commonly used mitogens and pseudomonas vaccine failed to demonstrate significant change from pretreatment values. Clinical trials to evaluate the therapeutic efficacy of pseudomonas vaccine with or without chemotherapy can be undertaken safely with this route and schedule.