Phase I evaluation of recombinant tumor necrosis factor given in combination with recombinant interferon-gamma.

In light of in vitro and preclinical animal model data suggesting potential additive or synergistic antitumor effects from the combined use of interferon-gamma (IFN-gamma) and tumor necrosis factor-alpha (TNF-alpha), we conducted a phase I study employing escalating doses of each agent in 36 patients with solid tumors to determine the maximum tolerated dose (MTD). Patients were given an intramuscular (i.m.) injection of IFN-gamma, followed 5 min later by an i.m. injection of TNF-alpha, each agent in different sites, every other day for ten doses over 20 days. Patients received 10, 50, or 100 micrograms/m2 of each agent throughout the treatment course. No dose modifications were made. Patients suffering serious toxicity had therapy stopped and were considered to be off-study. All patients experienced fatigue, and 36% spent over half their time in bed on treatment days. Fever and chills were nearly universal. Mild to moderate elevations in serum transaminase levels were noted in 44% of patients, and 44% developed transient microscopic hematuria. Although 81% of patients had anorexia, only 17% of patients lost more than 3 kg of body wt during the 3 weeks of therapy. Because two of three patients receiving 100 micrograms/m2 of both agents developed serious toxicity (one fever greater than 105 degrees F, one thrombocytopenia 43,000/mm3), the MTD was established to be 100 micrograms/m2 of IFN-gamma plus 50 micrograms/m2 of TNF-alpha. The use of aspirin did not significantly alter the toxic effects of the agents. One patient with melanoma had a mixed response and one patient with mesothelioma transiently cleared his ascites of malignant cells.