Phase III trial of recombinant interferon gamma in complete responders with small-cell lung cancer.

Abstract

We evaluated the effect of recombinant interferon gamma (rIFN-gamma) on survival and toxicity in small-cell lung cancer (SCLC) patients in complete remission (CR). One hundred patients in CR following treatment with six cycles of combination chemotherapy, thoracic radiotherapy (TRT), and prophylactic cranial irradiation (PCI) were studied. All patients had been enrolled onto a cooperative group trial (North Central Cancer Treatment Group [NCCTG] 86-20-51). Patients received observation only or rIFN-gamma at a dose of 4 x 10(6) U subcutaneously per day for 6 months. Six patients (12%) did not comply with rIFN-gamma treatment. Substantial nonhematologic toxicities consisting of chills, myalgia, lethargy, and alteration of mood-personality were observed. No patient experienced life-threatening or fatal toxicity. The median times to progression for rIFN-gamma treatment or observation were 6.9 and 8.1 months (P = .54). The median survival times were 13.3 and 18.8 months, respectively (P = .43). Approximately 70% of all patients relapsed within 2 years. Time to progression and survival were inferior in patients treated with rIFN-gamma compared with randomized control subjects, although this difference was not statistically significant. These data indicate that rIFN-gamma treatment is not associated with a 33% improvement in survival (P = .04). Because of the high rate of relapse, SCLC patients in CR are an ideal group in which to evaluate novel and minimally toxic agents.