To evaluate the safety, immune responses, and antitumor responses after the administration of alpha-galactosylceramide (alphaGalCer) KRN7000-pulsed PBMC cultured with IL-2 and GM-CSF (IL-2/GM-CSF-cultured PBMCs), a phase I-II study in patients with non-small cell lung cancer was conducted. Patients with advanced non-small cell lung cancer or recurrent lung cancer refractory to the standard therapy were eligible. alphaGalCer-pulsed IL-2/GM-CSF-cultured PBMCs (1 x 10(9)/m(2)) were i.v. administered four times. Immune responses were monitored weekly. Twenty-three patients were enrolled in this study and 17 cases (73.9%) completed. No severe adverse event related to the treatment was observed. After the injection of alphaGalCer-pulsed IL-2/GM-CSF-cultured PBMCs, an increased number of IFN-gamma-producing cells in the peripheral blood were detected in 10 patients (58.8%). Five cases remained as stable disease, and the remaining 12 cases were evaluated as progressive disease. The estimated median survival time (MST) of the 17 cases was 18.6 mo (range, 3.8 to 36.3 mo). Ten patients who displayed increased IFN-gamma-producing cells (> or =2-fold) showed prolonged MST (31.9 mo; range, 14.5 to 36.3 mo) as compared with poor-responder patients (n = 7) MST (9.7 mo; range, 3.8 to 25.0 mo) (log-rank test, p = 0.0015). The administration of alphaGalCer-pulsed IL-2/GM-CSF-cultured PBMCs was well tolerated and was accompanied by the successful induction of NKT cell-dependent immune responses. The increased IFN-gamma-producing cells that result from alphaGalCer stimulation in PBMCs were significantly associated with prolonged MST. These results are encouraging and warrant further evaluation for survival benefit of this immunotherapy.