Purpose: We report two clinical trials in non-small cell lung cancer (NSCLC) patients evaluating immune response, toxicity, and clinical outcome after vaccination with the telomerase peptide GV1001: a phase II trial (CTN-2006) in patients vaccinated after chemoradiotherapy and an 8-year update on a previously reported phase I/II trial (CTN-2000).
Experimental design: CTN-2006: 23 inoperable stage III patients received radiotherapy (2 Gy × 30) and weekly docetaxel (20 mg/m(2)), followed by GV1001 vaccination. CTN-2000: 26 patients were vaccinated with two telomerase peptides (GV1001 and I540). The immune responses were evaluated by T-cell proliferation and cytokine assays.
Results: CTN-2006 trial: a GV1001-specific immune response developed in 16/20 evaluable patients. Long-term immunomonitoring showed persisting responses in 13 subjects. Serious adverse events were not observed. Immune responders recorded a median PFS of 371 days, compared with 182 days for nonresponders (P = 0.20). CTN-2000 trial update: 13/24 evaluable subjects developed a GV1001 response. The immune responders achieved increased survival compared with nonresponders (median 19 months vs. 3.5 months; P < 0.001). Follow-up of four long-time survivors showed that they all harbored durable GV1001-specific T-cell memory responses and IFNγ(high)/IL-10(low)/IL-4(low) cytokine profiles. Two patients are free of disease after 108 and 93 months, respectively.
Conclusions: Vaccination with GV1001 is well tolerated, immunizes the majority of NSCLC patients and establishes durable T-cell memory. The considerable immune response rate and low toxicity in the phase II trial support the concept of combining chemoradiotherapy with vaccination. The survival advantage observed for immune responders warrants a randomized trial.