A phase II trial evaluating the clinical and immunologic response of HLA-A2(+) non-small cell lung cancer patients vaccinated with an hTERT cryptic peptide.

OBJECTIVES

The immunological and clinical responses of patients with NSCLC treated, in the context of an expanded action program, with the cryptic hTERT-targeting Vx-001 vaccine are presented.

MATERIALS AND METHODS

Forty-six HLA-A0201-positive patients with advanced NSCLC and residual (n=27) or progressive (n=19) disease following front-line treatment received two subcutaneous injections of the optimized TERT572Y peptide followed by four injections of the native TERT572 peptide, every 3 weeks. Peptide-specific immune responses were monitored by enzyme-linked immunosorbent spot assay at baseline, and after the 2nd and the 6th vaccinations. Thirty-eight HLA-A0201-positive matched patients were used as historical controls.

RESULTS

Twenty-three patients (50%) completed the vaccination protocol and 87% received at least two administrations. Twelve patients (26%) without disease progression after the 6th vaccination received boost vaccinations. Three (7%) patients achieved a partial response and 13 (28%) disease stabilization. The disease control rate was significantly higher in patients with non-squamous histology compared to those with squamous-cell histology [n=14 (45%) versus n=2 (13%); p=0.03]. The median progression-free survival (PFS) and overall survival (OS) was 3.8 (range, 0.7-99.4) and 19.8 months (range, 0.7-99.4), respectively. Patients who developed immune response had a numerically higher PFS compared to those who failed to mount any (6.7 versus 2.7 months; p=0.090). However, the median OS for the immune-responders was significantly prolonged compared to non-responders (40.0 versus 9.2 months, respectively; p=0.02). Toxicity was <grade 2.

CONCLUSION

Vx-001 vaccine is well tolerated and induced a TERT-specific immunological response, which was significantly correlated with improved clinical outcome.