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

a b s t r a c t 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-A*0201-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-A*0201-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,