BackgroundTherapeutic cancer vaccines represent a promising approach to improve clinical outcomes with immune checkpoint inhibition. UV1 is a second generation telomerase-targeting therapeutic cancer vaccine being investigated across multiple indications. Although telomerase is a near-universal tumor target, different treatment combinations applied across indications may affect the induced immune response. Three phase I/IIa clinical trials covering malignant melanoma, non-small cell lung cancer, and prostate cancer have been completed, with patients in follow-up for up to 8 years.Methods52 patients were enrolled across the three trials. UV1 was given as monotherapy in the lung cancer trial and concurrent with combined androgen blockade in the prostate cancer trial. In the melanoma study, patients initiated ipilimumab treatment 1 week after the first vaccine dose. Patients were followed for UV1-specific immune responses at frequent intervals during vaccination, and every 6 months for up to 8 years in a follow-up period. Phenotypic and functional characterizations were performed on patient-derived vaccine-specific T cell responses.ResultsIn total, 78.4% of treated patients mounted a measurable vaccine-induced T cell response in blood. The immune responses in the malignant melanoma trial, where UV1 was combined with ipilimumab, occurred more rapidly and frequently than in the lung and prostate cancer trials. In several patients, immune responses peaked years after their last vaccination. An in-depth characterization of the immune responses revealed polyfunctional CD4+ T cells producing interferon-γ and tumor necrosis factor-α on interaction with their antigen.ConclusionLong-term immunomonitoring of patients showed highly dynamic and persistent telomerase peptide-specific immune responses lasting up to 7.5 years after the initial vaccination, suggesting a plausible functional role of these T cells in long-term survivors. The superior immune response kinetics observed in the melanoma study substantiate the rationale for future combinatorial treatment strategies with UV1 vaccination and checkpoint inhibition for rapid and frequent induction of anti-telomerase immune responses in patients with cancer.

Summary New therapies, including the anti‐cytotoxic T lymphocyte antigen (CTLA)‐4 antibody, ipilimumab, is approved for metastatic melanoma. Prognostic biomarkers need to be identified, because the treatment has serious side effects. Serum samples were obtained before and during treatment from 56 patients with metastatic or unresectable malignant melanoma, receiving treatment with ipilimumab in a national Phase IV study (NCT0268196). Expression of a panel of 17 inflammatory‐related markers reflecting different pathways including extracellular matrix remodeling and fibrosis, vascular inflammation and monocyte/macrophage activation were measured at baseline and the second and/or third course of treatment with ipilimumab. Six candidate proteins [endostatin, osteoprotegerin (OPG), C‐reactive protein (CRP), pulmonary and activation‐regulated chemokine (PARC), growth differentiation factor 15 (GDF15) and galectin‐3 binding‐protein (Gal3BP)] were persistently higher in non‐survivors. In particular, high Gal3BP and endostatin levels were also independently associated with poor 2‐year survival after adjusting for lactate dehydrogenase, M‐stage and number of organs affected. A 1 standard deviation increase in endostatin gave 1·74 times [95% confidence interval (CI) = 1·10–2·78, P = 0·019] and for Gal3BP 1·52 times (95% CI = 1·01–2·29, P = 0·047) higher risk of death in the adjusted model. Endostatin and Gal3BP may represent prognostic biomarkers for patients on ipilimumab treatment in metastatic melanoma and should be further evaluated. Owing to the non‐placebo design, we could only relate our findings to prognosis during ipilimumab treatment.