Phase 1 trial of CV301 in combination with anti‐PD‐1 therapy in nonsquamous non‐small cell lung cancer

CV301, a poxviral‐based vaccine, has been evaluated in a phase 1 clinical trial (NCT02840994) and shown to be safe and immunologically active (phase 1a). Preclinical data support a combination of CV301 with programmed death‐1 inhibitors, which has been evaluated in the phase 1b part of this trial and is reported here. Patients with advanced nonsquamous non‐small cell lung cancer (NSCLC) without actionable genomic alterations received two priming doses of modified vaccinia Ankara‐BN‐CV301 (MVA) 4 weeks apart, followed by boosting doses of fowlpox‐CV301 (FPV) at increasing time intervals for a maximum of 17 doses in combination with nivolumab for cohort 1 (C1) and 15 doses in combination with pembrolizumab for cohort 2 (C2). The primary objective was evaluation of safety and tolerability. Between October 2017 and September 14, 2018, patients were enrolled (C1: 4; median age: 64 years). Mean treatment duration was 332 days in C1 and 289 days in C2. CTCAE ≥grade 3 adverse events (AEs) were observed in four (100%) patients in C1 and three (37.5%) patients in C2. There was one death on trial. Immune‐related AEs (irAEs) fulfilling criteria for a dose‐limiting toxicity included 1 case of pneumonitis. Among 11 evaluable patients, 1 (9%) had a complete response, 1 (9%) had a partial response and 9 (82%) had stable disease. We conclude that CV301 administered with PD‐1 inhibitors is safe and clinically active in patients with advanced NSCLC. The frequency or severity of AEs is not increased, including irAEs for each component of the combination. What's new? CV301 is a poxviral‐based cancer vaccine that generates antigen‐specific T‐cell responses to MUC‐1 and CEA, which are overexpressed in many non‐small cell lung cancers. We tested the hypothesis that CV301 in combination with programmed death‐1‐directed therapy is safe and immunologically active. Our trial demonstrates the tolerability and clinical activity of CV301 with nivolumab or pembrolizumab in patients with advanced non‐small cell lung cancer and its ability to generate multifunctional immune responses to MUC‐1 and CEA.