A reduced dose/administration schedule may be considered if required, based on emerging s afety data. B Patient group Patients with advanced NSCLC. C Sample size Approximately eight patients will be entered into this trial. The final number will depend on emerging safety data, the number of patient replacements required and vaccine availability . D Study intervention Patients will receive six AST -VAC2 vaccinations, administered weekly over six weeks . They will attend an end of vaccination visit 30 days after their last AST-VAC2 vaccination , and attend follow -up visits up to 12 months after their first AST -VAC2 vaccination . After which, patients will be followed up for safety quarterly by telephone for five years (post first vaccination). Information on OS will be collected for up to 2 years after the first vaccination for al l patient s or until all patients have died, whichever event occurs first. E Study analysis Safety evaluations will be conducted after the first patient has received AST -VAC2 and then again after the second and third patients have been treated. Once open recruitment has been initiated, safety review will be performed at regular intervals (as requ ired). A safety review committee, consisting of all Investigators, representatives of the Sponsor and representatives of the drug company (observers only), will review emerging study data, with particular reference to ensuring that patients are able to com plete the vaccination schedule without AST -VAC2 toxicity -related delays. See protocol Section 3.3.2. An interim analysis will be conducted once all patients administered AST-VAC2 have withdrawn, died or completed their 2- year follow - up visit for survival. Once this condition is met, a data cut -off will be established. All patient visits occurring on or before this date will be analysed and summarised in the clinical study report, including safety data to date and assessment of OS at 2 years. Any data collected after this date will be summarised in a supplemental report for the final analysis to satisfy the safety reporting requirements for AST -VAC2 as an advanced therapy investigational medicinal product (ATIMP). The final analysis will be conduct ed after one of the following conditions is met: • The trial is terminated early, e.g. due to toxicity; • The End of Trial has been reached (when all patients have either withdrawn from the trial or died, or the last patient SM.TEMP.013 version 5 CRUKD/17/003 RAP Version: 2.0 09Mar2023 FINAL 10 has completed their final follow -up visit [whichever is the latter]). Once one of the se conditions is met, a data cut -off will be established. All patient visits occurring on or before this date will be analysed and summarised in a supplemental report. Due to the small sample size, there ar e no formal statistical analyses planned for this trial. F Dose escalation schedule There is no dose escalation schedule for this study, only one dose will be explored. Stopping rule criteria can be found in protocol Section 3.3.3.