Improving patient selection for immuno‐oncology phase 1 trials: External validation of six prognostic scores in a French Cancer Center

We compared the performance of six prognostic scores (Royal Marsden Hospital, MDACC: MD Anderson Clinical Center and MDACC + NLR: neutrophil‐to‐lymphocyte ratio, MD Anderson ‐ immune checkpoint inhibitors (MDA‐ICI), GRIm: Gustave Roussy Immune Score and LIPI: Lung Immune Prognostic Index) in predicting overall survival (OS) in phase I trial patients treated with immune checkpoint inhibitors (ICI). Medical records of patients with advanced solid tumors enrolled in ICI phase I trials between 2015 and 2018 at Institut Universitaire du Cancer de Toulouse—Oncopole were reviewed. The performance of prognostic scores on OS was compared using different criteria. A total of 259 patients were included. Median age was 63 years (range: 18‐83). Main primary cancers were melanoma (19%), head and neck (16%), lung (13%) and bladder (10%). With a median follow‐up of 15 months (95% confidence interval [CI] = [11.6;17.5]), median OS was 12.5 months (95% CI = [10.3;16.0]). All scores were associated with OS. The MDACC, LIPI and GRIm scores performed better than the others. Concordance of risk group assignment between the scoring systems was poor. According to our results, the MDACC, GRIm and LIPI scores better suited to ICI phase I settings. Adequate scoring would allow better patient selection in early ICI trials, especially during the critical period of dose escalation, and in proof‐of‐concept expansion cohorts. What's new? Reducing enrollment of frail patients in early clinical trials evaluating dose and anti‐tumor activity of immune checkpoint inhibitors (ICIs) should be feasible through the use of scoring systems. The relative effectiveness of scores that take account prognostic factors associated with immunotherapy, however, remains unclear. Here, the performance of six prognostic scoring systems was compared for patients enrolled in phase1 ICI trials. Three systems – the MDACC, GRIm, and LIPI – performed best in terms of discrimination and calibration when applied to overall survival. The application of these scoring systems could contribute to more efficient patient enrollment in early ICI trials.