Results from a Cox proportional hazards model for overall survival with terms for TMB (numerical), PDL1 (binary, high vs. low\medium), the treatment (ipilimumab-nivolumab vs. pembrolizumab), and the two covariate-by-treatment interactions. *** High PDL1 was associated with reduced hazard compared to low-medium PDL1 (HR = 0.5, 95% CI [0.3, 0.84], p = 0.01). ** Ipilimumab-nivolumab treatment was associated with reduced hazard compared to pembrolizumab treatment (HR = 0.65, 95% CI [0.43, 0.99], p = 0.05). * The terms for TMB and for the treatment-by-covariate interactions were not statistically significant.