Multivariate logistic regression analysis of response to pembrolizumab assessed per RECIST V.1.1 by independent central review in the pooled pembrolizumab population
| Covariate | OR for ORR (95% CI) |
| TMB status (≥175 vs <175 mutations/exome) | 3.076 (2.243 to 4.220) |
| PD-L1 expression status (positive vs negative) | 2.187 (1.442 to 3.316) |
| MSI status (high vs non-high) | 3.798 (1.453 to 9.925) |
| Age (<65 vs ≥65 years) | 0.707 (0.525 to 0.952) |
| Sex (female vs male) | 1.004 (0.713 to 1.413) |
| ECOG performance status (0 vs 1 or 2) | 1.471 (1.094 to 1.978) |
| No. of lines of prior therapy for advanced disease (≤1 vs ≥2) | 1.237 (0.898 to 1.705) |
| Tumor type (HNSCC vs gastric*) | 1.841 (1.057 to 3.207) |
| Tumor type (melanoma vs gastric*) | 3.664 (1.877 to 7.153) |
| Tumor type (NSCLC vs gastric*) | 1.617 (0.971 to 2.695) |
| Tumor type (other vs gastric*) | 1.203 (0.517 to 2.802) |
| Tumor type (ovarian vs gastric*) | 0.882 (0.415 to 1.878) |
| Tumor type (prostate vs gastric*) | 0.718 (0.300 to 1.719) |
| Tumor type (TNBC vs gastric*) | 0.526 (0.211 to 1.312) |
| Tumor type (urothelial vs gastric*) | 2.224 (1.291 to 3.832) |
*Gastric cancer was chosen as the reference because alphabetically, it was the first tumor type group included in the analysis.
ECOG, Eastern Cooperative Oncology Group; HNSCC, head and neck squamous cell carcinoma; MSI, microsatellite instability; NSCLC, non-small-cell lung cancer; ORR, objective response rate; PD-L1, programmed death ligand 1; TMB, tumor mutational burden; TNBC, triple-negative breast cancer.