The principal PD-1/PD-L1 checkpoint inhibitors currently approved and in clinical development
| Nivolumab (BMS-936558) | Pembrolizumab (MK-3475) | Atezolizumab (MPDL3280A) | Durvalumab (MEDI4732) | Avelumab (MSB0010718C) | Pidilizumab (CT-011) | |
| Target | PD-1 | PD-1 | PD-L1 | PD-L1 | PD-L1 | PD-1 |
| Monoclonal antibody class | Fully human IgG4 | Humanised IgG4k | Humanised IgG1 | Engineered IgG1k | Fully human IgG1 | Humanised IgG1k |
| Stage of clinical development | FDA approved Phase III | FDA approved Phase III | FDA approved Phase III | FDA approved Phase III | FDA approved Phase III | Phase II |
| Approved indication | Melanoma (2014), NSCLC (2015), RCC (2015), urothelial carcinoma (2017), MMR-d colorectal cancer (2017) | Melanoma (2014), NSCLC (2016), HNSCC (2016), Hodgkin’s lymphoma (2017), MMR-d tumours (2017) | Urothelial carcinoma (2016), NSCLC (2016) | Urothelial carcinoma (2017) | Merkel cell carcinoma (2017) | |
| Companion PD-L1 assay | Dako 28–8 (rabbit) | Dako 22c3 (mouse) | Ventana SP142 (rabbit) | Ventana SP263 (rabbit) | NA | |
| Target cells | TC | TC IC | TC IC | TC IC | ||
| Cut-off for positivity | NSCLC >1%–5% RCC >5% | NSCLC >1% TC any IC (as second-line therapy) | Urothelial >5% IC NSCLC >10% IC or >50% TC | Urothelial: >25% TC or IC if IC present in>1% of specimen >25% TC or 100% IC if IC present in <1% of specimen NSCLC: >25% TC |
FDA, Food and Drug Administration; HNSCC, head and neck squamous cell carcinoma; IC, infiltrating cells; MMR-d, mismatch repair deficient; NSCLC, non-small cell lung cancer; PD-1, programmed death 1; PD-L1, programmed death ligand 1; RCC, renal cell carcinoma; TC, tumour cells.