Summary of anti-PD-L1 antibodies and companion assays
| Antibody clone | Assay | Platform | PD-L1 scoring for breast cancer | Companion diagnostic status | Companion diagnostic approval for TNBC |
| SP142 | VENTANA PD-L1 (SP142) | VENTANA | IC score=the percentage of the tumor area containing ICs labeling with PD-L1 at any intensity above background | Yes | IC score ≥1% indicates eligibility for atezolizumab (+nab-paclitaxel) |
| 22C3 | PD-L1 IHC 22C3 pharmDx | Dako | CPS=number of PD-L1 staining cells (including TCs, lymphocytes, and macrophages), divided by the total number of viable TCs, multiplied by 100 | Yes | CPS≥10 indicates eligibility for pembrolizumab (+chemotherapy) |
| 28–8 | PD-L1 IHC 28–8 pharmDx | Dako | Not applicable | No | None |
| SP263 | VENTANA PD-L1 (SP263) | VENTANA | Not applicable | Not for breast cancer | None |
CPS, combined positive score; IC, immune cell; IHC, immunohistochemistry; PD-L1, programmed death-ligand 1; TC, tumor cell; TNBC, triple-negative breast cancer.