Roche announced the expanded use of the VENTANA PD-L1 (SP142) Assay in triple-negative breast cancer (TNBC) for patients living in CE markets where the Roche cancer immunotherapy medicine Tecentriq is approved. It is the first companion diagnostic to aid in identifying TNBC patients eligible for treatment with Tecentriq (atezolizumab) plus chemotherapy (nab-paclitaxel). Assessment of PD-L1 biomarker status on tumor-infiltrating immune cells with the assay is essential for identifying those patients most likely to benefit from the treatment.
The announcement follows the U.S. Food and Drug Administration approval of the assay in March 2019 as the first companion diagnostic to identify TNBC patients eligible for the Tecentriq combination. A diagnosis of triple-negative breast cancer means that the three most common proteins associated with breast cancer growth – estrogen receptor, progesterone receptor and HER2/neu – are not expressed on the tumor.
The VENTANA PD-L1 (SP142) Assay was developed to enhance visual contrast of tumor-infiltrating immune cell staining. In triple-negative breast cancer, PD-L1 is primarily expressed on tumor-infiltrating immune cells rather than on tumor cells themselves.