For patients with breast cancer with a PDL1 expression, a new treatment targeting immune cells could make a major difference.
According to Leisha A. Emens, MD, PhD, professor of medicine at the UPMC Hillman Cancer Center, findings of the KATE2 trial showed that the addition of atezolizumab (Tecentriq) to TDM1 (Kadcyla) did not improve progression free survival (PFS) overall but did improve PFS in patients PDL1 expression in their immune cells.
At the European Society of Medical Oncology (ESMO) Congress 2019, OncLive®, a sister publication of Oncology Nursing News®, had the chance to interview Emens and discuss these findings as well as why researchers chose to asses for PDL1 in immune cells over other methods.
SP142 is an assay that has been co-developed along with atezolizumab, and I think the priority at the beginning of this clinical development program was to really focus on immune cells, because the target of the drug is unleashing immune cells, particularly T-cells, and their ability to attack the tumor. It turns out that in breast cancer there is not a significant level of tumor cell expression above and beyond what you find in immune cells, so at least for breast cancer, it appears that immune cell expression is the most important.