SAN ANTONIO — Debu Tripathy, MD, chair of breast medical oncology at the University of Texas MD Anderson Cancer Center and HemOnc Today Editorial Board member, discusses clinical updates presented at the San Antonio Breast Cancer Symposium which show that immunotherapy could provide a promising treatment for various forms of breast cancer.
“This is an area that has been a 'Holy Grail', if you will, in this field,” Tripathy told HemOnc Today. “We have long wondered whether the immune system itself could be harnessed to fight breast cancer cells. As we have learned more about how the immune system is controlled, there have been clear innovations in therapy that have made a big difference in melanoma, which is a type of cancer that does stimulate the immune system to a greater extent than breast cancer does.”
In particular, Tripathy highlighted study results that demonstrated that the PD-1 inhibitor pembrolizumab was well tolerated by women with recurrent or metastatic triple-negative breast cancer and showed early signs of effectiveness. In a second trial, the PD-L1 inhibitor MPDL3280A was also found to be safe and tolerable for women with metastatic triple-negative breast cancer, exhibiting tumor shrinkage in some patients.
“We are very encouraged by this because we believe that we can build on this as we understand more about the immune system and develop better drugs, and perhaps, better ways to select patients that are most likely to respond,” Tripathy said. “Also, it is possible that the immune system can be overwhelmed by a large number of cancer cells that you might see in someone with advanced breast cancer, and it may be in an early stage breast cancer, where we want to further lower the risk of recurrence, that [immunotherapy] may be more successful.”