Dr Lee Schwartzberg Discusses Results of Checkpoint Inhibitors in Breast Cancer

There is much excitement over the new checkpoint inhibitors, which have shown benefit across a variety of tumors. Right now, researchers are trying to define the subgroup of patients with breast cancer who might be most suited to checkpoint inhibitors, explained Lee Schwartzberg, MD, FACP, chief of Division of Hematology Oncology and professor of medicine at the University of Tennessee Health Science Center.

Transcript (slightly modified)

Are the results of trials evaluating the new checkpoint inhibitors in breast cancer encouraging?

There are trials evaluating the checkpoint inhibitors in breast cancer. We’re very excited about this group of agents, in general, which has shown benefit across a large variety of tumors. The data to date, in breast cancer, has been focused on metastatic disease and there are small populations, typically in phase 1 studies of the checkpoint inhibitors, the PD-1 inhibitors specifically, which have been reported.

The results show that there is some benefit in populations, particularly perhaps in the triple negative breast cancer population. The response rates seem a little bit lower than we see in some other diseases like lung cancer, and certainly lower than we see in a disease that’s very immune sensitive like melanoma. One of the hypotheses is that tumors that have large amount of genomic instability, lots of mutations like lung cancer, are more likely to respond to checkpoint inhibitors.

So part of the drive now in breast cancer is to define the subgroup of patients who might be most suited to checkpoint inhibitors. This is an area of very active discussion and investigation, and I think over the next year or 2 we’ll see much more about checkpoint inhibitors in metastatic breast cancer.