AACR 2019: Can B Cells Predict Response to Immunotherapy in Melanoma?
Posted: Thursday, April 11, 2019
B cells, specifically those with activated effector phenotypes, and tertiary lymphoid structures may predict response to immune checkpoint blockade treatment in melanoma. This new study finding was presented at the 2019 American Association for Cancer Research (AACR) Annual Meeting in Atlanta, by Jennifer Wargo, MD, of the MD Anderson Cancer Center, Houston.
“This is an exciting and emerging area of study that appears to hold promise for more accurately understanding which patients are most likely to be treated effectively with [immune checkpoint blockade] therapy, and it also could help us identify new therapeutic targets,” said Dr. Wargo in an institutional press release.
Researchers used samples from patients with melanoma who had received immune checkpoint inhibition as their initial therapy. Patient samples were labeled at responders or nonresponders. Whole transcriptomic analysis of these samples showed that the most differentially expressed genes by response were related to B cells and antibody production. Additionally, samples that responded well to immune checkpoint blockade had higher B-cell counts than did samples not responding well to this treatment. These B cells were present in organized tertiary lymphoid structures close to both T cells and dendritic cells. Data from melanoma samples were validated using a renal cell carcinoma cohort.
The intratumoral B cells in the neoadjuvant melanoma cohort was composed of naive, class switched and unswitched memory B cells and plasma cell–like populations. There were higher frequencies of class switched memory B cells and plasma-like cells in the responsive samples than in the unresponsive samples, which had higher amounts of naive B cells. B-cell activation markers were significantly associated with response to immune checkpoint blockade.
Disclosure: The study authors’ disclosure information may be found at abstractsonline.com.