At SABCS 2024, Dr. Erica Mayer presented findings from the TBCRC 056 Phase II trial, which investigated the combination of the PARP inhibitor niraparib and anti-PD-1 therapy dostarlimab in neoadjuvant treatment for BRCA- or PALB2-mutated ER+/HER2- breast cancer.
Among 18 patients, the pathologic complete response (pCR) rate was 16.7%, with 44.4% achieving RCB-0/I, indicating a subset benefited from this targeted approach. Notably, increased stromal tumor-infiltrating lymphocytes (sTILs) after one cycle highlighted an immune response to treatment, and higher baseline sTILs correlated with better outcomes.
While response rates were lower than those observed in triple-negative breast cancer treated with PARP inhibitors, the study underscores the potential of preoperative PD-1 inhibition in ER+ breast cancer. Further research is needed to optimize patient selection and understand immune interactions within the tumor microenvironment.
These findings contribute to the ongoing shift toward non-chemotherapy strategies in breast cancer treatment.
Thanks to the patients, investigators, and funding partners, including BCRF, Susan G. Komen, and GSK, for supporting this research.
For more details:https://lnkd.in/ee8ccJNT
