Hongnan Mo, MD, National Cancer Center/Cancer Hospital, Beijing, China, discussed results from a multicenter, randomized, phase 2 trial comparing metronomic chemotherapy plus PD-1 blockade to combined conventional chemotherapy plus immune checkpoint blockade for patients with HER2-negative metastatic breast cancer.

Results found that treatment with cyclophosphamide plus capecitabine, metronomic vinorelbine, and toripalimab resulted in clinical efficacy.

Dr Mo first shared these results at the 2023 San Antonio Breast Cancer Symposium.

Transcript:

Hello, I'm Dr Hongnan Mo from Cancer Hospital Chinese Academy of Medical Sciences and this is my first time to going to San Antonio [Breast Cancer Symposium]. My presentation describes our prospective phase 2 clinical trial comparing metronomic chemotherapy with conventional chemotherapy as the backbone for immunotherapy. We found that compared with the conventional chemotherapy, metronomic chemotherapy may be a more suitable backbone for immunotherapy.

Our study used Bayesian adaptive randomization and efficacy monitoring. Eligible patients had HER2-negative metastatic breast cancer with no more than 1 prior line of chemotherapy, and patients were randomized to receive different immunotherapy combinations. I will present the efficacy and safety profile of various immunotherapy combinations.

Meanwhile, we used mass cytometry to characterize the protein expression of peripheral mononuclear cells and we found that our results illuminated a specific remodeling of lymphoid and the myeloid cell subsets in the responder. The automation of patient’s systemic immune profile, rather than the baseline characteristics, has a substantial correlation with immunotherapy response and it’s worth noting that metronomic chemotherapy may program the patient's systemic immune profile to improve the immunotherapy response.

On one hand, metronomic chemotherapy had better progression-free survival and disease control rate. On the other hand, it may reprogram the patient's systemic immune profile to improve immunotherapy. We think that, for patients with metastatic breast cancer, metronomic chemotherapy may be the more suitable backbone for immunotherapy.

Source:

Mo H, Sun X, Zhai J, et al. Efficacy and safety of toripalimab plus metronomic chemotherapy in HER2 negative metastatic breast cancer: A multicenter phase II trial based on a Bayesian adaptive randomized design. Presented at the 2023 San Antonio Breast Cancer Symposium. December 4-9, 2023. Abstract RF01-06