New research suggests that combining the experimental drug evorpacept with the HER2-targeted therapy zanidatamab may help patients with heavily treated HER2-positive metastatic breast cancer. Evorpacept works by blocking CD47, a signal cancer cells use to avoid being destroyed by the immune system. Researchers also found that patients whose tumors had higher CD47 levels responded better to the treatment, suggesting this biomarker could help identify those most likely to benefit.
The combination was tested in a Phase 1/2 study involving patients who had already received an average of six previous treatments, including modern therapies such as trastuzumab deruxtecan. Among confirmed HER2-positive patients, the overall response rate was 55.6%, while disease control was achieved in 77.8% of patients. The median progression-free survival reached 7.4 months, which researchers consider encouraging for a group with such advanced disease. The treatment was also reported to have a manageable safety profile.
Researchers say the results support further study of this approach. Similar findings linking CD47 levels to treatment response have also been seen in gastric cancer studies. A larger trial is now underway to test evorpacept in combination with trastuzumab and chemotherapy in patients whose cancer has already progressed after treatment with trastuzumab deruxtecan.