Doctors from Yale Cancer Center presented new data at the American Society of Clinical Oncology meeting on the impact of combining the immune checkpoint inhibitor (durvalumab/MEDI4736) with chemotherapy as preoperative treatment for early stage triple negative breast cancer (TNBC). Overall patients with TNBC achieved a 71% pathologic complete response to the combination treatment in the initial clinical trial. By comparison, chemotherapies alone produce a pathologic complete response rate of only around 35-40% for women with TNBC.
About 10% of breast cancers are found to be triple negative, where the breast cancer cells have tested negative for estrogen receptors (ER-), progesterone receptors (PR-), and HER2 (HER2-). It is understood that there is a significant unmet need for new treatment options to increase cure rates for women with TNBC. One approach being evaluated is combining novel precision medicines and immunotherapy with traditional chemotherapy medicines.
About durvalumab (MEDI4736)
Durvalumab is an investigational human monoclonal antibody directed against programmed death ligand-1 (PD-L1). PD-L1 can be expressed by tumors to evade detection by the immune system through binding to PD-1 on cytotoxic T lymphocytes. Durvalumab blocks the PD-L1 interaction with PD-1, countering the tumor’s immune-evading tactics. Durvalumab is being developed, alongside other immunotherapies, to empower the patient’s immune system and attack the cancer.
Durvalumab was given breakthrough therapy designation by the FDA on the basis of early clinical data from a Phase I trial in patients with advanced bladder cancer that had progressed during or after one standard platinum-based regimen. Durvalumab is being evaluated in bladder cancer, breast cancer and a variety of other malignancies.
The phase I part of the Yale clinical trial sought to determine the safety and tolerability of durvalumab in combination with weekly nab-paclitaxel and dose dense doxorubicin/cyclophosphamide, a standard active chemotherapy treatment regimen. Overall the treatment was well tolerated and among the 7 patients in the this early trial, 5 achieved pathologic complete response, 1 had partial response with residual disease, and 1 had extensive residual cancer. This corresponds to a pathologic complete response rate of 71%. A larger confirmatory clinical trial is now open for patient accrual at Yale Cancer Center.
Reference: J Clin Oncol 35, 2017 (suppl; abstr 572).