Improving Effectiveness of Immunotherapy in Treating Cancer

Making tumors respond to new treatments

Immunotherapy—one of the most exciting fields of research today—shows promise in treating cancers such as metastatic melanoma, lung, bladder and possibly breast cancer, but not everyone responds. When immunotherapy works, it works well, according to Dr. Taha Merghoub and colleagues at Memorial Sloan Kettering Cancer Center. Drs. Merghoub, Wolchok and colleagues recently published new research that reviews why some patients do not respond to immunotherapy and potential discoveries that aim to improve response rates.

Cancer immunotherapy involves harnessing a patient’s own immune system to attack cancer cells. Scientists have known for more than a century that the immune system can detect and kill cancer cells, but the challenge has been how to unmask tumor cells and make them visible to the immune system. In this work, Dr. Merghoub and colleagues showed that some tumors recruit special cells (tumor-associated myeloid cells) that can prevent the immune system from attacking the tumor cells. They then showed that the drug, called IPI-549, was able to reduce the number of these cells and make these tumors more responsive to immunotherapy. Recent major discoveries in immune-targeted therapies are leading the way in a new era of cancer immunotherapy and clinical trials are ongoing in different cancer types including metastatic breast cancer.

BCRF is investing $6.5 million in immunology-related projects this year. In addition to Drs. Mergoub and Wolchok, BCRF investigators studying immunotherapy include Karen Anderson, Mary L. (Nora) Disis, Susan Domchek, Elizabeth Jaffee, Annette Khaled, Silvia Formenti, Sandra Demaria, Robert Vonderheide, and others. The studies aim to identify immune biomarkers that can ultimately be used to predict treatment response and new targeted and combination therapies that will hopefully lead to better outcomes in breast cancer.