Harnessing the Power

Bringing the Promise of Immunotherapy to Breast Cancer

After a residency at Parkland Health & Hospital System, a fellowship at Johns Hopkins and a faculty position at Northwestern University, Cesar Santa-Maria, M.D., recently returned to Johns Hopkins. Santa-Maria is a clinician-scientist who splits his time between treating breast cancer patients and researching new ways to fight the disease, working closely with laboratory scientists. This type of research is referred to as translational medicine, as experts take problems they see in the clinic back to the laboratory. Similarly, what they learn in the laboratory is then translated into novel treatment strategies for patients.

“My desire to improve outcomes for patients with breast cancer has motivated my entire academic career,” says Santa-Maria.

His main focus is immunotherapies, treatments that harness the power of the immune system to fight cancers. More drugs are gaining Food and Drug Administration approval, and they have had dramatic results for some patients, extending survival far beyond what’s been possible with other therapies. But, as single agents, they’ve shown only a modest benefit for patients with breast cancer.

Santa-Maria’s research aims to change that by finding ways to make breast cancers more immune-susceptible. He is leading a clinical trial to test combining immunotherapy drugs with other drugs known as Cyclin D Kinase inhibitors. These latter drugs are a standard of care for advanced breast cancers, halting the cell cycle so that cancer cells can’t replicate. Recent research suggests that they also cause localized inflammation in tumors. This inflammation is the result of immune activity, and his trial will see if it can make tumors more sensitive to immunotherapy drugs.

While at Northwestern, a different trial led by Santa- Maria showed that combining two immunotherapy drugs known as checkpoint blockers—a PD-L1 inhibitor and a CTLA-4 inhibitor—benefited patients with triple-negative breast cancers (those that tested negative for estrogen receptors, progesterone receptors and HER2). A new trial to confirm these results is planned. Much of the science behind immune checkpoint blockers—drugs that thwart the cancer cells’ ability to hide from the immune system— was developed at the Kimmel Cancer Center’s Bloomberg~ Kimmel Institute for Cancer Immunotherapy.

“By finding ways to make breast cancers more vulnerable to immunotherapies,” he says, “we’re hoping to attack this disease in a whole new way and ultimately improve outcomes for patients.”