In recent years, there have been major advances in the treatments for multiple myeloma, but it remains a mostly incurable disease for many patients. A cancer of the bone marrow, multiple myeloma arises from plasma cells and as the disease progresses, it can become increasingly resistant to therapy and challenging to treat

In March 2021, good news came to patients with refractory and relapsed multiple myeloma as the FDA approved a new form of chimeric antigen receptor T-cell therapy (CAR T) for this disease. CAR T therapy is a novel treatment that reengineers a patient’s own immune cells to fight cancer. The patient’s immune cells are removed from the body, reengineered in a lab and then infused back into the patient. These new immune cells seek out and destroy the cancerous cells.

“This new form of CAR T had remarkable response rates in clinical trials,” said Dr. Lauren Peres, a researcher in the Cancer Epidemiology Program at Moffitt Cancer Center. “But we really don’t know what’s going on in the real-world setting. Now that this therapy is commercially available with an increasing number of patients receiving it, we want to explore the outcomes, safety, and efficacy of the treatment within racially and ethnically diverse patient populations.”

Peres notes that race and ethnicity were not mentioned in the clinical trial data that led to FDA approval for CAR T therapy. She explains that this is problematic due to the notable racial and ethnic disparities that are known to exist. For example, Black individuals are twice as likely to develop multiple myeloma compared to their white counterparts. Black and non-white Hispanic patients are also less likely to receive novel therapies and enroll in clinical trials.

"It’s the only study investigating racial and ethnic disparities in CAR T that focused specifically on patients with multiple myeloma."

- Dr. Lauren Peres, Cancer Epidemiology Program

Leveraging data from the United States Multiple Myeloma Cellular Therapy Consortium, a multicenter observational analysis led by Dr. Doris Hansen of Moffitt’s Blood and Marrow Transplant and Cellular Immunotherapy Department, Peres and her team examined patient characteristics, safety profiles, responses, and outcomes by race and ethnicity. They presented their findings at the recent American Society of Hematology Annual Meeting and Exposition.

What they found indicated that there were potential racial and ethnic disparities among patients that received CAR T therapy.

“We observed that non-Hispanic Black patients had higher levels of baseline systemic inflammatory markers compared to non-Hispanic white and Hispanic patients,” Peres explained. “Non-Hispanic Black patients also had a higher prevalence of cytokine release syndrome and persistent severe cytopenia. Hispanic and non-Hispanic Black patients also had a higher prevalence of infections compared to non-Hispanic white patients.”

Peres’ team also observed lower response rates to CAR T therapy for Hispanic patients compared to non-Hispanic white and non-Hispanic Black patients. Peres says this may be explained by a higher prevalence of extramedullary disease among Hispanic patients, which is a high-risk feature for poor responses to CAR T therapy and occurs when myeloma cells form tumors outside the bone marrow in the surrounding soft tissues or organs.

The explanations for these disparities are not fully realized, but symptoms of the problem include access to care, social and economic factors, and patient and provider communication. While Peres emphasizes that this work is preliminary and that more data is needed to determine the extent of potential racial and ethnic disparities for these patients, she also says this study provides unique insight.

“Compared to previous studies, our study includes the largest number of patients with multiple myeloma commercially treated with CAR T,” Peres said. “It’s also the only study investigating racial and ethnic disparities in CAR T that focused specifically on patients with multiple myeloma.”