Study finds ‘substantial’ underrepresentation of Black patients in CAR-T clinical trials

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Disclosures: The authors report no relevant financial disclosures.

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Black patients appeared consistently underrepresented in pivotal clinical trials that led to FDA approval of several chimeric antigen receptor T-cell therapies, according to findings published in JAMA Network Open.

Researchers from the University of Arkansas for Medical Sciences observed a paucity of Black participants across pivotal trials regardless of the CAR-T product type or the disease being treated. A clinical trial evaluating an FDA-approved CAR-T for multiple myeloma had the most pronounced participation disparity, researchers noted.

Samer Al Hadidi, MD, MS, FACP
Data derived from Al Hadidi S, et al. JAMA Netw Open. 2022; doi: 10.1001 / jamanetworkopen.2022.8161.


CAR T-cell therapy for hematologic malignancies has provided considerable benefits to patients with advanced disease who have no other treatment options.

Samer Al Hadidi, MD, MS, FACP

Samer Al Hadidi

“Disparities that affect Black persons with various hematologic malignant neoplasms are substantial and have been previously reported,” Samer Al Hadidi, MD, MS, FACP, assistant professor at the myeloma center at the University of Arkansas for Medical Sciences’ Winthrop P. Rockefeller Cancer Institute, told Healio. “Little is known about disparities related to the use of FDA-approved CAR T-cell therapy, so we aimed to study this by conducting our analysis.”


Al Hadidi and colleagues conducted a cross-sectional analysis using publicly available data from five CAR T-cell therapies the FDA approved for seven commercial use indications between August 2017 and May 2021. The analysis also included published data from CAR-T products that led to FDA approval and recent cancer statistics for Black patients in the US

The study included patients with large B-cell lymphoma, follicular lymphoma, mantle cell lymphoma, acute lymphoblastic leukemia and multiple myeloma.

Investigators calculated a participation-to-prevalence ratio (PPR) to quantify how the proportion of Black patients treated in pivotal clinical trials compared with their prevalence among the overall disease population in the US PPR scores between 0.8 and 1.2 signified a proportion similar to that seen in the real-world disease population.

Key findings

The analysis showed 1,057 patients enrolled across all studies, with 746 patients (71%) receiving CAR-T and 729 (69%) having efficacy data available.

The number of Black patients treated during these studies with available efficacy data ranged from one to 12 (2% to 5%). A phase 2 study of tisagenlecleucel (Kymriah, Novartis) for patients aged 25 and under did not enroll any Black patients among its 88 participants.

Notably, despite having a higher disease prevalence among Black patients, the phase 2 trial of idecabtagene vicleucel (Abecma; Bristol Myers Squibb, bluebird bio) for relapse or refractory multiple myeloma included only eight Black participants among its 140 enrollees.

At a score of 0.8, only follicular lymphoma showed a reflective PPR score of proportional representation. Researchers reported PPR scores of 0.6 for large B-cell lymphoma and 0.4 for mantle cell lymphoma.

The PPR score of 0.2 for multiple myeloma showed the largest disparity among Black patients treated in pivotal clinical trials for CAR T-cell therapies.

Clinical implications

Al Hadidi said his group found “substantial disparities” among Black patient participation regardless of the approved CAR-T product or its indication.

He said both community-based general oncologists and those at academic centers can take an active role in addressing this disparity – from earlier patient referral to centers with clinical trials to studying the racial and ethnic distribution of patients treated at those institutions.

Al Hadidi’s group plans to further study access to clinical trials and factors leading to delayed referrals and treatment.

“I think the cancer care community will need to drive change,” he told Healio. “We need to implement regulations to ensure a certain percentage of minorities are enrolled in clinical trials based on disease prevalence, especially for registrational trials and in multiple myeloma.”

For more information:

Samer Al Hadidi, MD, MS, FACP, can be reached at Myeloma Center, Winthrop P. Rockefeller Cancer Institute, University of Arkansas for Medical Sciences, 4301 W. Markham St., # 816, Little Rock, AR 72205; email: [email protected]

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