CD19 CAR T Efficacy Is Consistent Across Race in B-Cell Lymphomas

A large, pooled analysis of more than 2000 patients across 9 pivotal clinical trials found that baseline clinical characteristics—specifically tumor burden and ECOG performance status—are the primary determinants of outcomes following CD19-directed chimeric antigen receptor T-cell (CAR T) therapy for B-cell lymphomas (BCL), with race showing no significant impact on efficacy.¹

Published in Blood Advances, the analysis provides a comprehensive look at the intersection of race and clinical variables in the CAR T landscape. Although the study highlighted a persistent and significant underrepresentation of non-White patients in these trials, researchers found that the feasibility and effectiveness of the therapy remained consistent across all racial and ethnic groups studied.

“Clinical trials involving CAR T in the United States have been characterized by significant underrepresentation of minorities,” the authors wrote.¹ “Importantly, thanks to the prospective nature of the collected data and the study design, we were able to show that race did not have impact on screen failure, highlighting that the underrepresentation of minorities in US clinical trials is not primarily due to screening or enrollment criteria but is more likely driven by referral patterns and the catchment areas of large cancer centers.”

Study Design and Cohort Characteristics

Prospective data from 9 phase 2 and 3 clinical trials conducted between 2015 and 2023 were sourced from the Medidata Clinical Cloud, amounting to a total of 2304 patients, of whom 1637 were assigned to receive CAR T-cell therapy. Two cohorts were formed among the patients who eventually underwent treatment: those with large BCL (n = 958), including diffuse large BCL, high-grade BCL, transformed follicular lymphoma (FL), T-cell large BCL, and grade 3B FL; and those with indolent BCL including patients with FL and marginal zone lymphoma (n = 349). Those with mantle cell lymphoma and primary mediastinal large BCL were excluded from the analysis.

Findings: No Difference in Efficacy/Safety by Race

A primary objective of the analysis was to evaluate whether racial or ethnic background influenced CAR T-cell treatment responses or the incidence of adverse events. The dataset revealed a stark demographic imbalance: non-White groups were severely underrepresented across all 9 trials, with 75% of patients with BCL enrolled across the trials were non-Hispanic White. Despite this, investigators observed no statistically significant differences in screening failure rates, CAR T-cell manufacturing success, or clinical outcomes including objective response rate, progression-free survival (PFS), and overall survival (OS) when comparing Black, Asian, Hispanic, and White populations.

Instead, clinical outcomes differed by clinical features. Among patients with large BCL, ECOG performance status of 2 or higher was linked to inferior outcomes, with these patients experiencing significantly shorter OS and PFS compared with those who had better functional status.

Similarly, high tumor burden emerged as a major negative prognostic factor. Patients with bulky disease had markedly worse survival outcomes, with a median OS of 12.3 months (95% CI, 10.1-48.7) and median PFS of 3.0 months (95% CI, 2.8-7.1) compared with a median OS of 33.8 months (95% CI, 26.8-50.6) and median PFS of 6.71 months (95% CI, 5.92-10.2) in patients without bulky disease.

The use of bridging therapy, which is often administered to control rapidly progressive disease prior to CAR T-cell infusion, was also associated with poorer outcomes. Patients who received bridging therapy also showed lower median OS (18.5 months; 95% CI, 14.3-24.4) and median PFS (4.3 months; 95% CI, 3.3-6.0), both shorter than those observed in patients who proceeded directly to infusion without bridging therapy (median OS, 43.1 months; 95% CI, 28.6-63.8; median PFS, 9.2 months; 95% CI, 6.2-17.1).

In the indolent BCL cohort, distinct clinical factors influenced outcomes. Older age (>75 years) and shorter interval from diagnosis to CAR T-cell infusion, likely reflecting more aggressive disease biology, were both associated with reduced OS and PFS.

Trial Equity vs Real-World Inequity in CAR T Access

The consistency of results across racial groups suggests that, within the controlled setting of clinical trials, CD19-directed CAR T-cell therapy delivers comparable efficacy and safety regardless of patient background. These findings suggest that when access is equitable, the therapy performs reliably across different backgrounds.

However, the marked underrepresentation of non-White patients points to systemic barriers occurring upstream of enrollment, including referral patterns, access to specialized treatment centers, and broader socioeconomic factors. The authors stressed that real-world barriers to CAR T access, such as insurance status and geographic proximity to specialized centers, likely play a larger role in disparately affecting real-world outcomes than biological differences between races. Current literature indicates racial and socioeconomic disparities in CAR T accessibility.² As a result, real-world outcomes may still diverge across populations despite similar efficacy observed in trials.

Addressing these gaps will require deliberate efforts to expand access pathways and improve representation in prospective studies. Ensuring that diverse patient populations are adequately included in future trials will be critical not only for equity, but also for confirming that emerging cellular therapies are effective across the full spectrum of patients seen in routine clinical practice.

REFERENCES

1. Kho SJ, Diamond S, Lafeuille P, et al. Racial and clinical determinants of response in 2304 large B-cell lymphomas treated with CD19 CAR T in clinical trials. Blood Adv. 2026;10(5):1497-1507. doi:10.1182/bloodadvances.2025016361

2. Warnakulasuriya H, Tiwari R. Racial and socioeconomic healthcare disparities in access to chimeric antigen receptor T (CAR-T) cell therapy for blood cancers. Cancer Med. 2026;15(2):e71457. doi:10.1002/cam4.71457