Abstract
Patients (pts) of minority race or ethnicity are often underrepresented in oncology clinical trials (Awidi et al. JCO Oncol Pract. 2021). Here, we extend previous work (Goldfinger et al. ASH 2022) to evaluate proportions of minority pts receiving CAR T therapy in the US by considering both cancer prevalence and proximity to authorized treatment centers (ATCs) using forecasted demographic and epidemiological changes between 2020−2025.
Stratified by age, sex, and race/ethnicity (non-Hispanic White [NHW], non-Hispanic Black [NHB], non-Hispanic other [NHO] and Hispanic, all races [HAR]), estimated 5-year limited duration prevalence (LDP) of five indications (large B-cell, follicular, mantle cell lymphoma [LBCL, FL, MCL], B-cell acute lymphoblastic leukemia [B-ALL], and multiple myeloma [MM]) spanning 2000–2019 for adults aged ≥ 20 years were extracted from the SEER Research Plus Data (17 registries, November 2021 submission [latest as of February 2023]) and were used to project LDPs for 2020–2025 using segmented logistic regression. These were combined with US population projections (Hauer Scientific Data 2019) which projected increases in proportions of NHB and HAR from 13.3% and 7.4% in 2020 to 13.5% and 8.1% in 2025, respectively, to estimate racial prevalence counts per indication and year. Proximity to CAR T therapy ATCs was considered by weighting US county populations according to landmass within a 1-hr drive isochrone. Bootstrapping method (10,000 sets of 1,000 draws) was used to estimate uncertainty.
Corresponding to the projected increases in the general US population's proportions of HAR and NHB, proportions of NHB and HAR pts aged ≥ 20 years were projected to increase from 2020−2025 across all indications (Table 1). Proportions of NHB and HAR pts from regions within 1-hr drive of CAR T therapy ATCs were higher than those of the entire US across all indications through 2020−2025. High proportions of NHB pts were observed in MM, increasing from 27.8% to 28.6% through 2020−2025 for regions within 1-hr drive of ATCs and 21.8% to 22.7% for the entire US. High proportions of HAR pts were seen in B-ALL, increasing from 32.6% in 2020 to 34.2% in 2025 for regions within 1-hr drive from ATCs and from 31.0% to 33.0% for the entire US.
This is the first study to project the trend in minority pts composition while considering the impact of proximity to ATCs. The results demonstrate a consistent trend of increasing proportions of minority pts in forthcoming years and higher proportions of minority pts in regions closer to ATCs. Further study is warranted to evaluate the impact of other factors on minority representation in clinical trials, including differential insurance coverage, commuting accessibility to ATCs, impact of COVID-19, burden of comorbidities, systemic racism, medical distrust, and patient-physician relationship.