Impact of Social Determinants of Health on Access to CAR-T Therapy and Outcomes in Multiple Myeloma Patients

CAR T therapy is a remarkable advance for treatment of patients with relapsed/refractory multiple myeloma (RRMM) but requires referral to specialized centers and often geographic relocation, which may exacerbate disparities in access. Data on the influence of social determinants of health (SDOH) on CAR T access and outcomes are limited. In this single center study at a referral academic center, we evaluated outcomes of patients receiving standard of care CAR T based on SDOH between 2021-2024. As autologous stem cell transplant (ASCT) is a well-established cell therapy, we compared sociodemographics of patients receiving CAR T vs ASCT to contextualize access patterns. Clinical data and SDOH variables (insurance, education, race, ethnicity, Stanford Integrated Psychosocial Assessment for Transplant (SIPAT) scores, relocation need, Area Deprivation Index (ADI)) were extracted from EMR. The study population distribution is seen in Figure 1. Among CAR T patients, 64.2% needed relocation; these patients had higher ADI scores and fewer years of education (p<0.05). Cilta-cel and ide-cel recipients had comparable baseline demographics but differed in socioeconomic factors and disease variables. Cilta-cel patients had fewer prior lines of therapy (median 4 vs 6; p<0.01), were more likely to have combined public/private insurance (20.7% vs 2.0%; p<0.01) and, among those with >12 years of education, more often held a bachelor's degree or higher (75.8% vs 33.3%; p<0.01). We observed no significant associations with race, ethnicity, ADI or other SDOH on clinical outcomes including toxicity and survival (PFS/OS) with the exception of relocation need. Patients who needed to relocate trended better PFS than those who lived closer to treatment centers, potentially due to confounding factors. Multivariable analyses showed no association between ADI, race, insurance, relocation, or education and PFS/OS. While not significant, patients with a higher SIPAT score on social worker assessment indicating poor candidacy for CAR T trended inferior PFS. Compared to ASCT, CAR T patients were older, which is expected with CAR T approved for later line therapy, and likely to identify as White (64% vs 46%). Racial differences were driven by patients who identified as Other or Asian/Pacific Islander. The distribution of Black patients was similar. Proportion of Hispanic patients was not statistically different (15% vs 21%, p=0.2). Sex and ADI distribution was similar for both. Among patients able to access CAR T therapy, survival and toxicity outcomes were similar across sociodemographic groups, suggesting equitable efficacy once treatment is delivered. The need for relocation and insurance approval may shape the ability of patients to access therapy. Our data highlights the importance of continuing to address SDOH to ensure equitable delivery of cellular therapies.