Social vulnerability by neighborhood of association correlates with CAR T referrals.

7025 Background: Chimeric antigen receptor T (CAR T) cell therapies are effective for relapsed/refractory (R/R) diffuse large B-cell lymphoma (DLBCL) and multiple myeloma (MM). However, factors influencing referrals remain unclear, particularly among the denominator of all eligible candidates. This study examines patterns of CAR T referral in the VA health system. Methods: A retrospective review identified veterans with R/R DLBCL or MM eligible for CAR T per FDA label during approval periods. Multivariable logistic regression assessed associations of CAR T referral with demographics, comorbidities, and social deprivation index (SDI). SDI is a composite social determinants of health measure at the zip code level, with higher SDI (range: 0-100) indicating greater social disadvantage. Results: Of 1,474 eligible patients across 112 VA hospitals, 25% (153/606) of DLBCL and 7.5% (65/868) of MM patients were referred for CAR T. Multivariable analysis showed that higher SDI (OR 0.90 per 10 points, 95% CI 0.84-0.96, p = 0.001) and older age (OR 0.58 per 10 years, 95% CI 0.49-0.69, p < 0.0001) were associated with a lower chance of referral, while DLBCL diagnosis (OR 3.22, 95% CI 2.28-4.59, p < 0.0001) and Hispanic ethnicity (OR 1.964, 95% 1.09-3.45, p = 0.02) were more likely to have referrals. Marital status, sex, race, psychiatric history, substance abuse, heart disease, kidney disease, cirrhosis, and rural/urban residence were not significant. Among referred patients, older age (OR 0.98, 95% CI 0.95-0.99) and substance abuse (OR 0.42, 95% CI 0.19-0.88) were linked to lower CAR T administration. Median lines of therapy for CAR T were 4 (range: 2-6) for DLBCL and 7 (range: 5-10) for MM. Common reasons for not receiving CAR T included death (23%), age/performance status (21%), alternative therapies (18%), adequate disease control (13%), comorbidities (8%), and patient preference (5%). Conclusions: Social vulnerability by neighborhood of association is associated with fewer CAR T referrals. Once referred, most variables minimally impacted CAR T administration. Efforts should focus on improving referral rates and addressing access barriers across all patients. Baseline characteristics of DLBCL and multiple myeloma cohorts. DLBCL (n = 606) Multiple Myeloma (n = 868) Median Age (range) 70 (30 – 96) 73 (36 – 97) Male Sex (%) 585 (97%) 829 (96%) Race/Ethnicity (%) Non-Hispanic White Non-Hispanic Black Hispanic Other 402 (66%)94 (16%)56 (9%)17 (3%) 458 (53%)320 (37%)53 (6%)14 (2%) Rural-Urban Residence (%) Urban Rural 410 (68%)188 (31%) 645 (74%)219 (25%) Marital Status (%) Married Never Married Divorced/Separated/ Widowed 361 (60%)64 (11%)178 (29%) 495 (57%)83 (10%)287 (33%) > 3 FACT-Accredited Centers in State (%) 342 (56%) 493 (57%) Median SDI (range) 52 (1-99) 55 (1-100) Comorbidities (%) Heart Disease Severe CKD Hepatic Cirrhosis Psychiatric Diagnosis Substance Abuse 226 (37%)55 (9%)36 (6%)336 (55%)100 (17%) 315 (36%)171 (20%)39 (4%)442 (51%)135 (16%)