Cossor, Furha

e23055 Background: Geographic distance to care has been associated with outcomes in solid tumors, reflecting differences in access, follow-up, and supportive care. However, its relationship with biologic transplant toxicities such as graft-versus-host disease (GVHD) has not been well characterized. Understanding whether access-related factors are associated with immune-mediated complications is important for systems-level optimization of post-transplant care and survivorship. Methods: We conducted a retrospective cohort study of adult patients undergoing allogeneic hematopoietic cell transplantation using the CIBMTR hs1802 publicly available dataset. Distance from patient residence to the transplant center was categorized as less than 20 miles, 20 to 50 miles, 50 to 150 miles, and greater than 150 miles, with less than 20 miles as the reference group. Primary outcomes were acute GVHD and chronic GVHD within one year after transplantation. Secondary outcomes included overall survival. Multivariable Cox proportional hazards models were used to evaluate associations between distance and outcomes, adjusting for age, sex, race and ethnicity, HCT comorbidity index, conditioning intensity, donor type, GVHD prophylaxis, transplant era, disease type, and total body irradiation use. Results: A total of 5,473 patients were included, with a median follow-up of 60.2 months. Crude rates of acute GVHD increased with greater distance from the transplant center, occurring in 40.2 percent of patients living less than 20 miles away and 45.1 percent of those living more than 150 miles away. In adjusted analyses, residence more than 150 miles from the transplant center was associated with a higher risk of acute GVHD compared with less than 20 miles, with an adjusted hazard ratio of 1.15 and a 95 percent confidence interval of 1.00 to 1.31. No significant differences were observed for intermediate distance categories. For chronic GVHD within one year, patients living more than 150 miles away had a lower recorded risk compared with those living less than 20 miles away, with an adjusted hazard ratio of 0.79 and a 95 percent confidence interval of 0.71 to 0.88. Distance to transplant center was not significantly associated with overall survival. Conclusions: Greater geographic distance from transplant centers is associated with a higher risk of severe GVHD after allo-HCT. These findings suggest that access to specialized post-transplant care and close monitoring may influence immune-mediated outcomes. Strategies to improve follow-up care, including enhanced care coordination and telemedicine, may help mitigate GVHD-related disparities and inform health policy efforts aimed at improving access to specialized transplant services, reimbursement for remote monitoring, and regional models of post-transplant care delivery.

e19537 Background: Chimeric antigen receptor (CAR) T cell therapy is a paradigm shifting modality for relapsed/refractory multiple myeloma (MM). Yet national scale delineation of immune effector toxicities, cardiopulmonary and renal sequelae, and economic burden across demographic and payer strata has not been adequately characterized. Methods: The National Inpatient Sample (2018–2022) was queried to identify adult MM hospitalizations receiving CAR T through ICD-10-PCS codes. Cytokine release syndrome (CRS) [all grades - 2021–2022], immune effector cell–associated neurotoxicity syndrome (ICANS) [all grades – 2022], cardiac events and infections were identified through ICD-10 codes. Age was stratified into 21-40, 41-60, 61-80, >81 years. Payer groups were Medicare, Medicaid, Private and Uninsured. Races were White, African American, Hispanic and others [Pacific Islanders, Native Indians, Asians]. Chi-square analysis was performed and multivariate regression adjusted for demographics, comorbidities and hospital characteristics. Results: Across >7,000 weighted hospitalizations, mortality, any grade CRS and ICANS were statistically similar across age, race, and payer (p>0.05). However, CRS was numerically higher in Hispanic patients (78.6%) than in White (63.2%), African American (68.1%), and other minor races (60.0%) (p=0.339). ICANS grade 4 was numerically higher in Hispanic (5.3%) versus White (0.8%) (p=0.278). Mortality was numerically highest in other minor races (9.5%) versus White (3.6%), Hispanic (2.8%), and African American (0.0%) (p=0.179). Age-stratified analyses showed significant heterogeneity in arrhythmias (22.2% [21–40 years] to 28.6% [≥81 years]; p=0.021), attenuating after adjustment. By race, arrhythmias ranged from 8.3% (Hispanic) to 25.0% (White) (p=0.113). Other cardiac events including myocardial infarction, stroke and cardiogenic shock were similar across groups. Payer stratified pneumonia varied (p=0.010) with uninsured 23.8% versus Private 5.1%, Medicare 7.3%, and Medicaid 6.4%, without persistence in adjusted models. Sepsis and septic shock rates showed no differences. Hispanic patients had higher adjusted costs versus White (Odds ratio [OR] 1.3, 1.04–1.7; p=0.023). Age-stratified costs differed (p=0.032), with elevated cost in ≥81 years (USD 394,617) versus 21–40 (USD 229,862), 41–60 (USD 214,974), and 61–80 (USD 269,844) but it was not significant in adjusted analysis. Conclusions: In this national cohort, CRS, ICANS and mortality were broadly stable across strata, while cardiac events displayed select divergences with elevated rates of arrhythmias among the elderly population suggesting robust cardiac surveillance in these patients. Cost differentials were evident with higher costs among Hispanic and elderly patients warranting validation in larger, prospectively harmonized datasets.

e19536 Background: Chronic kidney disease (CKD) may impair physiologic resilience during chimeric antigen receptor (CAR) T-cell therapy for multiple myeloma (MM). While cytokine response syndrome (CRS) and immune cell-associated neurotoxicity syndromes (ICANS) have been described in MM CAR-T recipients with CKD, the broader cardiopulmonary, infectious, renal, and economic implications of CKD remain insufficiently defined. We examined the national impact of CKD on mortality, immune cell effector toxicities, organ dysfunction, infections and resource utilization. Methods: Adult MM hospitalizations receiving CAR T-cell therapy were identified from the National Inpatient Sample (2018–2022) using ICD-10-PCS codes. Patients with ESRD were excluded. CKD was categorized as CKD3a+ (eGFR <60 mL/min) versus no CKD/CKD1–2. Outcomes included in-hospital mortality, CRS (2021–2022), ICANS (2022), cardiac arrhythmias, acute kidney injury (AKI), renal replacement therapy, respiratory failure, infections and total hospitalization cost (calculated using TOTCHG variable and adjusted cost to charge ratio). Comparative analysis was done using chi-square testing. Multivariate analysis adjusted for demographics, comorbidities, and hospital characteristics. Results: Among 2,045 weighted MM CAR-T hospitalizations, 7.6% had CKD3a+. Overall CRS rates were similar (66.7% vs 64.9%; p=0.839) between CKD3a+ vs no/CKD1-2. Overall ICANS rates were also comparable (16.7% vs 17.3%; p=0.941). Differences in CRS/ICANS grades were not significant. CKD3a+ patients experienced sharply higher AKI (58.1% vs 13.0%; p<0.001; adjusted odds ratio [OR] 9.2, p<0.001). Renal replacement therapy was more frequent in CKD3a+ but non-significant (3.2% vs 0.8%; p=0.196). Acute respiratory failure was more frequent (9.7% vs 2.9%; p=0.045) in patients with CKD. Cardiac arrhythmias were numerically higher but non-significant (25.8% vs 20.6%; p=0.527; adjusted OR 1.3, 95% CI 0.4–4.9; p=0.673). Infections were amplified, including gram-negative bacteremia (3.2% vs 0.3%; p=0.026), sepsis (9.7% vs 2.6%; p=0.040), and septic shock (3.2% vs 0.3%; p=0.027) in patients with CKD. Inpatient mortality was numerically higher (6.5% vs 1.9%; p=0.101), though nonsignificant after adjustment (OR 6.9; p=0.319). Hospital costs were substantially higher in CKD3a+ (USD 346,769 vs 239,175; p=0.006), though not significant in adjusted models (OR 1.3; p=0.120). Conclusions: CKD3a+ is associated with markedly increased AKI, higher respiratory failure and infections, with a trend towards higher hospitalization costs. Inpatient mortality, CRS and ICANS rates were similar. CKD3a+ represents a significant vulnerability that amplifies downstream complications in MM CAR-T recipients, warranting enhanced pre-treatment risk stratification, infection surveillance and renal-preserving strategies.

e19054 Background: Chronic kidney disease (CKD) may potentiate toxicity and impair organ resilience in recipients of chimeric antigen receptor (CAR) T-cell therapy for diffuse large B-cell lymphoma (DLBCL). While cytokine response syndrome (CRS) and immune cell effector neurotoxicity syndrome (ICANS) have been reported with CKD, the cardiac, infectious, and economic sequelae are insufficiently described. We evaluated these outcomes across CKD strata from a national database. Methods: Using the National Inpatient Sample (2017–2022), we identified adult DLBCL hospitalizations receiving CAR T-cell therapy. ESRD patients were excluded. CKD was examined in two frameworks: CKD3a+ (eGFR <60 mL/min) versus no/CKD1–2, and CKD3b+ (eGFR <45 mL/min) versus no–CKD3a. Outcomes included in-hospital mortality, CRS (2021–2022), ICANS (2022), cardiac events, infections, acute kidney injury (AKI), renal replacement therapy and total hospitalization costs (calculated using TOTCHG variable and adjusted cost to charge ratio) and comparative analyses was done using chi-square testing. Multivariable models adjusted for demographics, comorbidities, and hospital characteristics. Results: In a cohort of 5,400 hospitalized DLBCL patients receiving CAR-T, those with CKD stage 3a or higher (CKD3a+; n=165; 3.1%) had higher rates of AKI (33.3% vs 11.6%; p<0.001) and renal replacement therapy (6.1% vs 1.4%; p=0.040) compared to no/CKD1–2 (n=5,235. Total hospitalization cost was higher (USD 456,198 vs 365,182; p=0.024) and grade 4 ICANS occurred more frequently (10.0% vs 1.4%; p=0.046). Mortality (6.1% vs 2.8%; p=0.259), pneumonia (12.1% vs 6.1%; p=0.246) and cardiac arrhythmias (33.3% vs 21.2%; p=0.094) were increased numerically. After multivariable adjustment, most differences diminished (mortality odds ratio [OR] 1.8, p=0.617; AKI OR 1.2, p=0.735). Among patients with CKD stage 3b or higher (CKD3b+; n=80; 1.5%), complications were more pronounced. In-hospital mortality was substantially higher (12.5% vs 2.7%; p=0.017), along with grade 4 CRS (7.7% vs 1.0%; p=0.011), acute myocardial infarction (6.3% vs 0.7%; p=0.007) and AKI (50.0% vs 11.7%; p<0.001). The cost of hospitalization (USD 446,074 vs 366,826; p=0.197) trended higher. Adjusted models confirmed markedly increased mortality (OR 10.2, 1.5–67.8; p=0.016) but other outcomes were not significant. Conclusions: CKD3b+ is associated with substantially higher mortality with signal of augmented high-grade CRS and cardiac events, whereas CKD3a+ exhibited worsening in renal outcomes and higher cost that attenuated after adjustment. These findings position pre-existing renal dysfunction especially CKD3b+ as a clinically salient risk substrate warranting pre-emptive risk stratification, vigilant cardiac monitoring and proactive organ-support pathways to mitigate downstream morbidity and mortality.

e18579 Background: Outcomes after allogeneic hematopoietic cell transplantation (allo-HCT) are often summarized using overall survival (OS) or treatment related mortality (TRM), which may obscure distinct biologic and toxicity driven pathways of failure. Major organ toxicities are important causes of morbidity and mortality but are rarely evaluated as competing events alongside relapse. We sought to characterize relapse and major organ failure as distinct competing pathways after allo-HCT. Methods: We analyzed adult allo-HCT recipients from the CIBMTR RT17-01 publicly available dataset (2008-2016). The primary endpoint was the first post transplant failure pathway, defined as relapse, major organ failure (MOF) requiring dialysis or diagnosed as thrombotic microangiopathy (TMA), veno-occlusive disease (VOD), or idiopathic pneumonia syndrome (IPS), or death without prior relapse or MOF. Competing risk methods estimated cumulative incidence, and cause specific Cox models evaluated associations between conditioning intensity and outcomes, adjusting for clinical and transplant related covariates, with the renal component of the hematopoietic cell transplantation comorbidity index (HCT-CI) removed. Results: The cohort included 13,187 adult recipients with a median age of 58.6 years, of whom 59.3 percent were male. Conditioning intensity was myeloablative (MAC) in 6,134 patients, reduced intensity (RIC) in 4,795, and non myeloablative (NMA) in 2,221. The first failure pathway was relapse in 5,157 patients, MOF in 1,511, and death without relapse or MOF in 2,535. At one year, cumulative incidence was 32.4 percent for relapse, 10.4 percent for MOF, and 13.1 percent for death without either event. IPS and dialysis requiring renal failure were the most frequent MOF events. Compared with MAC, RIC was associated with higher relapse risk (adjusted hazard ratio [aHR] 1.14; 95 percent confidence interval [CI] 1.07-1.23) and lower MOF risk (aHR 0.72; 95 percent CI 0.64-0.82). NMA conditioning showed a further shift toward relapse (aHR 1.42; 95 percent CI 1.30-1.54) with greater reduction in MOF risk (aHR 0.55; 95 percent CI 0.46-0.66). Conclusions: Relapse and MOF represent distinct competing pathways of failure after allo-HCT. Conditioning intensity influences which pathway predominates, with less intensive regimens shifting risk from organ toxicity toward relapse. Pathway based competing risk analyses provide insight beyond traditional survival endpoints and may support more individualized transplant decision making.

7064 Background: Chimeric antigen receptor (CAR) T cell therapy has revolutionized care for relapsed/refractory diffuse large B cell lymphoma (DLBCL), yet granular delineation of real-world immune effector toxicities, organ-specific sequelae and economic burden across demographic and socioeconomic strata requires further exploration. Methods: Using the National Inpatient Sample (2017–2022), we identified adult DLBCL hospitalizations receiving CAR T through ICD-10-PCS codes. Cytokine release syndrome (CRS) [all grades - 2021–2022], immune effector cell–associated neurotoxicity syndrome (ICANS) [all grades – 2022], infections, cardiac events and acute kidney injury (AKI) were identified through ICD-10 codes. Age was stratified into 21-40, 41-60, 61-80 and >81 years. Payer groups were Medicare, Medicaid, Private and Uninsured. Races were White, African American, Hispanic and others [Pacific Islanders, Native Indians, Asians]. Chi-square analysis was performed, and multivariate regression adjusted for demographics, comorbidities, and hospital characteristics. Results: Across >11,000 weighted hospitalizations, inpatient mortality, all-grade CRS and ICANS were comparable across age, race, and payer groups (p>0.05). Inpatient mortality was numerically higher in other minor races (6.6%) vs White (3.3%), African American (3.1%), and Hispanic (0.9%; p=0.230). Any grade CRS was numerically higher in other minor races (72.5%) than in White (62.3%) and African American (60.6%; p=0.614). Any grade ICANS dispersion included 29.5% (White), 39.1% (African American), 22.5% (Hispanic) and 11.1% (Other; p=0.204). A race-specific signal for ICANS grade 5 (p=0.030) was seen, but numbers were small. Among cardiac events, arrhythmias rose from 7.6% (age 21–40 years) to 57.1% ( age ≥81 years) (p<0.001). By payer, arrhythmias were highest in Medicare (31.2%; p<0.001). Other cardiac events including myocardial infarction, stroke and cardiogenic shock were similar across groups. Pneumonia rates varied by payer, peaking in the Uninsured (23.8%; p=0.010). Sepsis and septic shock rates showed no differences. AKI (p=0.007) rates showed differences but attenuated after adjustment. Hispanic and other minor races had lower adjusted costs than White (Odds ratio [OR] 0.9, p=0.046; OR 0.8, p=0.006), while ages 61–80 had higher adjusted costs vs 21–40 (OR 1.2, p=0.023). Conclusions: In this national cohort, CRS, ICANS and mortality were similar across demographic and payer strata, indicating consistent immune effector safety. Cardiac arrhythmia rates were higher among the elderly and Medicare beneficiaries. There were lower expenditures among minor race groups and higher costs in elderly. These findings highlight discrete domains of variability and suggest intensified cardiac surveillance in elderly and equitable resource allocation to optimize outcomes with CAR-T.