Mahadevia, Himil

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.

e19543 Background: Multiple myeloma (MM) is a plasma cell malignancy characterized by immune dysfunction and end-organ damage. Emerging preclinical evidence suggests vitamin D is implicated in MM biology through effects on plasma cell differentiation and immune regulation. Vitamin D deficiency is common among patients with MM, yet its prognostic significance remains unclear. Clarifying its role may inform risk stratification and supportive management in MM. Methods: We conducted a retrospective cohort study using the multicenter TriNetX research network. Adults aged ≥20 years diagnosed with MM between 2011 and 2024 were included. Vitamin D status was defined using serum 25-hydroxyvitamin D levels, with deficiency defined as ≤30 ng/mL and normal levels defined as 31–80 ng/mL. Patients were stratified into two groups based on vitamin D status at the time of MM diagnosis. Propensity score matching (1:1) was performed to balance age, sex, race, baseline laboratory values, and clinically relevant comorbidities between groups. Kaplan–Meier survival analyses and Cox proportional hazards models were performed for outcome analyses. Results: A total of 36,273 patients with MM were included, of whom 42% (n = 15,262) had vitamin D deficiency. After propensity score matching, 14,023 vitamin D–deficient patients were well balanced with 14,006 non-deficient patients across baseline characteristics. In the matched cohort, the mean age was 64 years, 49% were female, and 64% were White. At five years, vitamin D deficiency was associated with a significantly higher risk of mortality (hazard ratio [HR] 1.63, 95% CI 1.54–1.72), with lower five-year overall survival (OS) compared with non-deficient patients (71.1% vs 80.8%, p<0.05). Vitamin D deficiency was also associated with increased risks of pneumonia (risk ratio [RR] 1.11), bacteremia (RR 1.22), and critical care admission (RR 1.30) (all p<0.05). Additionally, deficient patients had higher risks of acute kidney injury (AKI) (RR 1.19) and venous thromboembolism (RR 1.18) (both p<0.05). Notably, the risk of MM relapse was modestly increased among vitamin D-deficient patients (RR 1.07, 95% CI 1.01–1.13). No significant associations were observed between vitamin D deficiency and amyloidosis or pathologic fractures. In multivariable Cox regression, vitamin D deficiency remained independently associated with worse five-year OS (adjusted HR 1.60, 95% CI 1.52–1.67). Conclusions: This study highlights the negative impact of vitamin D deficiency in patients with MM. It identifies a high-risk subgroup of patients characterized by worse five-year OS, higher rates of serious infections, AKI, critical care utilization, and an increased risk of MM relapse. These findings suggest vitamin D deficiency as a clinically relevant prognostic marker in MM. Prospective studies are warranted to determine whether vitamin D level optimization can improve MM outcomes.

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.

e16488 Background: Small bowel adenocarcinoma (SBA) and ampullary adenocarcinoma (ampullary AC) are rare gastrointestinal (GI) malignancies. Treatment strategies are largely extrapolated from colorectal cancer, where oxaliplatin-based regimens are the most common first-line therapy in advanced disease. Although bevacizumab is considered safe in metastatic SBA, its efficacy remains unproven, and evidence is limited to small retrospective studies. We assessed the association of adding bevacizumab to FOLFOX with survival and toxicity in a large real-world cohort. Methods: We conducted a retrospective cohort study using the TriNetX Global Collaborative Network (January 2000-December 2025), including data from 105 healthcare organizations. Adults (≥18 years) with SBA or ampullary AC treated with FOLFOX with or without bevacizumab were identified. Cohorts were propensity score-matched on age, sex, race, comorbidities, and metastatic sites. Outcomes included overall mortality, GI perforation, bleeding, venous thromboembolism (VTE), hospital admission, and emergency department (ED) visits. Kaplan-Meier and Cox proportional hazards models were used for time-to-event analyses. Results: After matching, 818 patients were included in each cohort. In the FOLFOX + bevacizumab cohort, mean age was 66.1 ± 12.0 years and 53.8% were male; 63.7% were White, 13.8% Black, 5.6% Asian, 12.0% Unknown/Other, and 4.4% Hispanic/Latino. Over a median follow-up of 13 months, FOLFOX + bevacizumab was associated with higher overall mortality compared with FOLFOX alone (55.3% vs 45.2%; HR 1.24 [95% CI 1.1-1.4]; p = 0.002) and shorter median OS (15.1 vs 19.5 months). Rates of GI perforation (15.5% vs 16.7%; HR 0.90 [95% CI 0.71-1.15]; p = 0.39), GI bleeding (13.1% vs 13.6%; HR 0.96 [95% CI 0.73-1.25]; p = 0.74), and VTE (19.1% vs 21.4%; HR 0.88 [95% CI 0.71-1.09]; p = 0.23) were similar between groups. Hospital admissions were higher in the FOLFOX + bevacizumab cohort (2.8% vs 1.3%; HR 2.1 [95% CI 1.0-4.3]; p = 0.04). Findings were consistent at 5-year follow-up. Conclusions: In this real-world cohort, the addition of bevacizumab to FOLFOX was not associated with improved survival and was associated with higher healthcare utilization. Prospective, disease-specific studies are needed to define its role in this population. Outcomes at median 13-month follow-up after propensity matching (FOLFOX + bevacizumab vs FOLFOX). Outcome % vs % HR p Overall mortality 55.3 vs 45.2 1.24 0.002 Hospital admission 2.8 vs 1.3 2.1 0.04 ED visit 45.2 vs 42.4 1.02 0.75 GI perforation 15.5 vs 16.7 0.90 0.39 GI bleeding 13.1 vs 13.6 0.96 0.74 VTE 19.1 vs 21.4 0.88 0.23

e15713 Background: Fruquintinib demonstrated overall survival benefit in heavily pretreated metastatic colorectal cancer (mCRC) in FRESCO and FRESCO-2. The FDA approved fruquintinib on Nov 8, 2023 for adult patients with mCRC after standard chemotherapy plus anti-VEGF therapy, with anti-EGFR therapy when appropriate (e.g., RAS wild-type). Observed geographic variation in post-approval uptake suggests potential disparities in the delivery of evidence-based medicine across U.S. regions. Methods: We conducted a retrospective cohort study using Epic Cosmos, a database of over 300 million patient records from over 1,500 hospitals nationwide. We identified adults with metastatic colorectal cancer (mCRC) with prior standard systemic therapy exposure and recorded fruquintinib exposure following FDA approval beginning Nov 8, 2023. Fruquintinib uptake was analyzed by U.S. Census region and state, expressed as the proportion of eligible mCRC patients receiving fruquintinib within each geography. Results: Among 116,116 pre-treated mCRC patients, 6,722 (5.79%) had recorded fruquintinib exposure during the post-approval period. Uptake varied nearly five-fold across states (2.27%–11.33%) (Table). High-uptake states were disproportionately concentrated in the central U.S./Midwest, whereas multiple low-uptake states were observed in the West and Northeast, suggesting broader regional variation beyond state-to-state differences. Conclusions: In a large national EHR-derived cohort of pre-treated mCRC patients after U.S. approval, fruquintinib uptake demonstrated substantial geographic variation. These findings raise concern for inequities in delivery of evidence-based later-line therapy and highlight the need to identify modifiable system- and site-level drivers (e.g., access, referral patterns, treatment infrastructure) to promote equitable adoption. Fruquintinib uptake among eligible metastatic colorectal cancer patients by U.S. state. Rank Geography Eligible mCRC (N) Fruquintinib uptake (%) Overall Overall 116,116 5.79 Top 1 Oklahoma 1,236 11.33 2 Kansas 1,312 10.75 3 Indiana 2,448 10.70 4 Missouri 1,521 9.47 5 Connecticut 2,208 9.24 Bottom 1 Washington 1,232 2.27 2 Nevada 441 2.72 3 Rhode Island 476 2.73 4 Tennessee 1490 2.82 5 Maine 614 2.93 Fruquintinib uptake is reported as the proportion of eligible pre-treated metastatic colorectal cancer (mCRC) patients with recorded fruquintinib exposure following U.S. FDA approval. States are ranked by uptake percentage.

e14524 Background: Immune checkpoint inhibition has demonstrated meaningful clinical benefit in microsatellite instability–high (MSI-H) colorectal cancer (CRC); however, outcomes remain heterogeneous. The interaction between tumor immune microenvironment features, tumor mutational burden (TMB), and survival outcomes has not been fully characterized. We conducted an integrative analysis of publicly available genomic data to evaluate the prognostic impact of immune infiltration stratified by MSI status and TMB in CRC. Methods: Transcriptomic, somatic mutation, and clinical data for primary colorectal adenocarcinoma were obtained from TCGA-COAD and TCGA-READ. About 600 patients with overall survival data were analyzed. MSI status was taken from TCGA molecular subtype annotations. TMB was defined as the number of nonsynonymous somatic mutations per tumor and dichotomized at the median.Immune infiltration (CD8⁺ and CD4⁺ T cells, macrophages, neutrophils, dendritic cells) was estimated using TIMER. Patients were classified as high or low infiltration by the median. Overall survival was assessed using Kaplan–Meier analysis and Cox models adjusted for age, sex, and tumor stage., and tumor stage. Results: The cohort included approximately 15% MSI-H tumors, which demonstrated significantly higher TMB compared with microsatellite-stable (MSS) tumors. MSI-H tumors exhibited an inflamed immune phenotype, with approximately twofold higher CD8⁺ T-cell infiltration relative to MSS tumors. Across the overall cohort, high CD8⁺ T-cell infiltration was associated with improved OS compared with low infiltration (median OS not reached vs approximately 60–70 months). In contrast, increased macrophage infiltration was associated with inferior survival outcomes. When stratified by genomic features, the favorable prognostic association of CD8⁺ T-cell infiltration was most pronounced in MSI-H and TMB-high tumors, corresponding to an estimated 30–40% relative reduction in mortality risk compared with MSI-H/TMB-high tumors with low immune infiltration. Immune infiltration demonstrated weaker and less consistent associations with OS in MSS/TMB-low tumors. In multivariable analyses, CD8⁺ T-cell infiltration remained independently associated with improved OS after adjustment for clinical covariates, whereas macrophage infiltration remained independently associated with worse outcomes. Findings were consistent across colon and rectal cancer subgroups. Conclusions: In this integrative analysis of TCGA colorectal cancer datasets, features of the tumor immune microenvironment, together with MSI status and TMB, were associated with survival. These results support immune-genomic stratification and suggest that combining immune and molecular biomarkers may improve prognostic assessment and immunotherapy trial design in colorectal cancer.

9021 Background: An escape room is a team-based activity in which participants collaborate to solve puzzles within a fixed time limit and escape. Prior studies demonstrate high learner satisfaction and improved teamwork and communication with medical education escape rooms. To date, no published reports describe an escape room designed specifically for hematology/oncology (hem/onc) fellows. As part of Hem/Onc Curriculum, we designed and implemented a hem/onc-focused escape room and evaluated learner satisfaction and perceived learning impact. Methods: The escape room was designed using evidence-based learning science principles (Table 1). Teams worked to solve sequential puzzles, centered on a patient case, addressing key hem/onc concepts, including transfusion medicine, peripheral blood smears, lymphoma classification, and coagulation disorders. Each solved puzzle revealed additional patient laboratory and pathology data. Successful completion required teams to diagnose the patient and select appropriate treatment. Following the activity, teams participated in a facilitator-led debrief focused on team dynamics, communication, and problem solving. Teams observed each other and shared feedback. A larger group debrief co-led by chief fellows and faculty reviewed learning objectives and key takeaways. Learner outcomes were assessed using a post-activity survey evaluating satisfaction, engagement, and impact on learning. Results: Eighteen learners participated, including 14 hem/onc fellows, 1 APP hem/onc fellow, and 3 internal medicine residents. Three of four teams escaped within 1 hour (mean completion time, 52 minutes). All participants provided positive verbal feedback. Fifteen learners completed the post-activity survey, and all respondents reported satisfaction with the activity and would recommend it for future fellows. One-word descriptors included “engaging,” “fun,” and “challenging.” Most respondents (93.3%) agreed that the activity reinforced key hem/onc concepts and improved confidence in clinical problem-solving. All learners felt the activity supported learning, and 93.3% reported that collaboration enhanced the learning experience. Participants identified team-based problem solving, clinical application, and interactive puzzles as the most effective components. Conclusions: A hem/onc escape room resulted in high learner satisfaction and reinforced hem/onc knowledge and clinical problem-solving. This feasible, fun, and innovative activity complements traditional fellowship education by leveraging adult learning principles through gamified, team-based learning and should be incorporated into training programs’ curriculum. Learning science principles applied in a hem/onc escape room. Active Learning Belonging Contrasting Cases Debriefing Deliberate Practice Elaboration Generation Listening and Sharing Reward Worked Examples