Citations

6539 Background: The impact of insurance status on survival in diffuse large B‐cell lymphoma (DLBCL), the most common aggressive lymphoma, has not been evaluated after the implementation of the Affordable Care Act (ACA). The aim of this study is to compare overall survival (OS) in patients across insurance status groups and in the periods before and after the ACA. Methods: Adult patients with newly diagnosed DLBCL were identified from the National Cancer Database. The analysis was restricted to patients 64 years of age or younger as most patients 65 years or older are eligible for Medicare under the ACA. The 2004-2017 period was chosen to represent the immunochemotherapy era preceding and following the ACA. Logistic regression was used to explore associations between abstracted variables and insurance status groups. The Kaplan-Meier method and Cox proportional hazards model were used for survival analysis. Results: 93,692 adults (age < 64 years) with newly diagnosed DLBCL and known insurance status were identified (41.3% female, median age 54 years [range: 18 – 64], 81.8% White and 12.1% Black). 7,211 (7.7%) patients were uninsured, 64,744 (69.1%) had private insurance, 11,936 (12.7%) had Medicaid, and 9,801 (10.5%) had Medicare. When compared to insured patients (private insurance, Medicaid or Medicare), uninsured patients were more likely to have a median household outcome of < $38,000 [OR 1.93 (95% CI 1.79-2.07)], less likely to receive chemotherapy [OR 0.69 (0.64-0.77)], more likely to be male [OR 1.14 (1.07-1.21)], more likely to be non-White [OR 1.30 (1.20-1.40], and more likely to present with stage III or IV disease [OR 1.24 (1.16-1.32)]. Uninsured patients had an inferior OS [HR 1.21 (95% CI 1.15-1.27)] when compared to insured patients after adjustment for baseline comorbidity (Charlson-Deyo score ≥2), advanced stage, treatment with chemotherapy, and sociodemographic factors including sex, age, race, household income, facility type (academic/community), and location (urban/rural). With a median follow-up time of 14.8 years (95% CI 14.6-not reached), median OS was lower in uninsured patients [13.4 years (12.3-not reached) vs 14.8 years (14.7-not reached); p < 0.0001]. Despite the lack of major changes in DLBCL therapies, a diagnosis after the implementation of the ACA (in 2010 or later) was associated with a superior OS when compared with the outcomes of patients diagnosed in 2010 or earlier [HR 0.93 (95% CI 0.90-0.95)]. Similarly, five-year OS was superior in the insured group [HR 0.93 (95% CI 0.89-0.96)]. Conclusions: Uninsured patients with DLBCL and < 64 years old had inferior OS when compared with insured patients, and uninsured status emerged as an independent risk factor for inferior OS. Our data highlight the independent effect of insurance disparities - a potential indicator of variations in access to health care - on survival in DLBCL.

e19527 Background: While extra nodal involvement by MCL is relatively common, involvement of the central nervous system (CNS) is a rare ( < 5% of cases) complication with limited treatment options. We report the outcomes of a large cohort of patients (pts) with CNS MCL. Methods: MCL pts with CNS involvement seen at Mayo Clinic between 1/1/1995-9/16/2020 were identified. CNS involvement was defined by histologically confirmed CNS MCL, CSF analysis demonstrating lymphoma cells, and/or neuroimaging findings compatible with CNS lymphoma. Medical records were reviewed for baseline characteristics, treatment, and outcome. Kaplan-Meier method was used for time to event analysis. Results: Out of 1,753 pts with MCL, 36 (2%) had CNS involvement by MCL. Median age at MCL diagnosis was 64 years (range 36-83) and 26 were male (72%). At MCL diagnosis, non-CNS extranodal involvement was seen in 30 pts, 24 with 1 site and 6 with ≥ 2 sites; 24 had bone marrow involvement. 11 (31%) pts had blastoid variant. Median Ki-67 was 40% (range 15-100%). MIPI score was available in 17 pts [low risk (n = 5, 29%), intermediate risk (n = 9, 53%), high risk (n = 3, 18%)]. The most common frontline regimen for MCL was R-CHOP and 14 (39%) pts underwent autologous stem cell transplant in CR1. The incidence of CNS involvement was overall similar over the study period. Median time from MCL diagnosis to CNS involvement was 25 months (m) (range 0-167). 4 (11%) pts presented with CNS involvement at initial diagnosis and 32 presented at relapse (12 isolated CNS relapse and 20 concurrent CNS and systemic relapse. Abnormal CSF was noted in 27 (87%) pts [consistent with MCL diagnosis (n = 26), atypical lymphocytes (n = 1)]. Abnormal CNS imaging was reported in 27 (75%) pts [leptomeningeal (n = 18), leptomeningeal and parenchymal (n = 5), parenchymal (n = 2), ocular (n = 2)]. First line CNS-directed therapy data was available in 33 (92%) pts. 12 (34%) received intrathecal (IT) therapy alone, 19 (54%) received systemic +/- IT therapy, 2 (6%) received radiation alone, and 2 (6%) pts received no treatment (hospice). The overall CNS response to therapy was CR in 13 (42%) pts, PR in 3 (10%), SD in 8 (26%), and PD in 7 (22%) pts. Three pts received BTK inhibitors [ibrutinib (n = 2) or acalabrutinib (n = 1)] as the first CNS-directed therapy. One patient achieved a CR with a response lasting 4 m, another patient achieved a PR with response lasting 10 m. CNS response data was not available in the remaining pts. Median follow up from CNS involvement was 72 m (95% CI: 41-NR). Median EFS for the 1 st CNS-directed therapy was 3.7 m (95% CI: 1.6-6.1). At last follow up, 30 pts were deceased. The cause of death was CNS lymphoma in 10 (33%) pts and systemic lymphoma in 9 (30%) pts. Median OS from CNS involvement was 4.7 m (95% CI: 2.3-6.7). Conclusions: CNS involvement by MCL has dismal outcomes as evident by a median OS of approximately 5 m. BTK inhibitors may have a role in treatment of this rare complication, but further prospective investigation is needed.

7049 Background: Langerhans cell histiocytosis (LCH) can manifest as single system (SS) disease, multisystem (MS) disease, or pulmonary LCH (smoking-related). There is a paucity of data on prognostic factors including risk organ (RO) involvement (liver, spleen, and bone marrow) in adult LCH, which we sought to address in this study. Methods: Single-center retrospective study of patients ≥18y diagnosed with LCH from 1998 to 2020. Univariate and multivariate analyses for progression free survival (PFS) and overall survival (OS) were conducted using age, sex, organ involvement, LCH subtype, year of diagnosis, BRAF V600E status, and treatments. Results: We included 219 patients with LCH; median age 43y (range 19-88), females 51%, SS unifocal (23%), SS multifocal (6%), pulmonary (31%) and MS (40%). Commonly involved organs included lung (53%), bone (42%), skin (24%), pituitary (16%), and CNS (12%). BRAF V600E was positive in 40/88 (46%). Median follow-up duration was 6.1y (95% CI, 5.1- 7.1). On univariate analysis, factors associated with worse PFS were bone LCH, RO involvement, multifocal/MS LCH, and radiation therapy alone; those with worse OS included RO involvement, MS disease, BRAF V600E+, and age ≥45y at diagnosis. In multivariate analysis, BRAF V600E and age ≥45y at diagnosis were associated with worse mortality (Table). Median PFS was not reached (NR-NR) for SS unifocal LCH, 5mo (0-12.7) for SS multifocal LCH, 110mo (84.7-135.3) for pulmonary LCH, and 27mo (17.2-36.8) for MS LCH. 5-year OS was 97.4% for SS unifocal LCH, 100% for SS multifocal LCH, 96.1% for pulmonary LCH, and 79.9% for MS LCH. 41 (18.7%) developed a second primary malignancy (SPM), of which 11 were hematologic neoplasms. There was a trend towards a higher prevalence of SPMs in patients with BRAF V600E (28% vs. 17%; p = 0.22). Conclusions: In our large single-center study, PFS for multifocal and MS LCH was worse than SS unifocal or pulmonary LCH. RO involvement was not associated with outcomes in multivariate analysis. Overall prognosis was excellent for all subtypes except MS LCH. BRAF V600E and older age were associated with worse OS. The prevalence of SPMs was very high and needs to be explored further.[Table: see text]

Abstract Introduction: Recent results from two independent patient series have shown that chromosomal rearrangements of DUSP22 (DUSP22r+) and TP63 (TP63r+) can predict outcome in ALK-negative anaplastic large cell lymphoma (ALK-ALCL) and peripheral T-cell lymphoma, not otherwise specified (PTCL-NOS) with morphologic features resembling ALK-ALCL (Parilla-Castellar E, Blood 2014; Pedersen MB, Blood 2017). While DUSP22r+ is predictive for excellent survival similar to that of ALK+ALCL after CHOP/CHOP-like therapy, the rarely occurring TP63r+ is associated with an aggressive clinical behavior and poor outcome. The largest subgroup, i.e. patients with neither ALK nor DUSP22 nor TP63 rearrangements (triple negative), show a 5 year (yr) overall survival (OS) intermediate between that of ALK-/DUSP22r+ and ALK-/TP63r+ patients. The aim of the present study was to assess the impact of upfront high-dose therapy with autologous stem cell transplant (HDT/ASCT) on outcome in adult ALCL and PTCL-NOS patients according to their ALK, DUSP22 and TP63 status. The survival results from the two published series were pooled with those of a Nordic Lymphoma Group trial, the NLG-T-01 (d'Amore et al, JCO 2012), where patients were treated with 1st line CHOEP/CHOP followed, in chemosensitive cases, by upfront HDT/ASCT. Methods: Fluorescence in situ hybridization was performed on sections of previously constructed tissue microarrays using break-apart probes for the DUSP22-IRF4 and TP63 loci and a dual-fusion probe for TBL1XR1/TP63 fusion [inv(3)(q26q28)]. Evaluation of DUSP22 and TP63 rearrangements was performed in a blinded fashion without knowledge of PTCL subtype, clinical course, or outcome. Three independent patient cohorts were included: (i) one from Mayo Clinic consisting of 31 DUSP22r-, ALK-ALCL and PTCL-NOS (triple negative: 25; TP63r+: 6); (ii) one from Denmark consisting of 93 DUSP22r-, ALK-ALCL and PTCL-NOS (triple negative: 90; TP63r+: 3); and one from the NLG-T-01 trial consisting of 46 ALK-ALCL and PTCL-NOS (triple negative: 37; TP63r+: 1; DUSP22r+: 8), leading to a total study population of 170 patients. ALK+ ALCL was not included in the analysis, since no patients with this histology entered the NLG-T-01 trial. Association of genetic subtype with OS was assessed using Kaplan-Meier curves and Cox proportional models for hazard rate ratios (HR). Significant differences were defined as P &lt;0.05. Results: The eight DUSP22r+ patients (7 ALK-ALCL and 1 PTCL-NOS) from NLG-T-01 had a 5-yr OS of 83%, (95%CI 27-97), similar to that reported for DUSP22r+ in the Mayo and Danish cohorts (90% and 80%, respectively). No lymphoma-related events were observed in this subset. The only event was a septic death due to HDT-induced cytopenias in a patient who was in complete remission (CR). Among the 162 patients with DUSP22r-, ALK-ALCL and PTCL-NOS, those consolidated with HDT/ASCT (n=47) had a significantly better outcome (5-yr OS: 45%) than those treated with induction chemotherapy alone (5-yr OS: 30%) (n=115) (P=0.01). The patients in the HDT/ASCT group were younger (P&lt;0.001) and had more advanced stage disease (P=0.002). The improvement in OS persisted when the analysis was limited to transplant eligible patients and adjusted for age and stage (HR 0.52 95%CI 29-91, P=0.023) or International Prognostic Index (IPI) groups (HR 0.49, 95%CI 20-82, P=0.006). Of the 10 TP63r+ patients found within the pooled cohort, 6 were transplant eligible. Of these, 5 were not transplanted (intention-to-treat) while one was (Nordic trial). The latter patient achieved a still ongoing long-term CR, while all others died of lymphoma progression. Conclusion: In ALK-ALCL and PTCL-NOS patients from the NLG-T-01 trial, DUSP22r+ was associated with a very good outcome, similar to that seen in DUSP22r+ patients who had not undergone upfront autologous transplant. This observation supports the impression that upfront HDT/ASCT may not be of benefit in these patients. TP63r+ predicted poor outcome in non-transplanted patients. The impact of HDT/ASCT in the TP63r+ setting could not be adequately evaluated, since only one patient from the NLG-T-01 trial cohort was found to be TP63r+. Notably, this patient was the only survivor of the TP63r+ subset. For DUSP22r-, ALK-ALCL and PTCL-NOS patients taken as one group, those who received upfront HDT/ASCT had a superior survival compared to their age- and IPI-matched non-transplanted counterparts. Disclosures Ellin: ROCHE: Consultancy, Research Funding; CTI: Consultancy. Mannisto: Roche: Honoraria, Other: Travel expence; Takeda: Honoraria, Other: Travel expence; Amgen: Other: Travel expence; Novartis: Other: Travel expence; Celgene: Other: Travel expence; Gilead: Other: Travel expence; Pfizer: Honoraria; SOBI: Honoraria. Cerhan: Janssen: Other: Scientific Advisory Board (REMICADELYM4001); Janssen: Other: Multiple Myeloma Registry Steering . Toldbod: Takeda Pharma: Honoraria.

AbstractIntroductionHypoalbuminemia is a known adverse prognostic factor in lymphomas. Yet, it is unknown if axicabtagene ciloleucel (axi‐cel) overcomes the adverse prognostic impact of hypoalbuminemia in relapsed/refractory large B‐cell lymphoma.MethodsWe conducted a retrospective analysis across three Mayo Clinic centers to assess the relationship of hypoalbuminemia (defined as a serum albumin (SA) levels ≤ 3.5 g/dL) on outcomes of patients treated with axi‐cel.ResultsThis analysis included 81 patients. Two patients had no available SA levels preceding axi‐cel infusion. Eighteen patients (22.8%) had hypoalbuminemia with a median SA of 3.3 g/dL. Patients with normal SA had a statistically higher ORR than those without hypoalbuminemia (P = .018). There was no difference in 1‐year PFS and OS between the group with hypoalbuminemia and the group with normal SA levels (48% vs 49%, P = .81) and (74% vs 73%, P = .97), respectively. There was no difference in the severity or median duration of cytokine release syndrome or neurotoxicity between the two groups.ConclusionNotwithstanding the limitations related to the relatively small sample size, axi‐cel therapy appears to overcome the adverse effect of hypoalbuminemia on OS and PFS. Large multicenter clinical studies are certainly needed to validate these findings.

Abstract B-cell non-Hodgkin lymphoma cell survival depends on poorly understood immune evasion mechanisms. In melanoma, the composition of the gut microbiota (GMB) is associated with immune system regulation and response to immunotherapy. We investigated the association of GMB composition and diversity with lymphoma biology and treatment outcome. Patients with diffuse large B-cell lymphoma (DLBCL), marginal zone (MZL), and follicular lymphoma (FL) were recruited at Mayo Clinic, Minnesota, and Perlmutter Cancer Center, NYU Langone Health. The pretreatment GMB was analyzed using 16S ribosomal RNA gene sequencing. We examined GMB compositions in 3 contexts: lymphoma patients (51) compared with healthy controls (58), aggressive (DLBCL) (8) compared with indolent (FL, MZL) (18), and the association of GMB with immunochemotherapy treatment outcomes (8 responders, 6 nonresponders). Respectively, we found that the pretreatment GMB in lymphoma patients had a distinct composition compared with healthy controls (P &lt; .001); GMB compositions in DLBCL patients were significantly different than indolent patients (P = .01) with a trend toward reduced microbial diversity in DLBCL patients (P = .08); and pretreatment GMB diversity and composition were significant predictors of treatment responses (P = .01). The impact of these pilot results is limited by our small sample size, and should be considered a proof of principle. If validated, our results could lead toward improved treatment outcomes by improving medication stewardship and informing which GMB-targeted therapies should be tested to improve patient outcomes.

Background: Infection during the period of neutropenia following chemotherapy represents a major cause of morbidity and mortality in patients with malignancy.(Freifeld, et al, 2011, Baden LR, et al, 2012) Several guidelines recommend granulocyte colony stimulating factor (GCSF) to reduce the duration and severity of chemotherapy-induced neutropenia and abate infection risk.(Lyman, et al 2018, Aapro, et al, 2011, Smith, et al, 2015). Optimal GCSF administration following chimeric antigen receptor (CAR) T-cell therapy remains undefined and requires characterization. Methods: The Mayo Institutional Review Board approved this retrospective, single-center study. Electronic medical records for patients prescribed axicabtagene ciloleucel were reviewed until disease relapse, death, or a maximum of 60 days after infusion. Baseline characteristics and laboratory values were abstracted prior to lymphodepleting chemotherapy. GCSF support was originally prescribed when the absolute neutrophil count (ANC) declined below 500 cells/mm3 and discontinued when the ANC exceeded 1000 cells/mm3 (neutropenia) for 2 consecutive days. A practice change was made where GCSF was recommended only in those with febrile neutropenia and an increased concern for infection. The primary endpoint was the difference in the total days of neutropenia for patients receiving and not receiving GCSF. Secondary outcomes compared total days of severe neutropenia, number of neutropenia episodes, infection rates by GCSF use, and outcomes by protocol change. Neutropenia and severe neutropenia were defined as an ANC below 500 cells/mm3 and 100 cells/mm3, respectively. Updated data with more patients will be presented at the conference. Results: The 60 included patients had a median age of 59 (IQR: 44, 63) years, 38 (63%) were male and 53 (88%) were Caucasian. Significantly fewer patients were prescribed GCSF according to infection-related concerns compared to ANC-based indication, 18% vs. 94%, p&lt;0.001. Because only 3 subjects received GCSF based on infection-related concerns, results based on GCSF use versus no use is shown here. GCSF was prescribed to 35 (58%) patients for a median of 8 (IQR: 6, 12) doses with a median cumulative dosage of 3840 mcg (IQR 2100-5400) and median time to first dose of 3 days (IQR: 1, 4) post CAR T-cell infusion. Table 1 displays additional baseline characteristics and laboratory parameters according to GCSF support utilization. GCSF prescribed: Table 2 displays outcomes by GCSF use. Total days of neutropenia were similar between groups (13 vs. 16, p=0.52) with a trend towards significantly fewer days of severe neutropenia when prescribed GCSF (6 vs. 9, p=0.129). Patients prescribed GCSF were more likely to experience multiple episodes of neutropenia (83% vs. 43% p=0.002) with a significantly greater median number of episodes (3 vs. 1, p=0.002) when compared to those not prescribed GCSF. GCSF use significantly decreased the median days of the first neutropenia episode (6 vs. 12, p=0.001). There was a trend for decreased median days of severe neutropenia in the first episode with GCSF (5.0 vs. 8.0, p=0.236). Figure 1 displays a trend towards a lower overall risk of infection (HR 0.55, 95%CI: 0.16-1.87, p=0.34) and lower risk of bacterial infection (HR: 0.49, 95% CI: 0.18-1.31, p=0.15); however, these were not statistically significant. Conclusion: Patients prescribed GCSF according to ANC-based indication were significantly more likely to experience multiple neutropenia episodes; however, duration of first neutropenic episode and days of severe neutropenia during the first neutropenic episode were significantly reduced. Interestingly, the total days of neutropenia and severe neutropenia were similar between groups. It is possible that using the parameter of ANC more than 1000 cells/mm3 for 2 consecutive days is not the optimal criteria for stopping GCSF. Risk of overall and bacterial infection was lower with ANC-based initiation of GCSF, although non-significant likely due to small sample size. The potential benefit for using CSF and the optimal timing after CAR T-cell infusion requires further, rigorous, prospective investigation. Disclosures Ansell: ADC Therapeutics: Research Funding; Trillium: Research Funding; Affimed: Research Funding; Regeneron: Research Funding; AI Therapeutics: Research Funding; Takeda: Research Funding; Seattle Genetics: Research Funding; Bristol Myers Squibb: Research Funding. Bennani:Purdue Pharma: Other: Advisory Board; Kite/Gilead: Research Funding; Affimed: Research Funding; Verastem: Other: Advisory Board. Lin:Kite, a Gilead Company: Consultancy, Research Funding; Vineti: Consultancy; Sorrento: Consultancy, Membership on an entity's Board of Directors or advisory committees; Gamida Cells: Consultancy; Takeda: Research Funding; Merck: Research Funding; Legend BioTech: Consultancy; Juno: Consultancy; Bluebird Bio: Consultancy, Research Funding; Celgene: Consultancy, Research Funding; Novartis: Consultancy; Janssen: Consultancy, Research Funding.

Background: Langerhans cell histiocytosis (LCH) is the most common histiocytic disorder that is now recognized as a neoplasm by the World Health Organization. It is generally classified based on the site and extent of disease involvement (single system or multisystem). Pulmonary LCH (pLCH), an uncommon interstitial lung disease associated with smoking, often presents as isolated pulmonary disease. It is unclear whether patients with clinically isolated pLCH have extra-pulmonary lesions at diagnosis or during the course of their disease. The role of [18F] fluorodeoxyglucose positron emission tomography-computed tomography (FDG-PET-CT) in the staging of pLCH remains unclear. Our study aims to better characterize the utility of radiographic staging studies at time of diagnosis and prevalence of extrapulmonary disease at follow up in pLCH. Methods: We conducted a retrospective study of patients presenting with clinical findings consistent with isolated pLCH seen at the Mayo Clinic from January 2000 to January 2020. All patients had a diagnosis of pLCH determined by chest imaging studies [computed tomography (CT) or high-resolution CT (HRCT)] or by histopathologic findings from surgical or transbronchial lung biopsy. Histopathologic findings for the diagnosis of pLCH required the presence of Langerhans cells (S100+/CD1a+/Langerin+). Patients were excluded if they had clinically apparent extra-pulmonary organ involvement at the time of diagnosis. BRAF V600E mutation was determined by immunohistochemistry (IHC) or cell-free DNA (cfDNA). Staging was defined as FDG-PET-CT or whole body CT imaging obtained within 3 months of diagnosis of pLCH. Extra-pulmonary LCH involvement was determined by imaging characteristics or by histopathologic findings. Descriptive statistics and overall survival (OS) were analyzed with JMP software, version 14 (SAS Institute Inc., Cary, NC). Results: A total of 112 patients with clinically isolated pLCH were identified. The median age at diagnosis was 45 years (range 21-73), and 48 (43%) were male. The majority (n=110, 99%) were former or current smokers with a median pack year of 25 (range 1-57). Three (3%) patients were noted to have occupational industrial exposure. Nine patients had a history of another cancer prior to their diagnosis and staging of pLCH [lung (n=4), breast (n=2), neuroendocrine (n=2), thyroid (n=1)]. Presenting symptoms included dyspnea on exertion 49 (44%), cough 18 (16%), chest pain 14 (13%), and 29 (28%) were incidentally discovered on imaging studies. On HRCT, the following characteristics were observed: 42 (38%) cystic, 32 (29%) cystic and nodular, 37 (33%) nodular, 1 (&lt;1%) ground glass opacities. Seventy (63%) patients had lung biopsy confirmation, of which 11 (16%) patients underwent BRAF V600Emutation testing (7 by IHC, 4 by cfDNA). Six (55%) of these 11 patients were positive for BRAF V600E mutation. 34 (30%) patients underwent radiographic staging studies within 3 months of diagnosis of pLCH (25 FDG-PET-CT and 9 whole-body CT), and none of these imaging studies showed evidence of extra-pulmonary disease. Of the patients who had at least one year of follow-up (n=52), one (2%) developed extra-pulmonary disease. This patient did not undergo initial staging studies, developed headaches and was found to have a large calvarial lytic lesion within 2 months of pLCH diagnosis (BRAF V600E+). Among those who did not undergo staging at diagnosis (n=78), long term (&gt;5 years) follow up data were available for 23 (29%), and none developed extra-pulmonary disease as determined by clinical notes or imaging studies. No patient had evidence of new extra-pulmonary involvement or second malignancy at the time of last known follow-up. After a median follow-up duration of 2.4 years (95% CI: 1.5-3.6, range: 0.1-17) ten (9%) patients died, of which 5 died of pLCH related complications. The median OS for entire cohort was 15 years (95% CI 9.1-not reached, Figure 1). Conclusion: Our study shows that adult patients with clinically isolated pLCH rarely present with extra-pulmonary manifestations at diagnosis or at follow up. These findings suggest a limited role of routine radiographic staging studies in pLCH unless clinically indicated. Studies on longer follow up of this cohort would provide further insights into the natural history of pLCH and are underway. Disclosures Bennani: Purdue Pharma: Other: Advisory Board; Verastem: Other: Advisory Board; Kite/Gilead: Research Funding; Affimed: Research Funding. Shah:Dren Bio: Consultancy.

Background: Anti CD-19 chimeric antigen receptor T-cell therapy (CAR-T) is approved to treat relapsed/refractory (R/R) aggressive NHL after 2 or more lines of therapy. Randomized clinical trials are ongoing comparing CAR-T and autologous stem cell transplant (ASCT) in second line. In standard of care practice, patients refractory to second line chemotherapy are sometimes treated with third line chemotherapy and taken to ASCT if disease is chemo-sensitive. Current study aims to evaluate the impact of prior lines of therapy on the efficacy of CAR-T and ASCT. Methods: A retrospective review of patients who received ASCT and/or axicabtagene ciloleucel (axi-cel) for R/R aggressive NHL from June 2016 - January 2020 at Mayo Clinic, Rochester was performed. The lymphoma types included in the study were DLBCL, transformed lymphoma (TFL), high grade B-cell lymphoma (HGBL), and primary mediastinal large B-cell lymphoma (PMBCL). Response to all lymphoma-directed therapy was evaluated using 2014 Lugano criteria. Overall survival (OS) was defined as time from CAR-T or ASCT infusion to death, and progression free survival (PFS) was defined as time from CAR-T or ASCT infusion to disease progression, or next treatment. Categorical data was analyzed as Chi-square or fishers exact test as appropriate. Continuous variables were analyzed using Wilcoxon Rank Sum test. Analysis was performed in R3.6.3. Results: A total of 105 patients underwent ASCT and 53 patients underwent CAR-T therapy in the study period with at least 6 months follow-up. Of the 105 ASCT patients, 87 received ASCT after 2 lines of chemotherapy, ASCT(2), and 18 received ASCT after 3 lines of chemotherapy, ASCT(3). Twenty six of the ASCT [n=19, ASCT(2) and n=7, ASCT(3)] patients received CART in subsequent therapy. Baseline characteristics were comparable between the two groups except ASCT(3) had higher percent of refractory disease after first line (table 1). With a median follow up of 17.4 months, the PFS was significantly longer for the ASCT(2) group with a trend toward longer OS (Figure 1; PFS @ 1 year: ASCT(2) 67%, 95%CI 58-79%; ASCT(3) 27%, 95%CI 27-74%; p = 0.036). Among the CAR-T recipients, only 18 (33%) patients received CAR-T in the earliest possible indication, CAR-T(2): after 2 lines of chemotherapy (n=12) and/or after ASCT(2) (n=6), table 1. Compared to patients who received CAR-T in later lines (CAR-T 3+), OS was significantly longer for patients who received CAR-T(2), with a trend toward longer PFS (Figure 1; OS @ 1 year: CAR-T (2) 82%, 95%CI 65-100%; CAR-T later lines 62%, 95%CI 47-82%; p = 0.05). Additionally, 12 (23%) of patients received CAR-T immediately after ASCT (9 after ASCT(2), 3 after ASCT(3)). Baseline demographics in these 12 patients, CAR-T(ASCT), were comparable to the others who had chemoimmunotherapy as the last salvage therapy prior to CAR-T [CAR-T(chemo)], except a smaller proportion received bridging therapy (33% vs. 73%, p = 0.01). The CAR-T (ASCT) group had significantly prolonged PFS (median PFS - not reached [95%CI 3-not reached (NR)] vs. 3 months [95% CI 3-4 months]), and OS (median OS - NR, [95%CI 10.34-NR] vs. 15.1 months, [95%CI 11.9 - NR], p = 0.03). Updated analysis will be presented at the meeting with longer follow up (Figure 1). Conclusion: CAR-T use at the earliest current approved indication may confer survival advantage. Referral for earlier use of CAR-T remains low at only one third of our CAR-T practice volume. CAR-T use for relapse immediately after ASCT appear to have longer PFS and OS than after other systemic salvage therapy, although contributing parameters such as the need for bridging therapy requires further study. While patients who are chemo-refractory to second line chemotherapy may demonstrate chemo sensitivity with third line chemotherapy, PFS is shorter for ASCT(3). Comparison between ASCT(3) and CAR-T (2, chemorefractory) require larger cohorts with longer follow-up. Disclosures Bennani: Affimed: Research Funding; Purdue Pharma: Other: Advisory Board; Kite/Gilead: Research Funding; Verastem: Other: Advisory Board. Ansell:Takeda: Research Funding; ADC Therapeutics: Research Funding; Trillium: Research Funding; Bristol Myers Squibb: Research Funding; Seattle Genetics: Research Funding; Affimed: Research Funding; Regeneron: Research Funding; AI Therapeutics: Research Funding. Lin:Juno: Consultancy; Legend BioTech: Consultancy; Merck: Research Funding; Takeda: Research Funding; Gamida Cells: Consultancy; Sorrento: Consultancy, Membership on an entity's Board of Directors or advisory committees; Vineti: Consultancy; Bluebird Bio: Consultancy, Research Funding; Celgene: Consultancy, Research Funding; Novartis: Consultancy; Janssen: Consultancy, Research Funding; Kite, a Gilead Company: Consultancy, Research Funding.