Abstract: Introduction. Salvage chemotherapy followed by HDC-ASCT is considered standard of care for chemosensitive patients who have relapsed after initial therapy. CD30 is commonly expressed in Hodgkin Lymphoma (HL) and in some cases of non-Hodgkin lymphoma (NHL). Brentuximab vedotin (BV), an antibody-drug conjugate that targets CD30, induces high response rates and is now used in the salvage setting prior to HDC-ASCT. It is not clear if BV use peri-mobilization would influence mobilization and collection of autologous CD34+ stem cells. We therefore examined 42 patients who were treated with BV prior to HDC-ASCT. Methods. We retrospectively reviewed the HDC-ASCT databases of University Hospitals Case Medical Center (UHCMC) and MD Anderson Cancer Center (MDACC) and identified 42 patients who were treated with BV prior to HDC-ASCT between February 2009 and April 2014. The median age was 37 years (range, 18-67) and 52% (n=22) were male. Diagnoses were HL (n=30; 71%;), and NHL (n=12; 29%; anaplastic large cell, n=6; diffuse large B-cell, n=3; unknown subtype, n=3). Median times from diagnosis to transplant, from initial BV treatment to transplant and from last BV treatment to stem cell collection were: 21 months (range, 10-210), 5 months (range, 1.5-16.8), and 30 days (range, 2-280), respectively. Our subjects had failed multiple conventional treatments with a median of 3 (range, 2–8) lines of treatment before HDC-ASCT; 38% (n=16) received involved field radiation therapy. BV was given at 1.8 mg/kg IV every 21 days. Median number of BV cycles was 4 (range, 1-16) and the overall response rate to treatment was 71% (CR 55% + PR 16%). Thirty patients (71%) were in complete remission (CR) at the time of transplant (CR2 = 6; CR≥3 = 24), 4 (10%) were in partial remission (PR) (PR2 = 1; PR≥3 = 3), 6 patients (14%) had stable disease and 2 patients (5%) were transplanted with progressive disease. Stem cell collection target was 5 x 106 CD34+ cells/Kg. Mobilization regimens used were chemotherapy/G-CSF-based in 32 patients (76%) and Plerixafor/G-CSF-based in 10 patients (24%). Use of chemotherapy/G-CSF in first mobilization was standard at MDACC, whereas plerixafor/G-CSF was used as first mobilization at UHCMC. Results. Thirty-nine (92.8%) of 42 patients were successfully mobilized on the first attempt. Second mobilization was required in 3 cases (7.1%). Second mobilization regimens included Cyclophosphamide/G-CSF (n=2) and Plerixafor/G-CSF (n=1). The median number of infused CD34+ cells was 5.46 x106/kg (range, 1.65-54.78 x106/kg). All patients engrafted neutrophils and platelets at a median time of 10 days (range, 9-13), and 10.5 days (range, 7-35), respectively. The median time to RBC transfusion independence was 8 days (0-34). With a median follow-up of 12 months (range, 0–63), day 100 treatment-related mortality was 0%. The one-year actuarial event-free and overall survival is 50.5% and 84.1%, respectively. Conclusion. Within the limitations of this retrospective study, BV before HDC-ASCT did not adversely affect peripheral blood stem cell mobilization, collection and engraftment in a cohort of heavily pre-treated, relapsed/refractory patients with CD30+ lymphomas. Disclosures Caimi: Seattle Genetics: Equity Ownership.

Abstract: Determining whether neurofilament light chain (NfL) elevations in patients who develop immune effector cell–associated neurotoxicity syndrome (ICANS) occur before or after infusion of cellular product is important to identify high-risk patients and inform whether neuroaxonal injury is latent or a consequence of treatment. Objective To quantify serial NfL levels in patients undergoing cellular therapy. Design, Setting, and Participants This retrospective 2-center study examined plasma NfL levels in 30 patients with detailed medical and treatment history, including all major pretreatment and posttreatment risk factors. Exclusion criteria included dementia and severe, symptomatic central nervous system (CNS) involvement. Main Outcomes and Measures Patients’ NfL levels were measured at 7 time points: baseline (prelymphodepletion), during lymphodepletion, postinfusion day (D) 1, D3, D7, D14, and D30. Prediction accuracy for the development of ICANS was next modeled using receiver operating characteristic (ROC) classification. Finally, univariate and multivariate modeling examined the association between NfL levels, ICANS, and potential risk factors including demographic (age, sex), oncologic (tumor burden, history of CNS involvement), neurologic (history of nononcologic CNS disease or neuropathy), and neurotoxic exposure histories (vincristine, cytarabine, methotrexate, or CNS radiotherapy). Results A total of 30 patients (median [range] age, 64 [22-80] years; 12 women [40%] and 18 men [60%] ) were included. Individuals who developed ICANS had elevations in NfL prior to lymphodepletion and chimeric antigen receptor T-cell infusion compared with those who did not develop ICANS (no ICANS: 29.4 pg/mL, vs any ICANS: 87.6 pg/mL; P   & amp;lt; .001). Baseline NfL levels further predicted ICANS development with high accuracy (area under the ROC curve, 0.96), sensitivity (0.91), and specificity (0.95). Levels of NfL remained elevated across all time points, up to 30 days postinfusion. Baseline NfL levels correlated with ICANS severity but not demographic factors, oncologic history, nononcologic neurologic history, or history of exposure to neurotoxic therapies. Conclusions and Relevance In a subset of patients in this cross-sectional study, the risk of developing ICANS was associated with preexisting neuroaxonal injury that was quantifiable with plasma NfL level. This latent neuroaxonal injury was present prior to drug administration but was not associated with historic neurotoxic therapies or nononcologic neurologic disease. Preinfusion NfL may further permit early screening and identification of patients most at risk for ICANS. Additional studies are needed to determine NfL’s utility as a predictive biomarker for early (preemptive or prophylactic) intervention and to delineate the origin of this underlying neural injury.

Abstract: Chimeric antigen receptor (CAR) T-cell therapy is often associated with neurological complications termed immune effector cell-associated neurotoxicity syndrome (ICANS). There remains a critical need to identify patients most at risk for ICANS. Yet a biomarker for the development of ICANS is lacking. This retrospective multicenter study evaluates pre-infusion levels of plasma neurofilament light chain (NfL), a marker of neurodegeneration, as a predictive biomarker the development of ICANS. Study inclusion criteria included available pre-infusion (up to 4 weeks prior to lymphodepletion) plasma from patients treated with a CAR T cell therapy (n = 30, 36% with ICANS, ASTCT consensus ICANS grade range 1-4). Exclusion criteria included confounding diagnoses known to elevate NfL levels (e.g. dementia, recent stroke). Plasma NfL was assayed using a Simoa HD-X kit (Quanterix TM). Demographic (age, sex), oncologic (primary, stage, mean tumor volume (MTV), and history of central nervous system (CNS) involvement), and medical history (history of non-oncologic CNS disease or neuropathy) were obtained from the medical record. MTV was derived from total lesion burden on pre-infusion positron emission tomography (PET) scans using a 41% maximum standard uptake value (SUV) threshold. Pre-infusion (i.e. during lymphodepletion) and Post-infusion Day 1 (D1) platelet count, C-reactive protein (CRP), fibrinogen, lactate dehydrogenase (LDH), and ferritin levels were also obtained from the medical record. Group comparisons used log-rank testing, followed by receiver operating characteristic (ROC) curve classification and hierarchical clustering. Validation testing used a 10,000 fold cross-validation on 80% of the data. Finally, demographic and clinical characteristics correlated with pre-infusion biomarkers using point-biserial and Spearman (rank) correlation. Our results demonstrated that individuals who would go on to develop ICANS had elevations in pre-infusion NfL ([87.6 v 29.4 pg/ml; Fig 1A], p = 0.00004) with excellent classification accuracy for the development of ICANS (AUC 0.96; Fig 1B), sensitivity (0.91) and specificity (0.95). NfL further correlated with ICANS development (r = 0.74, p & lt; 0.0001; Fig 1C). Among known post-infusion risk factors, D1 ferritin had the highest classification accuracy, but was inferior to baseline NfL (p & lt; 0.05; Fig 1B). Both baseline NfL and D1 ferritin elevations clustered with ICANS grade (Fig 1D). Our findings show that pre-infusion plasma NfL levels are a robust early marker for the development of ICANS that exceeds known post-infusion markers. This suggests the risk of developing ICANS reflects pre-existing latent neuroaxonal injury. Predictive identification of patients at risk of developing ICANS prior to cellular infusion would permit early, preemptive or prophylactic ICANS-directed therapies, thereby improving patient outcomes. Figure 1: Baseline (pre-infusion) NfL Levels in ICANS (A) Baseline (pre-infusion) levels of NfL in patients who develop Grade 0 ICANS, Grade 1-2 ICANS, and Grade 3+ ICANS. (B) Receiver operating characteristic curve classification of patients who developed any grade ICANS (1+) vs grade 0 for baseline NfL and post-infusion day 1 (D1) markers. (C) Correlation between pre-treatment factors and pre-infusion biomarkers. All significant relationships after correction for multiple comparisons using false discovery rate (FDR) are outlined (*). (D) Hierarchical clustering of age, baseline NfL, and D1 markers. Clusters associating with ICANS are labeled in red, while those associating with cytokine release syndrome (CRS) are in blue. Figure 1 Figure 1. Disclosures Caimi: Verastem: Consultancy; ADC Theraputics: Consultancy, Research Funding; Genentech: Research Funding; XaTek: Patents & Royalties: Royalties from patents (wife); Kite Pharmaceuticals: Consultancy; Seattle Genetics: Consultancy; Amgen Therapeutics.: Consultancy; TG Therapeutics: Honoraria. de Lima: BMS: Membership on an entity's Board of Directors or advisory committees; Incyte: Membership on an entity's Board of Directors or advisory committees; Pfizer: Membership on an entity's Board of Directors or advisory committees; Miltenyi Biotec: Research Funding. Campian: AbbVie, Inc.: Speakers Bureau; NeoImmuneTech: Research Funding. Ghobadi: Amgen: Consultancy, Research Funding; Atara: Consultancy; Wugen: Consultancy; Celgene: Consultancy; Kite, a Gilead Company: Consultancy, Honoraria, Research Funding.

Abstract: Introduction: Novel approaches to treating patients (pts) with relapsed or refractory (R/R) classical Hodgkin lymphoma (cHL) have improved outcomes but some pts do not respond or, despite initial response, develop progressive disease and have limited treatment options. Camidanlumab tesirine (ADCT-301; Cami) is an antibody-drug conjugate composed of a human IgG1 anti-CD25 monoclonal antibody stochastically conjugated to a potent pyrrolobenzodiazepine (PBD) dimer warhead, which triggers cell death via formation of highly cytotoxic interstrand cross-links. Data from a Phase (Ph) 1 dose-escalation, dose-expansion trial demonstrated an overall response rate (ORR) in pts with cHL of 86.5% (48.6% complete response [CR] rate) at the 45 μg/kg dose. Cami had a generally acceptable safety profile at Ph 1 but there were 5/77 cases (6.5%) of Guillain-Barré syndrome (GBS)/polyradiculopathy (Preferred Terms: 4 GBS and 1 radiculopathy) (Collins et al, ICML June 18-22, 2019, Lugano, Switzerland, Abstract 055). Here, we present preliminary efficacy and safety results of a Ph 2 trial of single-agent Cami in pts with R/R cHL (NCT04052997). Methods: A single-arm, multi-center, open-label, Ph 2 trial is currently enrolling pts ≥16 yrs (US) and ≥18 yrs (outside US) with R/R cHL following ≥3 prior treatment lines (or ≥2 lines in pts ineligible for hematopoietic stem cell transplantation). Eligible pts had prior treatment with brentuximab vedotin and PD-1 blockade, measurable disease per 2014 Lugano Classification, and Eastern Cooperative Oncology Group performance status 0-2. The primary objective is to evaluate efficacy of single-agent Cami by ORR as determined by central review. Secondary objectives include further characterization of additional efficacy endpoints and safety. Pts receive 30-min IV infusions of Cami on Day 1 of each 3-week cycle at a dose of 45 μg/kg for 2 cycles, followed by 30 μg/kg for subsequent cycles for up to 1 yr or until discontinuation due to disease progression, unacceptable toxicity, or other reasons. Pts deriving clinical benefit at 1 yr may be able to continue treatment on a case-by-case basis. Treatment-emergent adverse events (TEAEs) were defined as AEs occurring/worsening from time of first dose to either 30 days post last dose or to start of new anticancer therapy/procedure, whichever occurs first. This analysis was conducted after meeting a protocol-specified criterion for pausing enrollment (≥2 cases of GBS or other relevant severe neurologic toxicity). Results: As of June 15, 2020, 47 pts with R/R cHL were enrolled and are included in this analysis. Median age was 36 (range 23-74) yrs and pts had received a median of 7 (range 3-20) lines of prior therapy, including transplant (Table 1). Pts received a median of 5 (range 2-10; mean 4.9 [SD 1.86]) cycles of Cami. ORR was 80.9% (38/47 pts), with 18 (38.3%) and 20 (42.6%) pts attaining CR and partial response, respectively; 6 pts (12.8%) had stable disease (Figure 1). TEAEs were experienced by all 47 pts; the most common (≥20% of pts) were fatigue (22, 46.8%); nausea, pyrexia, and maculopapular rash (18, 38.3% each); anemia and headache (12, 25.5% each); pruritus (11, 23.4%); arthralgia, constipation, diarrhea, hypophosphatemia, and rash (10, 21.3% each). TEAEs thought to be PBD-associated included skin reactions and nail disorders (36, 76.6%), liver function test abnormalities (14, 29.8%), and edema or effusion (7, 14.9%). There were 3 (6.4%) pts with GBS/polyradiculopathy (Preferred Terms: grade 4 subacute inflammatory demyelinating polyneuropathy, grade 2 radiculopathy, and grade 2 peripheral motor and sensory neuropathy updated to GBS after data cut-off date). In total, 27 (57.4%) pts had grade ≥3 TEAEs; the most common (≥5% of pts) were hypophosphatemia (6, 12.8%) and gamma-glutamyltransferase increased (3, 6.4%). Overall, 3 (6.4%) pts had TEAEs leading to dose reduction/delay and 6 (12.8%) pts had TEAEs leading to treatment discontinuation. Conclusions: Current data show that therapy with Cami has encouraging anti-tumor activity in heavily pretreated pts with R/R cHL. Safety was consistent with that reported at Ph 1, with no new safety concerns identified and similar incidence of GBS/polyradiculopathy. Following a positive risk-benefit assessment, the enrollment pause was lifted, and pts continue to be enrolled. Updated efficacy and safety results will be presented at the meeting. Funding: Study funded by ADC Therapeutics SA. Disclosures Herrera: Pharmacyclics: Research Funding; Bristol Myers Squibb: Consultancy, Other: Travel, Accomodations, Expenses, Research Funding; Merck: Consultancy, Research Funding; Gilead Sciences: Consultancy, Research Funding; Genentech, Inc./F. Hoffmann-La Roche Ltd: Consultancy, Research Funding; Seattle Genetics: Consultancy, Research Funding; Karyopharm: Consultancy; AstraZeneca: Research Funding; Immune Design: Research Funding. Carlo-Stella:Bristol-Myers Squibb, Merck Sharp & Dohme, Janssen Oncology, AstraZeneca: Honoraria; ADC Therapeutics and Rhizen Pharmaceuticals: Research Funding; Boehringer Ingelheim and Sanofi: Consultancy; Servier, Novartis, Genenta Science srl, ADC Therapeutics, F. Hoffmann-La Roche, Karyopharm, Jazz Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees. Collins:Taekda: Consultancy, Honoraria, Other: travel, accommodations, expenses, Speakers Bureau; Novartis: Consultancy, Honoraria, Speakers Bureau; Pfizer: Honoraria; Gilead: Consultancy, Honoraria, Speakers Bureau; ADC Therapeutics: Consultancy, Honoraria; BMS: Consultancy, Honoraria, Research Funding, Speakers Bureau; MSD: Consultancy, Honoraria, Research Funding; Celleron: Consultancy, Honoraria, Research Funding; Celgene: Research Funding; Amgen: Research Funding; BeiGene: Consultancy; Roche: Consultancy, Honoraria, Other: travel, accommodations, expenses , Speakers Bureau. Maddocks:Morphosys: Consultancy, Honoraria; BMS: Consultancy, Research Funding; Karyopharm: Consultancy; Seattle Genetics: Consultancy, Honoraria; ADC Therapeutics, AstraZeneca: Consultancy; Pharmacyclics: Consultancy, Honoraria; Celgene: Consultancy, Honoraria. Bartlett:Autolus: Research Funding; BMS/Celgene: Research Funding; Forty Seven: Research Funding; Immune Design: Research Funding; Seattle Genetics: Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Research Funding; Kite, a Gilead Company: Research Funding; Merck: Research Funding; Millennium: Research Funding; Pfizer: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Pharmacyclics: Research Funding; Seattle Genetics: Consultancy, Research Funding; Roche/Genentech: Consultancy, Research Funding; ADC Therapeutics: Consultancy; BTG: Consultancy; Acerta: Consultancy; Affimed Therapeutics: Research Funding. Savage:BeiGene: Other: Steering Committee; Roche (institutional): Research Funding; Merck, BMS, Seattle Genetics, Gilead, AstraZeneca, AbbVie: Honoraria; Merck, BMS, Seattle Genetics, Gilead, AstraZeneca, AbbVie, Servier: Consultancy. Caimi:ADCT, Kite Therapeutics, Genentech, Amgen, Verastem, TG Therapeutics, Bayer: Consultancy; ADC Therapeutics: Membership on an entity's Board of Directors or advisory committees; Genentech, ADC Therapeutics: Research Funding; Celgene: Speakers Bureau. Hess:ADC Therapeutics: Consultancy, Membership on an entity's Board of Directors or advisory committees; BMS, AstraZeneca: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Zinzani:ADC Therapeutics: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Sanofi: Consultancy, Membership on an entity's Board of Directors or advisory committees; Sandoz: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; EUSA Pharma: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celltrion: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Verastem: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Janssen-Cilag: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Kirin Kyowa: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Merck: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Portola: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Janssen: Consultancy, Honoraria, Speakers Bureau; Servier: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Roche: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; TG Therapeutics, Inc.: Honoraria, Speakers Bureau; BMS: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Incyte: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Gilead: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; AbbVie: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; MSD: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Eusapharma: Consultancy, Speakers Bureau; Kyowa Kirin: Consultancy, Speakers Bureau; Immune Design: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Immune Design: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Cruz:ADC Therapeutics SA: Current Employment, Current equity holder in publicly-traded company. Wang:ADC Therapeutics America, inc: Current Employment, Current equity holder in publicly-traded company. Feingold:ADC Therapeutics: Current Employment, Current equity holder in publicly-traded company. Wuerthner:ADC Therapeutics SA: Current Employment, Current equity holder in publicly-traded company. Ansell:Takeda: Research Funding; Bristol Myers Squibb: Research Funding; Seattle Genetics: Research Funding; Regeneron: Research Funding; Trillium: Research Funding; ADC Therapeutics: Research Funding; Affimed: Research Funding; AI Therapeutics: Research Funding.

Abstract: Introduction: Extra-nodal Natural Killer/T-Cell Lymphoma, Nasal Type (ENKL) is an aggressive, rare variant of non-Hodgkin lymphoma most frequently found in Asia, with 5-year survival estimates of 30-45%. The utility of stem cell transplant (HSCT) has been evaluated in a number of primarily small retrospective studies, almost exclusively from Asia, in which outcomes appear to be improved with HSCT by 10-20%. We conducted this study with the aim to determine the outcomes of autologous (AUTO) and allogeneic (ALLO) HSCT in patients with ENKL. Methods: This multi-center study was conducted in collaboration with 4 different centers, 3 in the United States, and 1 in Singapore. All patients with a diagnosis of ENKL who received either AUTO or ALLO HSCT after January 1, 2000 were eligible. Univariate probabilities of overall survival (OS) and progression-free survival (PFS) were estimated utilizing the Kaplan-Meier method using IBM SPSS version 22.0. Probabilities of non-relapse mortality (NRM) and relapse mortality (RM) were calculated by the cumulative incidence (CI) procedure to accommodate for competing risks utilizing EZR software. The log-rank test was used to assess for differences between groups in regard to OS and PFS, and the Fine-Gray analysis was performed to compare outcomes with competing risks. Results: Twenty-seven patients, with median age of 48 years (range 22-68), and a median of 2 prior chemotherapy lines (range 1-5) received HSCT for ENKL; 14 AUTO and 13 ALLO, of which 70% were performed at MD Anderson. Sixty-seven percent were male, 30% were not in complete remission (CR) at transplant, and 40% had an NK-IPI risk group of 3-4. Seventy-four percent of patients received myeloablative (MAC) conditioning, with the most common regimen being BEAM in 55% of ALLO and 65% of AUTO. All patients received peripheral blood as the stem cell source except one who received cord blood. With a median follow-up time of 11 years, OS and PFS for the entire group were 51% and 50%. The CI NRM was 19% at 1 and 2 years and the CI RM was 16% at 1 year, 26% at 2 years, and 40% at 11 years (Figure 1). Amongst ALLO recipients, there were 2 cases of grade II-IV acute GVHD (14% of ALLO) and 5 cases of chronic GVHD (1 limited, 4 extensive, 36% of ALLO). PFS was significantly better for patients in CR versus those not in remission at transplant (67% vs 13%, p=0.002). There was no impact of MAC vs non-MAC conditioning, disease stage at diagnosis (I-II vs III-IV), prior number of chemotherapy lines, comorbidity index, NK-IPI risk group 1-2 vs 3-4, age 〉 50, sex, or race on PFS or OS. We did an exploratory analysis of transplant outcomes between the AUTO versus ALLO groups. More patients in the ALLO group (46% vs 17%, p=0.082) were not in CR at transplant, though other characteristics were balanced. PFS for AUTO versus ALLO was 67% vs 31% at 1 and 3 years (p=0.032), (Figure 2). OS for AUTO vs ALLO was 75% vs 54% at 1 year, and 64% vs 39% at 3 years, (p=0.146). One patient received an ALLO with progressive disease and survived. Additionally, 3 of 4 patients who received ALLO after prior AUTO survived, though one died of a second malignancy 11 years post-transplant. One of these patients received a prior AUTO but developed graft failure and subsequently received an ALLO and was counted in the ALLO group. CI NRM was higher in the ALLO vs AUTO group at 1 year (39% vs 0%, p=0.013). CI of RM was higher in the first year in the AUTO vs ALLO group at 1 year (26% vs 8%), though by 3-years this difference was not significant (36% vs 23%, p=0.472). Conclusion: Here we present the results of a multi-center study of patients who received a HSCT for ENKL. Our results are similar to those seen in Asian studies, with long-term PFS and OS of 50%, demonstrating that HSCT is an effective therapy for patients with ENKL. Patients in CR at transplant had better OS and PFS than those not in CR; therefore, complete remission should be the goal prior to HSCT for ENKL. ALLO is an effective treatment option for relapse post-AUTO or for progressive disease at transplant, with less relapse than AUTO, particularly within the first year. This is particularly interesting given that 46% of patients who received ALLO were not in remission at transplant, indicating a strong graft-versus-lymphoma effect. However, these results are limited by an increased NRM. Strong consideration for AUTO should be given to patients who are in CR at the time of transplant, and ALLO should primarily be reserved for refractory disease or relapse post-AUTO. Figure 1. Figure 1. Figure 2. Figure 2. Disclosures Brammer: Celgene: Research Funding. Fanale:Merck: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; BMS: Research Funding; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Takeda: Honoraria, Research Funding; Infinity: Membership on an entity's Board of Directors or advisory committees; Spectrum: Membership on an entity's Board of Directors or advisory committees; Seattle Genetics: Honoraria, Research Funding; Genentech: Research Funding; Medimmune: Research Funding; Novartis: Research Funding; Bayer: Membership on an entity's Board of Directors or advisory committees; Amgen: Membership on an entity's Board of Directors or advisory committees; Molecular Templates: Research Funding; ADC Therapeutics: Research Funding; Onyx: Research Funding; Gilead: Research Funding. Maziarz:Novartis: Consultancy; Athersys: Consultancy, Patents & Royalties, Research Funding.