A Rare Case Of Eosinophilic Myocarditis Due To Subacute Sars-cov-2 Illness

Background: Eosinophilic myocarditis is a rare inflammatory cardiomyopathy with a poor prognosis. SARS-CoV-2 (COVID-19) illness has been associated with myocarditis, particularly of lymphocytic etiology. Although there have been cases of eosinophilic myocarditis associated with COVID-19 vaccination, there have been few reported cases secondary to COVID-19 illness, with the majority being diagnosed via post-mortem autopsy. Case: A 44-year-old woman with no significant medical history other than recent COVID-19 illness 6 weeks prior presented with progressive dyspnea. Patient developed acute dyspnea and diffuse pruritic rash after taking hydroxyzine. Labs were significant for mild eosinophilia. Echocardiography showed biventricular systolic dysfunction with left ventricular ejection fraction of 40%, and a moderate pericardial effusion that was drained percutaneously. She underwent left heart and right heart catheterization showing elevated biventricular filling pressures, Fick cardiac index of 1.6 L/min/m2, and no coronary disease. She was started on intravenous diuretics and transferred to our facility for further management. Her course was complicated by cardiogenic shock requiring intra-aortic balloon pump (IABP) support. Mixed venous saturations continued to decline and the patient was placed on veno-arterial extracorporeal membrane oxygenation (VA-ECMO) support. The patient underwent endomyocardial biopsy (EMB) showing marked interstitial infiltration of eosinophils and macrophages with myocyte injury (see image). She was intubated with mechanical ventilation as well due to worsening pulmonary edema and hypoxemia. She was started on intravenous steroids with improvement of hemodynamics and myocardial function and eventually VA- ECMO was decannulated to low-dose inotropic support which in turn was ultimately weaned after 3 days of mechanical support. Conclusion(s): Eosinophilic myocarditis is a rare and under-recognized sequela of acute COVID-19 infection associated with high mortality rates. It requires prompt diagnosis and aggressive supportive care, including temporary mechanical circulatory support. There are few literature-reported cases of COVID-19 myocarditis requiring use of both IABP and VA-ECMO, none of which were used in biopsy-proven eosinophilic myocarditis, with most of these cases resulting in either fatal or unreported outcomes. Most cases of covid myocarditis required IV glucocorticoids therapy in conjunction with IVIG or interferon therapy. Here, we present a rare case of cardiogenic shock secondary to biopsy-proven eosinophilic myocarditis associated with recent COVID-19 illness with a survival outcome after temporary use of IABP and VA-ECMO support, as well as aggressive immunosuppressive therapy.Copyright © 2022

A Competing Stimuli Intervention Package to Treat Automatically Reinforced Destructive Behavior

Behaviors maintained by automatic reinforcement are often more difficult to treat due to difficulty with identifying the relevant maintaining variable(s). One common intervention to treat automatically maintained behavior includes competing stimuli. Competing stimuli promote item engagement which may replace challenging behavior (i.e., response competition). Competing stimuli have shown to be a widely successful intervention across diverse topographies of challenging behavior;however, few studies have evaluated the use of competing stimuli on destructive behavior. The purpose of the current study was to treat automatically maintained destructive behavior with a competing stimuli intervention package for an adolescent with developmental disabilities. Results showed a decrease in destructive behavior when access to competing stimuli was a component of an intervention package in a clinic setting. Also, preliminary data are provided showing treatment effects when caregivers implemented the intervention. Due to the complexity of the final intervention package, recommendations for clinicians are provided which focus on improving feasibility, practicality, and sustainability of treatment components.Copyright © The Author(s) 2022.

Delayed-Onset Urticaria Following Vaccination for COVID-19

Background: As COVID-19 vaccines continue to be administered worldwide, there are an increasing number of studies documenting cutaneous reactions following vaccination. Systemic reactions, such as urticarial diseases, occur. Purpose(s): The main objective of this study was to investigate the association between urticaria and recent vaccination for COVID-19. Method(s): A retrospective chart review examining the association of urticaria and COVID vaccination was conducted. Result(s): We report 17 patients who developed an urticarial reaction following vaccination against COVID and one patient who developed an urticarial reaction following a COVID infection. The vast majority of the patients were women with a mean age of 42.8 years. Conclusion(s): Cutaneous manifestations often follow COVID vaccination and infection. It may be helpful to inquire about recent infections and vaccinations in patients presenting with urticarial diseases. Copyright © 2022 Journal of Dermatology and Dermatologic Surgery.

TREATMENT SUCCESS IN A RESISTANT CASE OF INSOMNIA WITH AN IRREGULAR CIRCADIAN RHYTHM DISORDER

Introduction: A 19-year-old non-verbal male with history of CHARGE syndrome, severe autism, intellectual disability, coloboma with blindness OD and severely imparied vision OS, deafness, self-injurious and aggressive behavior, Tetralogy of Fallot status post repair, pulmonary valve replacement, hypertension, hypothyroidism, megacolon, gastrostomy tube dependence, eosinophilic esophagitis and chronic kidney disease with an irregular sleep cycle who has failed multiple medications for insomnia has shown treatment success with suvorexant. Report of Cases: This patient's sleep schedule ranges from 1.5 to 5 hour segments at various times of day or night including naps at school with occasional longer periods of sleep up to 10 hours and longer periods of wakefulness up to 22 hours who has been treated with the following medications: trazodone, clonidine, hydroxyzine, diphenhydramine, quetiapine, gabapentin, mirtazapine, eszopiclone, melatonin and ramelteon. His behavioral problems have been treated with olanzapine. He continued to be aggressive and difficult to direct. His parents reported exhaustion. Then, suvorexant 5mg was added at bedtime while the following sleep medications were continued: gabapentin total daily dose of 1500mg (300mg in morning and 3pm;900mg at bedtime, 300mg one hour later if still awake), ramelteon 8mg, mirtazapine 7.5mg and olanzapine 10mg at bedtime and bid prn aggressive behavior. He also takes the following daily medications: bisacodyl, polyethylene glycol, simethicone, hyoscyamine, cholecalciferol, aspirin, levothyroxine, hypoallergenic nutritional formula, starch and albuterol prn. With the addition of suvorexant 5mg, he had been able to get 9.5 hours of consolidated sleep at night with improvement in his behavior until he contracted Covid-19 and regressed. The suvorexant dose was increased to 10mg which again improved his insomnia and behavior. Conclusion: Various medications have either not worked at all or have worked suboptimally for insomnia in this medically complex patient who has an irregular Circadian rhythm disorder. Adding an orexin receptor antagonist as a novel mechanism to his regimen has shown promise. At this time, this patient has been stable for one month with suvorexant 10mg at bedtime after regression on the 5mg dose that coincided with a Covid-19 infection. We are proceeding with cautious optimism.

Impaired mRNA Based COVID-19 Vaccine Response in Patients with B-Cell Malignancies after CD19 Directed CAR-T Cell Therapy

Introduction: Patients with hematologic malignancies are at an increased risk of morbidity and mortality from COVID-19 disease (Vijenthira, Blood 2020). This is likely a result of combination of immunodeficiency conferred by the disease and the therapeutics. The immunogenicity of the COVID-19 vaccines in patients with exposure to CD19 directed Chimeric Antigen Receptor (CAR)-T cell therapy is not established. CD19 CAR-T cell therapies cause B-cell aplasia, which in turn can affect humoral immune response against novel antigens. Herein, we present results from our prospectively conducted clinical study to evaluate immune responses against mRNA based COVID-19 vaccines in patients with lymphoma who have received CD19 directed CAR-T cell therapy. Methods: All patients and healthy controls were enrolled in a prospective clinical study evaluating immune responses against commercial COVID-19 RNA vaccines in patients with hematologic malignancies. Plasma samples were generated from heparinized peripheral blood of 4 heathy controls (HCs) receiving the same vaccines and 19 B cell lymphoma patients treated with CD19 CAR- T cells. Samples from ~4 weeks post second dose of the vaccine (d56) were available for 14 CAR-T patients, for 5 CAR-T patients samples were available from ~4 weeks after the first dose (d28). Plasma samples were analyzed in an enzyme-linked immunosorbent assay (ELISA) using different full-length recombinant SARS-CoV-2 proteins and control proteins. Neutralizing activity was measured using the cPass Neutralization Antibody Detection Kit (GenScript Biotech). Results: Results from 4 healthy controls and 19 patients (12 males and 7 females) with lymphoma are reported. Median age for the lymphoma patients is 65 years. Eleven patients had large B cell lymphoma, 5 had follicular lymphoma and 3 had mantle cell lymphoma as primary diagnoses. Seventeen patients had advance stage disease (III/IV stage) and had received a median of 3 prior lines of therapy. All patients received CD19 directed CAR-T cell therapy. Ten patients received Moderna vaccine and 9 received Pfizer vaccine. Median time between CAR-T infusion and first COVID-19 vaccine was 258 days. While the peripheral blood plasma from 3/4 HCs already showed substantial SARS-CoV-2 neutralizing activity at ~4 weeks after the first dose of COVID-19 mRNA vaccine, none of the 5 CD19 CAR-T patients analyzed evidenced any antibody-mediated neutralizing activity in their blood at the same point in time (Figure 1A). Around 4 weeks after receiving the second dose of the vaccine, all 4 HCs tested evidenced complete or almost complete neutralizing activity (Figure 1B). In marked contrast, only 1 out of 14 CAR-T patients analyzed evidenced any relevant antibody-mediated SARS-CoV-2 neutralizing activity in their blood (Figure 1B). Interestingly, when we asked whether a globally insufficient antibody-mediated immunity was the underlying cause of the lack of a response to the COVID-19 vaccine in our CAR-T patients, we found that that was clearly not the case since anti-Flu, -TT, and -EBV responses were equivalent to the ones observed in HCs (Figure 2A). However, while at ~4 weeks post second dose of the vaccine the HCs showed marked antibody titers against all the viral spike proteins including their “delta” variants (Figure 2B), that was not the case for our CAR-T patients. The vast majority of our CAR-T patients did not evidence IgG antibody responses against any of the SARS-CoV-2 proteins analyzed such as S1, S1 delta, RBD, RBD delta, or S2 (Figure 2B). Conclusion: In this prospectively conducted clinical study, 18 of 19 patients with lymphoma who have received CD19 CAR-T therapy had poor immunogenicity against mRNA based COVID-19 vaccines as measured by neutralization assays and antibody titers. The antibody titers against B.1.617.2 (delta variant, S1 and RBD protein) were also demonstrably poor. The antibody response to common pathogens (flu, EBV, TT) were preserved, suggesting impaired immune response against novel antigens. Long-term follow-up of this study is ongoin . APR and DJ contributed equally [Formula presented] Disclosures: Dahiya: Kite, a Gilead Company: Consultancy;Atara Biotherapeutics: Consultancy;BMS: Consultancy;Jazz Pharmaceuticals: Research Funding;Miltenyi Biotech: Research Funding. Hardy: American Gene Technologies, International: Membership on an entity's Board of Directors or advisory committees;InCyte: Membership on an entity's Board of Directors or advisory committees;Kite/Gilead: Membership on an entity's Board of Directors or advisory committees.

Do PROs Tell the Whole Story? Differential Outcomes Based on Patient-Reported Outcomes (PROs) Versus Performance-Based Metrics (PBM) on Cognition for Patients Receiving Chimeric Antigen Receptor (CAR)-T Cell Therapy

Introduction: As the use of CAR-T cell therapy grows, there is an increased need to understand its impact on the patient experience, especially symptom burden and cognitive function. While the immediate side-effects of CAR-T therapy have been reported, our study aims to describe the longitudinal impact of CAR-T therapy on patients' quality of life (QoL), including patient-reported cognitive function and performance-based cognition, which are not well understood. Methods: Patients with hematologic malignancies undergoing CAR-T therapy were prospectively recruited from two academic centers. The primary endpoint was feasibility of completing longitudinal PRO assessments and PBM of cognition. NIH PROMIS measures assessed physical, mental, cognitive, and social health. PROMIS measures use the t-score metric, where 50 is the average in the U.S. population and a 5 point (0.5 SD) change was considered clinically meaningful. The NIH Toolbox Cognition Battery measured 6 constructs of cognition, scored on the t-score metric (10 point = 1SD, change considered clinically meaningful). Exploratory analyses described change from baseline. PROMIS measures were completed at baseline, 7 and 14 days, 1, 3, 6, and 12 months (mo) after CAR-T. The Toolbox was assessed at baseline, 1 month, and 12 months. Due to COVID restrictions on in person research, the Toolbox could not be assessed for the first 13 patients. Results: From 8/2020 to 6/2021, 28 patients have been enrolled. Baseline, day 7, day 14, 1 mo, 3 mo, and 6 mo data were available in 27, 20, 21, 23, 15 (10 not yet reached), and 9 (16 not yet reached) patients, respectively. The mean age was 57 years (range 27-78);44% were female. Race distribution was: Caucasian 75%, Asian 8%, Hawaiian/Pacific Islander 4% and other race 8%;21% were Hispanic ethnicity. Patients received CAR-T for diagnoses of NHL (75%), MM (17%), and ALL (13%). CRS was seen in 86% (all grade 1-2), neurotoxicity (ICANS) in 34% (grade 1-2: N=5 and grade > 3: N=5). PROMIS questionnaires were completed in >70% of patients across all timepoints with current follow-up;thus it was feasible to collect these data at frequent intervals after CAR-T. Mean baseline PROMIS t-scores (N=27) were similar to the average US population in all domains (fatigue: 53, sleep: 52, pain: 52, anxiety: 53, depression: 49) except for decreased physical function (44) among patients (Fig 1a-b). Physical function, fatigue, and pain interference worsened during the first month but returned to baseline by month 3 (Fig 1a-b). PBM of cognition (NIH Toolbox) were assessed at baseline in 15 pts and 1 mo in 8 patients (4 incomplete, 3 not reached timepoint). The toolbox requires in-person administration and takes 35 minutes, but has been completed in 75% of evaluable patients. At baseline, the mean total composite score was 65 th percentile and t-score was 57;mean fluid composite score was 50 th percentile and t-score was 50;mean crystallized composite score was 69 th percentile and t-score was 58 (fluid composite score measures ability to reason, crystallized composite score measures accrual of knowledge over time, Weintraub et al Neurology 2013). Little change in scores was seen in language domains and some increase (not clinically significant) was seen in constructs on attention, executive function, and episodic memory. While not significant, a trend towards worsening working memory and processing speed and a trend towards worsening t-scores for all composite scores was seen (Figure 1c). 2 patients with neurotoxicity grade 3 and available baseline and 1-mo Toolboxes were noted to have decreases in all composite scores (clinically significant in 1). Patients did not self-report changes in cognitive function over 6 months (Fig 1d). Conclusion: This study reports early data from longitudinal neurocognitive assessments and PROs in patients undergoing CAR-T. It is feasible for patients undergoing CAR-T to complete PROMIS surveys (PROs) and NIH cognitive Toolboxes (performance-based test). Early and frequent PRO surveys captured initial worsening in hysical function, fatigue, and pain interference that returned to baseline by month 3. There was no change in patient-reported cognitive function over time, but using PBM cognition testing, we noted a trend towards worsening cognition in some domains. Continued patient accrual and longer follow up will allow assessment of degree and persistence of worsened PBM cognition associated with CAR-T. [Formula presented] Disclosures: Frank: Allogene Therapeutics: Research Funding;Kite-Gilead: Membership on an entity's Board of Directors or advisory committees;Adaptive Biotechnologies: Research Funding. Shah: Lily: Consultancy, Honoraria, Research Funding;Miltenyi Biotec: Consultancy, Honoraria, Research Funding;Epizyme: Consultancy;Legend: Consultancy;Kite: Consultancy;Incyte: Consultancy;Umoja: Consultancy. D'Souza: Imbrium, Pfizer, BMS: Membership on an entity's Board of Directors or advisory committees;Janssen, Prothena: Consultancy;Sanofi, Takeda, Teneobio, CAELUM, Prothena: Research Funding. Miklos: Pharmacyclics: Patents & Royalties;Kite, a Gilead Company, Amgen, Atara, Wugen, Celgene, Novartis, Juno-Celgene-Bristol Myers Squibb, Allogene, Precision Bioscience, Adicet, Pharmacyclics, Janssen, Takeda, Adaptive Biotechnologies and Miltenyi Biotechnologies: Consultancy;Pharmacyclics, Amgen, Kite, a Gilead Company, Novartis, Roche, Genentech, Becton Dickinson, Isoplexis, Miltenyi, Juno-Celgene-Bristol Myers Squibb, Allogene, Precision Biosciences, Adicet, Adaptive Biotechnologies: Research Funding;Adaptive Biotechnologies, Novartis, Juno/Celgene-BMS, Kite, a Gilead Company, Pharmacyclics-AbbVie, Janssen, Pharmacyclics, AlloGene, Precision Bioscience, Miltenyi Biotech, Adicet, Takeda: Membership on an entity's Board of Directors or advisory committees. Muffly: Pfizer, Amgen, Jazz, Medexus, Pfizer: Consultancy;Adaptive: Honoraria, Other: fees for non-CME/CE services:, Research Funding;Astellas, Jasper, Adaptive, Baxalta: Research Funding. Sidana: Janssen: Consultancy, Research Funding;Magenta Therapeutics: Consultancy, Research Funding;Allogene: Research Funding;BMS: Consultancy.

Unmasking pustular psoriasis subsequent to COVID-19

Various cutaneous manifestations have recently appeared within context of 2019 novel coronavirus diseases (COVID-19). Currently, outbreaks of psoriasis were reported during COVID-19. We reported a case of a 32-year-old woman with COVID-19 who presented with pustular psoriasis. She was treated with oral prednisolone, hydroxyzine and topical clobetasol. The two-week follow-up revealed that her lesions were desquamating and that she was in a favorable situation. The current report will highlight specific skin manifestations of COVID-19, allowing clinicians to further confirm our suspicions.

Randomized, Phase III Study of Early Intervention with Venetoclax and Obinutuzumab Versus Delayed Therapy with Venetoclax and Obinutuzumab in Newly Diagnosed Asymptomatic High-Risk Patients with Chronic Lymphocytic Leukemia/Small Lymphocytic Lymphoma (CLL/SLL): Evolve CLL/SLL Study (SWOG S1925;NCT#04269902)

Background: Currently, asymptomatic patients with CLL/SLL are observed without treatment until development of symptoms or cytopenias. Historically, early intervention studies in patients with CLL/SLL with non-specific chemoimmunotherapy agents have not resulted in an overall survival (OS) benefit and have resulted in toxicity. The introduction of targeted therapies, such as venetoclax (an oral BCL2 inhibitor;V) and obinutuzumab (an intravenous anti-CD20 monoclonal antibody;O), have provided tolerable/efficacious options for patients with CLL. In the CLL14 study, symptomatic patients with CLL receiving frontline therapy with VO had longer progression-free survival (PFS) and deeper remissions [more undetectable minimal residual disease (uMRD)] compared with those receiving chlorambucil and O (Fischer 2019). The CLL-International Prognostic Index (CLL-IPI;Table 1) is a validated prognostic model to predict which patients are at highest risk of a shorter time to first therapy and shorter OS. A score of ≥4 is considered high-risk on this scale. We aim to use VO as early intervention in asymptomatic, high-risk CLL patients, assessed by CLL-IPI, to potentially improve OS and thus alter the natural history of the disease. Methods: On 12/14/20, we activated the S1925 study (NCT#04269902 ) for adult patients with CLL or SLL, who were diagnosed within 12 months of enrollment. Eligible patients have a CLL-IPI score ≥4 (Table 1) or complex cytogenetics (≥3 cytogenetic abnormalities) and do not meet any criteria for initiation of treatment by the International Working Group for CLL (IWCLL;Hallek 2018) guidelines. Enrolled patients are randomized in a 2:1 manner to early versus delayed (at the time IWCLL indication for treatment is met) therapy with VO (Figure 1). VO is administered as previously described (Fischer 2019). The primary endpoint is OS. We hypothesize that early intervention with VO will improve the rate of 6-year OS from 60% to 80%. This design requires 222 eligible patients for 88% power (2-sided a=0.05) for the primary comparison. To allow for 10% ineligibility, we will enroll 247 patients. Estimated accrual time is 4 years. Secondary endpoints include: rates of response, PFS, and relapse-free survival;safety;time to second CLL-directed therapy;and quality of life (assessed by FACT-Leukemia). As COVID19 is an infection with particularly high morbidity and mortality in patients with CLL, incidence of this infection and complications including death will be recorded and compared between patients followed on the early versus delayed intervention arms. The primary translational objective is to evaluate the prognostic association between OS and peripheral blood MRD status at 15 months after treatment initiation by flow cytometry. Secondary translational objectives include describing the association of other clinical outcomes, baseline prognostic factors, and IWCLL-defined response with MRD status at multiple timepoints. Current Status: At the time of submission, 7 patients have been registered and randomized per protocol. Accrual is ongoing. [Formula presented] Disclosures: Stephens: Adaptive: Membership on an entity's Board of Directors or advisory committees;TG Therapeutics: Membership on an entity's Board of Directors or advisory committees;Epizyme: Membership on an entity's Board of Directors or advisory committees;Beigene: Membership on an entity's Board of Directors or advisory committees;Innate Pharma: Membership on an entity's Board of Directors or advisory committees;AstraZeneca: Consultancy;CSL Behring: Consultancy;Celgene: Consultancy;Novartis: Research Funding;Abbvie: Consultancy;JUNO: Research Funding;Arqule: Research Funding;Mingsight: Research Funding;Karyopharm: Membership on an entity's Board of Directors or advisory committees, Research Funding. Moseley: BioSight Ltd: Consultancy. Hill: AbbVie: Consultancy, Honoraria, Research Funding;Gentenech: Consultancy, Honoraria, Research Funding;Beigene: Consultancy, Honoraria, Research Funding;Pfizer: Consultancy, Honoraria;Kite, Gilead Company: Consultancy, Honoraria, Other: Travel Support, Research Funding;Karyopharm: Consultancy, Honoraria, Research Funding;AstraZenica: Consultancy, Honoraria;Celgene (BMS): Consultancy, Honoraria, Research Funding;Novartis: Consultancy, Honoraria, Research Funding;Epizyme: Consultancy, Honoraria;Incyte/Morphysis: Consultancy, Honoraria, Research Funding. Pagel: Pharmacyclics/AbbVie: Consultancy;Actinium Pharmaceuticals: Consultancy;Incyte/MorphoSys: Consultancy;BeiGene: Consultancy;Epizyme: Consultancy;Kite, a Gilead Company: Consultancy;AstraZeneca: Consultancy;Gilead: Consultancy;MEI Pharma: Consultancy. Shadman: Mustang Bio, Celgene, Bristol Myers Squibb, Pharmacyclics, Gilead, Genentech, Abbvie, TG Therapeutics, Beigene, AstraZeneca, Sunesis, Atara Biotherapeutics, GenMab: Research Funding;Abbvie, Genentech, AstraZeneca, Sound Biologics, Pharmacyclics, Beigene, Bristol Myers Squibb, Morphosys, TG Therapeutics, Innate Pharma, Kite Pharma, Adaptive Biotechnologies, Epizyme, Eli Lilly, Adaptimmune, Mustang Bio and Atara Biotherapeutics: Consultancy. Danilov: Genentech: Consultancy, Honoraria, Research Funding;Takeda Oncology: Research Funding;TG Therapeutics: Consultancy, Research Funding;Abbvie: Consultancy, Honoraria;Beigene: Consultancy, Honoraria;Pharmacyclics: Consultancy, Honoraria;Gilead Sciences: Research Funding;Bristol-Meyers-Squibb: Honoraria, Research Funding;Rigel Pharm: Honoraria;Bayer Oncology: Consultancy, Honoraria, Research Funding;SecuraBio: Research Funding;Astra Zeneca: Consultancy, Honoraria, Research Funding. Mato: Pharmacyclics LLC, an AbbVie Company: Consultancy, Research Funding;DTRM BioPharma: Consultancy, Research Funding;Acerta/AstraZeneca: Consultancy, Research Funding;Sunesis: Consultancy, Research Funding;BeiGene: Consultancy, Research Funding;Johnson and Johnson: Consultancy, Research Funding;Genentech: Consultancy, Research Funding;AbbVie: Consultancy, Research Funding;Nurix: Research Funding;Genmab: Research Funding;LOXO: Consultancy, Research Funding;Janssen: Consultancy, Research Funding;AstraZeneca: Consultancy;Adaptive Biotechnologies: Consultancy, Research Funding;MSKCC: Current Employment;TG Therapeutics: Consultancy, Other: DSMB, Research Funding. Brander: Juno Therapeutics/Celgene/Bristol Myers Squibb: Research Funding;Pfizer: Consultancy, Other: Biosimilars outcomes research panel;TG Therapeutics: Consultancy, Research Funding;Novartis: Research Funding;ArQule/Merck: Consultancy;Verastem: Consultancy;BeiGene: Research Funding;ArQule: Research Funding;NCCN: Other: panel member;AstraZeneca: Research Funding;Pharmacyclics LLC, an AbbVie Company: Consultancy, Research Funding;LOXO: Research Funding;Ascentage: Research Funding;Genentech: Consultancy, Research Funding;DTRM: Research Funding;MEI Pharma: Research Funding;AbbVie: Consultancy, Other: informCLL registry steering committee, Research Funding. Coutre: Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding;Pharmacyclics: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding;AbbVie: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding;AstraZeneca: Consultancy, Membership on an entity's Board of Directors or advisory committees;Beigene: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Data Safety Monitoring Committee, Research Funding;Genentech: Consultancy, Membership on an entity's Board of Directors or advisory committees;Acerta: Other: Data Safety Monitoring Committee, Research Funding. O'Brien: Kite, Regeneron, Acerta, Caribou, Gilead, Pharmacyclics, TG Therapeutics, Pfizer, Sunesis: Research Funding;Amgen, Astellas, Celgene, GlaxoSmithKline, Janssen Oncology, Aptose Biosciences Inc., Vaniam Group LLC, AbbVie, Alexion, Verastem, Juno Therapeutics, Vida Ventures, Autolus, Johnson and Johnson, Merck, Bristol Myers Squibb, NOVA Research Company, El Lill: Consultancy. Erba: AbbVie Inc;Agios Pharmaceuticals Inc;Bristol Myers Squibb;Celgene, a Bristol Myers Squibb company;Incyte Corporation;Jazz Pharmaceuticals Inc;Novartis: Speakers Bureau;AbbVie Inc: Other: Independent review committee;AbbVie Inc;Agios Pharmaceuticals Inc;ALX Oncology;Amgen Inc;Daiichi Sankyo Inc;FORMA Therapeutics;Forty Seven Inc;Gilead Sciences Inc;GlycoMimetics Inc;ImmunoGen Inc;Jazz Pharmaceuticals Inc;MacroGenics Inc;Novartis;PTC Therapeutics: Research Funding;AbbVie Inc;Agios Pharmaceuticals Inc;Astellas;Bristol Myers Squibb;Celgene, a Bristol Myers Squibb company;Daiichi Sankyo Inc;Genentech, a member of the Roche Group;GlycoMimetics Inc;Incyte Corporation;Jazz Pharmaceuticals Inc;Kura Oncology;Nov: Other: Advisory Committee. OffLabel Disclosure: The trial studies early intervention with venetoclax and obinutuzumab in patients with CLL/SLL who are asymptomatic and observation would be standardly recommended.

Debulking before Initiation of Venetoclax Therapy in Untreated Patients with Chronic Lymphocytic Leukemia: Results from a Phase 3b Study

Background: Venetoclax (VEN), an oral B-cell lymphoma 2 inhibitor, is approved for use in adult patients (pts) with chronic lymphocytic leukemia (CLL)/small lymphocytic lymphoma (SLL). As a targeted and highly active antitumor agent, VEN induces rapid and profound tumor reduction. Inpatient monitoring for initial doses of VEN is recommended by US Prescribing Information for pts with medium tumor burden and reduced renal function or high tumor burden. Administration of debulking agents, such as obinutuzumab (G), help reduce tumor burden and, consequently, facilitate subsequent administration of VEN in the outpatient setting. However, tumor reduction data are needed to definitively establish the utility of a debulking strategy. This study performed disease restaging after every 2 cycles of debulking to evaluate the safety and efficacy of G ± bendamustine (B) as a debulking regimen before VEN treatment in the outpatient community setting. The safety and efficacy of subsequent VEN+G treatment after debulking was also evaluated. Methods: This open-label, Phase 3b study (NCT03406156) enrolled adult pts with previously untreated CLL/SLL (except those with 17p deletion) who had medium (any lymph node [LN] 5 to <10 cm or absolute lymphocyte count [ALC] ≥25×10 9/L) or high (any LN ≥10 cm or any LN ≥5 cm and ALC ≥25×10 9/L) tumor burden. A maximum of six 28-day cycles of G±B were administered, and disease restaging was performed after every 2 cycles. Once low tumor burden was achieved (all LN <5 cm and ALC <25x10 9/L), VEN+G was administered for 5 cycles followed by VEN monotherapy for a total time on VEN of up to 1 year. Disease assessments were performed at the end of combination therapy (EoCT;5 mo after last dose of G) and at the end of therapy (EoT;3 mo after last dose of VEN), and peripheral blood was collected for assessment of minimal residual disease (MRD) using the clonoSEQ assay (Adaptive Biotechnologies). Undetectable MRD was defined as <1 CLL cell/10 4 leukocytes (<10 -4;uMRD4), <10 -5 (uMRD5), or <10 -6 (uMRD6). The primary endpoints were the percentage of pts achieving low tumor burden after 2, 4, and 6 cycles of G±B debulking and complete remission (CR) and CR with incomplete marrow recovery (CRi) rates among pts receiving VEN. Results: Of 120 pts treated, 81 received G for debulking and 39 received G+B. As of 13 May 2021, 2 pts remained on study treatment, 108 were in posttreatment follow-up, and 10 had discontinued the study for reasons including death (n=7), withdrawn consent (n=2), and COVID-19 infection (n=1). At baseline, 82.5% of pts had ALC ≥25x10 9/L, 33.3% had LN ≥5 cm, and 24.2%/75.0%/0.8% had high/medium/low tumor burden, respectively. Low tumor burden was achieved in 91.6% (109/119) of evaluable pts receiving G±B debulking. In the all-treated population (N=120), the objective response rate (ORR) was 90.0% and the CR/CRi rate was 35.8%. Among pts receiving VEN with disease assessment at EoT (N=76), the ORR was 98.7% and the CR/CRi rate was 44.7% (Table). The best uMRD4 rates in peripheral blood were 89.2% (107/120) for all-treated and 98.2% (107/109) for evaluable pts. Among evaluable pts, the uMRD4 rates were 100% (100/100) and 97.1% (68/70) at EoCT and EoT, respectively. Among pts with MRD assessments at both timepoints (N=67), 19.4% had a deepening of their MRD response from EoCT to EoT, and 67.2% maintained the same MRD level (Figure). At a median follow-up of 24.0 mo, 7 deaths (6 related to COVID-19 infection and 1 from cardiac complication after pancreatic mass resection) and no incidences of disease progression were reported;the estimated 18-mo PFS was 94.1%. In pts treated with G vs G+B debulking, respectively, the incidences of Grade ≥3 TEAEs were 71.6% vs 84.6% (most common was neutropenia at 28.4% vs 41.0%) and serious AEs were 23.5% vs 17.9% (most common were pneumonia and COVID-19 pneumonia, each at 3.7% vs 2.6%). Conclusion: In this study, most (91.6%) pts achieved low tumor burden after debulking. The uMRD4 rate was 98.2% among MRD-evaluable pts (89.2% among al pts), with 100% and 97.1% uMRD4 rates at EoCT and EoT, respectively. Overall, these results highlight the utility of G±B as an effective debulking strategy that can facilitate VEN treatment initiation in the outpatient setting. The efficacy and safety results are consistent with other VEN+G trials. Preventive measures for COVID-19 should be continuously emphasized for pts with CLL. [Formula presented] Disclosures: Flinn: AstraZeneca: Consultancy, Other: All consultancy and research funding payments made to Sarah Cannon Research Institute, Research Funding;Merck: Other: All research funding payments made to Sarah Cannon Research Institute, Research Funding;Karyopharm Therapeutics: Other: All research funding payments made to Sarah Cannon Research Institute, Research Funding;Teva: Other: All research funding payments made to Sarah Cannon Research Institute, Research Funding;Janssen: Consultancy, Other: All consultancy and research funding payments made to Sarah Cannon Research Institute, Research Funding;Kite, a Gilead Company: Consultancy, Other: All consultancy and research funding payments made to Sarah Cannon Research Institute, Research Funding;Genentech: Consultancy, Other: All consultancy and research funding payments made to Sarah Cannon Research Institute, Research Funding;Trillium Therapeutics: Other: All research funding payments made to Sarah Cannon Research Institute, Research Funding;BeiGene: Consultancy, Other: All consultancy and research funding payments made to Sarah Cannon Research Institute, Research Funding;Novartis: Consultancy, Other: All consultancy and research funding payments made to Sarah Cannon Research Institute, Research Funding;Loxo: Other: All research funding payments made to Sarah Cannon Research Institute, Research Funding;Yingli Pharmaceuticals: Consultancy, Other: All consultancy payments made to Sarah Cannon Research Institute;ArQule: Other: All research funding payments made to Sarah Cannon Research Institute, Research Funding;Celgene: Other: All research funding payments made to Sarah Cannon Research Institute, Research Funding;Roche: Consultancy, Other: All consultancy and research funding payments made to Sarah Cannon Research Institute, Research Funding;Constellation Pharmaceuticals: Other: All research funding payments made to Sarah Cannon Research Institute, Research Funding;AbbVie: Consultancy, Other: All Consultancy and Research Funding payments made to Sarah Cannon Research Institute, Research Funding;Portola Pharmaceuticals: Other: All research funding payments made to Sarah Cannon Research Institute, Research Funding;Rhizen Pharmaceuticals: Other: All research funding payments made to Sarah Cannon Research Institute, Research Funding;Incyte: Other: All research funding payments made to Sarah Cannon Research Institute, Research Funding;Infinity Pharmaceuticals: Other: All research funding payments made to Sarah Cannon Research Institute, Research Funding;IGM Biosciences: Other: All research funding payments made to Sarah Cannon Research Institute, Research Funding;Forty Seven: Other: All research funding payments made to Sarah Cannon Research Institute, Research Funding;Forma Therapeutics: Other: All research funding payments made to Sarah Cannon Research Institute, Research Funding;Curis: Other: All research funding payments made to Sarah Cannon Research Institute, Research Funding;Verastem: Consultancy, Other: All consultancy and research funding payments made to Sarah Cannon Research Institute, Research Funding;Seagen: Consultancy, Other: All consultancy and research funding payments made to Sarah Cannon Research Institute, Research Funding;Juno Therapeutics: Consultancy, Other: All consultancy and research funding payments made to Sarah Cannon Research Institute, Research Funding;Gilead Sciences: Consultancy, Other: All consultancy and research funding payments made to Sarah Cannon Research Institute, Research Funding;Acerta Pharma: Other: All research funding payments made to Sarah Cannon Research Institute, Research Funding;Agios: Other All research funding payments made to Sarah Cannon Research Institute, Research Funding;Calithera Biosciences: Other: All research funding payments made to Sarah Cannon Research Institute, Research Funding;Takeda: Consultancy, Other: All consultancy and research funding payments made to Sarah Cannon Research Institute, Research Funding;Pfizer: Other: All research funding payments made to Sarah Cannon Research Institute, Research Funding;Iksuda Therapeutics: Consultancy, Other: All consultancy payments made to Sarah Cannon Research Institute;Unum Therapeutics: Consultancy, Other: All consultancy and research funding payments made to Sarah Cannon Research Institute, Research Funding;TG Therapeutics: Consultancy, Other: All consultancy and research funding payments made to Sarah Cannon Research Institute, Research Funding;Pharmacyclics LLC, an AbbVie Company: Consultancy, Other: All consultancy and research funding payments made to Sarah Cannon Research Institute, Research Funding;MorphoSys: Consultancy, Other: All consultancy and research funding payments made to Sarah Cannon Research Institute, Research Funding;Nurix Therapeutics: Consultancy, Other: All consultancy payments made to Sarah Cannon Research Institute;Great Point Partners: Consultancy, Other: All consultancy payments made to Sarah Cannon Research Institute;Triphase Research & Development Corp.: Other: All research funding payments made to Sarah Cannon Research Institute, Research Funding;Century Therapeutics: Consultancy, Other: All consultancy payments made to Sarah Cannon Research Institute;Hutchison MediPharma: Consultancy, Other: All consultancy payments made to Sarah Cannon Research Institute;Vincerx Pharma: Consultancy, Other: All consultancy payments made to Sarah CannonResearch Institute;Sarah Cannon Research Institute: Current Employment;Servier Pharmaceuticals: Consultancy, Other: All consultancy payments made to Sarah Cannon Research Institute;Yingli Pharmaceuticals: Consultancy, Other: All consultancy payments made to Sarah Cannon Research Institute;Seagen: Consultancy, Other: All consultancy payments made to Sarah Cannon Research Institute;Servier Pharmaceuticals: Consultancy, Other: All consultancy payments made to Sarah Cannon Research Institute;Unum Therapeutics: Consultancy, Other: All consultancy payments made to Sarah Cannon Research Institute, Research Funding;Johnson & Johnson: Current holder of individual stocks in a privately-held company;Seattle Genetics: Research Funding. Andorsky: AbbVie: Research Funding;Celgene/Bristol Myers Squibb: Consultancy;Celgene/Bristol Myers Squibb: Research Funding;Epizyme: Research Funding;AstraZeneca: Other: served on steering committees;AbbVie: Consultancy. Melear: TG Therapeutics: Speakers Bureau;Astrazeneca: Speakers Bureau;Janssen: Speakers Bureau. Manda: Morphosys: Honoraria;Genmab: Current equity holder in publicly-traded company. Kolibaba: TG Therapeutics: Current Employment, Current holder of individual stocks in a privately-held company, Current holder of stock options in a privately-held company;Atara Biotechm: Consultancy;McKesson Specialty Health: Consultancy;Sunitomo Dainippon Pharma: Consultancy;Tolero Pharma: Consultancy, Other: TRAVEL, ACCOMMODATIONS, EXPENSES. Yimer: GSK: Speakers Bureau;Beigene: Speakers Bureau;Janssen: Speakers Bureau;Astrazeneca: Speakers Bureau;Karyopharm: Current equity holder in publicly-traded company, Speakers Bureau;Sanofi: Speakers Bureau;Amgen: Speakers Bureau;Pharmacyclics: Speakers Bureau;Texas Oncology: Current Employment. Burke: Kura: Consultancy;Epizyme: Consultancy;Kymera: Consultancy;Adaptive Biotechnologies: Consultancy;Roche/Genentech: Consultancy;Beigene: Consultancy, Speakers Bureau;MorphoSys: Consultancy;Verastem: Consultancy;AstraZeneca: Consultancy;AbbVie: Consultancy;Bristol Myers Squibb: Consultancy;X4 Pharmaceuticals: Consultancy;SeaGen: Consultancy, Speakers Bureau. Fanning: BMS: Speakers Bureau;TG Pharma: Membership on an entity's Board of Directors or advisory committees, Speakers Bur au;Genmab: Membership on an entity's Board of Directors or advisory committees;ADC Therapeutics: Membership on an entity's Board of Directors or advisory committees;Sanofi: Speakers Bureau;Takeda: Speakers Bureau;Genentech: Membership on an entity's Board of Directors or advisory committees. Islas-Ohlmayer: OHC/USON: Current Employment;AbbVie: Honoraria;Rigel: Honoraria, Speakers Bureau. Vizkelety: AbbVie: Current Employment, Current equity holder in publicly-traded company. Pesko: AbbVie: Current Employment, Current equity holder in publicly-traded company. Chyla: AbbVie: Current Employment, Current equity holder in publicly-traded company. Jiang: AbbVie: Current Employment, Current equity holder in publicly-traded company. Sharman: Pharmacyclics LLC, an AbbVie Company: Consultancy;BMS: Consultancy;Lilly: Consultancy;BeiGene: Consultancy;Centessa: Current holder of stock options in a privately-held company, Membership on an entity's Board of Directors or advisory committees;AstraZeneca: Consultancy;TG Therapeutics: Consultancy;AbbVie: Consultancy.

COVID-19 in Pediatric Hematopoietic Cell Transplant Recipients: A CIBMTR Study

Background: Adult recipients of hematopoietic cell transplantation (HCT) are at a very high risk of adverse outcomes after COVID-19 (Sharma A, Bhatt NS, et al. Clinical characteristics and outcomes of COVID-19 in haematopoietic stem-cell transplantation recipients: an observational cohort study. The Lancet Haematology. 2021 Mar 1;8(3): e185-93). While children are known to have better outcomes after COVID-19 compared to adults in general, data on risk factors and outcomes of COVID-19 among pediatric recipients of HCT are lacking. Methods: Using the data reported to the Center for International Blood and Marrow Transplant Research (CIBMTR) between March 2020 and May 2021, we describe characteristics, severity, treatment approaches, and outcomes of pediatric HCT recipients who were ≤21 years of age at COVID-19 diagnosis. All diagnoses, donor choice/graft sources, and conditioning regimens were included. Patient, disease, and HCT-related factors were described as frequency for categorical variables and median, range, and interquartile range (IQR) for continuous variables. The probability of overall survival after COVID-19 was calculated using the Kaplan Meier estimator. Additionally, an analysis was performed in the subset of allogeneic HCT COVID-19 cases from the United States (US) to identify risk factors for developing COVID-19. COVID-19 cases were compared with a cohort of all pediatric allogeneic HCT recipients without COVID-19 matched by the transplant center. Impact of hematopoietic cell transplant comorbidity index (HCT-CI), HCT indication, donor type, conditioning intensity, graft vs. host disease (GVHD) prophylaxis, and occurrence of acute and chronic GVHD on development of COVID-19 was examined using Cox proportional hazards model. Hazard ratio (HR) and 95% confidence intervals (CI) were provided. Cumulative incidence of COVID-19 among the US centers reporting at least 1 COVID-19 infection was also calculated, using death from any cause as a competing risk. P value <0.05 was considered statistically significant for the analyses. Results: A total of 167 pediatric HCT recipients (allogeneic, allo: 135 and autologous, auto: 32) met study inclusion criteria. Median age at COVID-19 diagnosis for allo and auto HCT recipients were 15 years (range <1-21y) and 7 years (range 1-21y), respectively. Median time from HCT to COVID-19 diagnosis was 15 months (IQR 7-45) for allo recipients and 16 months (IQR 6-59) for auto HCT recipients. Forty-two percent (42%) of the patients had at least one comorbidity prior to HCT. Thirteen percent (13%) were receiving immunosuppression within six months prior to COVID-19 diagnosis. COVID-19 disease severity was mild in 87% of patients, while 4% of patients had severe disease requiring mechanical ventilation or supplemental oxygen. Only 36 HCT recipients (22%) received any COVID-19 directed therapy. Median follow-up from COVID-19 diagnosis was 53 days (range 1-270) and 37 days (range 1-179) for allo and auto HCT recipients, respectively. The overall probability of survival at 45 days was 95% (95% CI 90-99%) and 90% (95% CI 74-99%) for allo and auto HCT recipients, respectively (Figure 1). Forty-five (45) day survival was lower among recipients transplanted at the transplant centers outside the US [non-US recipients 85% (95% CI 71-95%) versus US recipients 98% (95% CI 93-99%)]. No deaths occurred in patients who had received a transplant between 2000-2013. The primary cause of death was COVID-19 in 54% of patients and primary disease in 38% of patients. In the subset analysis restricted to pediatric allogeneic HCT recipients transplanted at the US centers (n=34), the cumulative incidence of COVID-19 infection was noted to be 1.9% (95% CI 1.2-2.9%) at 6 months post-HCT and increased to 4.7% (95% CI 3.4-6.3%) by 1-year post-HCT. Cox regression analysis showed that compared to HCT-CI score of 0, patients with HCT-CI score of 1-2 were more likely to develop COVID-19 (HR 1.95;95% CI 1.03-3.69, p=0.042). Underlying diagnosis, donor type, treatment exposures, or GVHD did not predict COVID- 9 incidence. Conclusions: This is the largest series to date summarizing the cumulative incidence, risk factors, and outcomes of pediatric HCT recipients with COVID-19. Patients with pre-HCT comorbidities were more likely to develop COVID-19. However, the overall disease severity and mortality after COVID-19 were low in this patient cohort. [Formula presented] Disclosures: Bhatt: Rite Aid Corporation: Divested equity in a private or publicly-traded company in the past 24 months;Pfizer Inc.: Divested equity in a private or publicly-traded company in the past 24 months;Moderna, Inc.: Divested equity in a private or publicly-traded company in the past 24 months;Johnson & Johnson: Divested equity in a private or publicly-traded company in the past 24 months. Sharma: Medexus Inc: Consultancy;Spotlight Therapeutics: Consultancy;Vindico Medical Education: Honoraria;CRISPR Therapeutics: Other, Research Funding;Novartis: Other: Salary support paid to institution;Vertex Pharmaceuticals/CRISPR Therapeutics: Other: Salary support paid to institution. Riches: ATARA Biotherapeutics: Other: Payment;Jazz Pharmaceuticals: Other: Payment;BioIntelect: Membership on an entity's Board of Directors or advisory committees. Dandoy: Omeros: Other: Consulted and received Honorarium.

Phase 2 Study of Zanubrutinib in BTK Inhibitor-Intolerant Patients (Pts) with Relapsed/Refractory B-Cell Malignancies

Background: Bruton tyrosine kinase inhibitors (BTKis) are important tools to treat B-cell malignancies. However, duration of treatment may be limited by adverse events (AEs). Zanubrutinib (zanu) is a BTKi approved for mantle cell lymphoma (MCL) and is in development for other hematologic malignancies. Data from phase 3 head-to-head trials of zanu vs ibrutinib (ibr) in pts with Waldenström macroglobulinemia (WM) or chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) demonstrated that pts treated with zanu showed lower rates of AEs leading to discontinuation (Blood 2020;136(18):2038-50;EHA 2021 LB1900). Preliminary results from BGB-3111-215 (NCT04116437) show that zanu was well-tolerated in pts who discontinued ibr and/or acalabrutinib (acala) treatment due to AEs (EHA 2021 EP642). Here, we report updated results from the BGB-3111-215 study with a median follow-up of 9 months. Methods: This study is an ongoing US, phase 2, multicenter, single-arm, open-label study. The safety and efficacy of zanu monotherapy (160 mg twice daily or 320 mg once daily) were evaluated in pts with B-cell malignancies who met criteria for continued treatment after having become intolerant to prior BTKi therapy. Pts were divided into cohort 1 (pts who were intolerant to ibr only) and cohort 2 (pts who were intolerant to acala alone/and ibr). Pts with documented progressive disease (PD) on prior BTKi therapy were excluded. Efficacy and safety, including recurrence of intolerant AEs to the prior BTKi, were evaluated. AEs were assessed for severity, seriousness, and relation to zanu;as well as dose reductions, holds, or discontinuations. Response was assessed by investigators based on response criteria for their respective indications (Blood 2008;131:2745;J Clin Oncol 2012;30:2820;J Clin Oncol 2014;32:3059;Br J Haemtol 2013;160:171). Disease parameters from study entry were the baseline for response assessment. Mutational analysis was performed on pts who discontinued treatment, and data will be shared once available. To support clinical findings, kinase selectivity was assessed using Kinome profiling at 100X IC50 (against BTK) for zanu, ibr, acala and its major metabolite, M27 (Reaction Biology Corp). Results: As of 7 June 2021 (data cutoff), 57 pts (n=44 CLL/SLL;n=9 WM;n=2 MCL;n=2 marginal zone lymphoma [MZL]) were enrolled in cohort 1, and 7 pts were enrolled in cohort 2 (n=4 CLL;n=1 WM;n=1 MCL;n=1 MZL). All received ≥1 dose of zanu and were analyzed for safety. The median age was 71 years (range, 49-91) in cohort 1 and 71 years (range, 65-76) in cohort 2;median duration of treatment was 8.7 months (range, 0.6-17.9) in cohort 1 and 8.2 months (range, 6.4-11.4) in cohort 2;median number of prior regimens was 1 (range, 1-12) in cohort 1 and 3 (range, 2-5) in cohort 2. Within cohort 2, 5 pts were intolerant to both ibr and acala. Median number of intolerant events per pt for both cohorts 1 and 2 was 2 (range, 1-5). Overall, 73% of pts did not experience recurrence of their ibr or acala intolerant events and 79% of recurrent events recurred at a lower severity (Figure 1). At cutoff, 54 pts remained on treatment. Reasons for treatment discontinuation were AEs (n=4), PD (n=4), physician's decision (n=1), and consent withdrawal (n=1). Grade ≥3 AEs were reported in 18 pts (28%), and serious AEs occurred in 7 pts (11%). AEs requiring dose interruptions occurred in 17 pts (27%), and AEs leading to dose reduction occurred in 3 pts (5%). One death, due to COVID-19, was reported. Pts demonstrated maintained (41%) and improved (53%) response with zanu treatment from their reported best overall response on prior BTKis for a total disease control rate of 94% (including a 42% partial response rate in pts with CLL/SLL, 30% in pts with WM, and a 20% very good partial response rate in pts with WM). Zanu also demonstrated good selectivity by kinase profiling. It showed >50% inhibition on 7/370 kinases, while ibr, acala, and M27 had more off-target binding (17, 15 and 23 kinases, respectively) at their respective 100X IC50 (BTK) c ncentrations (Figure 2). Conclusion: In pts with B-cell malignancies intolerant to ibr and/or acala, zanu treatment resulted in continued disease control or improved response. Zanu was well-tolerated, and most AEs that led to discontinuation of previous BTKi therapy did not recur or recurred at a lower grade. In support of clinical findings, differentiation between BTKi selectivity profiles favor zanu over ibr and acala. [Formula presented] Disclosures: Shadman: Abbvie, Genentech, AstraZeneca, Sound Biologics, Pharmacyclics, Beigene, Bristol Myers Squibb, Morphosys, TG Therapeutics, Innate Pharma, Kite Pharma, Adaptive Biotechnologies, Epizyme, Eli Lilly, and Atara Biotherapeutics, Adaptimmune: Consultancy;Mustang Bio, Celgene, Bristol Myers Squibb, Pharmacyclics, Gilead, Genentech, Abbvie, TG Therapeutics, Beigene, AstraZeneca, Sunesis, Atara Biotherapeutics, GenMab: Research Funding;Abbvie, Genentech, AstraZeneca, Sound Biologics, Pharmacyclics, Beigene, Bristol Myers Squibb, Morphosys, TG Therapeutics, Innate Pharma, Kite Pharma, Adaptive Biotechnologies, Epizyme, Eli Lilly, and Atara Biotherapeutics, Adaptimmune: Membership on an entity's Board of Directors or advisory committees. Flinn: Nurix Therapeutics: Consultancy, Other: All consultancy payments made to Sarah Cannon Research Institute;Seagen: Consultancy, Other: All consultancy and research funding payments made to Sarah Cannon Research Institute, Research Funding;MorphoSys: Consultancy, Other: All consultancy and research funding payments made to Sarah Cannon Research Institute, Research Funding;Forty Seven: Other: All research funding payments made to Sarah Cannon Research Institute, Research Funding;Calithera Biosciences: Other: All research funding payments made to Sarah Cannon Research Institute, Research Funding;Verastem: Consultancy, Other: All consultancy and research funding payments made to Sarah Cannon Research Institute, Research Funding;Curis: Other: All research funding payments made to Sarah Cannon Research Institute, Research Funding;Takeda: Consultancy, Other: All consultancy and research funding payments made to Sarah Cannon Research Institute, Research Funding;Yingli Pharmaceuticals: Consultancy, Other: All consultancy payments made to Sarah Cannon Research Institute;IGM Biosciences: Other: All research funding payments made to Sarah Cannon Research Institute, Research Funding;AbbVie: Consultancy, Other: All Consultancy and Research Funding payments made to Sarah Cannon Research Institute, Research Funding;Portola Pharmaceuticals: Other: All research funding payments made to Sarah Cannon Research Institute, Research Funding;Trillium Therapeutics: Other: All research funding payments made to Sarah Cannon Research Institute, Research Funding;Rhizen Pharmaceuticals: Other: All research funding payments made to Sarah Cannon Research Institute, Research Funding;Incyte: Other: All research funding payments made to Sarah Cannon Research Institute, Research Funding;Acerta Pharma: Other: All research funding payments made to Sarah Cannon Research Institute, Research Funding;Agios: Other: All research funding payments made to Sarah Cannon Research Institute, Research Funding;Kite, a Gilead Company: Consultancy, Other: All consultancy and research funding payments made to Sarah Cannon Research Institute, Research Funding;Gilead Sciences: Consultancy, Other: All consultancy and research funding payments made to Sarah Cannon Research Institute, Research Funding;Pharmacyclics LLC, an AbbVie Company: Consultancy, Other: All consultancy and research funding payments made to Sarah Cannon Research Institute, Research Funding;Karyopharm Therapeutics: Other: All research funding payments made to Sarah Cannon Research Institute, Research Funding;Forma Therapeutics: Other: All research funding payments made to Sarah Cannon Research Institute, Research Funding;Genentech: Consultancy, Other: All consultancy and research funding payments made to Sarah Cannon Research Institute, Research Funding;ArQule: Other: All research funding payments mad to Sarah Cannon Research Institute, Research Funding;Triphase Research & Development Corp.: Other: All research funding payments made to Sarah Cannon Research Institute, Research Funding;Roche: Consultancy, Other: All consultancy and research funding payments made to Sarah Cannon Research Institute, Research Funding;Pfizer: Other: All research funding payments made to Sarah Cannon Research Institute, Research Funding;Teva: Other: All research funding payments made to Sarah Cannon Research Institute, Research Funding;Infinity Pharmaceuticals: Other: All research funding payments made to Sarah Cannon Research Institute, Research Funding;Unum Therapeutics: Consultancy, Other: All consultancy and research funding payments made to Sarah Cannon Research Institute, Research Funding;Celgene: Other: All research funding payments made to Sarah Cannon Research Institute, Research Funding;Constellation Pharmaceuticals: Other: All research funding payments made to Sarah Cannon Research Institute, Research Funding;Juno Therapeutics: Consultancy, Other: All consultancy and research funding payments made to Sarah Cannon Research Institute, Research Funding;AstraZeneca: Consultancy, Other: All consultancy and research funding payments made to Sarah Cannon Research Institute, Research Funding;Iksuda Therapeutics: Consultancy, Other: All consultancy payments made to Sarah Cannon Research Institute;Loxo: Other: All research funding payments made to Sarah Cannon Research Institute, Research Funding;Merck: Other: All research funding payments made to Sarah Cannon Research Institute, Research Funding;Novartis: Consultancy, Other: All consultancy and research funding payments made to Sarah Cannon Research Institute, Research Funding;Great Point Partners: Consultancy, Other: All consultancy payments made toSarah Cannon Research Institute;BeiGene: Consultancy, Other: All consultancy and research funding payments made to Sarah Cannon Research Institute, Research Funding;Janssen: Consultancy, Other: All consultancy and research funding payments made to Sarah Cannon Research Institute, Research Funding;TG Therapeutics: Consultancy, Other: All consultancy and research funding payments made to Sarah Cannon Research Institute, Research Funding;Century Therapeutics: Consultancy, Other: All consultancy payments made to Sarah Cannon Research Institute;Hutchison MediPharma: Consultancy, Other: All consultancy payments made to Sarah Cannon Research Institute;Vincerx Pharma: Consultancy, Other: All consultancy payments made to Sarah Cannon Research Institute;Sarah Cannon Research Institute: Current Employment;Servier Pharmaceuticals: Consultancy, Other: All consultancy payments made to Sarah Cannon Research Institute;Yingli Pharmaceuticals: Consultancy, Other: All consultancy payments made to Sarah Cannon Research Institute;Seagen: Consultancy, Other: All consultancy payments made to Sarah Cannon Research Institute;Servier Pharmaceuticals: Consultancy, Other: All consultancy payments made to Sarah Cannon Research Institute;Unum Therapeutics: Consultancy, Other: All consultancy payments made to Sarah Cannon Research Institute, Research Funding;Johnson & Johnson: Current holder of individual stocks in a privately-held company;Seattle Genetics: Research Funding. Levy: Epizyme: Consultancy, Other: Promotional speaker;Amgen Inc.: Consultancy, Honoraria, Other: Promotional speaker, Speakers Bureau;Gilead Sciences, Inc.: Consultancy, Honoraria, Speakers Bureau;GSK: Consultancy, Other: Promotional speaker;Morphosys: Consultancy, Honoraria, Other: Promotional speaker, Speakers Bureau;AbbVie: Consultancy, Honoraria, Other: Promotional speaker, Speakers Bureau;Beigene: Consultancy, Honoraria, Speakers Bureau;Karyopharm: Consultancy, Honoraria, Other: Promotional speaker, Speakers Bureau;AstraZeneca: Consultancy, Honoraria, Speakers Bureau;Takeda: Consultancy, Honoraria, Other: Promotional speaker, Speakers Bureau;Novartis: Consultancy, Other: Promotional speaker;Dova: Consultancy, Other: Promotional speaker;TG Therapeutics: Co sultancy, Honoraria, Speakers Bureau;Bristol Myers Squibb: Consultancy, Honoraria, Other: Promotional speaker, Speakers Bureau;Seattle Genetics: Consultancy, Honoraria, Other: Promotional speaker, Speakers Bureau;Jazz Pharmaceuticals: Consultancy, Honoraria, Speakers Bureau;Janssen Pharmaceuticals: Consultancy, Honoraria, Other: Promotional speaker, Speakers Bureau. Burke: SeaGen: Consultancy, Speakers Bureau;Beigene: Consultancy, Speakers Bureau;MorphoSys: Consultancy;Bristol Myers Squibb: Consultancy;AstraZeneca: Consultancy;Epizyme: Consultancy;Verastem: Consultancy;Kura: Consultancy;Kymera: Consultancy;AbbVie: Consultancy;Adaptive Biotechnologies: Consultancy;Roche/Genentech: Consultancy;X4 Pharmaceuticals: Consultancy. Cultrera: Beigene: Research Funding. Yimer: Astrazeneca: Speakers Bureau;Karyopharm: Current equity holder in publicly-traded company, Speakers Bureau;Janssen: Speakers Bureau;Beigene: Speakers Bureau;GSK: Speakers Bureau;Sanofi: Speakers Bureau;Amgen: Speakers Bureau;Pharmacyclics: Speakers Bureau;Texas Oncology: Current Employment. Chaudhry: Medical Oncology Associates, PS (dba Summit Cancer Centers): Current Employment;Novartis, Immunomedics: Current holder of individual stocks in a privately-held company. Gandhi: TG Therapeutics: Honoraria;Karyopharm Therapeutics: Honoraria;GlaxoSmithKline: Honoraria. Kingsley: Comprehensive Cancer Centers of Nevada: Current Employment. Tumula: Texas Oncology: Current Employment. Manda: Morphosys: Honoraria;Genmab: Current equity holder in publicly-traded company. Chen: BeiGene: Current Employment, Divested equity in a private or publicly-traded company in the past 24 months. Cohen: BeiGene: Current Employment, Current equity holder in publicly-traded company, Other: Travel, Accommodations, Expenses. By: BeiGene, Ltd: Current Employment. Xu: Beigene: Current Employment;AstraZeneca: Ended employment in the past 24 months. Liu: BeiGene Co., Ltd: Current Employment, Current equity holder in publicly-traded company. Sharman: TG Therapeutics: Consultancy;Centessa: Current holder of stock options in a privately-held company, Membership on an entity's Board of Directors or advisory committees;Pharmacyclics LLC, an AbbVie Company: Consultancy;BMS: Consultancy;AbbVie: Consultancy;BeiGene: Consultancy;AstraZeneca: Consultancy;Lilly: Consultancy.

Ibrutinib Plus Rituximab Is Superior to FCR in Previously Untreated CLL: Results of the Phase III NCRI FLAIR Trial

Introduction: The most effective chemoimmunotherapy (CIT) in previously untreated CLL is the combination of fludarabine, cyclophosphamide and rituximab (FCR). Ibrutinib (I), the first irreversible inhibitor of Bruton's tyrosine kinase approved for CLL, has improved outcomes in numerous clinical trials compared to different CIT. Methods: FLAIR (ISRCTN01844152) is an ongoing, phase III, multicentre, randomised, controlled, open, parallel group trial for previously untreated CLL requiring therapy according to the IWCLL 2008 guidelines. Patients over 75 years or with >20% 17p-deleted cells were excluded. Participants were randomised on a 1:1 basis to receive 6 cycles of FCR (oral fludarabine 24mg/m 2/day for 5 days, oral cyclophosphamide 150mg/m 2/day for 5 days with IV rituximab [375 mg/m 2 on day 1/2 of cycle 1;500 mg/m 2 on day 1 of cycles 2-6]) every 28-days or IR (Ibrutinib [420mg/day] plus rituximab [6 doses as for FCR]) given for up to 6 years with stratification by disease stage, age, gender and centre. The primary endpoint was to assess whether IR was superior to FCR in terms of investigator-assessed PFS. Secondary endpoints included overall survival,;attainment of undetectable MRD;response to therapy;safety and toxicity;health-related quality of life and cost-effectiveness. A formal interim analysis was planned when 191 events were observed in both arms or 109 events in the FCR arm alone with a p-value of 0.005 leading to reporting of the trial. Here we report the results of this planned interim analysis. Results: A total of 771 patients were randomised (385 to FCR and 386 to IR) from 113 UK Centres between 9/19/2014 and 7/19/2018. The data was locked on 5/24/2021. 73.3% were male, median age was 62 years (33.6% >65yo) and 45.1% were Binet Stage C. IGHV data was available for 728 (94.4%) patients with 53.2% IGHV unmutated (≥98% homology to germline), 40.5% IGHV mutated and 6.3% Subset 2. Hierarchical FISH testing revealed 0.4% 17p del, 15.4% 11q del, 12.3% trisomy 12, 29.7% normal and 35% 13q del;with 7.1% failed. The arms were well-balanced for disease variables with no significance differences. Median follow-up was 52.7 months. IR had a superior PFS compared to FCR (Median PFS not reached for IR versus 67 months for FCR;HR: 0.44;p<0.001;see Figure). The PFS was significantly better for IR in patients with IGHV unmutated CLL (HR: 0.41;p<0.001), but not for patients with IGHV mutated CLL at this follow-up (HR: 0.66;p=0.179). There was no difference in overall survival between the two arms (HR: 1.01;p=0.956) with a total of 29 deaths in FCR arm (including 4 from CLL, 3 Richter's [RT], 3 AML/MDS, 3 COVID-19 and 2 cardiac/sudden) and 30 in the IR arm (including 3 CLL, 1 RT, 0 AML/MDS, 3 COVID-19 and 8 cardiac/sudden). Second line treatment was initiated for 59 patients after FCR (including 38 BTKi, 7 venetoclax+R [venR], 4 BendamustineR [BR] and 3 CHOP-R [RT]) and 21 after IR (including 7 FCR, 5 venR, 1 BR, 1 CHOP-R [RT], 1 ABVD [Hodgkin's]). Overall, 88.1% of patients have received targeted therapies for CLL progression after FCR. The overall survival with FCR in FLAIR is significantly improved compared to FCR in previous NCRI trials (ADMIRE and ARCTIC) which had the same inclusion criteria, the same Centres and an identical FCR schedule, but were conducted prior to widespread availability of targeted therapies in the relapse (recruited between 2009 and 2012). The 4 year overall survival for FCR in FLAIR was 94.5% compared to 84.2% for FCR between 2009 and 2012. SAEs were reported in 53.7% of patients on FCR and 53.4% on IR. Notable differences for SAEs by organ class for FCR vs IR: infections in 33.6% of patients vs 27.1%;blood and lymphatic in 19.8% vs 10.7%;and cardiac in 1.1% vs 8.3%. With current follow-up, there were 10 sudden or cardiac deaths: 8 IR and 2 FCR. Further analysis indicated that 7 of the 8 cardiac or sudden deaths in the IR arm had a history of hypertension or cardiac disease (further detailed in additional ;Munir et al.). Neither of the sudden deaths in the FCR arm ad a prior cardiac or hypertensive history or were on cardiac or anti-hypertensive treatment. There were 6 cases of secondary MDS/AML in the FCR arm and 1 in the IR arm. Conclusion: Ibrutinib plus rituximab resulted in a superior PFS compared to FCR. There was no difference in overall survival, most likely due to effective second-line targeted therapy in patients progressing after FCR. [Formula presented] Disclosures: Hillmen: Janssen: Honoraria, Other: Travel, Accommodations, Expenses, Research Funding;AbbVie: Honoraria, Other: Travel, Accommodations, Expenses, Research Funding;Pharmacyclics: Honoraria, Research Funding;Roche: Research Funding;Gilead: Research Funding;SOBI: Honoraria;BeiGene: Honoraria;AstraZeneca: Honoraria. Bloor: Novartis: Honoraria;Kite, a Gilead Company: Honoraria. Broom: AbbVie: Honoraria;AstraZeneca: Honoraria;Janssen-Cilag Ltd: Honoraria;Takeda UK Ltd: Honoraria;Celgene Ltd: Honoraria;Gilead: Honoraria. Furtado: Abbvie: Other: Conference support. Morley: Kite: Honoraria;Janssen: Honoraria;AbbVie;Takeda: Other: Conference support;Roche: Membership on an entity's Board of Directors or advisory committees, Other: Conference support. Cwynarski: Adienne, Takeda, Roche, Autolus, KITE, Gilead, Celgene, Atara, Janssenen: Other. Paneesha: Celgene: Honoraria;Roche: Honoraria;Janssen: Honoraria;Gilead: Honoraria;Bristol Myers Squibb: Honoraria;AbbVie: Honoraria. Howard: Roche: Current Employment. Cairns: Merck Sharpe and Dohme: Research Funding;Amgen: Research Funding;Takeda: Research Funding;Celgene / BMS: Other: travel support, Research Funding. Patten: NOVARTIS: Honoraria;ROCHE: Research Funding;JANSSEN: Honoraria;ASTRA ZENECA: Honoraria;ABBVIE: Honoraria;GILEAD SCIENCES: Honoraria, Research Funding. Munir: F. Hoffmann-La Roche: Consultancy;Alexion: Honoraria.

Safety and Efficacy of Sars-Cov-2 Vaccines in Hodgkin Lymphoma Patients Receiving PD-1 Inhibitors

Background: Patients (pts) with cancer are at higher risk for complications and mortality related to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Although mRNA vaccines have been granted Food and Drug Administration emergency use authorization (EUA) for prevention of COVID-19, the pivotal trials largely excluded pts with active cancer. Emerging data suggests suboptimal efficacy of these vaccines in pts with hematologic malignancies. There are also theoretical concerns that programmed cell death protein 1 inhibitors (PD-1i) could potentiate vaccine-related adverse events (AEs);conversely, these vaccines could activate the immune system, increasing the risk for immune-related reactions (IRRs) after PD-1i treatment. Pts with classic Hodgkin lymphoma (cHL) receiving PD-1i represent a unique cohort and should be investigated for safety and efficacy issues with SARS-CoV-2 vaccines. Methods: We conducted a retrospective analysis of pts with cHL who were treated with PD-1i within the past 12 months. Our primary objective was to determine the frequency of vaccine-related AEs and also subsequent IRRs to PD-1i after vaccination as reported in the medical records. Our secondary objective was to determine efficacy based on post-vaccine COVID-19 infection rates and by presence of adequate receptor binding domain (RBD) IgG antibody level to the SARS-CoV-2 spike protein. This assay was a clinically available institutional assay developed under EUA. While the level of antibody that is associated with immune protection has not yet been defined, we used RBD IgG > 0.700 AU as positive since it was previously correlated with virus neutralization titer in vitro. Results: From July 1, 2020 through June 31, 2021, we identified 27 pts who received PD-1i for cHL and were seen at the University of Pennsylvania. Seventeen (63%) pts received nivolumab and 10 (37%) received pembrolizumab. The median age was 42 years (23-86), median number of therapies was 4 (2-15), and 7 (26%) had prior history of COVID-19 infection (none required hospitalization). Twenty-three pts (85% of total) were vaccinated: 17 (74%) received Pfizer-BioNTech BNT162b2 and 6 (26%) had Moderna mRNA-1273 formulations. Of 19 (83%) pts who received at least one dose of PD-1i prior vaccine, the median time between last PD-1i infusion and first vaccine administration was 20 days (2-157). Of 19 (83%) pts who received any PD-1i after vaccine, the median time to infusion was 18 days (4-89). In pts who had prior COVID-19 infection, the median time between the prior infection and vaccine was 91 days (range 78-350). There were no unexpected toxicities noted and no severe adverse events or hospitalizations directly related to vaccination. No patient discontinued the vaccination series due to side effects. In 12 vaccinated pts who had vaccine-related AEs solicited by the medical provider, 7 (58%) developed injection site reaction/pain: grade 1 (6/12) and grade 2 (1/12). Six (50%) pts had systemic AEs: grade 1 fatigue (4/12), grade 2 fatigue (1/12), transient generalized lymphadenopathy (1/12), fever (1/12). No new IRRs occurred in pts receiving subsequent PD-1i after vaccination. Two weeks after second vaccination, 1 patient developed worsening cough with imaging suggestive of pneumonitis but improved with antibiotics. There were no post-vaccine COVID-19 infections noted. RBD IgG antibody levels were available in 12/23 (52%) of all vaccinated pts;11/12 (92%) pts had positive antibody titers. The only patient who did not mount positive RBD IgG antibody titers received brentuximab vedotin concurrently with PD-1i prior to vaccination. There were insufficient events to correlate pre-vaccine factors with AEs or efficacy. Conclusion: Pts with relapsed/refractory cHL on PD-1i who received SARS-CoV-2 vaccines had no unexpected toxicities and tolerated subsequent PD-1i without new IRRs. The efficacy based on post-vaccination COVID-19 rates and RBD IgG levels is encouraging in these heavily pretreated pts. We plan an additional prospective component of this study using atient reported outcomes and long-term safety and efficacy follow-up. Disclosures: Svoboda: Incyte: Research Funding;Genmab: Consultancy;Merck: Research Funding;Pharmacyclics: Consultancy, Research Funding;BMS: Consultancy, Research Funding;TG: Research Funding;Imbrium: Consultancy;Seattle Genetics: Consultancy, Research Funding;Astra Zeneca: Consultancy, Research Funding;Atara: Consultancy;Adaptive: Consultancy, Research Funding. Dwivedy Nasta: Roche: Research Funding;Merck: Other: Data safety monitoring board;Incyte: Membership on an entity's Board of Directors or advisory committees;AstraZeneca: Membership on an entity's Board of Directors or advisory committees;Pharmacyclics: Research Funding;ATARA: Research Funding;Millenium: Research Funding;Rafael: Research Funding;Debiopharm: Research Funding. Ruella: AbClon: Consultancy, Research Funding;BMS, BAYER, GSK: Consultancy;Novartis: Patents & Royalties;Tmunity: Patents & Royalties;viTToria biotherapeutics: Research Funding. Landsburg: Triphase: Research Funding;Takeda: Research Funding;Curis: Research Funding;ADCT: Membership on an entity's Board of Directors or advisory committees;Incyte: Membership on an entity's Board of Directors or advisory committees;Karyopharm: Membership on an entity's Board of Directors or advisory committees, Other: DSMB member;Morphosys: Membership on an entity's Board of Directors or advisory committees. Barta: Seagen: Honoraria;Daiichi Sankyo: Honoraria;Acrotech: Honoraria;Kyowa Kirin: Honoraria. Gerson: TG Therapeutics: Consultancy;Kite: Consultancy;Abbvie: Consultancy;Pharmacyclics: Consultancy. Schuster: Loxo Oncology: Consultancy;Nordic Nanovector: Consultancy;Genentech/Roche: Consultancy, Research Funding;Novartis: Consultancy, Honoraria, Patents & Royalties, Research Funding;Celgene: Consultancy, Honoraria, Research Funding;Acerta Pharma/AstraZeneca: Consultancy;BeiGene: Consultancy;Juno Theraputics: Consultancy, Research Funding;Tessa Theraputics: Consultancy;Pharmaclyclics: Research Funding;Abbvie: Consultancy, Research Funding;Alimera Sciences: Consultancy;Adaptive Biotechnologies: Research Funding;Merck: Research Funding;Incyte: Research Funding;TG Theraputics: Research Funding;DTRM: Research Funding.

Analysis of Outcomes and Predictors of Response in Patients with Relapsed Mantle Cell Lymphoma Treated with Brexucabtagene Autoleucel

Background: Brexucabtagene autoleucel (brexu-cel) is the first CD19 chimeric antigen receptor T-cell (CAR T) therapy approved for use in patients (pts) with relapsed mantle cell lymphoma (MCL). The ZUMA-2 trial demonstrated that brexu-cel induces durable remissions in these pts with an ORR of 85% (59% CR), estimated 12-month PFS rate of 61%, and similar toxicity profile to other CAR T therapies (Wang et al, NEJM 2020). We conducted a multicenter, retrospective study of pts treated with commercial brexu-cel to evaluate its safety and efficacy in the non-trial setting. Methods: We reviewed records of pts with relapsed MCL across 12 US academic medical centers. Pts who underwent leukapheresis between July 2020 and June 2021 with the intent to proceed to commercial brexu-cel were included. Baseline demographic and clinical characteristics were summarized using descriptive statistics. Survival curves were generated using the Kaplan-Meier method, and univariate models were fit to identify predictors of post-CAR T outcomes. Results: Fifty-five pts underwent leukapheresis. There were 3 manufacturing failures. Baseline characteristics of the 52 pts who received brexu-cel are summarized in Table 1. Median age was 66 yrs (range: 47-79 yrs) and 82% were male. Twenty of 29 (69%) pts with known baseline MIPI were intermediate or high risk. Seven pts had a history of CNS involvement. The median number of prior therapies was 3 (range: 2-8), including prior autologous stem cell transplant (ASCT) in 21 (40%) and prior allogeneic transplant in 2 pts (1 with prior ASCT and 1 without). Fifty percent had relapsed within 24 months of their initial therapy. All pts had previously received a Bruton's tyrosine kinase inhibitor (BTKi), including 29 (56%) with disease progression on a BTKi. Forty (77%) pts received bridging therapy (17 BTKi, 10 BTKi + venetoclax, 6 chemo, 3 venetoclax, 2 XRT only, 1 steroids only, 1 lenalidomide + rituximab). The ORR was 88% (CR 69%) among patients who received brexu-cel. Two pts had PD on initial restaging and 3 died prior to first response assessment (without evidence of relapse). Seven pts have not completed restaging due to limited follow-up (< 3 months) and were not included in the response assessment. Five pts have progressed, including 2 with CR and 1 with PR on initial restaging. With a median follow-up of 4.2 months, the estimated 6-month PFS and OS rates were 82.7% and 89.0%, respectively. All 7 pts with prior CNS involvement were alive without relapse at last follow-up. The incidence of cytokine release syndrome (CRS) was 84% (10% grade ≥ 3) with a median time to max grade of 5 days (range: 0-10 days). There were no cases of grade 5 CRS. The incidence of neurotoxicity (NT) was 57% (31% grade ≥ 3) with a median time to onset of 7 days (range: 4-15 days). NT occurred in 4/7 pts with prior CNS involvement (3 grade 3, 1 grade 4). Grade 5 NT occurred in 1 pt who developed cerebral edema and died 8 days after infusion. Thirty-five pts received tocilizumab, 33 received steroids, 7 received anakinra, and 1 received siltuximab for management of CRS and/or NT. Post-CAR T infections occurred in 8 pts, including two grade 5 infectious AEs (covid19 on day +80 and septic shock on day +40 after infusion). Rates of grade ≥ 3 neutropenia and thrombocytopenia were 38% and 37%, respectively. Among pts with at least 100 days of follow-up and lab data available, 5/34 (15%) had persistent grade ≥ 3 neutropenia and 4/34 (12%) had persistent grade ≥ 3 thrombocytopenia at day +100. Five pts have died, with causes of death being disease progression (2), septic shock (1), NT (1), and covid19 (1). Univariate analysis did not reveal any significant associations between survival and baseline/pre-CAR T MIPI, tumor pathologic or cytogenetic features, prior therapies, receipt of steroids/tocilizumab, or pre-CAR T tumor bulk. Conclusions: This analysis of relapsed MCL pts treated with commercial brexu-cel reveals nearly identical response and toxicity rates compared to those reported on ZUMA-2. Longer follow-up is require to confirm durability of response, but these results corroborate the efficacy of brexu-cel in a population of older adults with high-risk disease features. While all 7 pts with prior CNS involvement are alive and in remission, strategies to mitigate the risk of NT in this setting need to be evaluated. Further studies to define the optimal timing of CAR T, bridging strategies, and salvage therapies for post-CAR T relapse in MCL are warranted. [Formula presented] Disclosures: Gerson: TG Therapeutics: Consultancy;Kite: Consultancy;Abbvie: Consultancy;Pharmacyclics: Consultancy. Sawalha: TG Therapeutics: Consultancy, Research Funding;Celgene/BMS: Research Funding;BeiGene: Research Funding;Epizyme: Consultancy. Bond: Kite/Gilead: Honoraria. Karmali: Janssen/Pharmacyclics: Consultancy;BeiGene: Consultancy, Speakers Bureau;Morphosys: Consultancy, Speakers Bureau;Takeda: Research Funding;Genentech: Consultancy;AstraZeneca: Speakers Bureau;Roche: Consultancy;Karyopharm: Consultancy;Epizyme: Consultancy;Kite, a Gilead Company: Consultancy, Research Funding, Speakers Bureau;BMS/Celgene/Juno: Consultancy, Research Funding;EUSA: Consultancy. Torka: TG Therapeutics: Membership on an entity's Board of Directors or advisory committees. Chow: ADC Therapeutics: Current holder of individual stocks in a privately-held company, Research Funding;AstraZeneca: Research Funding. Shadman: Abbvie, Genentech, AstraZeneca, Sound Biologics, Pharmacyclics, Beigene, Bristol Myers Squibb, Morphosys, TG Therapeutics, Innate Pharma, Kite Pharma, Adaptive Biotechnologies, Epizyme, Eli Lilly, Adaptimmune, Mustang Bio and Atara Biotherapeutics: Consultancy;Mustang Bio, Celgene, Bristol Myers Squibb, Pharmacyclics, Gilead, Genentech, Abbvie, TG Therapeutics, Beigene, AstraZeneca, Sunesis, Atara Biotherapeutics, GenMab: Research Funding. Ghosh: Genentech: Research Funding;Pharmacyclics LLC, an AbbVie Company: Consultancy, Honoraria, Research Funding, Speakers Bureau;Karyopharma: Consultancy, Honoraria;Seattle Genetics: Consultancy, Honoraria, Speakers Bureau;Janssen: Consultancy, Honoraria, Speakers Bureau;TG Therapeutics: Consultancy, Honoraria, Research Funding;Incyte: Consultancy, Honoraria;Gilead: Consultancy, Honoraria, Research Funding, Speakers Bureau;Genmab: Consultancy, Honoraria;Epizyme: Honoraria, Speakers Bureau;Bristol Myers Squibb: Consultancy, Honoraria, Research Funding, Speakers Bureau;AstraZeneca: Consultancy, Honoraria, Speakers Bureau;ADC Therapeutics: Consultancy, Honoraria;Adaptive Biotech: Consultancy, Honoraria;AbbVie: Honoraria, Speakers Bureau. Moyo: Seattle Genetics: Consultancy. Fenske: TG Therapeutics: Consultancy, Speakers Bureau;Servier Pharmaceuticals: Consultancy;Seattle Genetics: Speakers Bureau;Sanofi: Speakers Bureau;Pharmacyclics: Consultancy;MorphoSys: Consultancy;Kite (Gilead): Speakers Bureau;KaryoPharm: Consultancy;CSL Therapeutics: Consultancy;Bristol-Myers Squibb: Speakers Bureau;Biogen: Consultancy;Beigene: Consultancy;AstraZeneca: Speakers Bureau;ADC Therapeutics: Consultancy;Adaptive Biotechnologies: Consultancy;AbbVie: Consultancy. Grover: Genentech: Research Funding;Novartis: Consultancy;ADC: Other: Advisory Board;Kite: Other: Advisory Board;Tessa: Consultancy. Maddocks: Seattle Genetics: Divested equity in a private or publicly-traded company in the past 24 months;BMS: Divested equity in a private or publicly-traded company in the past 24 months;Pharmacyclics: Divested equity in a private or publicly-traded company in the past 24 months;Novatis: Divested equity in a private or publicly-traded company in the past 24 months;Janssen: Divested equity in a private or publicly-traded company in the past 24 months;Morphosys: Divested equity in a private or publicly-traded company in the past 24 months;ADC Therapeutics: Divested equity in a private or publicly-traded company in the past 24 months;Karyopharm: Divested equity in a private or publicly-traded company in the past 24 months;Beigene: Divested equity in a private or publicly-traded company in the past 24 months;Merck: Divested equity in a private or publicly-traded company in the past 24 months;KITE: Divested equity in a private or publicly-traded company in the past 24 months;Celgene: Divested equity in a private or publicly-traded company in the past 24 months. Jacobson: Kite, a Gilead Company: Consultancy, Honoraria, Other: Travel support;Humanigen: Consultancy, Honoraria, Other: Travel support;Celgene: Consultancy, Honoraria, Other: Travel support;Pfizer: Consultancy, Honoraria, Other: Travel support, Research Funding;Lonza: Consultancy, Honoraria, Other: Travel support;AbbVie: Consultancy, Honoraria;Precision Biosciences: Consultancy, Honoraria, Other: Travel support;Novartis Pharmaceuticals Corporation: Consultancy, Honoraria, Other: Travel support;Nkarta: Consultancy, Honoraria;Axis: Speakers Bureau;Clinical Care Options: Speakers Bureau. Cohen: Janssen, Adaptive, Aptitude Health, BeiGene, Cellectar, Adicet, Loxo/Lilly, AStra ZenecaKite/Gilead: Consultancy;Genentech, Takeda, BMS/Celgene, BioInvent, LAM, Astra Zeneca, Novartis, Loxo/Lilly: Research Funding.

Hydroxyzine Use and Mortality in Patients Hospitalized for COVID-19: A Multicenter Observational Study.

(1) Background: Based on its antiviral activity, anti-inflammatory properties, and functional inhibition effects on the acid sphingomyelinase/ceramide system (FIASMA), we sought to examine the potential usefulness of the H1 antihistamine hydroxyzine in patients hospitalized for COVID-19. (2) Methods: In a multicenter observational study, we included 15,103 adults hospitalized for COVID-19, of which 164 (1.1%) received hydroxyzine within the first 48 h of hospitalization, administered orally at a median daily dose of 25.0 mg (SD = 29.5). We compared mortality rates between patients who received hydroxyzine at hospital admission and those who did not, using a multivariable logistic regression model adjusting for patients' characteristics, medical conditions, and use of other medications. (3) Results: This analysis showed a significant association between hydroxyzine use and reduced mortality (AOR, 0.51; 95%CI, 0.29-0.88, p = 0.016). This association was similar in multiple sensitivity analyses. (4) Conclusions: In this retrospective observational multicenter study, the use of the FIASMA hydroxyzine was associated with reduced mortality in patients hospitalized for COVID-19. Double-blind placebo-controlled randomized clinical trials of hydroxyzine for COVID-19 are needed to confirm these results, as are studies to examine the potential usefulness of this medication for outpatients and as post-exposure prophylaxis for individuals at high risk for severe COVID-19.