Citations

Abstract Background :COVID-19 adversely affects individuals with cancer. Several studies have found that seroconversion rates among patients with hematologic malignancies are suboptimal when compared to patients without cancer. Among patients with hematologic malignancies, seroconversion rates also appear to be influenced by recent treatment and the type of treatment they have received. Patients with non-Hodgkin lymphoma (NHL) and multiple myeloma (MM) are immunocompromised due to impaired humoral and cellular immunity in addition to prescribed immunosuppressive therapy. Chimeric antigen receptor T-cell (CAR T) therapy is now widely used for NHL and MM, but little is known about seroconversion rates after COVID-19 vaccination among these populations. Current national guidelines recommend COVID-19 vaccination to be offered to CAR T recipients as early as three months thereafter. We retrospectively evaluated SARS-CoV-2 spike-binding IgG antibody levels following COVID-19 vaccination among NHL and MM CAR T therapy recipients. Methods:This retrospective study was conducted at three Mayo Clinic sites on NHL and MM patients that received CAR T infusions from Sept 2016 to June 2021. Baseline characteristics were ascertained from medical records. All NHL and MM patients who had received CAR T at any point and were alive at the time that the COVID-19 vaccine first became available were eligible for inclusion for antibody response evaluation. For antibody response to vaccination, antibody spike values > 0.80 U/mL were considered positive. Results: Out of 104 CAR T infusions, 73 patients are alive at the time of this submission. We have had 7 patients with known COVID-19 pre-CAR T and all 7 are currently alive (5 have antibody titers and 2 have not been tested yet). Nineteen patients developed known COVID infection post-CAR T (13 alive and 6 deceased). The mortality of COVID post-CAR T in our sample was 31.5%. Furthermore, of the 13 patients that survived COVID-19, they received CAR T an average of 416 days prior to COVID-19 infection (median = 337, range = 54 - 1406); the 6 patients who died from COVID-19 had received CAR T an average of 250 days prior to COVID-19 infection (median = 164, range = 7 - 846). All 6 deceased patients did not receive COVID-19 vaccination pre-CAR T. Out of 17 CAR T patients tested for antibody spike titers post COVID-19 vaccination, 76.4% were able to mount an antibody response. More patients with MM had a higher titer response to the vaccine (>250 U/mL) compared to the NHL counterparts (0.80-249 U/mL). All patients that received the vaccine, regardless of antibody response, were alive at the time of this submission. Conclusions:The majority of CAR T recipients with NHL and MM are able to mount an antibody response following COVID-19 vaccination in our relatively small sample. The frequency of seroconversion among CAR T recipients seems to be similar to patients with hematologic malignancy who had received a hematopoietic cell transplant reported elsewhere. These findings are limited by our small sample size and may be influenced by the timing of vaccination relative to CAR T. Furthermore, almost half of our patients received IVIG post CAR T which could potentially cause false positive antibody results as pooled immunoglobulin preparations may contain COVID-19 antibodies from vaccinated healthy donors. To better understand the characteristics of the immunologic response against SARS-CoV-2 in patients post-CAR T, larger multicenter studies exploring both humoral and cellular immunity will be needed. JEWN, MI and JM are co-first authors and PV, HM and AR are co-senior authors. Figure 1 Figure 1. Disclosures Munoz: Physicians' Education Resource: Honoraria; Seattle Genetics: Honoraria; Bayer: Research Funding; Gilead/Kite Pharma: Research Funding; Celgene: Research Funding; Merck: Research Funding; Portola: Research Funding; Incyte: Research Funding; Genentech: Research Funding; Pharmacyclics: Research Funding; Seattle Genetics: Research Funding; Janssen: Research Funding; Millennium: Research Funding; Gilead/Kite Pharma, Kyowa, Bayer, Pharmacyclics/Janssen, Seattle Genetics, Acrotech/Aurobindo, Beigene, Verastem, AstraZeneca, Celgene/BMS, Genentech/Roche.: Speakers Bureau; Pharmacyclics/Abbvie, Bayer, Gilead/Kite Pharma, Pfizer, Janssen, Juno/Celgene, BMS, Kyowa, Alexion, Beigene, Fosunkite, Innovent, Seattle Genetics, Debiopharm, Karyopharm, Genmab, ADC Therapeutics, Epizyme, Beigene, Servier: Consultancy; Targeted Oncology: Honoraria; OncView: Honoraria; Kyowa: Honoraria. Bergsagel: Oncopeptides: Consultancy, Honoraria; Novartis: Consultancy, Honoraria, Patents & Royalties: human CRBN mouse; Pfizer: Consultancy, Honoraria; Celgene: Consultancy, Honoraria; Janssen: Consultancy, Honoraria; Genetech: Consultancy, Honoraria; GSK: Consultancy, Honoraria. Wang: Incyte: Membership on an entity's Board of Directors or advisory committees, Research Funding; LOXO Oncology: Membership on an entity's Board of Directors or advisory committees, Research Funding; Genentech: Research Funding; InnoCare: Research Funding; Novartis: Research Funding; MorphoSys: Research Funding; Eli Lilly: Membership on an entity's Board of Directors or advisory committees; TG Therapeutics: Membership on an entity's Board of Directors or advisory committees. Fonseca: Juno: Consultancy; Kite: Consultancy; Aduro: Consultancy; OncoTracker: Consultancy, Membership on an entity's Board of Directors or advisory committees; GSK: Consultancy; AbbVie: Consultancy; Patent: Prognosticaton of myeloma via FISH: Patents & Royalties; Caris Life Sciences: Membership on an entity's Board of Directors or advisory committees; Scientific Advisory Board: Adaptive Biotechnologies: Membership on an entity's Board of Directors or advisory committees; BMS: Consultancy; Amgen: Consultancy; Sanofi: Consultancy; Merck: Consultancy; Mayo Clinic in Arizona: Current Employment; Celgene: Consultancy; Takeda: Consultancy; Bayer: Consultancy; Janssen: Consultancy; Novartis: Consultancy; Pharmacyclics: Consultancy. Palmer: Sierra Oncology: Consultancy, Research Funding; CTI BioPharma: Consultancy, Research Funding; Protagonist: Consultancy, Research Funding; Incyte: Research Funding; PharmaEssentia: Research Funding. Dingli: Novartis: Research Funding; GSK: Consultancy; Apellis: Consultancy; Alexion: Consultancy; Sanofi: Consultancy; Janssen: Consultancy. Kapoor: Sanofi: Research Funding; AbbVie: Research Funding; Takeda: Research Funding; Karyopharm: Consultancy; Cellectar: Consultancy; BeiGene: Consultancy; Pharmacyclics: Consultancy; Sanofi: Consultancy; Amgen: Research Funding; Ichnos Sciences: Research Funding; Regeneron Pharmaceuticals: Research Funding; Glaxo SmithKline: Research Funding; Karyopharm: Research Funding. Kumar: Roche-Genentech: Consultancy, Research Funding; Oncopeptides: Consultancy; Abbvie: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; BMS: Consultancy, Research Funding; Beigene: Consultancy; Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Research Funding; Adaptive: Membership on an entity's Board of Directors or advisory committees, Research Funding; Astra-Zeneca: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Tenebio: Research Funding; Merck: Research Funding; Carsgen: Research Funding; KITE: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Takeda: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Amgen: Consultancy, Research Funding; Bluebird Bio: Consultancy; Antengene: Consultancy, Honoraria; Sanofi: Research Funding. Paludo: Karyopharm: Research Funding. Bennani: Kymera: Other: Advisory Board; Vividion: Other: Advisory Board; Kyowa Kirin: Other: Advisory Board; Daichii Sankyo Inc: Other: Advisory Board; Purdue Pharma: Other: Advisory Board; Verastem: Other: Advisory Board. Ansell: Bristol Myers Squibb, ADC Therapeutics, Seattle Genetics, Regeneron, Affimed, AI Therapeutics, Pfizer, Trillium and Takeda: Research Funding. Lin: Kite, a Gilead Company: Consultancy, Research Funding; Merck: Research Funding; Gamida Cell: Consultancy; Takeda: Research Funding; Juno: Consultancy; Bluebird Bio: Consultancy, Research Funding; Celgene: Consultancy, Research Funding; Novartis: Consultancy; Janssen: Consultancy, Research Funding; Sorrento: Consultancy; Legend: Consultancy; Vineti: Consultancy. Murthy: CRISPR Therapeutics: Research Funding.

Abstract Background: ZUMA-1 is the registrational Phase 1/2 study of axi-cel, an autologous anti-CD19 chimeric antigen receptor (CAR) T-cell therapy, in pts with refractory LBCL. In ZUMA-1 Cohorts 1+2 (C1+2; N=101), rates of Grade (Gr) ≥3 cytokine release syndrome (CRS) and neurologic events (NEs) were 13% and 28%, respectively, at the 6-mo primary analysis; the objective response rate (ORR) was 82% (54% complete response [CR]; Neelapu et al. NEJM. 2017). ZUMA-1 safety management C6 assessed whether prophylactic and earlier corticosteroids and/or tocilizumab could reduce incidence and severity of CRS and NEs. With a median follow-up of 8.9 mo (N=40) for C6, there were no Gr ≥3 CRS, a low rate of Gr ≥3 NEs (13%), and high response rates (Oluwole et al. BJH. 2021). Here, we present a 1-yr updated analysis of C6 supported by propensity score matching (PSM) analysis to compare outcomes for pts in C6 vs C1+2. Methods: Eligible pts could receive optional bridging therapy after leukapheresis. Pts received conditioning chemotherapy for 3 d prior to a single axi-cel infusion. Pts received once-daily oral dexamethasone 10 mg on Days 0 (before axi-cel), 1, and 2; corticosteroids and/or tocilizumab for adverse event (AE) management were given earlier vs C1+2. The primary endpoints were incidence and severity of CRS and NEs. Other endpoints included efficacy outcomes and biomarker analyses. To ensure comparability for pts in C6 and C1+2, an exploratory PSM analysis was performed after balancing for key baseline disease characteristics (tumor burden, IPI score, no. of prior lines of chemotherapy, disease stage, and LDH level). Results: As of December 16, 2020, the median follow-up time was 14.9 mo. Gr ≥3 AEs were reported in all 40 treated pts, and the most common were neutropenia (45%), neutrophil count decreased (33%), and white blood cell count decreased (23%). No Gr ≥3 CRS occurred. Gr ≥3 NEs were reported in 15% of pts. Median time to CRS and NE onset was 5 and 6 d, respectively, after axi-cel infusion. Infections of any grade occurred in 50% of pts (20% Gr ≥3). Since the 6-mo analysis, no new cases of CRS were observed. Four new axi-cel-related NEs occurred in 2 pts (pt 1: Gr 2 mental status changes and seizure-like phenomena both on Day 441; pt 2: Gr 1 dementia [occurred on Day 93 but was reported late] and Gr 5 toxic encephalopathy on Day 369 [resultant from a Gr 4 event that started on Day 351]). Two new infections of Gr 2 pneumonia and Gr 1 bronchitis were observed; the latter was axi-cel-related. One death due to progressive disease occurred. The investigator-assessed ORR was 95% (80% CR). Median DOR, PFS, and OS were not reached. Kaplan-Meier estimates of the 12-mo DOR, PFS, and OS rates were 60%, 63%, and 82%, respectively. At data cutoff, 53% of pts were in ongoing response. Median peak CAR T-cell levels were comparably high in pts with ongoing response and relapse (64 cells/µL [n=21] and 66 cells/µL [n=15], respectively) at 12 mo and considerably lower in nonresponders (18 cells/µL [n=2]). In all, 32 matched pts each in C6 and C1+2 were identified during PSM analysis; 8 pts from C6 were not included due to nonavailability of matched pts in C1+2. No Gr ≥3 CRS was observed in C6 vs 13% of pts in C1+2. Incidence of Gr ≥3 NEs was comparable in C6 and C1+2 (19% and 22%, respectively), with median time to onset of 12 d in C6 vs 7 d in C1+2. The ORR was 94% in both C6 and matched C1+2 (75% and 78% CR rates, respectively); 47% and 59% of pts were in ongoing response at 12 mo. The Kaplan-Meier estimate of the 12-mo PFS rate was 61% in both C6 and matched C1+2. Median peak CAR T-cell levels were 65 and 43 cells/µL, respectively, in C6 and C1+2. Serum levels of inflammatory biomarkers associated with CAR T-cell treatment-related AEs (IFN-γ, IL-2, GM-CSF, and ferritin) were lower in C6 vs C1+2. Median cumulative corticosteroid dose including prophylaxis was 1252 mg in C6 (n=32) and 7418 mg in C1+2 (n=6). Conclusion: With ≥1-y follow-up, prophylactic and earlier corticosteroid and/or tocilizumab intervention continued to demonstrate a manageable safety profile, absence of new safety signals, and high, durable response rates, which was corroborated by PSM analysis. Although fewer pts in C1+2 received corticosteroids after matching, the median cumulative corticosteroid dose was 4-fold lower in C6 vs C1+2. These findings suggest that the C6 AE management strategy can improve long-term safety of axi-cel in R/R LBCL without compromising durability of responses. Disclosures Oluwole: Pfizer: Consultancy; Curio Science: Consultancy; Janssen: Consultancy; Kite, a Gilead Company: Consultancy, Research Funding. Forcade: Jazz: Other: Travel Support, Speakers Bureau; MSD: Other: Travel Support; Gilead: Other: Travel Support, Speakers Bureau; Novartis: Consultancy, Other: Travel Support, Speakers Bureau. Muñoz: Targeted Oncology: Honoraria; Seagen: Consultancy, Honoraria, Speakers Bureau; Physicians' Education Resource: Honoraria; Kyowa Kirin: Consultancy, Honoraria, Speakers Bureau; OncView: Honoraria; Pharmacyclics: Consultancy, Speakers Bureau; Bayer: Consultancy, Speakers Bureau; Kite, a Gilead Company: Consultancy, Speakers Bureau; Pfizer: Consultancy; Janssen: Consultancy, Speakers Bureau; Juno/Celgene: Consultancy; Bristol Myers Squibb: Consultancy; Alexion: Consultancy; BeiGene: Consultancy, Speakers Bureau; Fosunkite: Consultancy; Innovent: Consultancy; Debiopharma: Consultancy; Karyopharm: Consultancy; Genmab: Consultancy; ADC Therapeutics: Consultancy; Epizyme: Consultancy; Servier: Consultancy; Acrotech: Speakers Bureau; Verastem: Speakers Bureau; AstraZeneca: Speakers Bureau; Celgene/Bristol Myers Squibb: Speakers Bureau; Genentech: Speakers Bureau; Aurobindo: Speakers Bureau. de Guibert: Gilead: Consultancy, Honoraria; AbbVie: Consultancy, Honoraria; Janssen: Consultancy, Honoraria. Vose: Kite, a Gilead Company: Honoraria, Research Funding. Bartlett: Roche/Genentech: Consultancy; Seagen: Consultancy, Research Funding; Autolus: Research Funding; Bristol Myers Squibb: Research Funding; Celgene: Research Funding; Forty Seven: Research Funding; Genentech: Research Funding; Janssen: Research Funding; Kite, a Gilead Company: Research Funding; Merck: Research Funding; Millennium: Research Funding; Pharmacyclics: Research Funding; ADC Therapeutics: Consultancy, Research Funding. Lin: Juno: Consultancy; Takeda: Research Funding; Gamida Cell: Consultancy; Vineti: Consultancy; Merck: Research Funding; Sorrento: Consultancy; Legend: Consultancy; Celgene: Consultancy, Research Funding; Novartis: Consultancy; Janssen: Consultancy, Research Funding; Bluebird Bio: Consultancy, Research Funding; Kite, a Gilead Company: Consultancy, Research Funding. Deol: Kite, a Gilead Company: Consultancy. McSweeney: Kite, a Gilead Company: Consultancy, Honoraria, Research Funding, Speakers Bureau; Novartis: Research Funding; Autolus: Research Funding; Allovir: Research Funding. Goy: Acerta: Consultancy, Research Funding; AstraZeneca: Membership on an entity's Board of Directors or advisory committees; Xcenda: Consultancy, Honoraria; Vincerx: Honoraria, Membership on an entity's Board of Directors or advisory committees; Elsevier's Practice Update Oncology, Intellisphere, LLC(Targeted Oncology): Consultancy; MorphoSys: Honoraria, Other; Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Consultancy, Honoraria; Bristol Meyers Squibb: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; AbbVie/Pharmacyclics: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; LLC(Targeted Oncology): Consultancy; Kite Pharma: Membership on an entity's Board of Directors or advisory committees; OncLive Peer Exchange: Honoraria; Rosewell Park: Consultancy; Genomic Testing Cooperative: Current holder of stock options in a privately-held company, Membership on an entity's Board of Directors or advisory committees, Other: Leadership role; COTA (Cancer Outcome Tracking Analysis): Current holder of stock options in a privately-held company, Membership on an entity's Board of Directors or advisory committees, Other: Leadership role; Celgene: Consultancy, Honoraria, Research Funding; Xcenda: Consultancy; Gilead: Membership on an entity's Board of Directors or advisory committees; Michael J Hennessey Associates INC: Consultancy; Bristol Meyers Squibb: Membership on an entity's Board of Directors or advisory committees; Medscape: Consultancy; AbbVie/Pharmacyclics: Membership on an entity's Board of Directors or advisory committees; Hoffman la Roche: Consultancy; Infinity/Verastem: Research Funding; Genentech/Hoffman la Roche: Research Funding; Physicians' Education Resource: Consultancy, Other: Meeting/travel support; Janssen: Membership on an entity's Board of Directors or advisory committees; Vincerx pharma: Membership on an entity's Board of Directors or advisory committees; Incyte: Honoraria; AstraZeneca: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Kite, a Gilead Company: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Elsevier PracticeUpdate: Oncology: Consultancy, Honoraria; Janssen: Research Funding; Karyopharm: Research Funding; Phamacyclics: Research Funding; Constellation: Research Funding; Hackensack Meridian Health, Regional Cancer Care Associates/OMI: Current Employment. Kersten: Miltenyi Biotec: Consultancy, Honoraria, Other: Travel support; Roche: Consultancy, Honoraria, Other: Travel support, Research Funding; BMS/Celgene: Consultancy, Honoraria; Takeda: Research Funding; Celgene: Research Funding; Kite, a Gilead Company: Consultancy, Honoraria, Other: Travel support, Research Funding; Novartis: Consultancy, Honoraria, Other: Travel support. Jacobson: Nkarta: Consultancy, Honoraria; Novartis Pharmaceuticals Corporation: Consultancy, Honoraria, Other: Travel support; Humanigen: Consultancy, Honoraria, Other: Travel support; Lonza: Consultancy, Honoraria, Other: Travel support; AbbVie: Consultancy, Honoraria; Pfizer: Consultancy, Honoraria, Other: Travel support, Research Funding; Precision Biosciences: Consultancy, Honoraria, Other: Travel support; Kite, a Gilead Company: Consultancy, Honoraria, Other: Travel support; Celgene: Consultancy, Honoraria, Other: Travel support; Axis: Speakers Bureau; Clinical Care Options: Speakers Bureau. Farooq: Kite, a Gilead Company: Honoraria. Minnema: Cilag: Consultancy; BMS: Consultancy; Janssen: Consultancy; Celgene: Other: Travel expenses; Kite/Gilead: Consultancy; Alnylam: Consultancy. Thieblemont: Bristol Myers Squibb/Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses ; Kyte: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses ; Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses ; Roche: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses , Research Funding; Gilead Sciences: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses ; Incyte: Honoraria, Membership on an entity's Board of Directors or advisory committees; Abbvie: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses ; Cellectis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses ; Hospira: Research Funding; Bayer: Honoraria; Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses . Timmerman: Spectrum Pharmaceuticals: Research Funding; Bristol Myers Squibb: Research Funding; Kite, a Gilead Company: Consultancy, Research Funding; Bluebird Bio: Current equity holder in publicly-traded company; TG Therapeutics: Current equity holder in publicly-traded company; Marker Therapeutics: Current equity holder in publicly-traded company; Corvus: Current equity holder in publicly-traded company; Genmab: Current equity holder in publicly-traded company; Merck: Research Funding. Stiff: Macrogenics: Research Funding; Amgen: Research Funding; Kite, a Gilead Company: Research Funding; Seagen: Research Funding; Gamida Cell: Research Funding; Janssen: Research Funding; CRISPR Therapeutics: Consultancy, Honoraria; Karyopharm: Consultancy, Honoraria; Cellectar: Research Funding; Bristol Myers Squibb: Research Funding; Incyte: Research Funding; BioLineRX: Research Funding; Cellectar: Research Funding; MorphoSys: Consultancy, Honoraria; Actinium: Research Funding. Avivi: Novartis: Speakers Bureau; Kite, a Gilead Company: Speakers Bureau. Tzachanis: Fate Therapeutics: Research Funding; Incyte: Research Funding; Genentech: Research Funding; Bristol Myers Squibb: Research Funding; Magenta: Consultancy; Kyowa Kirin: Consultancy; Kite, a Gilead Company: Consultancy, Research Funding, Speakers Bureau; EUSA: Consultancy; Takeda: Consultancy, Speakers Bureau; Partner: Consultancy. Kim: Kite, a Gilead Company: Current Employment; Gilead Sciences: Current equity holder in publicly-traded company. Zheng: Kite, a Gilead Company: Current Employment; Gilead Sciences: Current equity holder in publicly-traded company. Shen: Gilead Sciences: Current equity holder in publicly-traded company; Atara: Current Employment, Current equity holder in publicly-traded company, Other: Leadership role, Patents & Royalties; Kite, a Gilead Company: Current Employment, Other: Leadership role, Patents & Royalties. Vardhanabhuti: Kite, a Gilead Company: Current Employment, Other: Travel support, Research Funding; Gilead Sciences: Current equity holder in publicly-traded company. Van Meerten: Kite, a Gilead Company: Honoraria; Janssen: Consultancy.

Abstract Background: Multiple myeloma (MM) is a heterogenous cancer of terminally differentiated plasma cells that typically express elevated levels of antiapoptotic proteins, such as BCL-2. Venetoclax (Ven), a highly selective, potent, oral BCL-2 inhibitor, induces apoptosis in MM cells, and when combined with bortezomib and dexamethasone showed promising efficacy in patients (pts) with relapsed/refractory MM (RRMM; Moreau et al. Blood. 2017;130:2392-2400). The Phase 3 BELLINI study primary analysis showed significantly improved response rates and progression-free survival (PFS) in pts with RRMM treated with Ven added to bortezomib and dexamethasone versus placebo (Pbo); however, increased mortality was observed in the Ven group (Kumar et al. Lancet Oncol. 2020;21:1630-1642). At the initial data cutoff (November 26, 2018), the PFS hazard ratio (HR) was 0.63 (95% CI, 0.44-0.90) and overall survival (OS) HR was 2.03 (95% CI, 1.04-3.95). Pts with t(11;14) translocation or high BCL2 expression showed improved responses and PFS without increased mortality. Here, we present updated safety and efficacy data from the prespecified final OS analysis. Methods: BELLINI (NCT02755597) is a Phase 3, randomized, double-blind, multicenter study of Ven or Pbo combined with bortezomib and dexamethasone in pts with RRMM who had received 1-3 prior lines of therapy and were either sensitive or naïve to proteasome inhibitors. Pts were randomized 2:1 to receive Ven 800 mg/day or Pbo plus bortezomib and dexamethasone. Cycles 1-8 were 21-day cycles with bortezomib 1.3 mg/m 2 on Days 1, 4, 8, and 11 and dexamethasone 20 mg on Days 1, 2, 4, 5, 8, 9, 11, and 12. Cycles 9 and beyond were 35-day cycles with bortezomib 1.3 mg/m 2 on Days 1, 8, 15, and 22 and dexamethasone 20 mg on Days 1, 2, 8, 9, 15, 16, 22, and 23. The primary endpoint was PFS assessed by independent review committee. Key secondary endpoints included overall response rate and OS. BCL2 expression was measured by quantitative polymerase chain reaction with the cutoff for high BCL2 determined using bootstrapping and aggregating thresholds from trees. Results: Of 291 randomized pts (194 to Ven and 97 to Pbo), 33 pts were receiving ongoing treatment (28 with Ven and 5 with Pbo) as of the final OS analysis data cutoff (March 15, 2021). At a median follow-up of 45.6 months, there were 78 (40%) deaths in the Ven arm versus 36 (37%) in the Pbo arm. Updated PFS and OS among all pts and those with t(11;14) or high BCL2 expression are shown in the Table. Among all pts, the median PFS per investigator was 23.4 months in the Ven arm versus 11.4 months in the Pbo arm (HR, 0.58 [95% CI, 0.43-0.78]). In pts with t(11;14), the median PFS was 36.8 months in the Ven arm versus 9.3 months in the Pbo arm (HR, 0.12 [95% CI, 0.03-0.44]). In pts with high BCL2, the median PFS was 30.1 months in the Ven arm versus 9.9 months in the Pbo arm (HR, 0.37 [95% CI, 0.21-0.64]). Median OS was not reached in the Ven or Pbo arm among all pts (HR, 1.19 [95% CI, 0.80-1.77]), pts with t(11;14) (HR, 0.61 [95% CI, 0.16-2.32]), pts with high BCL2 (HR, 0.70 [95% CI, 0.32-1.51]), and pts with t(11;14) or high BCL2 (HR, 0.82 [95% CI, 0.40-1.70]). The most common treatment-emergent adverse events (AEs) with Ven (versus Pbo) were diarrhea (60% versus 50%), nausea (38% versus 23%), and constipation (35% versus 31%). The most common Grade 3/4 AEs (Ven versus Pbo) were thrombocytopenia (16% versus 30%), neutropenia (23% versus 8%), pneumonia (19% versus 13%), anemia (16% versus 15%), and diarrhea (15% versus 11%). Serious AEs occurred in 57% of Ven- and 55% of Pbo-treated pts, with serious infections and infestations occurring in 35% and 29% of pts, respectively. Overall, 26% of pts in the Ven arm and 11% of pts in the Pbo arm experienced an AE leading to Ven or Pbo discontinuation. AEs led to 12 deaths in the Ven arm, with 9 of these deaths due to serious infection; an AE led to 1 death in the Pbo arm. A total of 16 (6%) treatment-emergent deaths occurred (14 [7%] with Ven and 2 [2%] with Pbo), with 3 of these deaths due to disease progression (2 [1%] with Ven and 1 [1%] with Pbo). Conclusion: In the final OS analysis, the addition of Ven to bortezomib and dexamethasone showed significantly improved PFS but resulted in increased mortality versus Pbo in the total population. Consistent with results from previous analyses, Ven added to bortezomib and dexamethasone showed the greatest PFS improvement in pts with t(11;14) or high BCL2, with a favorable benefit-risk profile. Figure 1 Figure 1. Disclosures Kumar: Beigene: Consultancy; Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; Bluebird Bio: Consultancy; Merck: Research Funding; Astra-Zeneca: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; KITE: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Amgen: Consultancy, Research Funding; Tenebio: Research Funding; BMS: Consultancy, Research Funding; Antengene: Consultancy, Honoraria; Roche-Genentech: Consultancy, Research Funding; Novartis: Research Funding; Abbvie: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Takeda: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Oncopeptides: Consultancy; Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Carsgen: Research Funding; Adaptive: Membership on an entity's Board of Directors or advisory committees, Research Funding; Sanofi: Research Funding. Harrison: Abbvie: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Celgene/ Juno/ BMS: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Sanofi: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Janssen Cilag: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Roche/Genentech: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Haemalogix: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; GSK: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Eusa: Consultancy, Honoraria, Speakers Bureau; Terumo BCT: Consultancy, Honoraria; Takeda: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees. Cavo: Novartis: Honoraria; GlaxoSmithKline: Consultancy, Honoraria; Sanofi: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; AbbVie: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Takeda: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Adaptive Biotechnologies: Consultancy, Honoraria; Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel Accommodations, Speakers Bureau; Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: TRAVEL, ACCOMMODATIONS, EXPENSES, Speakers Bureau; Bristol-Myers Squib: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. de la Rubia: Ablynx/Sanofi: Consultancy; Amgen, Bristol Myers Squibb,: Honoraria, Speakers Bureau; Amgen: Consultancy, Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy; Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: TRAVEL, ACCOMMODATIONS, EXPENSES; Celgene, Takeda, Janssen, Sanofi: Honoraria; AbbVie: Consultancy; Bristol Myers Squibb: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Travel Accommodations; GSK: Consultancy; Takeda: Consultancy; Sanofi: Membership on an entity's Board of Directors or advisory committees. Popat: Abbvie, Takeda, Janssen, and Celgene: Consultancy; AbbVie, BMS, Janssen, Oncopeptides, and Amgen: Honoraria; Takeda: Honoraria, Other: TRAVEL, ACCOMMODATIONS, EXPENSES; GlaxoSmithKline: Consultancy, Honoraria, Research Funding; Janssen and BMS: Other: travel expenses. Gasparetto: Sanofi: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Karyopharm Therapeutics Inc.: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: TRAVEL, ACCOMMODATIONS, EXPENSES, Speakers Bureau; Oncopeptite: Consultancy, Honoraria, Speakers Bureau; Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Abbvie: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; BMS: Consultancy; Connect Registry: Membership on an entity's Board of Directors or advisory committees; GSK: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: TRAVEL, ACCOMMODATIONS, EXPENSES, Research Funding, Speakers Bureau. Hungria: Sanofi: Honoraria, Other: Support for attending meetings/travel ; Takeda: Honoraria; Abbvie: Honoraria; Amgen, BMS, Celgene, Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Support for attending meetings/travel . Salwender: Oncopeptides: Honoraria; GlaxoSmithKline: Honoraria, Other: TRAVEL, ACCOMMODATIONS, EXPENSES; Sanofi: Honoraria, Other: TRAVEL, ACCOMMODATIONS, EXPENSES; Takeda: Honoraria; Pfizer: Honoraria; Amgen: Honoraria, Other: TRAVEL, ACCOMMODATIONS, EXPENSES; Chugai: Honoraria; AbbVie: Honoraria, Other: TRAVEL, ACCOMMODATIONS, EXPENSES; Janssen-Cilag: Honoraria, Other: TRAVEL, ACCOMMODATIONS, EXPENSES; Bristol-Myers Squibb/Celgene: Honoraria, Other: TRAVEL, ACCOMMODATIONS, EXPENSES. Suzuki: Japanese Red Cross Medical Center: Current Employment; Janssen: Honoraria; AbbVie: Honoraria; Sanofi: Honoraria; Bristol-Myers Squibb: Honoraria, Research Funding; Takeda: Consultancy, Honoraria; Celgene: Consultancy, Honoraria, Research Funding; Janssen: Consultancy, Honoraria; Amgen: Consultancy, Honoraria, Research Funding; ONO: Honoraria; Novartis: Honoraria. Kim: Seoul National University Hospital: Current Employment. Onishi: Roche: Current Employment, Current equity holder in publicly-traded company; Genentech: Current Employment. Ku: Roche: Current Employment, Current equity holder in publicly-traded company, Other: TRAVEL, ACCOMMODATIONS, EXPENSES; Genentech: Current Employment, Other: TRAVEL, ACCOMMODATIONS, EXPENSES. Pothacamury: AbbVie: Current Employment, Current equity holder in publicly-traded company, Current holder of individual stocks in a privately-held company. Sehgal: AbbVie: Current Employment, Current equity holder in publicly-traded company, Current holder of individual stocks in a privately-held company. Masud: AbbVie: Current Employment, Current equity holder in publicly-traded company, Current holder of individual stocks in a privately-held company. Ross: AbbVie: Current Employment, Current equity holder in publicly-traded company, Current holder of individual stocks in a privately-held company. Dobkowska: AbbVie: Current Employment, Current equity holder in publicly-traded company, Other: TRAVEL, ACCOMMODATIONS, EXPENSES; Pharmacyclics: Current Employment. Moreau: Celgene BMS: Honoraria; Amgen: Honoraria; Abbvie: Honoraria; Janssen: Honoraria; Sanofi: Honoraria; Oncopeptides: Honoraria.

Abstract Background Patients (pts) with aggressive B-cell non-Hodgkin lymphoma (NHL) progressing after anti-CD19 chimeric antigen receptor T (CART) cell therapy have poor prognosis and may benefit from new therapy options through clinical trials. However, in a single center report, only 12% of such pts were treated in trials (Chow et al. Am J Hematol, 2019). Identifying the reasons for this low enrollment is needed to design future studies for this population. Here, we evaluated the eligibility criteria for recent landmark trials for relapsed/refractory aggressive B-cell NHL to learn what eligibility barriers are present. Methods Pts with aggressive B-cell NHL who received FDA-approved CART cell therapy at Mayo Clinic (Rochester, Arizona, Florida) since 2018 and progressed after CART cell therapy were identified. The potential eligibility for the following key trials was evaluated: a) polatuzumab + bendamustine + rituximab, b) tafasitamab + lenalidomide, c) selinexor and d) loncastuximab. The eligibility for each trial was retrospectively assessed at the time of disease progression after CART cell therapy based on hemoglobin (Hb), absolute neutrophils count (ANC), platelet count (Plt), renal and liver function tests, ECOG performance status (PS), and central nervous system (CNS) involvement. Results Seventy-five pts had disease progression to axicabtagene ciloleucel (N=73, 97%) or tisagenlecleucel (N=2, 3%) and are included in this analysis. Median time to progression after CART was 2.1 months (IQR: 1.0 - 3.1). Thirteen (17%) pts were treated in clinical trials after progression following CART cell therapy, while 46 (61%) were treated off trials, and 16 (22%) pts never received any treatment after progression. At a median follow-up of 13.6 months (IQR: 9.1 - 26.7) from CART progression, the median overall survival (mOS) from CART progression was 5.8 months (95% CI 3.5 - 10.1) and 53 (71%) pts died. Thirty-eight pts (51%) did not meet eligibility criteria for any of the 4 recent landmark trials. Hematologic impairment was the most common barrier to inclusion of these patients in clinical trials: Hb < 9 g/dL n=23 (31%) or Hb < 10 g/dL n=36 (48%), ANC < 1.0 x 10 9/L n=19 (25%) or ANC < 1.5 x 10 9/L n=32 (43%), and Plt < 75 x 10 9/L n=30 (40%) or Plt < 90 x 10 9/L n=34 (45%). Renal (n=11, 15%) or liver dysfunction (n=5, 7%), CNS involvement (n=8, 11%) and ECOG PS > 2 (n=3, 4%) were less common reasons leading to exclusion from trials. Post CART trial ineligible pts had significantly shorter time to progression (median 1.7 months, IQR: 1.0 - 2.6 vs. 3.0 months IQR: 1.9 - 3.4, p < 0.01) and inferior overall response to CART (45% vs 67%, p = 0.06) compared to pts who met trial eligibility post CART. Baseline Hb (median Hb 9.5 g/dL, IQR: 8.5 - 10.5 vs. 10.9 g/dL, IQR: 9.7 - 12.2, p < 0.01) and Plt (median Plt 106 x 10 9/L IQR: 54 - 165 vs. 201 x 10 9/L IQR: 141 - 243, p < 0.01) were also significantly lower in pts ineligible for trials post CART. There were no significant differences between pts eligible or ineligible for trials with regards to age (median 59 vs. 60 years), number of prior therapies (median 3 vs. 3), prior autologous stem cell transplant (41% vs. 37%), bridging therapy (65% vs. 63%), baseline ANC (median 4,1 vs. 3,0 x10 9/L), or high-grade (grade ≥ 2) cytokine release syndrome (19% vs. 21%) or neurotoxicity (32%, vs. 42%), respectively. Survival after CART progression was significantly shorter (mOS 2.5 months, 95% CI: 1.6 - 5.1) for the 38 pts ineligible for trials compared to pts eligible for trials (mOS 10.6 months, 95% CI: 8.9 - NA), (p < 0.01). In the 59 pts who received therapy post CART progression, the mOS of pts treated on (n = 13) or off (n = 46) trials was 13.8 months (95% CI: 9.2 - NA) vs. 6.6 months (4.9 - 10.7), respectively (p = 0.047). Conclusion Approximately half of the pts (51%) with aggressive B-cell NHL progressing after CART cell therapy would have be excluded from landmark clinical trials. The current hematologic exclusion criteria are a major barrier to enrollment in clinical trials, which would exclude many pts who have disease progression within 3 months of CART cell therapy (ie, primary refractory disease), in whom cytopenia as a toxicity from therapy is prevalent. Given the known delayed hematologic recovery after CART cell therapy and the unmet need of pts progressing to CART cell therapy, the hematologic exclusion criteria should be adjusted to increase trial participation of this population, especially of those with primary refractory disease. Figure 1 Figure 1. Disclosures Munoz: Gilead/Kite Pharma, Kyowa, Bayer, Pharmacyclics/Janssen, Seattle Genetics, Acrotech/Aurobindo, Beigene, Verastem, AstraZeneca, Celgene/BMS, Genentech/Roche.: Speakers Bureau; Janssen: Research Funding; Pharmacyclics/Abbvie, Bayer, Gilead/Kite Pharma, Pfizer, Janssen, Juno/Celgene, BMS, Kyowa, Alexion, Beigene, Fosunkite, Innovent, Seattle Genetics, Debiopharm, Karyopharm, Genmab, ADC Therapeutics, Epizyme, Beigene, Servier: Consultancy; Seattle Genetics: Research Funding; Millennium: Research Funding; Pharmacyclics: Research Funding; Genentech: Research Funding; Incyte: Research Funding; Portola: Research Funding; Merck: Research Funding; Celgene: Research Funding; Gilead/Kite Pharma: Research Funding; Bayer: Research Funding; Seattle Genetics: Honoraria; Physicians' Education Resource: Honoraria; Targeted Oncology: Honoraria; OncView: Honoraria; Kyowa: Honoraria. Murthy: CRISPR Therapeutics: Research Funding. Maurer: Morphosys: Membership on an entity's Board of Directors or advisory committees, Research Funding; Nanostring: Research Funding; Kite Pharma: Membership on an entity's Board of Directors or advisory committees; Celgene: Research Funding; Genentech: Research Funding; Pfizer: Consultancy, Membership on an entity's Board of Directors or advisory committees. Bennani: Purdue Pharma: Other: Advisory Board; Daichii Sankyo Inc: Other: Advisory Board; Kyowa Kirin: Other: Advisory Board; Vividion: Other: Advisory Board; Kymera: Other: Advisory Board; Verastem: Other: Advisory Board. Paludo: Karyopharm: Research Funding. Wang: Genentech: Research Funding; Incyte: Membership on an entity's Board of Directors or advisory committees, Research Funding; MorphoSys: Research Funding; TG Therapeutics: Membership on an entity's Board of Directors or advisory committees; Eli Lilly: Membership on an entity's Board of Directors or advisory committees; LOXO Oncology: Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Research Funding; InnoCare: Research Funding. Ansell: Bristol Myers Squibb, ADC Therapeutics, Seattle Genetics, Regeneron, Affimed, AI Therapeutics, Pfizer, Trillium and Takeda: Research Funding. Witzig: Karyopharm Therapeutics, Celgene/BMS, Incyte, Epizyme: Consultancy, Membership on an entity's Board of Directors or advisory committees; Celgene/BMS, Acerta Pharma, Kura Oncology, Acrotech Biopharma, Karyopharm Therapeutics: Research Funding. Nowakowski: Celgene, NanoString Technologies, MorphoSys: Research Funding; Celgene, MorphoSys, Genentech, Selvita, Debiopharm Group, Kite/Gilead: Consultancy, Membership on an entity's Board of Directors or advisory committees. Lin: Vineti: Consultancy; Takeda: Research Funding; Sorrento: Consultancy; Novartis: Consultancy; Juno: Consultancy; Legend: Consultancy; Janssen: Consultancy, Research Funding; Bluebird Bio: Consultancy, Research Funding; Celgene: Consultancy, Research Funding; Merck: Research Funding; Gamida Cell: Consultancy; Kite, a Gilead Company: Consultancy, Research Funding.

Abstract Introduction: Axicabtagene ciloleucel (axi-cel) is an autologous anti-CD19 Chimeric Antigen Receptor (CAR) T-cell therapy that induces durable responses in patients with relapsed or refractory large B-cell lymphoma. At a median of 27.1 months follow-up on the ZUMA-1 trial, median overall survival (OS) was 25.8 months with 39% progression free survival (PFS) at 2 years post-infusion (Locke, Lancet Onc 2019). We previously reported outcomes of axi-cel patients treated with standard of care therapy at a median follow up of 12.9 months, including 42% who did not meet eligibility criteria for ZUMA-1 based on co-morbidities (Nastoupil, JCO 2020). Here we report results from this cohort at a median follow up of 32.4 months, as well as late outcomes of interest including cytopenias, infections and secondary malignancies. Methods and Results: The US Lymphoma CAR-T Consortium comprised of 17 US academic centers who contributed data independent of the manufacturer. Two hundred and ninety-eight patients underwent leukapheresis with intent to manufacture standard of care axi-cel as of September 30, 2018. In infused patients (n=275), OS and PFS were calculated from date of infusion. After median follow-up of 32.4 months (95% CI 31.1 - 34.3), median OS was not reached (95% CI 25.6 - not evaluable) (Figure 1A) with 1-, 2- and 3-year OS of 68.5% (95% CI 62.6-73.7), 56.4% (95% CI 50.1-62.2) and 52.2% (95% CI 45.7-58.2%), respectively. Median PFS was 9 months (95% CI 5.9-19.6) (Figure 1B); 1-, 2- and 3-year PFS was 47.4% (95% CI 41.4-53.2), 41.6% (95% CI 35.6-47.5) and 37.3% (95% CI 31.3-43.2), respectively. Twenty-seven PFS events occurred at or after 1 year post infusion;19 events were progressive lymphoma, with the latest relapse observed 28 months after axi-cel infusion. Eight patients died while in remission from their lymphoma: 4 from secondary malignancy, 3 from infection, and 1 from unknown causes. Results of multivariable modeling were similar to our prior analysis: factors associated with both a shorter PFS and shorter OS included male sex, elevated pre-lymphodepletion LDH, and poor ECOG status. Complete blood count and B- and T-cell recovery data were collected at 1 and 2-years post-infusion, excluding patients who had relapsed or been treated for secondary malignancy at time of collection (Table 1). Rates of neutropenia (absolute neutrophil count ≤1000) at 1- and 2- years were 9.2% (10/109) and 11.2% (9/80) and rates of CD4 count ≤200/ul were 62% (23/37) and 27% (7/26). Recovery of B cells was seen in 54% (15/28) and 57% (13/23) at 1-and 2-years post infusion. Infections were reported in 31.2% (34/109) patients between 6- and 12-months post infusion, and 17% (18/109) were severe, requiring either hospitalization and/or IV antibiotics. Twenty-one patients (24%, 21/89) had an infection between 1- and 2- years, 11% of which were severe. Twenty percent (10/49) of patients between 2- and 3-years had an infection and 4 (8%) were severe. Neutropenia, low CD4 counts, and IgG levels were not associated with infection, though patients with infection between 6-12 months were more likely to have received IVIG (p<0.001). No patient in this cohort died of COVID-19. Twenty-two of 275 (8%) patients were diagnosed with subsequent malignancy after axi-cel treatment: 14/275 (5%) patients were diagnosed with myeloid malignancies (MDS (n=12), AML (n=1), CMML (n=1)); other malignancies included squamous cell carcinoma of skin (n=3); sarcoma (n=1); endometrial (n=1); lung (n=1); mesothelioma (n=1) and AITL (n=1). Patients with myeloid malignancy had a median age of 62 at axi-cel apheresis (IQR 56-67), 64% were male and median lines of prior therapy was 4 (IQR 3-6), including 36% with a prior autologous stem cell transplant. Eleven patients were in remission from lymphoma at myeloid malignancy diagnosis, while 3 were diagnosed after progression and interval therapy. Conclusion: This multi-center retrospective study showed similar long-term results to the ZUMA-1 trial, despite including patients who did not meet ZUMA-1 eligibility criteria based on comorbidities. Sixteen percent of PFS events were seen after 1 year, largely due to disease progression. Late infection was common but was not explained by persistent neutropenia or low CD4 counts. Subsequent malignancy, including MDS, occurred in 8% of patients and require further study to better identify patients at risk. J.Y.S and M.D.J contributed equally; S.D and M.L contributed equally. Figure 1 Figure 1. Disclosures Jain: BMS, Kite/Gilead, Novartis, Precision Biosciences, Takeda: Consultancy. Nastoupil: Pfizer: Honoraria, Research Funding; MorphoSys: Honoraria; Takeda: Honoraria, Other: DSMC, Research Funding; ADC Therapeutics: Honoraria; IGM Biosciences: Research Funding; Genentech: Honoraria, Research Funding; Epizyme: Honoraria, Research Funding; Caribou Biosciences: Research Funding; Gilead/Kite: Honoraria, Research Funding; TG Therapeutics: Honoraria, Research Funding; Denovo Pharma: Other: DSMC; Bayer: Honoraria; Janssen: Honoraria, Research Funding; Novartis: Honoraria, Research Funding; Bristol Myers Squibb/Celgene: Honoraria, Research Funding. Ghobadi: Atara: Consultancy; Amgen: Consultancy, Research Funding; Wugen: Consultancy; Celgene: Consultancy; Kite, a Gilead Company: Consultancy, Honoraria, Research Funding. Lin: Gamida Cell: Consultancy; Juno: Consultancy; Merck: Research Funding; Bluebird Bio: Consultancy, Research Funding; Celgene: Consultancy, Research Funding; Novartis: Consultancy; Janssen: Consultancy, Research Funding; Sorrento: Consultancy; Legend: Consultancy; Takeda: Research Funding; Vineti: Consultancy; Kite, a Gilead Company: Consultancy, Research Funding. Reagan: Seagen: Research Funding; Kite, a Gilead Company: Consultancy; Genentech: Research Funding; Curis: Consultancy. Oluwole: Curio Science: Consultancy; Janssen: Consultancy; Pfizer: Consultancy; Kite, a Gilead Company: Consultancy, Research Funding. McGuirk: EcoR1 Capital: Consultancy; Gamida Cell: Research Funding; Bellicum Pharmaceuticals: Research Funding; Novartis: Research Funding; Kite/ Gilead: Consultancy, Honoraria, Other: travel accommodations, expense, Kite a Gilead company, Research Funding, Speakers Bureau; Novartis: Research Funding; Juno Therapeutics: Consultancy, Honoraria, Research Funding; Astelllas Pharma: Research Funding; Pluristem Therapeutics: Research Funding; Fresenius Biotech: Research Funding; Allovir: Consultancy, Honoraria, Research Funding; Magenta Therapeutics: Consultancy, Honoraria, Research Funding. Deol: Kite, a Gilead Company: Consultancy. Sehgal: Juno/Celgene: Research Funding; Kite/Gilead: Research Funding. Goy: AstraZeneca: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; LLC(Targeted Oncology): Consultancy; Xcenda: Consultancy, Honoraria; Xcenda: Consultancy; Acerta: Consultancy, Research Funding; AbbVie/Pharmacyclics: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Membership on an entity's Board of Directors or advisory committees; Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Vincerx: Honoraria, Membership on an entity's Board of Directors or advisory committees; Elsevier's Practice Update Oncology, Intellisphere, LLC(Targeted Oncology): Consultancy; Hoffman la Roche: Consultancy; Gilead: Membership on an entity's Board of Directors or advisory committees; AbbVie/Pharmacyclics: Membership on an entity's Board of Directors or advisory committees; Janssen: Research Funding; AstraZeneca: Membership on an entity's Board of Directors or advisory committees; Phamacyclics: Research Funding; Bristol Meyers Squibb: Membership on an entity's Board of Directors or advisory committees; Kite Pharma: Membership on an entity's Board of Directors or advisory committees; Michael J Hennessey Associates INC: Consultancy; Genentech/Hoffman la Roche: Research Funding; MorphoSys: Honoraria, Other; Karyopharm: Research Funding; Vincerx pharma: Membership on an entity's Board of Directors or advisory committees; Physicians' Education Resource: Consultancy, Other: Meeting/travel support; Incyte: Honoraria; Medscape: Consultancy; Novartis: Consultancy, Honoraria; Genomic Testing Cooperative: Current holder of stock options in a privately-held company, Membership on an entity's Board of Directors or advisory committees, Other: Leadership role; Infinity/Verastem: Research Funding; Rosewell Park: Consultancy; Bristol Meyers Squibb: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Kite, a Gilead Company: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; OncLive Peer Exchange: Honoraria; Elsevier PracticeUpdate: Oncology: Consultancy, Honoraria; Celgene: Consultancy, Honoraria, Research Funding; Constellation: Research Funding; COTA (Cancer Outcome Tracking Analysis): Current holder of stock options in a privately-held company, Membership on an entity's Board of Directors or advisory committees, Other: Leadership role; Hackensack Meridian Health, Regional Cancer Care Associates/OMI: Current Employment. Hill: Pfizer: Consultancy, Honoraria; Beigene: Consultancy, Honoraria, Research Funding; Gentenech: Consultancy, Honoraria, Research Funding; Kite, a Gilead Company: Consultancy, Honoraria, Other: Travel Support, Research Funding; Karyopharm: Consultancy, Honoraria, Research Funding; AstraZenica: Consultancy, Honoraria; Epizyme: Consultancy, Honoraria; Incyte/Morphysis: Consultancy, Honoraria, Research Funding; Novartis: Consultancy, Honoraria, Research Funding; Celgene (BMS): Consultancy, Honoraria, Research Funding; AbbVie: Consultancy, Honoraria, Research Funding. Andreadis: CRISPR Therapeutics: Research Funding; GenMAB: Research Funding; Novartis: Research Funding; Roche: Current equity holder in publicly-traded company, Ended employment in the past 24 months; Epizyme: Honoraria; Incyte: Honoraria; TG Therapeutics: Honoraria; Kite: Honoraria; Karyopharm: Honoraria; Atara: Consultancy, Honoraria; BMS: Research Funding; Merck: Research Funding. Muñoz: Seagen: Consultancy, Honoraria, Speakers Bureau; Pharmacyclics: Consultancy, Speakers Bureau; Bayer: Consultancy, Speakers Bureau; Kite, a Gilead Company: Consultancy, Speakers Bureau; Pfizer: Consultancy; Janssen: Consultancy, Speakers Bureau; Juno/Celgene: Consultancy; Bristol Myers Squibb: Consultancy; Alexion: Consultancy; BeiGene: Consultancy, Speakers Bureau; Fosunkite: Consultancy; Innovent: Consultancy; Debiopharma: Consultancy; Karyopharm: Consultancy; Genmab: Consultancy; ADC Therapeutics: Consultancy; Epizyme: Consultancy; Servier: Consultancy; Acrotech: Speakers Bureau; Verastem: Speakers Bureau; AstraZeneca: Speakers Bureau; Celgene/Bristol Myers Squibb: Speakers Bureau; Genentech: Speakers Bureau; Aurobindo: Speakers Bureau; Physicians' Education Resource: Honoraria; Kyowa Kirin: Consultancy, Honoraria, Speakers Bureau; OncView: Honoraria; Targeted Oncology: Honoraria. Westin: AstraZeneca: Consultancy, Research Funding; 47 Inc: Research Funding; Bristol Myers Squibb: Consultancy, Research Funding; Novartis: Consultancy, Research Funding; Kite, a Gilead Company: Consultancy, Research Funding; Morphosys: Research Funding; ADC Therapeutics: Consultancy, Research Funding; Umoja: Consultancy; Iksuda Therapeutics: Consultancy; MorphoSys: Consultancy, Research Funding; Curis: Research Funding; Genentech: Consultancy, Research Funding. Chavez: Bristol Myers Squibb: Speakers Bureau; Karyopharm Therapeutics: Consultancy; ADC Therapeutics: Membership on an entity's Board of Directors or advisory committees, Research Funding; Merck: Research Funding; Kite/Gilead: Consultancy; Abbvie: Consultancy; MorphoSys: Speakers Bureau; BeiGene: Speakers Bureau; Novartis: Consultancy; Adaptive: Research Funding; Epizyme: Speakers Bureau; AstraZeneca: Research Funding. Bennani: Kyowa Kirin: Other: Advisory Board; Daichii Sankyo Inc: Other: Advisory Board; Purdue Pharma: Other: Advisory Board; Verastem: Other: Advisory Board; Vividion: Consultancy, Other: Advisory Board. Vose: Kite, a Gilead Company: Honoraria, Research Funding. Miklos: Pharmacyclics: Patents & Royalties; 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; 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. Neelapu: Takeda Pharmaceuticals and related to cell therapy: Patents & Royalties; Kite, a Gilead Company, Merck, Bristol Myers Squibb, Novartis, Celgene, Pfizer, Allogene Therapeutics, Cell Medica/Kuur, Incyte, Precision Biosciences, Legend Biotech, Adicet Bio, Calibr, Unum Therapeutics and Bluebird Bio: Honoraria; Kite, a Gilead Company, Bristol Myers Squibb, Merck, Poseida, Cellectis, Celgene, Karus Therapeutics, Unum Therapeutics (Cogent Biosciences), Allogene, Precision BioSciences, Acerta and Adicet Bio: Research Funding; Kite, a Gilead Company, Merck, Bristol Myers Squibb, Novartis, Celgene, Pfizer, Allogene, Kuur, Incyte, Precision BioSciences, Legend, Adicet Bio, Calibr, and Unum Therapeutics: Other: personal fees. Locke: GammaDelta Therapeutics: Consultancy, Other: Scientific Advisory Role; BMS/Celgene: Consultancy, Other: Scientific Advisory Role; Bluebird Bio: Consultancy, Other: Scientific Advisory Role; Calibr: Consultancy, Other: Scientific Advisory Role; Amgen: Consultancy, Other: Scientific Advisory Role; Allogene Therapeutics: Consultancy, Other: Scientific Advisory Role, Research Funding; Cellular Biomedicine Group: Consultancy, Other: Scientific Advisory Role; Wugen: Consultancy, Other; Takeda: Consultancy, Other; Novartis: Consultancy, Other, Research Funding; Umoja: Consultancy, Other; Cowen: Consultancy; EcoR1: Consultancy; Emerging Therapy Solutions: Consultancy; Gerson Lehrman Group: Consultancy; Moffitt Cancer Center: Patents & Royalties: field of cellular immunotherapy; Legend Biotech: Consultancy, Other; Janssen: Consultancy, Other: Scientific Advisory Role; Kite, a Gilead Company: Consultancy, Other: Scientific Advisory Role, Research Funding; Iovance Biotherapeutics: Consultancy, Other: Scientific Advisory Role. Dahiya: Kite, a Gilead Company: Consultancy; Atara Biotherapeutics: Consultancy; Miltenyi Biotech: Research Funding; Jazz Pharmaceuticals: Research Funding; BMS: Consultancy. Lunning: Spectrum: Consultancy; AstraZeneca: Consultancy; Acrotech: Consultancy; Legend: Consultancy; Novartis: Consultancy; Kyowa Kirin: Consultancy; Karyopharm: Consultancy; Morphosys: Consultancy; TG Therapeutics: Consultancy; Janssen: Consultancy; AbbVie: Consultancy; Verastem: Consultancy; Myeloid Therapeutics: Consultancy; Celgene, a Bristol Myers Squibb Co.: Consultancy; Daiichi-Sankyo: Consultancy; Beigene: Consultancy; ADC Therapeutics: Consultancy; Kite, a Gilead Company: Consultancy.

Abstract Background Allogeneic (off the shelf) chimeric antigen receptor (CAR) T-cell therapy addresses the logistical challenges, availability (including insufficient T-cell yields from low baseline absolute lymphocyte count), and variable product quality of autologous CAR T therapy. ALLO-501A is a genetically modified anti-CD19 AlloCAR T™ cell product that uses TALEN ® gene editing to disrupt the T-cell receptor alpha constant gene (TRAC) and the CD52 gene to reduce the risk of graft-versus-host disease (GvHD) and permit the use of ALLO-647, an anti-CD52 monoclonal antibody (mAb), for selective and transitory host lymphodepletion (LD). Here we present an update on the preliminary safety, efficacy, and correlative data. ALLO-501A uses Cellectis technologies. Methods ALPHA2 (NCT04416984) is a single-arm, open-label, Phase 1/2 trial of ALLO-501A in patients (pts) with relapsed/refractory (R/R) large B-cell lymphoma (LBCL including [R/R] diffuse LBCL [DLBCL], transformed follicular lymphoma [tFL], marginal zone lymphoma [tMZL], primary mediastinal B-cell lymphoma [PMBCL], follicular lymphoma grade 3B [FL3B]) who received ≥2 prior lines of therapy (including an anthracycline and anti-CD20 mAb), have an ECOG performance status of 0 or 1. Subjects with donor specific antibodies are excluded. Following LD with ALLO-647, fludarabine 30 mg/m 2/d x 3d (F), and cyclophosphamide 300 or 500 mg/m 2/d x 3d (C), either a single (40 [DL1] or 120 [DL2] x 10 6 viable CAR T cells) or consolidation dose of ALLO-501A (DL2) are given. For consolidation dose, pts with ≥stable disease (SD) at day 28 receive consolidation with second ALLO-647 (no chemo) for LD and ALLO-501A (DL2) cell infusion. Results As of July 9, 2021, 20 pts were enrolled; 15 pts were treated with ALLO-501A (12 evaluable and 3 pending D28 assessment); 3 pts pending treatment; 2 pts withdrew due to adverse event (AE)/progressing disease (PD) prior to dosing. Patients were heavily pretreated with advanced-stage disease (Stage III: 4 [22.2%], Stage IV: 8 [44.4%]), median number of prior treatments was 3 with a high of 7. Three pts (16.7%) had primary refractory disease. Safety profile was manageable in both single dose and consolidation cohorts. Events of interest in the single dose cohort have been previously reported (ASCO 2021). In the consolidation cohort (13 enrolled, 9 pts dosed thus far), no cytokine release syndrome (CRS), no GvHD, no immune effector cell-associated neurotoxicity syndrome (ICANS), no dose-limiting toxicities (DLTs), no dose reductions, no Grade (Gr) 3+ infections and no related serious adverse events (SAEs) occurred, and infusion-related reactions were Gr 1. Among all treated, cytopenias were the most common AE and occurred in 72% of pts. Of the 12 evaluable pts (6 each treated in the single dose and consolidation dose cohort), both the overall response rate (ORR) and complete response (CR) were 50% (95% CI: 21.1, 78.9). In the consolidation cohort, both ORR and CR rate were 66.7% (95% CI: 22.3, 95.7) with 3/3 partial responses (PRs) converting to CR after consolidation; 1 pt had CR at days 28 and 56 post consolidation and 2 pts had PD at month 1 and did not receive consolidation. In single dose cohort, 2 pts have ongoing CR at 9 and 12+ months. CAR T expansion was greater in pts who achieved a CR with a geometric mean area under the curve (AUC) at D1-28 of 206,990 copies/ug*days (n=6; GSD 4.94) compared to pts who did not achieve a CR with AUC at D1-28 of 3,571 copies/ug*days (n=3; GSD 2.41). Pts who received the consolidation dose continued to have CAR T expansion after the 2 nd CAR T infusion with geometric mean AUC from D30-56 of 92,893 copies/ug*days (n=4; GSD 5.42). Conclusions ALLO-501A with consolidation dosing demonstrated comparable safety and an improved efficacy profile compared to single dosing with all 4 pts who received consolidation remaining in CR. Persistence of CAR T at D28 and expansion after consolidation dose was observed in addition to the observed deepening of responses in pts whose initial response was PR. Additional follow up is needed to determine whether consolidation also improves the durability of response. Consolidation was well tolerated and given the generally favorable overall safety profile, ALLO-501A may have the potential to be given in the outpatient setting. Enrollment is ongoing. Updated efficacy and follow-up will be presented at the meeting. Currently, an ALLO-501A Phase 2 trial is planned. Disclosures Locke: Cowen: Consultancy; Umoja: Consultancy, Other; Wugen: Consultancy, Other; Takeda: Consultancy, Other; Novartis: Consultancy, Other, Research Funding; Janssen: Consultancy, Other: Scientific Advisory Role; Bluebird Bio: Consultancy, Other: Scientific Advisory Role; BMS/Celgene: Consultancy, Other: Scientific Advisory Role; Calibr: Consultancy, Other: Scientific Advisory Role; Amgen: Consultancy, Other: Scientific Advisory Role; GammaDelta Therapeutics: Consultancy, Other: Scientific Advisory Role; Cellular Biomedicine Group: Consultancy, Other: Scientific Advisory Role; Kite, a Gilead Company: Consultancy, Other: Scientific Advisory Role, Research Funding; Legend Biotech: Consultancy, Other; Iovance Biotherapeutics: Consultancy, Other: Scientific Advisory Role; EcoR1: Consultancy; Allogene Therapeutics: Consultancy, Other: Scientific Advisory Role, Research Funding; Emerging Therapy Solutions: Consultancy; Gerson Lehrman Group: Consultancy; Moffitt Cancer Center: Patents & Royalties: field of cellular immunotherapy. Neelapu: Kite, a Gilead Company, Merck, Bristol Myers Squibb, Novartis, Celgene, Pfizer, Allogene Therapeutics, Cell Medica/Kuur, Incyte, Precision Biosciences, Legend Biotech, Adicet Bio, Calibr, Unum Therapeutics and Bluebird Bio: Honoraria; Kite, a Gilead Company, Merck, Bristol Myers Squibb, Novartis, Celgene, Pfizer, Allogene, Kuur, Incyte, Precision BioSciences, Legend, Adicet Bio, Calibr, and Unum Therapeutics: Other: personal fees; Kite, a Gilead Company, Bristol Myers Squibb, Merck, Poseida, Cellectis, Celgene, Karus Therapeutics, Unum Therapeutics (Cogent Biosciences), Allogene, Precision BioSciences, Acerta and Adicet Bio: Research Funding; Takeda Pharmaceuticals and related to cell therapy: Patents & Royalties. Hamadani: Janssen, Incyte, ADC Therapeutics, Omeros, Morphosys, Kite: Consultancy; Sanofi, Genzyme, AstraZeneca, BeiGene: Speakers Bureau; Takeda, Spectrum Pharmaceuticals and Astellas Pharma: Research Funding. Frank: Allogene Therapeutics: Research Funding; Kite-Gilead: Membership on an entity's Board of Directors or advisory committees; Adaptive Biotechnologies: Research Funding. Popplewell: Novartis: Other: Travel; Pfizer: Other: Travel; Hoffman La Roche: Other: Food. Abramson: Bluebird Bio: Consultancy; Kymera: Consultancy; BeiGene: Consultancy; Incyte Corporation: Consultancy; Astra-Zeneca: Consultancy; Allogene Therapeutics: Consultancy; Seagen Inc.: Research Funding; AbbVie: Consultancy; Karyopharm: Consultancy; Novartis: Consultancy; Morphosys: Consultancy; Kite Pharma: Consultancy; C4 Therapeutics: Consultancy; Genmab: Consultancy; EMD Serono: Consultancy; Bristol-Myers Squibb Company: Consultancy, Research Funding; Genentech: Consultancy. Munoz: Pharmacyclics/Abbvie: Consultancy, Research Funding, Speakers Bureau; Bayer: Consultancy, Research Funding, Speakers Bureau; Gilead/Kite Pharma: Consultancy, Research Funding, Speakers Bureau; Pfizer: Consultancy; Janssen: Consultancy, Research Funding, Speakers Bureau; Juno/Celgene: Consultancy, Research Funding, Speakers Bureau; BMS: Consultancy, Speakers Bureau; Kyowa: Consultancy, Honoraria, Speakers Bureau; Alexion: Consultancy; Beigene: Consultancy, Speakers Bureau; Fosunkite: Consultancy; Innovent: Consultancy; Seattle Genetics: Consultancy, Honoraria, Research Funding, Speakers Bureau; Debiopharm: Consultancy; Karyopharm: Consultancy; Genmab: Consultancy; ADC Therapeutics: Consultancy; Epizyme: Consultancy; Servier: Consultancy; Merck: Research Funding; Portola: Research Funding; Incyte: Research Funding; Genentech: Research Funding, Speakers Bureau; Millennium: Research Funding; Targeted Oncology: Honoraria; OncView: Honoraria; Physicians' Education Resource: Honoraria; Roche: Speakers Bureau; AstraZeneca: Speakers Bureau; Verastem: Speakers Bureau; Acrotech/Aurobindo: Speakers Bureau. Shin: Allogene Therapeutics, Inc.: Current Employment, Current equity holder in publicly-traded company. Loomis-Navale: Allogene: Current Employment, Current equity holder in publicly-traded company. Miklos: 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; 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; 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; Pharmacyclics: Patents & Royalties. OffLabel Disclosure: Discussion of fludarabine and cyclophosphamide in combination with ALLO-647 as conditioning regimen prior to administration of ALLO-501A in patients with R/R LBCL.

Abstract INTRODUCTION Dendritic cells (DCs) are potent antigen presenting cells that can be exploited to initiate an adaptive anti-tumoral immune response. DC vaccine clinical trials for primary glioblastoma (GBM) have reported prolonged progression-free survival without any impact on overall survival (OS). We report a radiomics approach that identifies a subpopulation of patients with prolonged OS in clinical trial MC1272. METHODS Twenty adults with primary GBM undergoing standard-of-care therapy were enrolled in MC1272. Autologous DCs were pulsed with allogenic GBM cell lines to generate vaccines that were administered for up to twelve cycles. Standard brain imaging was obtained at the initiation of treatment and two months afterwards. An independent cohort of image-localized biopsies underwent RNA sequencing followed by cellular deconvolution to estimate T cell abundance. A machine learning model was trained to predict intratumoral T cell abundance from imaging features, and the model was applied to MC1272 patient imaging. RESULTS Voxelwise predictions of T cell abundance were generated for each patient’s pre- and post-treatment images. The difference in total intratumoral T cell abundance between imaging timepoints classified patients into increasing or decreasing T cell groups. Patients whose T cells increased had longer OS (median, 21 months) than those whose T cells decreased (median, 10 months; p=0.0035). The significance remained in a Cox proportional hazards analysis that adjusted for patient age and sex (p=0.011). CONCLUSIONS A spatially-resolved radiomics model detected that an intratumoral T cell influx after DC vaccine therapy was associated with prolonged OS. The “post-treatment” imaging in this study was obtained a mere two months after DC vaccine initiation, suggesting that our radiomics model can provide an early indication of treatment responsiveness and prognosis in these patients.

AbstractAimsWe evaluated the occurrence and physiology of respiration‐related beat‐to‐beat variations in resting Pd/Pa and FFR during intravenous adenosine administration, and its impact on clinical decision‐making.Methods and ResultsCoronary pressure tracings in rest and at plateau hyperemia were analyzed in a total of 39 stenosis from 37 patients, and respiratory rate was calculated with ECG‐derived respiration (EDR) in 26 stenoses from 26 patients. Beat‐to‐beat variations in FFR occurred in a cyclical fashion and were strongly correlated with respiratory rate (R2 = 0.757, p < 0.001). There was no correlation between respiratory rate and variations in resting Pd/Pa. When single‐beat averages were used to calculate FFR, mean ΔFFR was 0.04 ± 0.02. With averaging of FFR over three or five cardiac cycles, mean ΔFFR decreased to 0.02 ± 0.02, and 0.01 ± 0.01, respectively. Using a FFR ≤ 0.80 threshold, stenosis classification changed in 20.5% (8/39), 12.8% (5/39) and 5.1% (2/39) for single‐beat, three‐beat and five‐beat averaged FFR. The impact of respiration was more pronounced in patients with pulmonary disease (ΔFFR 0.05 ± 0.02 vs 0.03 ± 0.02, p = 0.021).ConclusionBeat‐to‐beat variations in FFR during plateau hyperemia related to respiration are common, of clinically relevant magnitude, and frequently lead FFR to cross treatment thresholds. A five‐beat averaged FFR, overcomes clinically relevant impact of FFR variation.