Miklos, David B

PURPOSE Brexucabtagene autoleucel (brexu-cel) is an autologous CD19-directed chimeric antigen receptor (CAR) T-cell therapy approved for relapsed/refractory mantle cell lymphoma (MCL). This therapy was approved on the basis of the single-arm phase II ZUMA-2 trial, which showed best overall and complete response rates of 91% and 68%, respectively. We report clinical outcomes with brexu-cel in the standard-of-care setting for the approved indication. PATIENTS AND METHODS Patients who underwent leukapheresis between August 1, 2020 and December 31, 2021, at 16 US institutions, with an intent to manufacture commercial brexu-cel for relapsed/refractory MCL, were included. Patient data were collected for analyses of responses, outcomes, and toxicities as per standard guidelines. RESULTS Of 189 patients who underwent leukapheresis, 168 (89%) received brexu-cel infusion. Of leukapheresed patients, 79% would not have met ZUMA-2 eligibility criteria. Best overall and complete response rates were 90% and 82%, respectively. At a median follow-up of 14.3 months after infusion, the estimates for 6- and 12-month progression-free survival (PFS) were 69% (95% CI, 61 to 75) and 59% (95% CI, 51 to 66), respectively. The nonrelapse mortality was 9.1% at 1 year, primarily because of infections. Grade 3 or higher cytokine release syndrome and neurotoxicity occurred in 8% and 32%, respectively. In univariable analysis, high-risk simplified MCL international prognostic index, high Ki-67, TP53 aberration, complex karyotype, and blastoid/pleomorphic variant were associated with shorter PFS after brexu-cel infusion. Patients with recent bendamustine exposure (within 24 months before leukapheresis) had shorter PFS and overall survival after leukapheresis in intention-to-treat univariable analysis. CONCLUSION In the standard-of-care setting, the efficacy and toxicity of brexu-cel were consistent with those reported in the ZUMA-2 trial. Tumor-intrinsic features of MCL, and possibly recent bendamustine exposure, may be associated with inferior efficacy outcomes.

Abstract The SCHOLAR-1 international retrospective study highlighted poor clinical outcomes and survival among patients with refractory large B-cell lymphoma (LBCL) treated with conventional chemotherapy. Axicabtagene ciloleucel (axi-cel), an autologous anti-CD19 chimeric antigen receptor (CAR) T-cell therapy, demonstrated durable responses in patients with refractory LBCL in the pivotal phase 1/2 ZUMA-1 study (NCT02348216). Here, we compared SCHOLAR-1 with the 2-year outcomes of ZUMA-1. Prior to comparison of clinical outcomes, propensity scoring (based on a broad set of prognostic covariates) was used to create balance between ZUMA-1 and SCHOLAR-1 patients. In the pivotal phase 2 portion of ZUMA-1, 101 patients received axi-cel and were evaluable for response and survival. In SCHOLAR-1, 434 and 424 patients were evaluable for response and survival, respectively. ZUMA-1 patients were more heavily pretreated than were SCHOLAR-1 patients. The median follow-up was 27.1 months in ZUMA-1. The objective response rate (ORR) and complete response rate were 83% and 54% in ZUMA-1 vs 34% and 12% in SCHOLAR-1, respectively. The 2-year survival rate was 54% in ZUMA-1 and 20% in SCHOLAR-1, and a 73% reduction in the risk of death was observed in ZUMA-1 vs SCHOLAR-1. These results were consistent with those of an additional standardization analysis in which strata were limited to 2 prognostic factors (refractory categorization and presence/absence of stem cell transplant after refractoriness to chemotherapy) to conserve sample size. Despite the limitations of a nonrandomized analysis, these results indicate that axi-cel produces durable responses and a substantial survival benefit vs non–CAR T-cell salvage regimens for patients with refractory LBCL.

8023 Background: MGTA-145 (GroβT), a CXCR2 agonist, has shown promising activity for HSC mobilization with plerixafor in pre-clinical models and healthy volunteers. Methods: This phase 2 single center study evaluates HSC mobilization with MGTA-145 + plerixafor and same day apheresis in patients with multiple myeloma. Patients received plerixafor 0.24 mg/kg (0.16 mg/kg if renal dysfunction) SQ, followed 2 hours later by MGTA-145 (0.03 mg/kg) IV over 3-10 minutes and apheresis within 30 minutes. Mobilization was repeated for a second day if day 1 yield was < 6 x 106 CD34+ cells/kg. This interim analysis reports on mobilization in 10 patients (of 25 planned), including safety cohort of first 6 patients completing transplant. Primary endpoint is collection of 2 x 106 CD34+ cells/kg. Results: Median age was 63 years (range: 46-68), 50% were female, 22% had ISS stage 3 & 50% had high-risk FISH. Induction therapy was VRD in 7 and daratumumab + VRD in 3 patients; median induction duration: 4 months (3-6) & median lenalidomide exposure: 6 cycles (4-6), with > VGPR in 70%. Median total stem cell yield (CD34+ cells/kg x 106) was 7.1 (3-16.2), day 1 yield was 5.4 (1.1-16.2) & yield per apheresis session was 4 (1.1-16.2). 100% of patients met the primary endpoint of collecting sufficient HSCs in < 2 days of mobilization + apheresis to proceed to transplant (2 x 106 CD34+ cells/kg). Secondary endpoints of 4 and 6 x 106 CD34+ cells/kg in < 2 days were met in 90% & 80% patients. 30% patients underwent 1 apheresis, while 70% underwent 2 sessions. MGTA-145 was well tolerated. At least 1 adverse event (AE) was seen in 90% of patients, 20% had grade 2 AEs (anemia, hypokalemia) and 20% had grade 3 AEs (worsening of baseline grade 3 anemia; hypocalcemia); all resolved. Acute & transient bone pain was seen in 40% of patients (back-2, hip-1, sternum-1), all grade 1, all on day 1, & resolved without intervention after 6 minutes (3-10). All 6 patients in the safety cohort have completed transplant with melphalan 200 mg/m2. Median of 4.1 (3.4-5.6) x 106 CD34+ cells/kg were infused. All patients have engrafted timely (DiPersio Blood 2009); median time to neutrophil engraftment: 12 days (11-13) & platelet engraftment: 17 days (16-19). Apheresis graft analysis is available in these 6 patients. Grafts with MGTA-145+plerixafor showed high enrichment for CD90+CD45RA- among CD34+ cells, a CD34 subset of long term engrafting HSCs (median: 31% of CD34+ cells, 27-52), higher than seen with G-CSF (6%, Goncalves TCT 2021). 67% of grafts were minimal residual disease negative with next generation flow cytometry. Conclusions: This is the first study to evaluate the novel regimen of MGTA-145 + plerixafor for same day stem cell mobilization & collection in myeloma/hematologic malignancies, with 100% efficacy in interim analysis and the first to demonstrate successful engraftment in patients with cells collected with this GCSF free regimen. Clinical trial information: NCT04552743.

7552 Background: Axi-cel is approved in the US for the treatment of adult patients with relapsed or refractory LBCL after 2 or more lines of systemic therapy. Post-market long term follow up study of commercial Axi-cel recipients using the Center for International Blood and Marrow Transplant Research was recently completed. Methods: From October 2017 to August 2020, 1,500 Axi-cel recipients from 79 centers were enrolled. Of these, 1001 patients with at least 6 months of follow-up were included in this analysis. Outcomes include complete and overall responses rates (CR and ORR), duration of response (DOR), progression-free and overall survival (PFS and OS), cytokine release syndrome (CRS) (Lee D 2014 and American Society for Transplantation and Cellular Therapy [ASTCT]), immune effector cell associated neurotoxicity syndrome (ICANS), hematologic recovery and subsequent neoplasm (SN). Subgroup analysis by sensitivity to therapy, defined as responsive to the last line of therapy prior to Axi-cel. Median follow-up was 12 months (range, 6-28 months). Results: The median age overall was 62 years, 37% were ≥ 65 years, 83% with Eastern Cooperative Oncology Group (ECOG) performance score 0-1, 28% with transformed lymphoma, 14% with high grade lymphoma, 29% with prior autologous transplant, and 66% with chemotherapy-resistant disease prior to Axi-cel. The median time from diagnosis to Axi-cel infusion was 15 months. Best ORR was 70% (CR 53%). Landmark analysis of patients in CR at 6 months post Axi-cel demonstrates a low number of subsequent progression/death events. With respect to outcomes for chemotherapy-sensitive disease versus resistant disease, the ORR, CR, 12-month PFS and OS were 78% vs. 66%, 60% vs. 48%, 55% (95% CI, 48-62%) vs. 40% (95% CI, 37-44%), and 70% (95% CI, 63-76%) vs. 54% (95% CI, 50-58%), respectively. CRS of any grade was reported in 83% of patients. Incidence of Grades ≥ 3 CRS was 10% according to Lee et al 2014, and 13% according to ASTCT Consensus Grading. Median time to any grade CRS was 4 days (range, 1-28 days), and 93% of CRS cases resolved with a median duration of 7 days (range, 1-121 days). ICANS were reported in 576 (57%) patients, grade >3 was 26%. The median time to onset of ICANS was 7 days (range, 1-82 days), and 86% resolved with a median duration of 9 days (range, 1 to 115 days). Twenty-nine patients (2.9%) reported SN: hematologic (N = 17), solid tumors (N = 12). Conclusions: This is the largest report on Axi-cel in the real-world setting and demonstrates consistent efficacy outcomes and further characterizes safety outcomes. Patients in CR at 6 months have sustained disease control with low number of relapse events. Although patients with therapy-sensitive disease experience better outcomes than patients with therapy-resistant, the overall outcomes on both groups of patients are favorable.

Abstract ZUMA-1 demonstrated a high rate of durable response and a manageable safety profile with axicabtagene ciloleucel (axi-cel), an anti-CD19 chimeric antigen receptor (CAR) T-cell therapy, in patients with refractory large B-cell lymphoma. As previously reported, prespecified clinical covariates for secondary end point analysis were not clearly predictive of efficacy; these included Eastern Cooperative Oncology Group performance status (0 vs 1), age, disease subtype, disease stage, and International Prognostic Index score. We interrogated covariates included in the statistical analysis plan and an extensive panel of biomarkers according to an expanded translational biomarker plan. Univariable and multivariable analyses indicated that rapid CAR T-cell expansion commensurate with pretreatment tumor burden (influenced by product T-cell fitness), the number of CD8 and CCR7+CD45RA+ T cells infused, and host systemic inflammation, were the most significant determining factors for durable response. Key parameters differentially associated with clinical efficacy and toxicities, with both theoretical and practical implications for optimizing CAR T-cell therapy. This trial was registered at www.clinicaltrials.gov as #NCT02348216.

PURPOSE Axicabtagene ciloleucel (axi-cel) is an autologous CD19-directed chimeric antigen receptor (CAR) T-cell therapy approved for relapsed/refractory large B-cell lymphoma (LBCL) on the basis of the single-arm phase II ZUMA-1 trial, which showed best overall and complete response rates in infused patients of 83% and 58%, respectively. We report clinical outcomes with axi-cel in the standard-of-care (SOC) setting for the approved indication. PATIENTS AND METHODS Data were collected retrospectively from all patients with relapsed/refractory LBCL who underwent leukapheresis as of September 30, 2018, at 17 US institutions with the intent to receive SOC axi-cel. Toxicities were graded and managed according to each institution’s guidelines. Responses were assessed as per Lugano 2014 classification. RESULTS Of 298 patients who underwent leukapheresis, 275 (92%) received axi-cel therapy. Compared with the registrational ZUMA-1 trial, 129 patients (43%) in this SOC study would not have met ZUMA-1 eligibility criteria because of comorbidities at the time of leukapheresis. Among the axi-cel–treated patients, grade ≥ 3 cytokine release syndrome and neurotoxicity occurred in 7% and 31%, respectively. Nonrelapse mortality was 4.4%. Best overall and complete response rates in infused patients were 82% (95% CI, 77% to 86%) and 64% (95% CI, 58% to 69%), respectively. At a median follow-up of 12.9 months from the time of CAR T-cell infusion, median progression-free survival was 8.3 months (95% CI, 6.0 to15.1 months), and median overall survival was not reached. Patients with poor Eastern Cooperative Oncology Group performance status of 2-4 and elevated lactate dehydrogenase had shorter progression-free and overall survival on univariable and multivariable analysis. CONCLUSION The safety and efficacy of axi-cel in the SOC setting in patients with relapsed/refractory LBCL was comparable to the registrational ZUMA-1 trial.

Abstract Introduction Axi-cel is an autologous anti-CD19 CAR T-cell therapy approved by the US FDA 10/18/2017, for the treatment of adults with relapsed or refractory (r/r) large B-cell lymphoma (DLBCL), primary mediastinal large B-cell lymphoma (PMBCL), transformed lymphoma (tFL), and high-grade B-cell lymphoma (HGBCL) who have failed at least two prior systemic lines of therapy. In the pivotal ZUMA-1 trial, 108 patients (pts) with r/r DLBCL were treated with axi-cel: the best overall response rate (ORR) was 82% and complete response (CR) rate was 58%. At a median follow-up of 15.4 months, 42% of the pts had ongoing remission (Neelapu and Locke et al. NEJM 2017). Grade 3 or higher cytokine release syndrome (CRS) by Lee criteria and neurologic events (NEs) occurred in 13% and 31% of the pts, respectively. Here, we evaluated the real world outcomes of pts treated with standard of care axi-cel under the commercial FDA label. Methods and Results Seventeen US academic centers contributed data to this effort independently of the manufacturer. As of 6/30/2018, 211 pts were leukapheresed with intention to manufacture commercial axi-cel. Of these, 165 (78%) pts completed axi-cel infusion as of 6/30/18 and a further 23 (11%) pts are scheduled for axi-cel infusion in July 2018. Of the 23 remaining pts, 7 (3%) received axi-cel therapy on ZUMA-9 expanded access trial (NCT03153462) due to non-conforming cell therapy product, 15 (7%) pts died before axi-cel infusion (14 from lymphoma progression and 1 from sepsis) and 1 (1%) patient attained CR from bridging therapy and was not infused. Safety was evaluable in 163 pts receiving axi-cel. Grade ³3 CRS and NEs occurred in 7% and 31% of pts. Tocilizumab was administered in 62% of pts and 57% received corticosteroids. Outside of lymphoma progression, 3 deaths occurred post-axi-cel; 1 due to HLH, 1 due to systemic candidiasis, and a third due to septic shock. There were no grade 5 NEs observed. Response assessment was done for pts infused with axi-cel and who were re-staged at day 30 and/or day 100, or were deemed to have clinical progression. Of 112 pts evaluable at day 30, ORR was 79% with 50% CR, 29% PR, 6% SD and 14% with PD. Of 39 pts evaluable at day 100, 59% of pts had ongoing response (CR 49%, PR 10%). At the time of abstract submission, more detailed patient characteristics and treatment course data were available in 134/165 pts infused. Median age was 59 (range 21-82) with 57% male. Performance status (PS) was ECOG 0-1 (81%), ECOG 2 (16%) and ECOG 3 (3%). By histology, 61% of pts had DLBCL including HGBCL, 31% had tFL and 8% PMBCL. Thirty-one percent had a prior autologous stem cell transplant. Bridging therapy between apheresis and infusion was given in 56% of patients, the majority of which consisted of chemotherapy. Sixty-six of 134 (49%) would not have met eligibility criteria for ZUMA-1 at the time of leukapheresis. Common criteria that would have made these patients ineligible for ZUMA-1 included ECOG PS >1 (n = 22), platelets <75k (n = 17), GFR <60 (n =12), active DVT/PE (n = 13), liver enzyme abnormalities (n = 10), a history of CNS lymphoma (n = 8), recent checkpoint inhibitor therapy (n = 7), ejection fraction <50% (n = 4), prior CD19 CAR T therapy (n = 4), and prior allogeneic transplant (n=2). Median time from leukapheresis to start of conditioning chemotherapy was 21 days and median time from leukapheresis to axi-cel infusion was 26 days. Median hospitalization period was 14 days. Conclusions This multicenter retrospective study delineates the real world outcomes of axi-cel CAR T-cell therapy for r/r aggressive B-cell lymphoma when used as a standard of care. Though limited by relatively short follow up, 30 day responses in the real world setting are comparable to the best responses observed on the pivotal ZUMA-1 clinical trial (Table 1). Importantly, safety appears comparable to the ZUMA-1 trial despite nearly half the pts failing to meet ZUMA-1 eligibility criteria. Updated results including PFS and OS will be presented at the meeting. L.J.N. and M.D.J. contributed equally; D.B.M., S.S.N. and F.L.L. contributed equally. Disclosures Nastoupil: Merck: Honoraria, Research Funding; Celgene: Honoraria, Research Funding; TG Therappeutics: Research Funding; Karus: Research Funding; Genentech: Honoraria, Research Funding; Janssen: Research Funding; Gilead: Honoraria; Juno: Honoraria; Novartis: Honoraria; Spectrum: Honoraria. Lunning:Celgene: Consultancy; Spectrum: Consultancy; Portola: Consultancy; Genzyme: Consultancy; Janssen: Consultancy; Seattle Genetics: Consultancy; Kite: Consultancy; Juno: Consultancy; AbbVie: Consultancy; Astra-Zeneca: Consultancy; Genentech: Consultancy; Gilead: Consultancy; Genentech: Consultancy; Bayer: Consultancy; TG Therapeutics: Consultancy; Verastem: Consultancy. Reagan:Seattle Genetics: Research Funding. McGuirk:Gamida Cell: Research Funding; Astellas Pharma: Research Funding; Fresenius Biotech: Research Funding; Bellicum Pharmaceuticals: Research Funding; Novartis Pharmaceuticals Corporation: Honoraria, Other: speaker, Research Funding; Kite Pharma: Honoraria, Other: travel accommodations, expenses, speaker ; Pluristem Ltd: Research Funding. Deol:Novartis: Consultancy; Kite Pharmaceuticals: Consultancy. Hill:Pharmacyclics: Honoraria, Membership on an entity's Board of Directors or advisory committees; Genentech: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Seattle Genetics: Honoraria, Membership on an entity's Board of Directors or advisory committees; Amgen: Research Funding; Seattle Genetics: Honoraria, Membership on an entity's Board of Directors or advisory committees; Abbvie: Honoraria, Membership on an entity's Board of Directors or advisory committees; Pfizer: Honoraria, Membership on an entity's Board of Directors or advisory committees; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees; Pfizer: Honoraria, Membership on an entity's Board of Directors or advisory committees; Pharmacyclics: Honoraria, Membership on an entity's Board of Directors or advisory committees; Abbvie: Honoraria, Membership on an entity's Board of Directors or advisory committees. Andreadis:Gilead: Consultancy; Genentech: Consultancy, Employment; Astellas: Consultancy; Bayer: Consultancy; Celgene: Consultancy; Seattle Genetics: Consultancy; Pharmacyclics: Consultancy; Juno: Research Funding; Kite: Consultancy; Novartis: Consultancy, Research Funding. Munoz:Pfizer: Consultancy; Bayer: Consultancy, Speakers Bureau; Juno: Consultancy, Honoraria; Janssen: Consultancy; Genentech: Consultancy, Honoraria; Bristol-Myers Squibb: Consultancy; Pharmacyclics: Consultancy, Honoraria; Kite: Consultancy, Honoraria, Speakers Bureau; Alexion: Consultancy; Gilead: Speakers Bureau. Westin:Novartis Pharmaceuticals Corporation: Membership on an entity's Board of Directors or advisory committees; Celgen: Membership on an entity's Board of Directors or advisory committees; Kite Pharma: Membership on an entity's Board of Directors or advisory committees; Apotex: Membership on an entity's Board of Directors or advisory committees. Vose:Kite Pharma: Research Funding; Acerta Pharma: Research Funding; Celgene: Research Funding; Novartis: Honoraria, Research Funding; Roche: Honoraria; Seattle Genetics, Inc.: Research Funding; Legend Pharmaceuticals: Honoraria; Merck Sharp & Dohme Corp.: Research Funding; Abbvie: Honoraria; Epizyme: Honoraria; Bristol Myers Squibb: Research Funding; Incyte Corp.: Research Funding. Miklos:Genentech: Research Funding; Kite - Gilead: Consultancy, Research Funding; Novartis: Consultancy, Research Funding; Pharmacyclics - Abbot: Consultancy, Research Funding; Janssen: Consultancy, Research Funding; Adaptive Biotechnologies: Consultancy, Research Funding. Locke:Kite Pharma: Other: Scientific Advisor; Cellular BioMedicine Group Inc.: Consultancy; Novartis Pharmaceuticals: Other: Scientific Advisor.