Ulrickson, Matthew L.

PURPOSE Axicabtagene ciloleucel (axi-cel) is an autologous CD19 chimeric antigen receptor (CAR) T-cell therapy that is approved for the treatment of relapsed or refractory large B-cell lymphoma. Little is known about the long-term survivorship after CAR T-cell therapy. METHODS We previously reported the results of 298 patients who were leukapheresed with the intent to receive standard-of-care axi-cel (n = 275 infused) after two or more previous lines of therapy at a median follow-up of 12.9 months. Here, we report extended follow-up of this cohort to a median of 58 months, with a focus on late survivorship events. RESULTS Among axi-cel–infused patients, progression-free survival at 5 years was 29% and overall survival (OS) at 5 years was 40%. The 5-year lymphoma-specific survival was 53% with infrequent late relapses. However, the 5-year nonrelapse mortality (NRM) was 16.2%, with over half of NRM events occurring beyond 2 years. Patients who were 60 years and older had a lower risk of relapse ( P = .02), but a higher risk of NRM compared with patients younger than 60 years (NRM odds ratio, 4.5 [95% CI, 2.1 to 10.8]; P < .001). Late NRM was mainly due to infections and subsequent malignant neoplasms (SMNs). In total, SMNs occurred in 24 patients (9%), including therapy-related myeloid neoplasms (n = 15), solid tumors (n = 7), and unrelated lymphoid malignancies (n = 2). CONCLUSION In the standard-of-care setting, axi-cel exhibits outcomes consistent with those reported in clinical trials, with sustained, durable responses observed at the 5-year time point. However, late infections and the development of SMN are key survivorship issues that reduce long-term survival after CAR T-cell therapy, particularly in the elderly.

1604 Background: Diversity in clinical studies is essential to address health disparities, but racial and ethnic minorities are often underrepresented in clinical studies, especially in precision medicine studies using genetic data (1). BASECAMP-1 (NCT04981119) is an ongoing prescreening study to identify patients with unresectable advanced or metastatic solid tumors and tumor-associated HLA-A*02 LOH for the EVEREST-1 and -2 Tmod chimeric antigen receptor T-cell therapy trials. When enrollment began in 2021, eligibility for Part 1 was restricted to patients with germline HLA-A*02:01 based on preclinical data. Additional analysis revealed the blocker in the Tmod construct had activity across HLA-A*02 subtypes (Mock, et al. Mol Ther Oncolytics.2022). Eligibility for Part 1 was then expanded to all HLA-A*02 subtypes, allowing enrollment of more diverse patient populations. HLA-A*02 allele subtypes vary by ethnicity and race; the frequency of HLA-A*02:01 is 96% in non-Hispanic Whites, but ranges from 53% to 73% in other ethnicities and races. The frequency of all other HLA-A*02 allele subtypes (HLA-A*02:XX) is <5% in non-Hispanic Whites but up to 66% in other ethnicities and races (2,3). Methods: Patients eligible for BASECAMP-1 were identified at United States study sites. All patients screened before January 16, 2024, for Part 1 were included for demographic and central lab HLA-A typing. The % increase in eligibility and % of heterozygous HLA-A*02 patients with HLA-A*02:XX were calculated by ethnicity and race. Results: A total of 1124 patients were screened for germline HLA-A*02 typing; 431 patients were HLA-A*02:01 heterozygous, of whom 37 (9%) were Hispanic, 14 (3%) African American (AA), 2 (<1%) American Indian or Alaska Native, 17 (4%) Asian or Pacific Islander (API), and 324 (75%) non-Hispanic White (Table). The eligibility expansion identified 62 patients with HLA-A*02:XX heterozygosity, of whom 6 (10%) were Hispanic, 6 (10%) AA, 19 (31%) API, and 25 (40%) non-Hispanic White. Conclusions: By expanding enrollment to include HLA-A*02:XX, 16% more Hispanic, 43% more AA, and 112% more API patients were identified, improving the diversity in this trial compared with that of initial enrollment. 1. Aldrighetti, et al. JAMA Netw Open 2021. 2. Ellis, et al. Human Immunol. 2000. 3. Gragert, et al. Human Immunol.2013. Clinical trial information: NCT04981119 . [Table: see text]

Background: Axi-cel is an autologous anti-CD19 chimeric antigen receptor (CAR) T-cell therapy approved for the treatment of relapsed/refractory (R/R) LBCL. ZUMA-12 (NCT03761056) is a Phase 2, multicenter, single-arm study of axi-cel as part of first-line treatment in patients with high-risk LBCL. In the primary efficacy analysis (n=37; median follow-up of 15.9 months), axi-cel demonstrated a high rate of investigator-assessed complete response (CR; 78%; 95% CI, 62-90) and an 89% objective response rate (ORR; 95% CI, 75-97). Axi-cel also had a manageable safety profile, with no new safety signals observed in the first-line setting (Neelapu et al. Nat Med. 2022). Here, we report updated efficacy and safety outcomes from ZUMA-12 in all patients treated with axi-cel after a median follow-up of ≥40 months. Methods: Eligible adults had high-risk LBCL, with MYC and BCL2 and/or BCL6 rearrangements (double- or triple-hit histology) per investigator or an International Prognostic Index (IPI) score ≥3, plus a positive interim PET per Lugano classification (Deauville score 4/5) after 2 cycles of an anti-CD20 monoclonal antibody and anthracycline-containing regimen. Patients underwent leukapheresis, followed by lymphodepleting chemotherapy (cyclophosphamide and fludarabine) on Days -5, -4, and -3, and a single axi-cel infusion of 2×10 6 CAR T cells/kg on Day 0. Per investigator discretion, non-chemotherapy bridging could be administered. The primary endpoint was investigator-assessed CR rate per Lugano classification (Cheson et al. J Clin Oncol. 2014). Secondary endpoints included ORR, duration of response (DOR), event-free survival (EFS), progression-free survival (PFS), overall survival (OS), safety, and levels of CAR T cells in blood and cytokines in serum. Results: As of May 3, 2023, 42 patients were enrolled and 40 were treated with axi-cel, with a median follow-up of 40.9 months (range, 29.5-50.2). In total, 37 patients were evaluable for response (centrally confirmed double- or triple-hit histology or IPI score ≥3). The CR rate was 86% (95% CI, 71-95), and 92% (95% CI, 78-98) of patients had an objective response. Patients with centrally confirmed double- or triple-hit histology (n=10) had a CR rate of 90%. Responses were ongoing in 73% of response-evaluable patients at data cutoff. Medians for DOR, EFS, PFS, and OS were not reached. The 36-month estimates for DOR, EFS (Figure 1), PFS, and OS (Figure 2) were 82%, 73%, 75%, and 81%, respectively. All treated patients (n=40) experienced adverse events (AEs) of any grade and 88% of patients had grade ≥3 AEs. Similar to the primary analysis, the most common any-grade AEs were pyrexia (100%), headache (70%), and neutrophil count decreased (55%). No new cases of cytokine release syndrome (CRS) or neurologic events of any grade occurred since the prior data cut and all cases of CRS and neurologic events reported were resolved by data cutoff. Prolonged cytopenias of any grade (present Day ≥30 post-infusion) occurred in 9 patients (n=7 neutrophil count decreased) and were resolved by data cutoff. There were 8 deaths due to progressive disease (n=5) and other causes not related to axi-cel (1 COVID-19, 1 esophageal adenocarcinoma, 1 septic shock on Days 350, 535, and 287 post axi-cel infusion, respectively). Two of the 8 deaths (1 progressive disease and 1 esophageal adenocarcinoma) occurred after the primary analysis. Among treated patients, post-infusion CAR T-cell expansion by peak and area under the curve was 36.9 cells/µL and 368.0 cells/µL×days, respectively, in those with ongoing responses at data cutoff (n=17), 45.1 cells/µL and 413.4 cells/µL×days in those who relapsed (n=6), and 34.7 cells/µL and 566.8 cells/µL×days in non-responders (n=3). Conclusion: In this updated analysis of ZUMA-12 with a median follow-up of ≥40 months, axi-cel demonstrated a high rate of durable responses and no new safety signals. Axi-cel may benefit patients exposed to fewer prior therapies and those with high-risk LBCL, a population with high unmet need and poor outcomes after standard first-line chemoimmunotherapy.

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 63.1 months follow-up on the ZUMA-1 trial, median overall survival (OS) was 25.8 months with 5-year OS and PFS (progression-free survival) estimates of 42.6% (95% CI, 32.8-51.9) and 31.8% (95% CI, 22.9-41.1), respectively (Neelapu, Blood 2023). We previously reported outcomes of axi-cel patients treated with standard of care therapy, 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 58 months, as well as late outcomes of interest. Results The US Lymphoma CAR-T Consortium is 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 (n=298) as of September 30, 2018. In infused patients (n=275), OS and PFS were calculated from date of infusion. After a median follow-up of 58 months, median OS was 34.9 months (95% CI 23.4 - 44.8) with the OS at 3, 4, and 5 years of 49.1% (95% CI 42.9 - 54.9%), 43% (95% CI 36.8 - 48.9%), and 40.3% (95% CI 34.2 - 46.4%), respectively. The median PFS was 8.7 months (95% CI 5.87 - 16.6) and the 3-,4-, and 5- year PFS were 36.1% (95% CI 30.4 - 41.8%), 30.7 (95% CI 25.2 - 36.4%), and 28.5% (95% CI 23 - 34.2%), respectively. Results of multi-variable modeling were similar to our prior analysis: male sex (HR 1.56, 95% CI 1.08 - 2.27, p =0.02); LDH above the upper limit of normal (HR 1.6, 95% CI 1.12 - 2.30, p = 0.01); ECOG status of 2-4 (HR 2.02, 95% CI 1.33 - 3.07, p = &lt;0.001); and elevated bilirubin &gt; 1.5 (HR 5.68, 95% CI 2.21 - 14.6, p = &lt;0.001) were associated with decreased OS. Factors associated with decreased PFS included male sex (HR 1.68, 95% CI 1.20 - 2.37, p = 0.003), LDH above the upper limit of normal (HR 1.82, 95% CI 1.31 - 2.53, p = &lt;0.001), ECOG status of 2-4 (HR 1.93, 95% CI 1.30 - 2.86, p = 0.001), elevated bilirubin (HR 3.68, 95% CI 1.45 - 9.37, p = 0.006) and receipt of 3 or more prior lines of therapy (HR 1.49, 95% CI 1.03 - 2.13, p = 0.032). We also assessed events of interest including late PFS events and causes of non-relapse mortality (NRM). One hundred and ninety-one PFS events occurred after axi-cel infusion during the follow-up period, 151 due to lymphoma progression and 40 NRM. In the first 12 months post infusion, 131 progression events occurred,13 between 1 and 2 years post infusion, and 7 relapses after 2 years with the latest occurring 46.4 months after infusion. Thirteen NRM events occurred in the 1st year post infusion, 6 between 1- and 2-years post infusion and 21 occurring later than 2 years after infusion. Of the 40 NRM events, 21 were secondary to infection including fungal infections (n = 3, 2 candidemia, 1 candidemia and pneumocystis jiroveci pneumonia), JC encephalitis (n=1) and COVID-19 (n = 2). Nine deaths were attributed to secondary malignancy. Other causes of NRM included cerebral edema (n=1), HLH (n=1), intracranial hemorrhage (n=1), suicide (n=1), and unknown (n=6). The 5-year cumulative risk of relapse was 55.2% and the 5-year risk of non-relapse mortality was 16.2%. Excluding non-melanoma skin cancers, twenty-three of 275 (8%) patients were diagnosed with subsequent malignancy after axi-cel treatment: 14/275 (5%) patients were diagnosed with myeloid malignancies (MDS (n=11), AML (n=2), CMML (n=1)); other malignancies included anal squamous cell carcinoma (ca) (n=1); histiocytic sarcoma (n=1); prostate ca (n=1); endometrial ca (n=1); lung ca (n=1); merkel cell ca (n = 1), mesothelioma (n=1), B-ALL (n = 1), and AITL (n=1). Conclusion This multi-center retrospective study showed similar 5-year results to the ZUMA-1 trial with a 5-year PFS and OS of 28.5% and 40.3%, despite including patients who did not meet ZUMA-1 eligibility criteria based on comorbidities. Non-relapse mortality was primarily due to infection and secondary malignancy. This report supports the curative potential of axi-cel but highlights the competing risk of NRM in this high-risk patient population.

Abstract Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a rare hematological malignancy with a poor prognosis and considered incurable with conventional chemotherapy. Small observational studies reported allogeneic hematopoietic cell transplantation (allo-HCT) offers durable remissions in patients with BPDCN. We report an analysis of patients with BPDCN who received an allo-HCT, using data reported to the Center for International Blood and Marrow Transplant Research (CIBMTR). We identified 164 patients with BPDCN from 78 centers who underwent allo-HCT between 2007 and 2018. The 5-year overall survival (OS), disease-free survival (DFS), relapse, and nonrelapse mortality (NRM) rates were 51.2% (95% confidence interval [CI], 42.5-59.8), 44.4% (95% CI, 36.2-52.8), 32.2% (95% CI, 24.7-40.3), and 23.3% (95% CI, 16.9-30.4), respectively. Disease relapse was the most common cause of death. On multivariate analyses, age of ≥60 years was predictive for inferior OS (hazard ratio [HR], 2.16; 95% CI, 1.35-3.46; P = .001), and higher NRM (HR, 2.19; 95% CI, 1.13-4.22; P = .02). Remission status at time of allo-HCT (CR2/primary induction failure/relapse vs CR1) was predictive of inferior OS (HR, 1.87; 95% CI, 1.14-3.06; P = .01) and DFS (HR, 1.75; 95% CI, 1.11-2.76; P = .02). Use of myeloablative conditioning with total body irradiation (MAC-TBI) was predictive of improved DFS and reduced relapse risk. Allo-HCT is effective in providing durable remissions and long-term survival in BPDCN. Younger age and allo-HCT in CR1 predicted for improved survival, whereas MAC-TBI predicted for less relapse and improved DFS. Novel strategies incorporating allo-HCT are needed to further improve outcomes.

Abstract Purpose: Older patients with relapsed/refractory (R/R) large B-cell lymphoma (LBCL) may be considered ineligible for curative-intent therapy including high-dose chemotherapy with autologous stem-cell transplantation (HDT-ASCT). Here, we report outcomes of a preplanned subgroup analysis of patients ≥65 years in ZUMA-7. Patients and Methods: Patients with LBCL refractory to or relapsed ≤12 months after first-line chemoimmunotherapy were randomized 1:1 to axicabtagene ciloleucel [axi-cel; autologous anti-CD19 chimeric antigen receptor (CAR) T-cell therapy] or standard of care (SOC; 2–3 cycles of chemoimmunotherapy followed by HDT-ASCT). The primary endpoint was event-free survival (EFS). Secondary endpoints included safety and patient-reported outcomes (PROs). Results: Fifty-one and 58 patients aged ≥65 years were randomized to axi-cel and SOC, respectively. Median EFS was greater with axi-cel versus SOC (21.5 vs. 2.5 months; median follow-up: 24.3 months; HR, 0.276; descriptive P &lt; 0.0001). Objective response rate was higher with axi-cel versus SOC (88% vs. 52%; OR, 8.81; descriptive P &lt; 0.0001; complete response rate: 75% vs. 33%). Grade ≥3 adverse events occurred in 94% of axi-cel and 82% of SOC patients. No grade 5 cytokine release syndrome or neurologic events occurred. In the quality-of-life analysis, the mean change in PRO scores from baseline at days 100 and 150 favored axi-cel for EORTC QLQ-C30 Global Health, Physical Functioning, and EQ-5D-5L visual analog scale (descriptive P &lt; 0.05). CAR T-cell expansion and baseline serum inflammatory profile were comparable in patients ≥65 and &lt;65 years. Conclusions: Axi-cel is an effective second-line curative-intent therapy with a manageable safety profile and improved PROs for patients ≥65 years with R/R LBCL.

Abstract Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a rare hematologic malignancy with historically poor outcomes and no worldwide consensus treatment approach. Unique among most hematologic malignancies for its frequent cutaneous involvement, BPDCN can also invade other extramedullary compartments, including the central nervous system. Generally affecting older adults, many patients are unfit to receive intensive chemotherapy, and although hematopoietic stem cell transplantation is preferred for younger, fit individuals, not all are eligible. One recent therapeutic breakthrough is that all BPDCNs express CD123 (IL3Rα) and that this accessible surface marker can be pharmacologically targeted. The first-in-class agent for BPDCN, tagraxofusp, which targets CD123, was approved in December 2018 in the United States for patients with BPDCN aged ≥2 years. Despite favorable response rates in the frontline setting, many patients still relapse in the setting of monotherapy, and outcomes in patients with relapsed/refractory BPDCN remain dismal. Therefore, novel approaches targeting both CD123 and other targets are actively being investigated. To begin to formally address the state of the field, we formed a new collaborative initiative, the North American BPDCN Consortium (NABC). This group of experts, which includes a multidisciplinary panel of hematologists/oncologists, hematopoietic stem cell transplant physicians, pathologists, dermatologists, and pediatric oncologists, was tasked with defining the current standard of care in the field and identifying the most important research questions and future directions in BPDCN. The position findings of the NABC’s inaugural meetings are presented herein.