Modi, Dipenkumar

Abstract Tisagenlecleucel (tisa-cel) is a CD19-directed chimeric antigen receptor T-cell therapy for relapsed/refractory precursor B-cell acute lymphoblastic leukemia (R/R B-ALL). We report infectious complications for 100 days (D100) following tisa-cel therapy in 471 pediatric and young adults (median age 13.8 years) with R/R B-ALL reported from September 2017 to June 2022. By D100, 137 (29%) patients had an infectious event, with an infection density of 0.542 per 100 person-days at risk. D100 cumulative incidences of bacterial, viral, and fungal infections were 14.1%, 11.6%, and 1.3%, corresponding to infection density scores of 0.296, 0.213, and 0.033 per 100 person-days at risk, respectively. In a multivariable analysis, receipt of ≥3 lines of therapy before tisa-cel (hazard ratio [HR], 1.86; 95% confidence interval [CI], 1.13-3.08; P = .015), any-grade cytokine release syndrome (HR, 1.78; 95% CI, 1.17-2.71; P = .007), and lack of neutrophil recovery (HR, 2.63; 95% CI, 1.47-4.69; P = .001) were associated with an increased risk for any infection. Similar associations were observed for bacterial infections, with the addition of younger age as an adverse risk (<6 vs 6-15 years; HR, 2.38; 95% CI, 1.23-4.61; P = .01). Risk factors for viral infections included increasing age (1-year increase; HR, 1.05; 95% CI, 1.01-1.09; P = .016), prior history of any infection (HR, 2.76, 95% CI, 1.40-5.46; P = .004), and prior hematopoietic cell transplant (HR, 2.10; 95% CI, 1.18-3.71; P = .011). D100 infection-related mortality (IRM) rate was low at 0.2% (95% CI, 0.0-0.8). In this multicenter real-world study, we observed a high incidence of infectious complications but a low IRM following tisa-cel for R/R B-ALL.

Summary CD19 chimeric antigen receptor T‐cell (CAR‐T) therapy is a pivotal part of the treatment algorithm for large B‐cell lymphoma (LBCL) in the second‐ and third‐line settings based on numerous clinical trials. However, these studies included very few patients with a diagnosis of high‐grade B‐cell lymphoma, not otherwise specified (HGBCL‐NOS) and it is unclear if outcomes are similar to those observed with more common LBCL histologies. Using the Center for International Blood and Marrow Transplant Research (CIBMTR) registry, we identified 111 HGBCL‐NOS patients who received CAR‐T therapy. The cytokine release syndrome (CRS) rate was 74% (7.7% grade 3+), median onset was 4 days (1–17) and immune effector cell‐associated neurotoxicity syndrome rate was 45.2% (22.6% grade 3+), median onset was 7 days (1–17). At 2 years post‐CAR‐T infusion, the probability of overall survival and progression‐free survival were 41.6% and 28.7% respectively. The 2‐year non‐relapse mortality and relapse/progression were 3.1% (95% confidence interval [CI]: 0.6–7.6) and 68.1% (95% CI: 57.9–77.6) respectively. Our analysis illustrates that patients with HGBCL‐NOS represent a particularly difficult group to treat, even with CAR‐T therapy. We observed that one third of patients achieved a durable response; however, the overall results were less favourable, with lower overall response rate, overall survival and progression‐free survival as compared to published reports on LBCL.

Abstract Infection is increasingly recognized as a significant cause of morbidity and mortality in patients with relapsed/refractory (R/R) large B-cell lymphoma (LBCL) receiving CD19 chimeric antigen receptor (CAR) T-cell therapy. The current study analyzed the natural history, risk factors, and outcomes of infection in 3350 patients with R/R LBCL receiving commercial CD19 CAR T-cell therapy (n = 2804 axicabtagene ciloleucel [axi-cel], n = 546 tisagenlecleucel) from December 2017 to June 2022. Infection developed in 834 patients (24.9%) within 100 days after infusion, resulting in an infection density of 0.43 per 100 patient days and a 100-day cumulative incidence of 22%. Bacterial, viral, and fungal infections were recorded in 527 (15.7%), 374 (11.2%), and 108 patients (3.2%), respectively, with corresponding infection densities of 0.23, 0.15, and 0.04 per 100 patient days. After a 24-month median follow-up, 1482 patients (44%) had died, with infection as the primary cause in 173 cases (12%). The 100-day infection-related mortality (IRM) was 1.6% (95% confidence interval, 1.2-2.0). Patients with a Karnofsky performance score of ≤80, infection history before CAR T-cell therapy, axi-cel therapy, severe cytokine release syndrome (grade ≥3), and severe immune effector cell–associated neurotoxicity syndrome (grade ≥3) had increased infection risk. Infections within 100 days were an independent risk factor for inferior overall survival beyond day 100 after CD19 CAR T-cell therapy. In conclusion, study results show a significant incidence of infection and IRM in patients with R/R LBCL treated with CD19 CAR T-cell therapy. Furthermore, results identify patients at a heightened risk of infection, offering insights to guide potential interventions aimed at mitigating infection and improving patient outcomes after CAR T-cell therapy.

Abstract T-cell/histiocyte–rich large B-cell lymphoma (THRLBCL) is a rare histologic variant of LBCL. Limited data regarding CD19–directed chimeric antigen receptor T-cell (CART) therapy in relapsed/refractory (R/R) THRLBCL suggest poor efficacy. We investigated CART outcomes for R/R THRLBCL through the Center for International Blood and Marrow Transplant Research registry. A total of 58 adult patients with R/R THRLBCL who received commercial CD19-CART therapy between 2018 and 2022 were identified. Most patients (67%) had early relapse of disease (45% primary refractory) with a median of 3 (range, 1-7) prior therapies and were treated with axicabtagene ciloleucel (69%). At median follow-up of 23 months after CART therapy, 2-year overall and progression-free survival were 42% (95% confidence interval [CI], 27-57) and 29% (95% CI, 17-43), respectively. In univariable analysis, poor performance status before CART therapy was associated with higher mortality (hazard ratio, 2.35; 95%CI, 1.02-5.5). The 2-year cumulative incidences of relapse/progression and nonrelapse mortality were 69% and 2%, respectively. Grade ≥3 cytokine release syndrome and immune effector cell–associated neurologic syndrome occurred in 7% and 15% of patients, respectively. In this largest analysis of CD19-CART therapy for R/R THRLBCL, ∼30% of patients were alive and progression free 2 years after CART therapy. Despite a high incidence of progression (69% at 2 years), these results suggest a subset of patients with R/R THRLBCL may have durable responses with CARTs.

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.

SummaryThere have been no large studies comparing reduced‐intensity/non‐myeloablative conditioning (RIC/NMA) to myeloablative conditioning (MAC) regimens in T‐cell non‐Hodgkin lymphoma (T‐NHL) patients undergoing allogeneic transplant (allo‐HCT). A total of 803 adults with peripheral T‐cell lymphoma, anaplastic large cell lymphoma and angioimmunoblastic T‐cell lymphoma (age 18–65 years), undergoing allo‐HCT between 2008–2019 and reported to the Center for International Blood and Marrow Transplant Research with either MAC (n = 258) or RIC/NMA regimens (n = 545) were evaluated. There were no significant differences between the two cohorts in terms of patient sex, race and performance scores. Significantly more patients in the RIC/NMA cohort had peripheral blood grafts, haematopoietic cell transplantation‐specific comorbidity index (HCT‐CI) of ≥3 and chemosensitive disease compared to the MAC cohort. On multivariate analysis, overall survival (OS) was not significantly different in the RIC/NMA cohort compared to the MAC cohort (hazard ratio (HR) = 1.01, 95% confidence interval (CI) = 0.79–1.29; p = 0.95). Similarly, non‐relapse mortality (NRM) (HR = 0.85, 95% CI = 0.61–1.19; p = 0.34), risk of progression/relapse (HR = 1.29; 95% CI = 0.98–1.70; p = 0.07) and therapy failure (HR = 1.14; 95% CI = 0.92–1.41, p = 0.23) were not significantly different between the two cohorts. Relative to MAC, RIC/NMA was associated with a significantly lower risk of grade 3–4 acute graft‐versus‐host disease (HR = 0.67; 95% CI = 0.46–0.99, p = 0.04). Among chemorefractory patients, there was no difference in OS, therapy failure, relapse, or NRM between RIC/NMA and MAC regimens. In conclusion, we found no association between conditioning intensity and outcomes after allo‐HCT for T‐cell NHL.