Anakinra for Refractory Cytokine Release Syndrome or Immune Effector Cell-Associated Neurotoxicity Syndrome after Chimeric Antigen Receptor T Cell Therapy.

Chimeric antigen receptor-engineered (CAR)-T cell therapy remains limited by significant toxicities, including cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS). The optimal management of severe and/or refractory CRS/ICANS remains ill-defined. Anakinra has emerged as a promising agent based on preclinical data, but its safety and efficacy in CAR-T therapy recipients are unknown. The primary objective of this study was to evaluate the safety of anakinra to treat refractory CRS and ICANS after CAR-T therapy. The secondary objective was to evaluate the impact of key treatment-, patient-, and disease-related variables on the time to CRS/ICANS resolution and treatment-related mortality (TRM). We retrospectively analyzed the outcomes of 43 patients with B cell or plasma cell malignancies treated with anakinra for refractory CRS or ICANS at 9 institutions in the United States and Spain between 2019 and 2022. Cause-specific Cox regression was used to account for competing risks. Multivariable cause-specific Cox regression was used to estimate the effect of anakinra dose on outcomes while minimizing treatment allocation bias by including age, CAR-T product, prelymphodepletion (pre-LD) ferritin, and performance status. Indications for anakinra treatment were grade ≥2 ICANS with worsening or lack of symptom improvement despite treatment with high-dose corticosteroids (n = 40) and grade ≥2 CRS with worsening symptoms despite treatment with tocilizumab (n = 3). Anakinra treatment was feasible and safe; discontinuation of therapy because of anakinra-related side effects was reported in only 3 patients (7%). The overall response rate (ORR) to CAR-T therapy was 77%. The cumulative incidence of TRM in the whole cohort was 7% (95% confidence interval [CI], 2% to 17%) at 28 days and 23% (95% CI, 11% to 38%) at 60 days after CAR-T infusion. The cumulative incidence of TRM at day 28 after initiation of anakinra therapy was 0% in the high-dose (>200 mg/day i.v.) recipient group and 47% (95% CI, 20% to 70%) in the low-dose (100 to 200 mg/day s.c. or i.v.) recipient group. The median cumulative incidence of CRS/ICANS resolution from the time of anakinra initiation was 7 days in the high-dose group and was not reached in the low-dose group, owing to the high TRM in this group. Univariate Cox modeling suggested a shorter time to CRS/ICANS resolution in the high-dose recipients (hazard ratio [HR], 2.19; 95% CI, .94 to 5.12; P = .069). In a multivariable Cox model for TRM including age, CAR-T product, pre-LD ferritin level, and pre-LD Karnofsky Performance Status (KPS), higher anakinra dose remained associated with lower TRM (HR, .41 per 1 mg/kg/day increase; 95% CI, .17 to .96; P = .039. The sole factor independently associated with time to CRS/ICANS resolution in a multivariable Cox model including age, CAR-T product, pre-LD ferritin and anakinra dose was higher pre-LD KPS (HR, 1.05 per 10% increase; 95% CI, 1.01 to 1.09; P = .02). Anakinra treatment for refractory CRS or ICANS was safe at doses up to 12 mg/kg/day i.v. We observed an ORR of 77% after CAR-T therapy despite anakinra treatment, suggesting a limited impact of anakinra on CAR-T efficacy. Higher anakinra dose may be associated with faster CRS/ICANS resolution and was independently associated with lower TRM. Prospective comparative studies are needed to confirm our findings.

A retrospective study of treosulfan versus busulfan-based conditioning in pediatric patients.

OBJECTIVES: To compare the outcomes of treosulfan-based vs busulfan-based conditioning regimens in allogeneic hematopoietic stem cell transplantation (HSCT) in pediatric patients. METHODS: Retrospective study of all consecutive patients (2012-2019) treated with allogenic HSCT and treosulfan- or busulfan-based conditioning regimens at a single center. RESULTS: A total of 101 HSCT were included: 66 HSCT with busulfan and 35 with treosulfan. In malignant diseases (n = 62), busulfan-based conditioning was more commonly employed than treosulfan: 82.3% vs 17.7%. However, the use of treosulfan for malignant diseases increased over time: 6.5% of HSCT in 2012-2015 vs 29% of HSCT in 2015-2019 (p = .02). The cohort of treosulfan had more children under 1-year of age than the busulfan cohort (31 vs 13%; p = .033). The percentage of patients who received serotherapy was 73 and 89% in the nonmalignant and malignant groups, respectively. The engraftment, time to neutrophil, and platelet engraftment were not significantly different between the busulfan and the treosulfan cohorts. Rate of grade II-IV acute GvHD was significantly higher in the busulfan cohort than the treosulfan cohort (39% vs 15%; p = .016). No differences were observed in endothelial damage complications, chronic GvHD, relapse, overall survival, and transplant-related mortality. CONCLUSIONS: Busulfan-based conditioning regimens are used more frequently for children undergoing allogenic HSCT, but treosulfan-based conditioning is gaining acceptance. Treosulfan-based conditioning is associated with lower rates of acute GvHD, and no significant differences on overall survival were observed compared with busulfan.

Ruxolitinib for steroid-refractory graft versus host disease in pediatric HSCT: high response rate and manageable toxicity.

Ruxolitinib, a selective Janus Kinase (JAK) 1/2 inhibitor, is a promising treatment for the steroid-refractory graft-vs-host disease (GvHD) after hematopoietic stem cell transplantation (HSCT). Most studies have been performed in the adult population showing efficacy against GvHD. In this retrospective study, we evaluated the outcomes of 19 children who received ruxolitinib for refractory acute or chronic GvHD (cGvHD) after HSCT from two Pediatric Hemato-Oncology Departments in Spain between March 2017 and December 2018. Patients received a median number of 4 (IQR 2) previous lines of treatment before starting ruxolitinib. The overall response rate in acute GvHD (aGvHD) and cGvHD was 87% and 91%, respectively. Complete response (CR) was observed in 37% of aGvHD and 8.3% of cGvHD. Remarkably, 43% and 40% of patients with steroid-refractory gastrointestinal aGvHD and lung cGvHD achieved CR. During ruxolitinib treatment, there were 36%, 31%, and 10% infections caused by viruses, bacteria, and fungi, respectively. Overall, four patients interrupted ruxolitinib due to infectious complications, hematological, and liver toxicity. The 2-year overall survival was 71.9% (CI 95% 58.6-85.2). Our experience supports the use of ruxolitinib as an effective treatment for steroid-refractory acute and cGvHD in children with a moderate toxicity profile.

Abatacept as salvage therapy in chronic graft-versus-host disease-a retrospective analysis.

The immunomodulatory fusion protein abatacept has recently been investigated for the treatment of steroid-refractory chronic graft-versus-host disease (cGvHD) in a phase 1 clinical trial. We analyzed the safety and efficacy of abatacept for cGvHD therapy in a retrospective study with 15 patients who underwent allogeneic hematopoietic stem cell transplantation (allo-HSCT) and received abatacept for cGvHD with a median age of 49 years. Grading was performed as part of the clinical routine according to the National Institute of Health's (NIH) consensus criteria at initiation of abatacept and 1, 3, 6, 9 and 12 months thereafter. The median time of follow-up was 191 days (range 55-393 days). Best overall response rate (ORR) was 40%. In particular, patients with bronchiolitis obliterans syndrome showed significant clinical improvement and durable responses following abatacept treatment with a response rate of 89% based on improvement in lung severity score (n = 6) or stabilized lung function (n = 4) or both (n = 3). Infectious complications CTCAE °III or higher were observed in 3/15 patients. None of the patients relapsed from the underlying malignancy. Thus, abatacept appears to be a promising treatment option for cGvHD, in particular for patients with lung involvement. However, further evaluation within a phase 2 clinical trial is required.