In this global study of CAR T-cell therapy, a single infusion of tisagenlecleucel provided durable remission with long-term persistence in pediatric and young adult patients with relapsed or refractory B-cell ALL, with transient high-grade toxic effects. (Funded by Novartis Pharmaceuticals; ClinicalTrials.gov number, NCT02435849 .).

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Purpose Several open-label randomized studies have suggested that in vivo T-cell depletion with anti-T-lymphocyte globulin (ATLG; formerly antithymocyte globulin-Fresenius) reduces chronic graft-versus-host disease (cGVHD) without compromising survival. We report a prospective, double-blind phase III trial to investigate the effect of ATLG (Neovii Biotech, Lexington, MA) on cGVHD-free survival. Patients and Methods Two hundred fifty-four patients 18 to 65 years of age with acute leukemia or myelodysplastic syndrome who underwent myeloablative HLA-matched unrelated hematopoietic cell transplantation (HCT) were randomly assigned one to one to placebo (n =128 placebo) or ATLG (n = 126) treatment at 27 sites. Patients received either ATLG or placebo 20 mg/kg per day on days -3, -2, -1 in addition to tacrolimus and methotrexate as GVHD prophylaxis. The primary study end point was moderate-severe cGVHD-free survival. Results Despite a reduction in grade 2 to 4 acute GVHD (23% v 40%; P = .004) and moderate-severe cGVHD (12% v 33%; P < .001) in ATLG recipients, no difference in moderate-severe cGVHD-free survival between ATLG and placebo was found (2-year estimate: 48% v 44%, respectively; P = .47). Both progression-free survival (PFS) and overall survival (OS) were lower with ATLG (2-year estimate: 47% v 65% [ P = .04] and 59% v 74% [ P = .034], respectively). Multivariable analysis confirmed that ATLG was associated with inferior PFS (hazard ratio, 1.55; 95% CI, 1.05 to 2.28; P = .026) and OS (hazard ratio, 1.74; 95% CI, 1.12 to 2.71; P = .01). Conclusion In this prospective, randomized, double-blind trial of ATLG in unrelated myeloablative HCT, the incorporation of ATLG did not improve moderate-severe cGVHD-free survival. Moderate-severe cGVHD was significantly lower with ATLG, but PFS and OS also were lower. Additional analyses are needed to understand the appropriate role for ATLG in HCT.

Tisagenlecleucel is an anti-CD19 chimeric antigen receptor (CAR19) T-cell therapy approved for the treatment of children and young adults with relapsed/refractory (r/r) B-cell acute lymphoblastic leukemia (B-ALL). We evaluated the cellular kinetics of tisagenlecleucel, the effect of patient factors, humoral immunogenicity, and manufacturing attributes on its kinetics, and exposure-response analysis for efficacy, safety and pharmacodynamic endpoints in 79 patients across two studies in pediatric B-ALL (ELIANA and ENSIGN). Using quantitative polymerase chain reaction to quantify levels of tisagenlecleucel transgene, responders ( = 62) had ≈2-fold higher tisagenlecleucel expansion in peripheral blood than nonresponders ( = 8; 74% and 104% higher geometric mean Cmax and AUC0-28d, respectively) with persistence measurable beyond 2 years in responding patients. Cmax increased with occurrence and severity of cytokine release syndrome (CRS). Tisagenlecleucel continued to expand and persist following tocilizumab, used to manage CRS. Patients with B-cell recovery within 6 months had earlier loss of the transgene compared with patients with sustained clinical response. Clinical responses were seen across the entire dose range evaluated (patients ≤50 kg: 0.2 to 5.0 × 10/kg; patients >50 kg: 0.1 to 2.5 × 10 CAR-positive viable T cells) with no relationship between dose and safety. Neither preexisting nor treatment-induced antimurine CAR19 antibodies affected the persistence or clinical response. Response to tisagenlecleucel was associated with increased expansion across a wide dose range. These results highlight the importance of cellular kinetics in understanding determinants of response to chimeric antigen receptor T-cell therapy.

Tisagenlecleucel is a chimeric antigen receptor–T cell therapy that facilitates the killing of CD19 + B cells. A model was developed for the kinetics of tisagenlecleucel and the impact of therapies for treating cytokine release syndrome (tocilizumab and corticosteroids) on expansion. Data from two phase II studies in pediatric and young adult relapsed/refractory B cell acute lymphoblastic leukemia were pooled to evaluate this model and evaluate extrinsic and intrinsic factors that may impact the extent of tisagenlecleucel expansion. The doubling time, initial decline half‐life, and terminal half‐life for tisagenlecleucel were 0.78, 4.3, and 220 days, respectively. No impact of tocilizumab or corticosteroids on the expansion rate was observed. This work represents the first mixed‐effect model‐based analysis of chimeric antigen receptor–T cell therapy and may be clinically impactful as future studies examine prophylactic interventions in patients at risk of higher grade cytokine release syndrome and the effects of these interventions on chimeric antigen receptor–T cell expansion.

• Active infection pretransplant adversely impacts survival (81% in patients with active infection vs 95% in infectionfree patients; P 5 .009).• Preparative chemotherapy improved 1-year post-HCT median CD4 counts (P 5 .02) and freedom from IV immunoglobulin (P , .001).The Primary Immune Deficiency Treatment Consortium (PIDTC) is enrolling children with severe combined immunodeficiency (SCID) to a prospective natural history study. We analyzed patients treated with allogeneic hematopoietic cell transplantation (HCT) from 2010 to 2014, including 68 patients with typical SCID and 32 with leaky SCID, Omenn syndrome, or reticular dysgenesis. Most (59%) patients were diagnosed by newborn screening or family history. The 2-year overall survival was 90%, but was 95% for those who were infection-free at HCT vs 81% for those with active infection (P 5 .009). Other factors, including the diagnosis of typical vs leaky SCID/Omenn syndrome, diagnosis via family history or newborn screening, use of preparative chemotherapy, or the type of donor used, did not impact survival. Although 1-year post-HCT median CD4 counts and freedom from IV immunoglobulin were improved after the use of preparative chemotherapy, other immunologic reconstitution parameters were not affected, and the potential for late sequelae in extremely young infants requires additional evaluation. After a T-cell-replete graft, landmark analysis at day 1100 post-HCT revealed that CD3 < 300 cells/mL, CD8 < 50 cells/mL, CD45RA < 10%, or a restricted Vb T-cell receptor repertoire (<13 of 24 families) were associated with the need for a second HCT or death. In the modern era, active infection continues to pose the greatest threat to survival for SCID patients. Although newborn screening has been effective in diagnosing SCID patients early in life, there is an urgent need to identify validated approaches through prospective trials to ensure that patients proceed to HCT infection free. The trial was registered at www.clinicaltrials.gov as #NCT01186913. (Blood. 2017;130(25):2718-2727

BACKGROUND Tisagenlecleucel is an FDA approved chimeric antigen receptor (CAR)-T cell therapy that reprograms T cells to eliminate CD19+ B cells. ELIANA (NCT02435849) is a phase 2 pivotal study of tisagenlecleucel in pediatric/young adult patients (pts) with CD19+ r/r B-cell acute lymphoblastic leukemia (ALL), the first global trial of a CAR-T cell therapy. The primary objective was met, with an overall remission rate (ORR) of 81% (complete remission [CR] + CR with incomplete blood count recovery [CRi]). Here we present an update of ELIANA, with additional pts and additional 11 mo follow-up from the previous report (Maude et al. N Engl J Med 2018). METHODS Eligible pts were aged ≥3 y at screening and ≤21 y at diagnosis and had ≥5% leukemic blasts in bone marrow. Tisagenlecleucel was centrally manufactured at 2 sites (Morris Plains, NJ, USA and Leipzig, Germany) by lentiviral transduction of autologous T cells with a vector encoding for a second generation 4-1BB anti-CD19 CAR and expanded ex vivo. Tisagenlecleucel was provided to pts at 25 study centers in 11 countries on 4 continents using cryopreserved apheresed mononuclear cells, central production facilities, and a global supply chain. The primary endpoint, ORR within 3 mo and maintained for ≥28 d among infused pts, was assessed by an independent review committee. Secondary endpoints included duration of remission (DOR), overall survival (OS), safety, and cellular kinetics. RESULTS As of April 13, 2018, 113 pts were screened and 97 enrolled. There were 8 manufacturing failures (8%) and 10 pts (10%) were not infused due to death or adverse events (AEs). Following lymphodepleting chemotherapy in most pts (76/79; fludarabine/cyclophosphamide [n=75]), 79 pts were infused with a single dose of tisagenlecleucel (median dose, 3.0×106 [range, 0.2-5.4×106] CAR-positive viable T cells/kg), and all had ≥3 mo of follow-up or discontinued earlier (median time from infusion to data cutoff, 24 mo [range, 4.5-35 mo]). Median age was 11 y (range, 3-24 y); 61% of pts had prior hematopoietic stem cell transplant (SCT). Among the 65 pts with CR/CRi, 64 (98%) were MRD- within 3 mo. Median DOR by K-M analysis was not reached (Figure): responses were ongoing in 29 pts (max DOR, 29 mo and ongoing); 19 pts relapsed before receiving additional anticancer therapy (13 died subsequently); 8 pts underwent SCT while in remission, 8 received additional anticancer therapy (non-SCT) and 1 discontinued while in remission. The probability of relapse-free survival at 18 mo was 66% (95% CI, 52%-77%). Median OS was not reached; OS probability at 18 mo was 70% (95% CI, 58%-79%). Cytokine release syndrome (CRS) occurred in 77% of pts (grade [G] 3/4; 48%; graded using the Penn scale); 39% of pts received tocilizumab for treatment of CRS with or without other anti-cytokine therapies; 48% of pts required ICU-level care for CRS, with a median ICU stay of 7 d. All cases of CRS were reversible. Most common G 3/4 nonhematologic AEs (>15%) other than CRS were neutropenia with a body temperature >38.3°C (62% within 8 wk of infusion), hypoxia (20%), and hypotension (20%). 13% of pts experienced G 3 neurological events, with no G 4 events or cerebral edema. Based on laboratory results, 43% and 54% of pts had G 3/4 thrombocytopenia and neutropenia not resolved by d 28; the majority of events resolved to G ≤2 by 3 mo. 25 post-infusion deaths were reported: 2 within 30 d (1 disease progression, 1 cerebral hemorrhage); 23 after 30 d of infusion (range, 53-859 d; 18 disease progression, 1 each due to encephalitis, systemic mycosis, VOD [hepatobiliary disorders related to allogeneic-SCT], bacterial lung infection, and an unknown reason after study withdrawal). Tisagenlecleucel expansion in vivo correlated with CRS severity, and persistence of tisagenlecleucel along with B-cell aplasia in peripheral blood was observed for ≥2.5 y in some responding pts. Analysis of B-cell recovery and correlation with relapse will be presented. CONCLUSIONS With longer follow-up, the ELIANA study continues to confirm the efficacy of a single infusion of tisagenlecleucel in pediatric and young adults with ALL without additional therapy. AEs were effectively and reproducibly managed globally by appropriately trained personnel at study sites. The achievement of high overall response rates and deep remissions, in combination with the median duration of response and overall survival not being reached, further corroborate previously reported results. Figure. Figure. Disclosures Grupp: Novartis Pharmaceuticals Corporation: Consultancy, Research Funding; Jazz Pharmaceuticals: Consultancy; Adaptimmune: Consultancy; University of Pennsylvania: Patents & Royalties. Maude:Novartis Pharmaceuticals Corporation: Consultancy, Membership on an entity's Board of Directors or advisory committees. Rives:Shire: Consultancy, Other: Symposia, advisory boards ; Jazz Pharma: Consultancy, Other: Symposia, advisory boards ; Novartis Pharmaceuticals Corporation: Consultancy, Other: Symposia, advisory boards ; Amgen: Consultancy, Other: advisory board . Baruchel:Celgene: Consultancy; Amgen: Consultancy; Roche: Consultancy; Jazz Pharmaceuticals: Consultancy, Honoraria, Other: Travel, accommodations or expenses; Novartis: Membership on an entity's Board of Directors or advisory committees; Shire: Research Funding; Servier: Consultancy. Bittencourt:Novartis Pharmaceuticals Corporation: Consultancy; Jazz Pharmaceuticals: Consultancy, Honoraria. Bader:Riemser: Research Funding; Cellgene: Consultancy; Medac: Patents & Royalties, Research Funding; Neovii: Research Funding; Novartis: Consultancy, Speakers Bureau. Laetsch:Bayer: Consultancy; Pfizer: Equity Ownership; Eli Lilly: Consultancy; Novartis Pharmaceuticals Corporation: Consultancy; Loxo Oncology: Consultancy. Stefanski:Novartis Pharmaceuticals Corporation: Consultancy, Honoraria, Speakers Bureau. Myers:Novartis Pharmaceuticals Corporation: Consultancy, Honoraria, Research Funding, Speakers Bureau. Qayed:Novartis: Consultancy. Pulsipher:CSL Behring: Consultancy; Amgen: Honoraria; Adaptive Biotech: Consultancy, Research Funding; Novartis: Consultancy, Honoraria, Speakers Bureau. Martin:Novartis Pharmaceuticals Corporation: Research Funding; Jazz Pharmaceuticals: Research Funding. Nemecek:Novartis Pharmaceuticals Corporation: Other: advisory boards. Boissel:Servier: Consultancy, Membership on an entity's Board of Directors or advisory committees; Novartis Pharmaceuticals Corporation: Honoraria, Membership on an entity's Board of Directors or advisory committees. Leung:Novartis Pharmaceuticals Corporation: Employment. Eldjerou:Novartis Pharmaceuticals Corporation: Employment. Yi:Novartis Pharmaceuticals Corporation: Employment. Mueller:Novartis Institutes for Biomedical Research: Employment; Novartis Pharmaceuticals Corporation: Equity Ownership, Other: Patent pending. Bleickardt:Novartis Pharmaceuticals Corporation: Employment.

Treatment of acute lymphoblastic leukemia (ALL) continues to advance, as evidenced by the improved risk stratification of patients and development of newer treatment options. Identification of ALL subtypes based on immunophenotyping and cytogenetic and molecular markers has resulted in the inclusion of Philadelphia-like ALL and early T-cell precursor ALL as subtypes that affect prognosis. Identification of Ikaros mutations has also emerged as a prognostic factor. In addition to improved prognostication, treatment options for patients with ALL have expanded, particularly with regard to relapsed/refractory ALL. Continued development of second-generation tyrosine kinase inhibitors and the emergence of immunotherapy, including blinatumomab and chimeric antigen receptor T-cell therapy, have improved survival. Furthermore, incorporation of minimal residual disease (MRD) monitoring has shown insight into patient outcomes and may lead to treatment modification or alternative treatment strategies in select populations. This excerpt focuses on the sections of the ALL guidelines specific to clinical presentation and diagnosis, treatment of relapsed/refractory ALL, and incorporation of MRD monitoring. To view the most recent complete version of these guidelines, visit NCCN.org. (J Natl Compr Canc Netw 2015;13:1240-1279 NCCN Categories of Evidence and ConsensusCategory 1: Based upon high-level evidence, there is uniform NCCN consensus that the intervention is appropriate. Category 2A: Based upon lower-level evidence, there is uniform NCCN consensus that the intervention is appropriate. Category 2B: Based upon lower-level evidence, there is NCCN consensus that the intervention is appropriate. Category 3: Based upon any level of evidence, there is major NCCN disagreement that the intervention is appropriate. These guidelines are also available on the Internet. For the latest update, visit NCCN.org.