Henrique Bittencourt

Tisagenlecleucel in Children and Young Adults with B-Cell Lymphoblastic Leukemia

Background In a single‐center phase 1–2a study, the anti‐CD19 chimeric antigen receptor (CAR) T‐cell therapy tisagenlecleucel produced high rates of complete remission and was associated with serious but mainly reversible toxic effects in children and young adults with relapsed or refractory B‐cell acute lymphoblastic leukemia (ALL). Methods We conducted a phase 2, single‐cohort, 25‐center, global study of tisagenlecleucel in pediatric and young adult patients with CD19+ relapsed or refractory B‐cell ALL. The primary end point was the overall remission rate (the rate of complete remission or complete remission with incomplete hematologic recovery) within 3 months. Results For this planned analysis, 75 patients received an infusion of tisagenlecleucel and could be evaluated for efficacy. The overall remission rate within 3 months was 81%, with all patients who had a response to treatment found to be negative for minimal residual disease, as assessed by means of flow cytometry. The rates of event‐free survival and overall survival were 73% (95% confidence interval [CI], 60 to 82) and 90% (95% CI, 81 to 95), respectively, at 6 months and 50% (95% CI, 35 to 64) and 76% (95% CI, 63 to 86) at 12 months. The median duration of remission was not reached. Persistence of tisagenlecleucel in the blood was observed for as long as 20 months. Grade 3 or 4 adverse events that were suspected to be related to tisagenlecleucel occurred in 73% of patients. The cytokine release syndrome occurred in 77% of patients, 48% of whom received tocilizumab. Neurologic events occurred in 40% of patients and were managed with supportive care, and no cerebral edema was reported. Conclusions 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.)

Association of drug metabolism gene polymorphisms with toxicities, graft-versus-host disease and survival after HLA-identical sibling hematopoietic stem cell transplantation for patients with leukemia.

Individual differences in drug efficacy or toxicity can be influenced by genetic factors. We investigated whether polymorphisms of pharmacogenes that interfere with metabolism of drugs used in conditioning regimen and graft-versus-host disease (GvHD) prophylaxis could be associated with outcomes after HLA-identical hematopoietic stem cell transplantation (HSCT). Pharmacogenes and their polymorphisms were studied in 107 donors and patients with leukemia receiving HSCT. Candidate genes were: P450 cytochrome family (CYP2B6), glutathione-S-transferase family (GST), multidrug-resistance gene, methylenetetrahydrofolate reductase (MTHFR) and vitamin D receptor (VDR). The end points studied were oral mucositis (OM), hemorrhagic cystitis (HC), toxicity and venoocclusive disease of the liver (VOD), GvHD, transplantation-related mortality (TRM) and survival. Multivariate analyses, using death as a competing event, were performed adjusting for clinical factors. Among other clinical and genetic factors, polymorphisms of CYP2B6 genes that interfere with cyclophosphamide metabolism were associated with OM (recipient CYP2B6*4; P=0.0067), HC (recipient CYP2B6*2; P=0.03) and VOD (donor CYP2B6*6; P=0.03). Recipient MTHFR polymorphisms (C677T) were associated with acute GvHD (P=0.03), and recipient VDR TaqI with TRM and overall survival (P=0.006 and P=0.04, respectively).Genetic factors that interfere with drug metabolisms are associated with treatment-related toxicities, GvHD and survival after HLA-identical HSCT in patients with leukemia and should be investigated prospectively.

Comparison of outcomes after single or double cord blood transplantation in adults with acute leukemia using different types of myeloablative conditioning regimen, a retrospective study on behalf of Eurocord and the Acute Leukemia Working Party of EBMT

We report outcomes after single (s) and double (d) umbilical cord blood transplantation (UCBT) after myeloablative conditioning (MAC) regimen for 239 patients transplanted for acute leukemia in first complete remission (CR1). All sUCBT patients received a total nucleated cell dose >2.5 × 107/kg. Conditioning regimen for sUCBT was total body irradiation (TBI)12 Gy- or busulfan (BU)-based±fludarabine (Flu) (n=68, group 1), thiotepa+BU+Flu (TBF) (n=88, group 2), and for dUCBT it was TBI12 Gy+cyclophosphamide±Flu (n=83, group 3). dUCBT recipients were younger, received higher cell dose and less frequently antithymocyte globulin. In multivariate analysis, we found similar neutrophil recovery among the three groups; however, acute graft-versus-host disease II–IV was higher in dUCBT compared with others. Non-relapse mortality and relapse incidence were not statistically different among the three groups. Leukemia-free survival was 30% for sUCBT using TBI- or BU-based MAC compared with 48% for sUCBT TBF and 48% for dUCBT (P=0.02 and P=0.03, respectively), and it was not statistically different between sUCBT with TBF and dUCBT. In conclusion, use of sUCBT with adequate cell dose (>2.5 × 107/kg) and a specific conditioning regimen in the MAC setting results in similar outcomes as dUCBT. The choice of TBF conditioning regimen for sUCBT may improve results, and whether this regimen may be effective in dUCBT should be further analyzed.

An evaluation of the cardiotoxicity of imatinib mesylate

We studied 103 consecutive patients with chronic myeloid leukaemia on treatment with imatinib (IM) and 57 patients with chronic myeloproliferative disorders not treated with IM in order to evaluate its cardiotoxicity. There was no statistical difference regarding cardiac symptoms and signs, BNP levels and echocardiographic measurements for IM and control groups, except for peripheral oedema, more frequent in the IM group. Four patients in the IM group presented a BNP level >100pg/ml, one of them with depressed LVEF. IM was not related to systematic deterioration of cardiac function, but there is still a possibility of isolated cases of cardiotoxicity.

Influence of CD34 + marrow cell dose on outcome of HLA-identical sibling allogeneic bone marrow transplants in patients with chronic myeloid leukaemia

In order to study the influence of bone marrow CD34+ cell dose on the outcome of allogeneic bone marrow transplantation (BMT), we analysed the results of BMT from HLA-identical siblings donors in 50 patients with chronic myeloid leukaemia (CML). The median numbers of nucleated cells (NC) and CD34+ cells infused were 2.18 × 108/kg (0.05–4.14 × 108/kg) and 3.12 × 106/kg (0.35–8.52 × 106/kg), respectively. All patients engrafted. In univariate analysis, there was no correlation between the number of CD34+ cells infused and the time to neutrophil recovery (P = 0.17). The Kaplan–Meier estimate of grade II–IV acute graft-versus-host disease (GVHD) at day 100 was 53 ± 14% and 2-year survival was 46 ± 15%. A number of CD34+ cells infused greater than the median was the main factor increasing survival (P = 0.0006) and decreasing 100 day transplant-related mortality (P = 0.009). Patient-, disease- and transplant-related characteristics were not statistically different among patients receiving more or less than the median number of CD34+ cells. The rate of infectious deaths was significantly higher in patients receiving less than 3.12 × 106 CD34/kg (48% vs 16%, P = 0.01). In a multivariable analysis, two factors associated with increased risk of death were advanced disease status at transplant (HR: 2.5 (95% CI: 1.09–5.75), P = 0.03) and a lower number of marrow CD34+ cells infused/kg (HR: 4.55 (95% CI: 1.87–10.90), P = 0.0008). Bone Marrow Transplantation (2001) 27, 575–580.

Analysis of risk factors influencing outcomes after cord blood transplantation in children with juvenile myelomonocytic leukemia: a EUROCORD, EBMT, EWOG-MDS, CIBMTR study

We retrospectively analyzed 110 patients with juvenile myelomonocytic leukemia, given single-unit, unrelated donor umbilical cord blood transplantation. Median age at diagnosis and at transplantation was 1.4 years (age range, 0.1-6.4 years) and 2.2 years (age range, 0.5-7.4 years), respectively. Before transplantation, 88 patients received chemotherapy; splenectomy was performed in 24 patients. Monosomy of chromosome 7 was the most frequent cytogenetic abnormality, found in 24% of patients. All but 8 patients received myeloablative conditioning; cyclosporine plus steroids was the most common graft-versus-host disease prophylaxis. Sixteen percent of units were HLA-matched with the recipient, whereas 43% and 35% had either 1 or 2 to 3 HLA disparities, respectively. The median number of nucleated cells infused was 7.1 × 10(7)/kg (range, 1.7-27.6 × 10(7)/kg). With a median follow-up of 64 months (range, 14-174 months), the 5-year cumulative incidences of transplantation-related mortality and relapse were 22% and 33%, respectively. The 5-year disease-free survival rate was 44%. In multivariate analysis, factors predicting better disease-free survival were age younger than 1.4 years at diagnosis (hazard ratio [HR], 0.42; P = .005), 0 to 1 HLA disparities in the donor/recipient pair (HR, 0.4; P = .009), and karyotype other than monosomy 7 (HR, 0.5; P = .02). Umbilical cord blood transplantation may cure a relevant proportion of children with juvenile myelomonocytic leukemia. Because disease recurrence remains the major cause of treatment failure, strategies to reduce incidence of relapse are warranted.

Impact of pretransplant minimal residual disease after cord blood transplantation for childhood acute lymphoblastic leukemia in remission: an Eurocord, PDWP-EBMT analysis.

To address the prognostic value of minimal residual disease (MRD) before unrelated cord blood transplantation (UCBT) in children with acute lymphoblastic leukemia (ALL), we analyzed 170 ALL children transplanted in complete remission (CR) after myeloablative conditioning regimen. In all, 72 (43%) were in first CR (CR1), 77 (45%) in second CR (CR2) and 21 (12%) in third CR (CR3). The median interval from MRD quantification to UCBT was 18 days. All patients received single-unit UCBT. Median follow-up was 4 years. Cumulative incidence (CI) of day-60 neutrophil engraftment was 85%. CI of 4 years relapse was 30%, incidence being lower in patients with negative MRD before UCBT (hazard ratio (HR)=0.4, P=0.01) and for those transplanted in CR1 and CR2 (HR=0.3, P=0.002). Probability of 4 years leukemia-free survival (LFS) was 44%, (56, 44 and 14% for patients transplanted in CR1, CR2 and CR3, respectively (P=0.0001)). Patients with negative MRD before UCBT had better LFS after UCBT compared with those with positive MRD (54% vs 29%; HR=2, P=0.003). MRD assessment before UCBT for children with ALL in remission allows identifying patients at higher risk of relapse after transplantation. Approaches that may decrease relapse incidence in children given UCBT with positive MRD should be investigated to improve final outcomes.

Association between busulfan exposure and outcome in children receiving intravenous busulfan before hematopoietic stem cell transplantation

Background and Objective: Intravenous (IV) busulfan (Bu) combined with therapeutic drug monitoring-guided dosing is associated with better event-free survival (EFS), lower transplant-related mortality. But optimal target steady-state concentration (Css) of Bu in children undergoing hematopoietic stem cell transplantation (HSCT) remains unclear. This study aimed to evaluate the relation between Css of Bu and clinical outcomes in children receiving Bu before HSCT. Methods: This study includes 75 children receiving IV Bu in 16 doses, with first dose assigned based on age. Bu first-dose pharmacokinetic parameters were estimated from Bu plasma concentrations measured at 6 time points by high-performance liquid chromatography. Doses were adjusted at the fifth dose to a target Css of 600–900 ng/mL. Cumulative incidence of overall survival (OS), EFS, transplant-related mortality, acute graft-versus host disease (aGVHD), and other toxicities in relation to Css of Bu were analyzed using Kaplan–Meier curves in univariate and Coxs proportional hazards model in multivariate analysis. Results: After the first dose, median Css was 578 (325–1227) ng/mL. Forty-one patients had Bu IV dose increased by > 10%. Neutrophil and platelet recoveries, grade 2–4 aGVHD, and nonrelapse mortality (NRM) incidences were 90%, 91%, 12%, and 13%, respectively. Relapse incidence was 33%. Incidence of veno-occlusive disease, hemorrhagic cystitis, and lung toxicities were 13%, 24%, and 7%, respectively. OS and EFS were 70% and 58%. First-dose Bu Css >600 ng/mL was associated with a higher NRM (P < 0.001) and grade 2–4 aGVHD (P = 0.04), a lower EFS (P < 0.001), and OS (P = 0.001). Conclusions: This study demonstrated a significant association between the first-dose pharmacokinetics of Bu and NRM, OS, and EFS. Bu therapeutic drug monitoring provides information that potentially influences outcomes of HSCT in pediatric patients.

Influence of bone marrow graft lymphocyte subsets on outcome after HLA-identical sibling transplants

OBJECTIVE The aim of this study was to analyze bone marrow lymphocyte subsets and CD34 cell dose and their influence on the outcomes of bone marrow transplantation. MATERIALS AND METHODS Forty-eight patients (median age 30 years, range 5-54) receiving HLA-identical sibling bone marrow transplantation for hematologic malignancies were analyzed. RESULTS Median number (range) of nucleated cells and CD34+ cells infused were 2.4 (0.4-6.0) x 10(8)/kg and 3.5 (0.5-13.0) x 10(6)/kg, respectively. Probability of neutrophil recovery was 97%. In a multivariate analysis, time to neutrophil recovery was shortened when a higher number of CD3/CD8 cells was infused (> or =1.0 x 10(7)/kg) (hazard ratio [HR] = 2.13, p = 0.018); when the patient was female or had negative cytomegalovirus serology (HR = 2.03, p = 0.03; HR = 0.41, p = 0.009; respectively). The incidence of grade II to IV acute graft-vs-host disease (GVHD) was 47%. Infusion of >1 x 10(7) CD4 infused/kg increased the risk of acute GVHD (HR = 2.86, p = 0.03). Nineteen of 40 patients at risk experienced chronic GVHD, the risk of which was increased by diagnosis of chronic leukemia (p = 0.03), <2.0 x 10(8) nucleated cells infused/kg (p = 0.05), and a low number of all lymphocyte subsets, except CD19. Estimated 3-year survival rate was 54%. Risk of death was increased in patients receiving <3.5 x 10(6)CD34 infused/kg (HR = 0.37, p = 0.02). Only six patients relapsed. CONCLUSIONS A high cell dose of CD3/CD8 is associated with faster neutrophil recovery, whereas a high cell dose of CD4+ cells increases the incidence of acute GVHD. A high number of nucleated cells and CD34+ cells infused was associated with decreased risk of chronic GVHD and improved survival, respectively.

Efficacy of glutamine-supplemented parenteral nutrition on short-term survival following allo-SCT: a randomized study

Fifty-three patients with hematological malignancies who underwent Allo-SCT from HLA-identical siblings were randomly assigned to receive glutamine-enriched parenteral nutrition—PN (GlPN, n=27) or standard PN (PN, n=26), in isonitrogenous solutions. Deaths (D+100 and D+180), infections, acute GVHD, length of stay, time of neutropenia and intestinal permeability (IP) were studied. Ages, gender, diagnosis, disease status and treatment variables were equally distributed between groups. Survival on D+180 was increased in GlPN (74%) vs PN (46%), P=0.03 (log-rank), as on D+100 (P=0.05). Most deaths occurred before D+100, especially in PN (10/26, 39%) vs GlPN (4/27, 15%). GVHD was the most frequent cause of death (8/21, 38%), especially in PN (n=6, five before D+100). Other outcomes were not affected. IP was affected on admission, was not affected by glutamine enrichment, but consistently worsened throughout the study. Results showed that GlPN was efficacious in increasing short-term survival after Allo-SCT. Benefits of glutamine seem to be independent of mucosal protection, as IP was not affected by its use. A trend to a lower incidence of GVHD deaths may suggest an immunomodulatory role of glutamine.