Karima Yakouben

NOTCH1 and FBXW7 mutations have a favorable impact on early response to treatment, but not on outcome, in children with T-cell acute lymphoblastic leukemia (T-ALL) treated on EORTC trials 58881 and 58951

Risk-adjusted treatment stratification in T-cell acute lymphoblastic leukemias (T-ALLs) is currently based only on early response to chemotherapy. We investigated the prognostic implication of hyperactivation of NOTCH pathway resulting from mutations of NOTCH1 or FBXW7 in children with T-ALL enrolled in EORTC-CLG trials. Overall, 80 out of 134 (60%) patients were NOTCH+ (NOTCH1 and/or FBXW7 mutated). Although clinical presentations were not significantly associated with NOTCH status, NOTCH+ patients showed a better early response to chemotherapy as compared with NOTCH− patients, according to the rate of poor pre-phase ‘responders’ (25% versus 44%; P=0.02) and the incidence of high minimal residual disease (MRD) levels (11% (7/62) versus 32% (10/31); P=0.01) at completion of induction. However, the outcome of NOTCH+ patients was similar to that of NOTCH− patients, with a 5-year event-free survival (EFS) of 73% and 70% (P=0.82), and 5-year overall survival of 82% and 79% (P=0.62), respectively. In patients with high MRD levels, the 5-year EFS rate was 0% (NOTCH+) versus 42% (NOTCH−), whereas in those with low MRD levels, the outcome was similar: 76% (NOTCH+) versus 78% (NOTCH−). The incidence of isolated central nervous system (CNS) relapses was relatively high in NOTCH1+ patients (8.3%), which could be related to a higher propensity of NOTCH+ leukemic blasts to target the CNS.

Randomized Study of Early versus Late Immunization with Pneumococcal Conjugate Vaccine after Allogeneic Stem Cell Transplantation

BACKGROUND Invasive pneumococcal disease is a life-threatening complication after allogeneic stem cell transplantation, and at least 20% of cases occur within 1 year after transplantation. The 23-valent pneumococcal polysaccharide vaccine (PPV23) has limited efficacy, especially during the first year after transplantation. The immune response to the conjugated vaccines is expected to be better than that to the polysaccharide vaccine, but the optimal timing of vaccination is not defined. Our objective was to show that a 7-valent pneumococcal conjugate vaccine (PCV7; Prevnar) was not inferior when first given 3 months after transplantation, compared with when first given 9 months after transplantation. METHODS We performed a multicenter, randomized, noninferiority study involving 158 patients from 13 European Group for Blood and Marrow Transplantation centers who were randomly allocated at approximately 100 days after myeloablative stem cell transplantation to receive a series of vaccinations (3 doses of PCV7 given 1 month apart) that was started immediately (i.e., 3 months after transplantation) or 6 months later (i.e., 9 months after transplantation). The primary evaluation criterion was the rate of response (antibody level, > or = 0.15 microg/mL for each of the 7 serotypes) at 1 month after the third dose of PCV7. The noninferiority margin was 20%. All patients were followed up for 24 months after transplantation or until death, whichever occurred first. RESULTS We found that the response rate was not lower after early vaccination (79% [45 of 57 patients]) than after late vaccination (82% [47 of 57 patients]) (difference, -3.5%; 90% confidence interval, -15.6 to 8.6; not significant). CONCLUSIONS We conclude that PCV7 vaccination at 3 months after stem cell transplantation is not inferior to PCV7 vaccination at 9 months after transplantation. Because invasive pneumococcal disease can occur early, we recommend starting the PCV7 vaccination series at 3 months after transplantation to ensure earlier protection against Streptococcus pneumoniae. However, the early vaccination may result in only short-lasting response and may not prime for a 23-valent pneumococcal polysaccharide vaccine boost as efficiently as the late vaccination.

An intragenic ERG deletion is a marker of an oncogenic subtype of B-cell precursor acute lymphoblastic leukemia with a favorable outcome despite frequent IKZF1 deletions.

Oncogenic subtypes in childhood B-cell precursor acute lymphoblastic leukemia (BCP-ALL) are used for risk stratification. However, a significant number of BCP-ALL patients are still genetically unassigned. Using array-comparative genomic hybridization in a selected BCP-ALL cohort, we characterized a recurrent V(D)J-mediated intragenic deletion of the ERG gene (ERGdel). A breakpoint-specific PCR assay was designed and used to screen an independent non-selected cohort of 897 children aged 1–17 years treated for BCP-ALL in the EORTC-CLG 58951 trial. ERGdel was found in 29/897 patients (3.2%) and was mutually exclusive of known classifying genetic lesions, suggesting that it characterized a distinct leukemia entity. ERGdel was associated with higher age (median 7.0 vs 4.0 years, P=0.004), aberrant CD2 expression (43.5% vs 3.7%, P<0.001) and frequent IKZF1 Δ4-7 deletions (37.9% vs 5.3%, P<0.001). However, ERGdel patients had a very good outcome, with an 8-year event-free survival (8-y EFS) and an 8-year overall survival of 86.4% and 95.6%, respectively, suggesting that the IKZF1 deletion had no impact on prognosis in this genetic subtype. Accordingly, within patients with an IKZF1 Δ4-7 deletion, those with ERGdel had a better outcome (8-y EFS: 85.7% vs 51.3%; hazard ratio: 0.16; 95% confidence interval: 0.02–1.20; P=0.04). These findings have implications for further stratification including IKZF1 status.

Immune response to the 23-valent polysaccharide pneumococcal vaccine after the 7-valent conjugate vaccine in allogeneic stem cell transplant recipients : Results from the EBMT IDWP01 trial

The current recommendations for active immunization after stem cell transplant (SCT) include 3 doses of 7-valent pneumococcal conjugate vaccine (PCV7) from 3 months after transplant, followed by a 23-valent polysaccharide pneumococcal vaccine (PPV23). However, until now, the immune response to PPV23 after PCV7 has not been assessed after SCT. In the EBMT IDWP01 trial, 101 patients received 1 dose of PPV23 at 12 or 18 months, both after 3 doses of PCV7. The efficacy of PPV23 was assessed 1 month later and at 24 months after transplant by the pneumococcal serotype 1 and 5 antibody levels. Serotype 1 and 5 are not included in PCV7. Although the geometric mean concentrations were significantly higher 1 month after PPV23, for both antigens, the response rates (> or =0.15 microg/mL), in the range of 68-94%, were not different between groups independent of the assessment date. One PPV23 dose after 3 PCV7 doses, already known to increase the response to PCV7, also extends the serotype coverage given 12 or 18 months after transplant.

Improved outcome with pulses of vincristine and corticosteroids in continuation therapy of children with average risk acute lymphoblastic leukemia (ALL) and lymphoblastic non-Hodgkin lymphoma (NHL): report of the EORTC randomized phase 3 trial 58951

The European Organisation for Research and Treatment of Cancer 58951 trial for children with acute lymphoblastic leukemia (ALL) or non-Hodgkin lymphoma (NHL) addressed 3 randomized questions, including the evaluation of dexamethasone (DEX) versus prednisolone (PRED) in induction and, for average-risk patients, the evaluation of vincristine and corticosteroid pulses during continuation therapy. The corticosteroid used in the pulses was that assigned at induction. Overall, 411 patients were randomly assigned: 202 initially randomly assigned to PRED (60 mg/m(2)/d), 201 to DEX (6 mg/m(2)/d), and 8 nonrandomly assigned to PRED. At a median follow-up of 6.3 years, there were 19 versus 34 events for pulses versus no pulses; 6-year disease-free survival (DFS) rate was 90.6% (standard error [SE], 2.1%) and 82.8% (SE, 2.8%), respectively (hazard ratio [HR] = 0.54; 95% confidence interval, 0.31-0.94; P = .027). The effect of pulses was similar in the PRED (HR = 0.56) and DEX groups (HR = 0.59) but more pronounced in girls (HR = 0.24) than in boys (HR = 0.71). Grade 3 to 4 hepatic toxicity was 30% versus 40% in pulses versus no pulses group and grade 2 to 3 osteonecrosis was 4.4% versus 2%. For average-risk patients treated according to Berlin-Frankfurt-Muenster-based protocols, pulses should become a standard component of therapy.

Weight-based strategy of dose administration in children using intravenous busulfan: clinical and pharmacokinetic results.

A prospective clinical trial was performed in order to validate the pharmacokinetic (PK) and clinical benefits of a new dosing schedule of intravenous busulfan (IV Bu) in children.

Efficacy of fractionated gemtuzumab ozogamicin combined with cytarabine in advanced childhood myeloid leukaemia

Gemtuzumab ozogamicin (GO) monotherapy is reported to yield a 20–30% response rate in advanced acute myeloid leukaemia (AML). This study examined the efficacy and tolerability of GO combined with cytarabine (GOCYT) in children with refractory/relapsed CD33+ AML. Seventeen children received GO 3 mg/m2 on days 1, 4 and 7 plus cytarabine 100 mg/m2/d for 7 d on a compassionate‐use basis. Seven patients then received GO‐based consolidation. At the outset of GOCYT, two patients were refractory; eight patients were in refractory first relapse; six patients had relapsed after stem cell transplantation (SCT); and one patient [del(5q) therapy‐related AML (t‐AML)] had not yet been treated. Mean follow‐up was 17 months (8–33 months). Ten responses were obtained after GOCYT induction, including complete remission (CR) or CR without complete recovery of platelets (CRp) in six patients (35%). The responses improved in three children who received GOCYT consolidation, increasing the CR + CRp rate to 53%. SCT was subsequently performed in eight responders. Grade 3–4 adverse events consisted of haematological disorders (n = 17, 100%) and documented infections (n = 5, 29%). No cases of sinusoidal obstructive syndrome occurred. Three patients were alive at the cut‐off date for this analysis, all of whom had responded to GOCYT. GOCYT combination therapy yielded a high response rate (53%) and showed acceptable toxicity in heavily pretreated children with refractory/relapsed AML. These results warrant a larger prospective study.

Dexamethasone (6 mg/m2/day) and prednisolone (60 mg/m2/day) were equally effective as induction therapy for childhood acute lymphoblastic leukemia in the EORTC CLG 58951 randomized trial.

Dexamethasone could be more effective than prednisolone at similar anti-inflammatory doses in the treatment of childhood acute lymphoblastic leukemia. In order to check if this “superiority” of dexamethasone might be dose-dependent, we conducted a randomized phase III trial comparing dexamethasone (6 mg/m2/day) to prednisolone (60 mg/m2/day) in induction therapy. All newly diagnosed children and adolescents with acute lymphoblastic leukemia in the 58951 EORTC trial were randomized on prephase day 1 or day 8. The main endpoint was event-free survival; secondary endpoints were overall survival and toxicity. A total of 1947 patients with acute lymphoblastic leukemia were randomized. At a median follow-up of 6.9 years, the 8-year event-free survival rate was 81.5% in the dexamethasone arm and 81.2% in the prednisolone arm; the 8-year overall survival rates were 87.2% and 89.0% respectively. The 8-year incidences of isolated or combined central nervous system relapse were 2.9% and 4.5% in the dexamethasone and prednisolone arms, respectively. The incidence of grade 3–4 toxicities during induction and the frequency of osteonecrosis were similar in the two arms. In conclusion, dexamethasone and prednisolone, used respectively at the doses of 6 and 60 mg/m2/day during induction, were equally effective and had a similar toxicity profile. Dexamethasone decreased the 8-year central nervous system relapse incidence by 1.6%. This trial was registered at www.clinicaltrials.gov as #NCT00003728.

Hyperdiploidy with 58-66 chromosomes in childhood B-acute lymphoblastic leukemia is highly curable: 58951 CLG-EORTC results.

The aim of our study was to analyze the factors contributing to heterogeneity of prognosis in patients with hyperdiploidy>50 chromosomes (HD>50), a group of B-cell precursor acute lymphoblastic leukemia with favorable outcome. The 541 HD>50 patients registered prospectively in the 58951 European Organisation for Research and Treatment of Cancer (EORTC) Childrens Leukemia Group (CLG) trial, identified by karyotype (446 patients) and by DNA index (DI) (490 patients), had a 6-year event-free survival (EFS) of 89.0% (standard error [SE] = 1.5%) and a 6-year overall survival (OS) of 95.9% (SE = 0.9%). The strongest prognostic factor was the modal number of chromosomes (MNC): the 6-year EFS of 51-53, 54-57, and 58-66 MNC groups were 80%, 89%, and 99%, respectively (P < .0001). Ploidy assessed by DI was also a favorable factor: the higher the DI, the better the outcome. The 6-year EFS of the 3 subgroups of DI < 1.16/≥1.16-<1.24/≥1.24 were 83%, 90%, and 95%, respectively (P = .009). All usual combinations of trisomies (chromosomes 4, 10, 17, 18) were significant favorable factors but had lower EFS when MNC was lower than 58. In multivariate analysis, MNC remained the strongest factor. Consequently, the best indicator for excellent outcome was ploidy assessed by karyotype because patients with 58-66 chromosomes stood every chance of being cured (OS of 100% at 6-year follow-up) with less-intensive therapy. This trial was registered at www.clinicaltrials.gov as #NCT00003728. Registered: http://www.eortc.org/, http://clinicaltrials.gov/show/NCT00003728.

Long-term results of CD34(+) cell transplantation in children with neuroblastoma.

BACKGROUND This is the first report of the long-term results of CD34(+) cell transplantation in children with neuroblastoma. We investigated the hematologic and immune recovery, posttransplant morbidity, and clinical outcome of these children. PROCEDURE Twenty-three children with advanced neuroblastoma had PBPCs (20 patients) or BM (3 patients) collected, followed by CD34(+) cell selection on Ceprate column. The purge of residual neuroblastoma cells was evaluated using an RT-PCR for tyrosine hydroxylase (TH) mRNA assay. Reinfusion of CD34(+) cells followed busulfan + melphalan myeloablative chemotherapy. RESULTS A median of 2.9 x 10(6) CD34(+) cells/kg was reinjected. Median days to achieve ANC > 0.5 x 10(9)/liter and platelets > 50 x 10(9)/liter were 13 (range 9-33) and 59 (range 22-259), respectively. Circulating T cells were primarily CD4(-)/CD8(+) with fewer than 0.2 10(9)CD4(+) cells/liter throughout the first 6 months. CD19(+) cells and CD56(+) cells were not detectable up to day +35 posttransplant. At 1 year posttransplant, 16 evaluable patients had stable hematopoiesis with 2.3 x 10(9) ANC/liter (range 0.8-4.1), 1.4 x 10(9) lymphocytes/liter (range 0.5- 2.0) and 251 x 10(9) PLT/liter (range 35-490). After the completion of hematopoietic reconstitution, six events of severe septicemia/septic shock were noted. Six children had severe VZV infections, and 2 had EBV-associated lymphoproliferation. Thirteen patients are alive with a median follow-up of 40 months (range 2-54). Ten patients have died; 8 relapsed or developed progressive disease, 1 died from nondocumented pneumopathy at day 56, and 1 developed AML-M4 at 3 years posttransplant. CONCLUSIONS In children, CD34(+) cell transplantation can be accomplished with a reduction of neuroblastoma cell inoculum in the selected graft as assessed by RT-PCR analysis. CD34(+) cell grafts provide successful neutrophil reconstitution. However, delayed platelet recovery, persistent decrease in CD4(+) lymphocyte levels and a high incidence of serious and life-threatening late infections were observed in these children. There remains a critical need to evaluate any real clinical benefit of CD34(+) cell autografts in neuroblastoma patients.