Results of successive EORTC-CLG 58 881 and 58 951 trials in paediatric T-cell acute lymphoblastic leukaemia (ALL)

Outcomes in childhood T-cell acute lymphoblastic leukaemia (T-ALL) are steadily improving due to intensive therapy. Between 1989 and 2008, 599 children with newly diagnosed T-ALL were enrolled in two successive European Organization for Research and Treatment of Cancer - Children's Leukaemia Group trials (58881 and 58951), both based on the Berlin-Frankfurt-Munster protocol and without cranial irradiation. In the latter trial induction chemotherapy was intensified. The most important randomizations were Medac Escherichia coli asparaginase versus Erwinia asparaginase in trial 58881, and dexamethasone (6 mg/m(2)/day) versus prednisolone (60 mg/m(2)/day) and prolonged versus conventional asparaginase duration in trial 58951. 8-year event-free survival (EFS) increased from 65 center dot 1% to 74 center dot 0% in trial 58951. Improvement was most profound for patients with white blood cell (WBC) counts E. coli asparaginase was associated with longer EFS [hazard ratio (HR) 0 center dot 54, P = 0 center dot 0015] and overall survival (HR 0 center dot 51, P = 0 center dot 0018). Induction therapy with dexamethasone did not improve EFS compared to prednisolone. Remarkably, intensification of central nervous system (CNS)-directed therapy in trial 58951 resulted in fewer bone marrow relapses, while the incidence of CNS relapses remained low. In summary, we showed that adequate asparaginase therapy, intensified induction treatment and intensification of CNS-directed chemotherapy can result in an improvement of outcome in T-ALL patients with good prephase response and initial WBC counts <100 x 10(9)/l, representing approximately 50% of T-ALL patients

CD200/BTLA deletions in pediatric precursor B-cell acute lymphoblastic leukemia treated according to the EORTC-CLG 58951 protocol

DNA copy number analysis has been instrumental for the identification of genetic alterations in B-cell precursor acute lymphoblastic leukemia. Notably, some of these genetic defects have been associated with poor treatment outcome and might be relevant for future risk stratification. In this study, we characterized recurrent deletions of CD200 and BTLA genes, mediated by recombination-activating genes, and used breakpoint-specific polymerase chain reaction assay to screen a cohort of 1154 cases of B-cell precursor acute lymphoblastic leukemia uniformly treated according to the EORTC-CLG 58951 protocol. CD200/BTLA deletions were identified in 56 of the patients (4.8%) and were associated with an inferior 8-year event free survival in this treatment protocol [70.2% +/- 1.2% for patients with deletions versus 83.5% +/- 6.4% for non-deleted cases (hazard ratio 2.02; 95% confidence interval 1.23-3.32; P=0.005)]. Genetically, CD200/BTLA deletions were strongly associated with ETV6-RUNX1-positive leukemias (P<0.0001), but were also identified in patients who did not have any genetic abnormality that is currently used for risk stratification. Within the latter population of patients, the presence of CD200/BTLA deletions was associated with inferior event-free survival and overall survival. Moreover, the multivariate Cox model indicated that these deletions had independent prognostic impact on event-free survival when adjusting for conventional risk criteria. All together, these findings further underscore the rationale for copy number profiling as an important tool for risk stratification in human B-cell precursor acute lymphoblastic leukemia

Efficacy and tolerability of gemtuzumab ozogamicin (anti-CD33 monoclonal antibody, CMA-676, Mylotarg(®)) in children with relapsed/refractory myeloid leukemia

BACKGROUND: Gemtuzumab ozogamicin (GO) is a cytotoxic anti-CD33 monoclonal antibody that has given promising preliminary results in adult myeloid CD33+ AML. We conducted a retrospective multicenter study of 12 children treated with GO on a compassionate basis (median age 5.5 y). Three patients (2 MDS/AML, 1 JMML) were refractory to first-line treatment, 8 patients with de novo AML were in refractory first relapse, and one patient with de novo AML was in 2(nd )relapse after stem cell transplantation (SCT). CD33 expression exceeded 20% in all cases. METHODS: GO was administered alone, at a unit dose of 3–9 mg/m(2), once (3 patients), twice (3 patients), three (5 patients) or five times (1 patient). Mean follow-up was 128 days (8–585 d). RESULTS: There were three complete responses (25%) leading to further curative treatment (SCT). Treatment failed in the other nine patients, and only one patient was alive at the end of follow-up. NCI-CTC grade III/IV adverse events comprised hematological toxicity (n = 12), hypertransaminasemia (n = 2), allergy and hyperbilirubinemia (1 case each). There was only one major adverse event (grade IV allergy). No case of sinusoidal obstruction syndrome occurred. CONCLUSION: These results warrant a prospective trial of GO in a larger population of children with AML

CAR-T cells : indications actuelles en pédiatrie et perspectives de développement

International audienceLes leucémies aiguës lymphoblastiques B (LAL-B) représentent la première cause de cancer chez l’enfant. Malgré un taux de survie à 5 ans supérieur à 90 %, les LAL sont une des causes majeures de décès lié au cancer dans l’enfance. Une nouvelle classe d’immunothérapie se basant sur des lymphocytes T génétiquement modifiés pour exprimer à leur surface un récepteur antigénique chimérique (CAR) ciblant le CD19, marqueur présent sur la majorité des cellules leucémiques B, va potentiellement révolutionner la prise en charge des LAL B en rechute ou réfractaire. Les taux de réponse au traitement vont de 60 % à 90 % dans des essais de phase I/II incluant des patients en deuxième rechute ou plus ou porteurs d’une maladie réfractaire. Des rémissions persistantes voire des guérisons ont été observées. Ces très bons résultats préliminaires permettent d’envisager dans un futur proche leur utilisation en 1re ligne dans le cas de maladies de particulièrement mauvais pronostic. Cependant la production de ces cellules, leur coût ainsi que la gestion des effets secondaires sont des enjeux majeurs pour le futur de cette thérapeutique. La survenue de rechutes « CD19 négatives » a conduit à élaborer des CARs multispécifiques. Les CAR-T cells allogéniques permettraient quant à elles d’avoir à disposition un arsenal thérapeutique adapté à la cible dès le diagnostic. Les perspectives de développement des CAR T cells résident désormais dans l’optimisation des techniques dans les leucémies et lymphomes et dans l’extension des domaines d’application aux tumeurs solides de l’enfant

[Involvement of thyroid gland at non-Hodgkin lymphoma initial diagnosis: 2 pediatric cases]

International audienceExtranodal thyroid lymphomatous involvement is rare in childhood. We report here 2 children, 1 with vertical transmission-acquired human immunodeficiency virus (HIV), presenting with lymphomatous infiltration of the thyroid gland at diagnosis. One child had infra-clinical endocrine impairment and both responded well to chemotherapy. Although the cases are too scarce to be affirmative, thyroid gland involvement doesn't seem to alter the good prognosis of childhood Burkitt's lymphoma. The third child's cancer in frequency is Non-Hodgkin Lymphomas. Presenting as the initial AIDS event in 1 patient, this case report also highlights the need to systematically propose antiretroviral therapy in vertically HIV infected children