Cladribine and cytarabine in refractory multisystem Langerhans cell histiocytosis: results of an international phase 2 study

International audienceAn international phase 2 study combining cladribine and cytarabine (Ara-C) was initiated for patients with refractory, risk-organ–positive Langerhans cell histiocytosis (LCH) in 2005. The protocol, comprising at least two 5-day courses of Ara-C (1 g/m2 per day) plus cladribine (9 mg/m2 per day) followed by maintenance therapy, was administered to 27 patients (median age at diagnosis, 0.7 years; median follow-up, 5.3 years). At inclusion, all patients were refractory after at least 1 course of vinblastine (VBL) plus corticosteroid, all had liver and spleen involvement, and 25 patients had hematologic cytopenia. After 2 courses, disease status was nonactive (n = 2), better (n = 23), or stable (n = 2), with an overall response rate of 92%. Median disease activity scores decreased from 12 at the start of therapy to 3 after 2 courses (P \textless .0001). During maintenance therapy, 4 patients experienced reactivation in risk organs. There were 4 deaths; 2 were related to therapy toxicity and 2 were related to reactivation. All patients experienced severe toxicity, with World Health Organization grade 4 hematologic toxicity and 6 documented severe infections. The overall 5-year survival rate was 85% (95% confidence interval, 65.2%-94.2%). Thus, the combination of cladribine/Ara-C is effective therapy for refractory multisystem LCH but is associated with high toxicit

Vemurafenib for Refractory Multisystem Langerhans Cell Histiocytosis in Children: An International Observational Study

International audiencePURPOSE:Off-label use of vemurafenib (VMF) to treat BRAFV600E mutation-positive, refractory, childhood Langerhans cell histiocytosis (LCH) was evaluated.PATIENTS AND METHODS:Fifty-four patients from 12 countries took VMF 20 mg/kg/d. They were classified according to risk organ involvement: liver, spleen, and/or blood cytopenia. The main evaluation criteria were adverse events (Common Terminology Criteria for Adverse Events [version 4.3]) and therapeutic responses according to Disease Activity Score.RESULTS:LCH extent was distributed as follows: 44 with positive and 10 with negative risk organ involvement. Median age at diagnosis was 0.9 years (range, 0.1 to 6.5 years). Median age at VMF initiation was 1.8 years (range, 0.18 to 14 years), with a median follow-up of 22 months (range, 4.3 to 57 months), whereas median treatment duration was 13.9 months (for 855 patient-months). At 8 weeks, 38 complete responses and 16 partial responses had been achieved, with the median Disease Activity Score decreasing from 7 at diagnosis to 0 (P < .001). Skin rash, the most frequent adverse event, affected 74% of patients. No secondary skin cancer was observed. Therapeutic plasma VMF concentrations (range, 10 to 20 mg/L) seemed to be safe and effective. VMF discontinuation for 30 patients led to 24 LCH reactivations. The blood BRAFV600E allele load, assessed as circulating cell-free DNA, decreased after starting VMF but remained positive (median, 3.6% at diagnosis, and 1.6% during VMF treatment; P < .001) and was associated with a higher risk of reactivation at VMF discontinuation. None of the various empirical therapies (hematopoietic stem-cell transplantation, cladribine and cytarabine, anti-MEK agent, vinblastine, etc) used for maintenance could eradicate the BRAFV600E clone.CONCLUSION:VMF seemed safe and effective in children with refractory BRAFV600E-positive LCH. Additional studies are needed to find effective maintenance therapy approaches

Outcome and prognostic factors of relapse in children and adolescents with mature b-cell lymphoma and leukemia treated in 3 consecutive prospective "lymphomes malins B" protocols : A Société Française des Cancers de l’Enfant study

To describe relapsed B-cell lymphoma or leukemia in children/adolescents treated with a “Lymphomes Malins B” regimen and their outcome and to identify prognostic factors for survival, we studied relapses in the LMB89, 96 and 2001 studies of the Société Française d’Oncologie Pédiatrique (Société Française des Cancers de l’Enfant). Therapeutic guidelines at relapse were to obtain a second complete remission and to consolidate the remission with high-dose chemotherapy followed by autologous stem-cell transplantation. Between July 1989 and March 2007, 67 patients of 1322 (5%) relapsed: 57 had Burkitt lymphoma and 10 had large-cell histology. Three patients were initially treated in risk group A, 41 in group B and 23 in group C. Thirty-three patients had a relapse in one site (15 in the central nervous system) and 34 at multiple sites. Sixty-five patients received salvage chemotherapy and 33 achieved complete remission. Forty-one patients also received high-dose chemotherapy followed by autologous (n=33) or allogeneic (n=8) transplantation. With a median follow-up of 6.4 years, the 5-year survival rate was 29.9%. Nineteen patients were still alive, all but one (group A) received consolidation treatment. Multivariate analysis showed the following factors to be significantly associated with better survival: relapse at one site (P=0.0006), large-cell histology (P=0.012), initial prognostic group A or B with lactate dehydrogenase level below twice the normal value (P=0.005), and time to relapse more than 6 months (P=0.04)