Lookup NU author(s): Dr Paul Milne
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PURPOSE: 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.
Author(s): Donadieu J, Larabi IA, Tardieu M, Visser J, Hutter C, Sieni E, Kabbara N, Barkaoui M, Miron J, Chalard F, Milne P, Haroche J, Cohen F, Helias-Rodzewicz Z, Simon N, Jehanne M, Kolenova A, Pagnier A, Aladjidi N, Schneider P, Plat G, Lutun A, Sonntagbauer A, Lehrnbecher T, Ferster A, Efremova V, Ahlmann M, Blanc L, Nicholson J, Lambilliote A, Boudiaf H, Lissat A, Svojgr K, Bernard F, Elitzur S, Golan M, Evseev D, Maschan M, Idbaih A, Slater O, Minkov M, Taly V, Collin M, Alvarez J-C, Emile J-F, Heritier S
Publication type: Article
Publication status: Published
Journal: Journal of Clinical Oncology : Official Journal of the American Society of Clinical Oncology
Online publication date: 22/09/2019
Acceptance date: 17/07/2019
Date deposited: 11/11/2019
ISSN (print): 0732-183X
ISSN (electronic): 1527-7755
Publisher: American Society of Clinical Oncology
PubMed id: 31513482
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