Effectiveness and safety of Dabrafenib in the treatment of 20 Chinese
children with BRAFV600E-mutated LCH
Abstract
Background Langerhans cell histiocytosis (LCH) is a rare disease with a
high frequency of the BRAFV600E mutation. We sought to investigate the
effectiveness and safety of Dabrafenib in children with
BRAFV600E-mutated LCH. Procedure A retrospective analysis was performed
on 20 children with BRAFV600E -mutated LCH, who were treated with
Dabrafenib and followed up from November 1, 2016, to June 1, 2020.
Results The median age at which the patients started taking Dabrafenib
was 2.3 (0.6-6.5) years old . All patients were initially treated with
chemotherapy and then changed to targeted therapy due to poor response
or intolerance to chemotherapy. The overall objective response rate and
disease control rate were 65% and 75%, respectively. Among the 15
patients who had positive circulating cell-free BRAFV600E (cfBRAFV600E)
mutation before Dabrafenib treatment, decreased cfBRAFV600E level was
observed at the end of treatment (P=0.029). In 9 of 15 (60%) patients,
cfBRAFV600E level became negative within a median time of 3.0 months
(1.0-9.0 months). All patients survived, and a half of them suffered a
relapse or progression after Dabrafenib treatment. Grade 2 or 3 adverse
effects occurred in 5 patients. Relief of adverse effects was obtained
after symptomatic treatment, reduction of dosage or withdrawal.
Conclusions Some children with BRAFV600E-mutated LCH may benifit from
monotherapy of Dabrafenib, especially high-risk patients with
concomitant HLH and intolerance to chemotherapy. The safety of
Dabrafenib is notable. A prospective study with a larger sample size are
required to determine the optimal dosage and duration of Dabrafenib.