6ER-011 Drug utilisation study of bevacizumab in a teaching referral paediatric hospital

Background Bevacizumab is a humanised monoclonal antibody against vascular endothelial growth factor authorised for adult cancer treatments. There are several case series and clinical trials on the use of bevacizumab in paediatric tumours at dose range of 5 to 15 mg/kg every 2 to 4 weeks. Purpose To describe the use of bevacizumab in oncologic patients of a paediatric referral hospital. Material and methods Data from patients treated with bevacizumab were obtained based on off-label use and medical history records from January to September 2017. We focused on indication, treatment duration, dose regimen and, if any, reason for discontinuation. Each case was previously authorised by our Medical Director and a signed informed consent obtained. Indication was classified as per tumour type and location: central nervous system (CNS) tumours, neurofibromatosis (NF) -related tumours, extra CNS malignant and benign tumours: the fifth group was treatment of brain radionecrosis. We also divided the reason for discontinuation into three groups: end of treatment, disease progression and intolerable side-effects. Results After analysing data from 62 patients, 71% of tumours were CNS-located, 14.5% of which were NF-related, followed by 12.9% of radionecrosis treatment and extra CNS malignant (11.3%) and benign tumours (4.8%). The median duration of treatment was 5.5 months (IQR 13.75) and the most common dose regimen was 10 mg/kg (83.9%) every 2 weeks (79%). Only 22.6% of treatments remained active at the end of the study. Discontinuation reason was mostly disease progression (43.5%) followed by end of treatment (27.4%). Side-effects were similar to those reported in the literature, causing treatment discontinuation in 6.5% of patients. Conclusion Bevacizumab was mainly used to treat CNS tumours at a dose of 10 mg/kg every 2 weeks. After a median duration of 5.5 months, the drug appeared to be safe since only 6.5% of the treatments were discontinued due to side-effects. Our results are consistent with the literature except for radionecrosis. More studies are needed to assess its efficacy and long term adverse events. Reference and/or Acknowledgements 1. Benesch M, et al. Compassionate use of bevacizumab (Avastin ® ) in children and young adults with refractory or recurrent solid tumours. Annals of Oncology2008April 1;19(4):807–813. https://doi.org/10.1093/annonc/mdm510 No conflict of interest