Cost Saving Analysis Of Reduced-Dose Versus Standard-Dose Bevacizumab In Recurrent Glioblastoma

e18910 Background: FDA approval for bevacizumab (BEV) in progressive glioblastoma (GBM) was based on two phase II studies, both of which used a 10mg/kg every 2 weeks regimen. However, other studies have shown similar benefits and less toxicities at lower doses, thus the optimal dose regimen is yet to be established due to a lack of randomised trials. Reducing the dose of BEV would have substantial savings for institutional and government healthcare spending. We performed a drug cost analysis of differing doses of BEV in a national neuro-oncology center in Ireland. Methods: A retrospective review of the use of BEV in progressive GBM after first-line standard chemoradiotherapy with temozolomide was performed. Patient characteristics, outcomes and tolerability were evaluated. Two dosing schedules were utilized, standard dose BEV (10mg/kg) and reduced-dose BEV (5mg/kg) every 2 weeks, in 118 GBM patients (n = 69 vs 49, respectively). This analysis focused on cost savings. BEV drug costs per year were calculated for a normally distributed population with an average weight of 70kg using both a 10mg/kg and 5mg/kg dose regimen. Drug doses were dose banded, as per national guidelines. BEV cost was calculated factoring 100mg and 400mg BEV vials availability only. The annual cost of the two regimens were compared. Results: Overall survival (OS) analysis of the two dose regimens was similar, with median OS of 5.6 months (standard-dose cohort) and 5.5 months (reduced-dose cohort), p= 0.55. Reducing the dose from 10mg/Kg to 5mg/Kg for a 70kg adult with progressive GBM resulted in an average annual drug cost reduction of 44.18%, or a cost saving of €24,456.90 ($29,966.02, at current rates) per patient. Within our study population, if all standard-dose patients (n = 69) were treated with the reduced-dose BEV regimen there would have been a €534,167 ($654,045) cost saving total. Conclusions: Lowering the dose of BEV from standard 10mg/kg to 5mg/kg every 2 weeks for patients with progressive GBM could offer significant cost savings in Ireland if adopted, with similar overall survival. This justifies further study.