Off-Label Use Of Bevacizumab In Age-Related Macular Degeneration: Some Pharmaceutical Aspects Related To The Clinical Practice

Rosario

Congreso; 2ª Reunión Internacional de Ciencias Farmacéuticas / RICiFA; 2012

Introduction Age-related macular degeneration (AMD) is the leading cause of severe visual loss in the developed world.1 The introduction of anti-vascular endothelial growth factor (VEGF) therapy has change the treatment of neovascular AMD (AMD-NV) and has become a standard treatment for neovascular AMD.2 Currently, the most commonly used VEGF antagonists are Ranibizumab (Lucentis®; Genentech, San Francisco, California, USA) and Bevacizumab (Avastin®; Genentech). Both molecules are derived from the same murine monoclonal antibody against VEGF. While Ranibizumab (RNB) was specifically designed and approved for intravitreal treatment of exudative AMD, Bevacizumab (BVZ) was approved for the systemic intravenous treatment of metastatic colorectal cancers.3 This anti-angiogenic monoclonal antibody is not currently FDA approved for injection into the eye, although the efficacy and tolerability of intravitreal bevacizumab was reported by hundreds of articles.4-6 Now is currently used off-label not only for the treatment of exudative AMD but also for the treatment of other ischemic retinopathy as well.7-8 The purpose of this work was to evaluate different accessibility to neovascular AMD treatment in clinical practice and estimate its impact in therapeutic effects and visual outcome in order to collaborate in making decisions and health care policies. Materials and Methods The design of the study was a retrospective cohort study based on analysis of clinical charts and complementary studies of 78 patients (96 eyes) who were treated with RNB or BVZ for AMD-NV in one of three major ophthalmological centers of Córdoba, Argentine, from January 2009 to December 2011. Patients with history of laser photocoagulation treatment, verteporfin photodynamic therapy (PDT) or prior intravitreal therapy were excluded from the analysis Main outcomes measured included time delay and mean visual-acuity (VA) change between diagnosis and treatment, mean number of injections and follow-up examinations and the major clinical outcomes (mean VA change and proportion of patient who lost <15 letters and proportion of patients who gained > 15 letters) at 3 month, 6 month and 1 year of follow-up Results: The delay time between diagnostic and treatment and the decrease in visual acuity in this period were significantly higher for patients treated with Ranibizumab than those one treated with Bevacizumab (153.8 vs. 36.06 days, p<0.0001), (-13.01 vs. -5.46 letters, p<0,01).After initiation of treatment, there was a significant improvement in visual acuity for both groups, with a difference in favor of BVZ but not statistical significant (+10.06 vs. +6.27 letters p=0.097). Both groups showed a significant decrease of follow-up examinations in the second half of the follow-up period and a drop in VA in the same period. Throughout the year of treatment, BVZ-group received significantly more injections than RNB-group (4.71 vs 2.98 p <0.0001) and also had better clinical outcomes. Conclusions: waiting times and availability of dose are crucial in the treatment of AMD-NV, and patients suffer must face significant bureaucratic or economic barriers limit their ability to preserve vision. This complex situation should be attended to by those responsible for ensuring the global efficiency of the health system, trying to regulate it in some sense.