Anti-vascular endothelial growth factor therapies in ophthalmology: current use, controversies and the future

摘要

Use of anti-vascular endothelial growth factor (VEGF) therapies was introduced for the treatment of ocular disorders in 2005. In the UK, the current licensed and NICE approved indications are for the treatment of neovascular age-related macular degeneration (nAMD), diabetic macular oedema (DMO), macular oedema secondary to a retinal vein occlusion (RVO) and choroidal neovascularization in pathological myopia. These diagnoses alone account for two-thirds of the main causes of legally registrable visual impairment and blindness. Ranibizumab (Lucentis (R); Genentech/Novartis), a drug specifically designed for intraocular use, is the primary licensed medication. Controversially however, clinicians have been using an unlicensed cheaper drug, bevacizumab (Avastin (R); Genentech/Roche), originally designed for systemic administration, with a similar mode of action and shown to have a similar efficacy. However, there are fears of greater side effects with bevacizumab though studies have not been sufficiently powered to show statistical difference. In the current global economic climate, anti-VEGF treatment places huge financial and logistical pressure on already strained health care systems. Bevacizumab is considerably more cost effective than ranibizumab, and thus using bevacizumab would widen access to treatment particularly in developing countries. This licensing issue also places clinicians in a difficult medico-legal position especially in Europe, where doctors are duty bound to use a licensed drug for a particular indication if this is available. As the indications of anti-VEGF therapies expand and the cost of health care provision becomes more expensive, the controversies surrounding their use will inevitably become more important.