What is Anti-VEGF Injections – Avastin, Lucentis, Macugen ?
There has been a lot of excitement in management of retinal diseases, ever since the newer anti-VEGF injections have become available. These agents are being used for many eye diseases, especially for wet form of AMD (Age related Macular Degeneration), CNVM (Choroidal Neo Vascular Membrane), Severe Diabetic Retinopathy, Macular Edema (swelling), Vascular Blocks, Neovascular Glaucoma (NVG), Vitreous Hemorrhage, etc. These retinal diseases, which were earlier considered incurable, or had very poor results with existing treatments are now being tackled with good results with these anti-VEGF agents.
Avastin has not been approved by the EMEA for the use of treatment in the eye as it has not gone through proper clinical trials to determine safety and how effective it is.
Avastin has been approved as a treatment for colon and rectal cancer and is therefore readily available. When used for colorectal cancers, the drug is given into the vein of an arm. When Avastin is used for the treatment of wet AMD, it is given into the eye.
Ophthalmologists worldwide have been using Avastin off-label for AMD (‘off label’ refers to prescribing medications for purposes for which they are not licensed).
Avastin has been showing success in stopping new blood vessel growth and clinical observation suggest that its effectiveness and side effects may be similar to those observed in Lucentis and Macugen. Two large-scale long-term randomised controlled trials of Avastin have taken place and are due to report shortly. These results will allow questions about the safety of Avastin in the eye to be properly addressed. It is uncertain at this time how often Avastin injections are given.
Lucentis gained EMEA approval in Jan 2007. Again, this is based on extensive trials to show it is safe and effective. It can be used for all lesion types in wet AMD.
The trials have shown it to stabilise sight in more than 90 per cent of cases and improve sight in up to 40 per cent of cases.
The licence lays down a treatment plan which starts with three injections at four-weekly intervals followed by further injections based on the consultant’s assessment of the patient. Patients need to be monitored every four weeks. In practice, patients receive on average eight injections in the first year and six injections in the second year
Macugen was approved by the European Medicines Evaluation Agency (EMEA) in Feb 2006 following extensive trials to show that it is safe and effective.
Macugen stabilises sight in approximately 70 per cent of cases and has been shown to improve sight in 20 per cent of patients who have been diagnosed early on in the disease process. It can be used for all lesion types in wet AMD.
Treatment consists of an injection into the eye every six weeks, usually for a minimum of two years.