Macugen® was approved on December 12, 2004, for the treatment of neovascular (wet) ARMD. This novel treatment involves injection of an “aptamer” directly into the eye every 6 weeks. Results are comparable to Ocular Photodynamic Therapy with Visudyne®. Macugen was the first anti-VEGF and intraocular injection approved by the FDA for the treratment of wet macular degeneration.
The excitement of Macugen®’s approval was not its clinical efficacy, but rather the vilification of a new approach to treat degenerative neovascular disease. This is the first human disease treated with an aptamer. An aptamer is an oligonucleotide (DNA or RNA), which binds proteins (e.g. VEGF) and neutralizes its ability to bind to cellular receptors. In this way, the pathway that leads to neovascular disease is chemically derailed. It is important to note that the results of the two modalities are comparable to each other. It may be that certain patients respond better to one treatment over the other.
The mainstay of treatment for wet ARMD had been OPDT (Ocular Photodynamic Therapy). After the introduction of Macugen, PDT became obsolete. While there are certain circumstances where a less invasive procedure may be needed, PDT is not used often.
The potential for the development of endophthalmitis (infection inside the eye) was most concerning at the initial time of approval in 2004. Initial reports sited rates as high as 2% although recent analysis has decreased this rate to just over 1%. The risk of endophthalmitis for intravitreal Kenalog injection (similar type of injection) is about 0.1%. As of this writing, January 2011, intravitreal injections have become standard of care.
Macugen has fallen by the wayside. Its successors, namely Avastin and Lucentis, are the most common anti-VEGF treatments to date.
Randall V. Wong, M.D.