Dry Age-related Macular Degeneration (Geographic Atrophy)
Ophthotech is currently conducting a randomized, double–masked, sham controlled, multi-center Phase 2b clinical trial evaluating the safety and efficacy of Zimura monotherapy in patients with GA secondary to dry AMD.
There are two forms of AMD: dry AMD and wet AMD. Dry AMD is characterized by the development of yellow-white deposits under the retina, known as drusen, along with deterioration of the retinal tissue. Geographic atrophy (GA), a disease characterized by atrophy of the retina, leads to central vision loss, and is an advanced form of dry AMD.
The progression of dry macular degeneration with age can result in a severe form of retinal degeneration known as GA, which typically leads to profound and irreversible vision loss. GA is readily diagnosed during retinal examination using standard diagnostic instruments utilized by ophthalmologists. GA appears as abrupt and deep levels of macular tissue loss. It has sharp margins of characteristic degeneration compared to surrounding healthier macular tissue, resulting in progressive and chronic degeneration of the retina characterized by variable thinning and dysfunction of retinal tissue. A comprehensive epidemiology study published in 2004 in Archives of Ophthalmology estimates that there are approximately 1 million people in the United States with GA.
Wet Age-related Macular Degeneration
The Company has initiated an open-label Phase 2a clinical trial of Zimura in combination with anti-VEGF therapy for wet AMD.
Wet AMD occurs when new and abnormal blood vessels proliferate under or within the retina. These abnormal new blood vessels originate beneath the retina, in a layer called the choroid, and invade into the overlying retinal layers. Abnormal new blood vessels tend to be fragile and often bleed and leak fluid into the macula. Untreated, new blood vessel growth and associated leakage typically lead to retinal distortion and rapid vision loss. The end stage of the disease features scarring with irreversible destruction of the macula.
Idiopathic Polypoidal Choroidal Vasculopathy
The Company has initiated an open-label Phase 2a clinical trial evaluating Zimura in combination with the anti-VEGF agent Eylea® (aflibercept) for the treatment of idiopathic polypoidal choroidal vasculopathy in treatment experienced patients.
Idiopathic polypoidal choroidal vasculopathy, or IPCV, is an age-related disease of the choroid characterized by the presence of polypoidal vascular lesions with or without an associated vascular network. In IPCV, leakage under the RPE, subretinal hemorrhage and RPE detachment are common. When leakage or hemorrhage occurs in the macular region, central vision loss occurs. IPCV is often diagnosed as a variant of wet AMD, although it may occur without the associated neovascularization. IPCV is more prevalent in certain populations with pigmented eye color, including Asian populations. Although anti-VEGF therapy is typically administered for IPCV, multiple studies demonstrate that anti-VEGF therapy may not be as effective in IPCV as it is in wet AMD.