Back of the Eye Diseases
Dry Age-related Macular Degeneration (Geographic Atrophy)
The Company is in the process of modifying its geographic atrophy program, a form of dry age-related macular degeneration (AMD). Following the recent announcements of competitors’ conflicting topline results from two clinical trials assessing the role of two different types of complement inhibitors, one blocking the alternative complement pathway (did not meet primary endpoint) and the other blocking all three complement pathways (met primary endpoint), in the treatment of GA, Ophthotech has decided to modify its ongoing Phase 2/3 clinical trial of Zimura monotherapy (which blocks all three complement pathways) in geographic atrophy. Ophthotech had originally planned to enroll 300 patients in an initial stage of the ongoing trial, with an interim analysis scheduled for the 18-month time point, and to potentially enroll up to an additional 600 patients thereafter.
The trial will be modified to accelerate the anticipated timeline to obtain topline data by reducing the number of patients, shortening the time point for attaining the primary efficacy endpoint and thereby reducing the cost to complete the study. The modified study design will incorporate patients already enrolled in the study.
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, a disease characterized by atrophy of the retina, leads to central vision loss, and is a form of dry AMD.
Wet Age-related Macular Degeneration
The Company has initiated a Phase 2a clinical trial of Zimura in combination with anti-VEGF therapy for wet AMD. This trial is scheduled to start by the end of 2017.
Wet AMD is the second form of AMD and it is generally caused by the infiltration of abnormal new blood vessels into the retina. In patients with wet AMD, abnormal new blood vessels tend to be fragile and often bleed and leak fluid into the macula, the central-most portion of the retina. This can result in the distortion of detailed central vision necessary for daily activities such as reading, face recognition, watching television and driving, and can lead to loss of central vision and blindness. While wet AMD represents approximately 10% of all cases of AMD, it is responsible for 90% of the severe vision loss associated with the disease and is the leading cause of blindness in patients over the age of 55 in the US and EU.
Idiopathic Polypoidal Choroidal Vasculopathy
The Company plans to start Phase 2a clinical trial of Zimura in combination with anti-VEGF therapy for idiopathic polypoidal choroidal vasculopathy by the end of 2017.
Idiopathic Polypoidal Choroidal Vasculopathy (IPCV) is a retinal disease involving the choroidal vasculature characterized by the presence of polypoidal lesions, which leads to vision loss. The estimated prevalence in the US is approximately 80,000 to 160,000 patients.1
- OPHT Estimate based on published data.