Avacincaptad pegol is a medication developed for the treatment of geographic atrophy, an advanced form of age-related macular degeneration. This drug is an RNA aptamer designed to bind to specific targets. It aims to slow the progression of this eye condition, which can lead to significant vision loss.
Understanding Geographic Atrophy
Geographic atrophy (GA) is a progressive eye disease that causes irreversible damage to the macula, the central part of the retina responsible for sharp, detailed vision. It is a late stage of dry age-related macular degeneration (AMD), which is a common cause of vision loss in older adults. In GA, light-sensitive cells in the retina, including the retinal pigment epithelium (RPE) and photoreceptors, begin to die off, creating patches of atrophy or blind spots.
These atrophic lesions enlarge over time, leading to a gradual decline in central vision. The fovea, the most sensitive part of the macula, can be threatened by these expanding lesions, further impairing the ability to see fine details. This vision loss can significantly affect a person’s quality of life, impacting daily activities such as reading, driving, and recognizing faces.
The exact causes of GA are complex, but aging and an overactive immune response, particularly involving the complement system, play a role. Currently, GA cannot be prevented, as aging is the primary risk factor.
How Avacincaptad Pegol Works
Avacincaptad pegol targets the complement cascade, a part of the immune system. This system is a series of proteins that work together to defend the body against pathogens, but when overactive or improperly regulated, it can contribute to the destruction of healthy cells, as seen in geographic atrophy.
Avacincaptad pegol is a pegylated RNA aptamer, a single strand of RNA modified with polyethylene glycol (PEG) to improve its stability and duration. This aptamer binds to complement factor 5 (C5), a protein in the later stages of the complement cascade.
By binding to C5, avacincaptad pegol prevents it from being cleaved into its active components, C5a and C5b. These components normally contribute to inflammation and the formation of the membrane attack complex (MAC), which can lead to cell death.
Inhibiting C5 cleavage limits inflammatory signals and MAC formation, reducing retinal cell destruction. The drug dampens excessive complement activity around GA lesions, helping preserve retinal cells and reduce vision loss.
Treatment Administration and Side Effects
Avacincaptad pegol, marketed as Izervay, is FDA-approved for geographic atrophy secondary to age-related macular degeneration. It is administered directly into the eye via intravitreal injection, ensuring the drug reaches the retina effectively. Patients typically receive monthly injections.
During the procedure, the eye is numbed with anesthetic drops, and a very fine needle is used to deliver the medication into the vitreous humor. The injection process is quick, and patients may experience mild discomfort or pressure.
Following the injection, patients might notice temporary blurry vision, floaters, or a feeling of grittiness in the eye. Common side effects include eye discomfort, conjunctival hemorrhage (a small bruise on the white of the eye), and increased eye pressure. These effects are generally mild and resolve on their own.
Serious, less common side effects include endophthalmitis (a severe eye infection) and retinal detachment (where the retina pulls away from its supporting tissue). There is also an increased risk of developing choroidal neovascularization (wet AMD) in the treated eye, characterized by abnormal blood vessel growth under the retina. Regular follow-up appointments monitor for complications.