Ophthalmology

Tissue factor (TF) overexpression plays a role in a number of serious retinal diseases, including age-related macular degeneration (AMD) and diabetic retinopathy. These diseases are characterized by inflammation and abnormal blood vessel growth, which can cause patients to lose their vision.

Neovascular (wet) AMD: A Leading Cause of Blindness

AMD is a devastating progressive retinal disease that affects the macula, the part of the eye responsible for central vision. AMD is most common in people older than 55, generally first diagnosed in the early stages as dry AMD. About 1 in 10 patients initially diagnosed with dry AMD will progress to the most advanced form, commonly known as neovascular or wet AMD. An equivalent percentage will progress to advanced dry AMD, with geographic atrophy.  AMD is a leading cause of blindness in industrialized countries.  An estimated 22 million people worldwide are affected. With approximately 200,000 new diagnoses each year, more than 2 million people in the U.S. suffer from the sight-threatening disease.¹

TF plays an important role in the early stages of AMD, characterized by inflammation and in later stages in the formation of choroidal neovasculature (CNV), the pathologic blood vessels that represent the major feature of wet AMD. These blood vessels (lesions) leak blood and fluid, causing inflammation and edema (swelling). Typically, a patient’s central vision deteriorates, and they experience blind spots.

A class of U.S. Food and Drug Administration (FDA) approved drugs known as anti-VEGF therapies are currently the standard of care for advanced forms of exudative wet AMD.  However, the effectiveness of these therapies long-term remains limited as the underlying disease continues to develop and progress despite ongoing treatment. Patients treated with anti-VEGF agents may experience initial visual gains, but they may deteriorate over time and many continue to loss of vision. It has been reported that 20-37 percent of patients ultimately become legally blind (20/200 or worse vision) despite anti-VEGF therapy.^{2, 3}

New treatment options are needed for patients at all stages, early and late AMD, that can interfere with other biological pathways to halt disease progression and prevent long-term loss of vision. It is also critical to provide patients with therapeutic options that impact the earlier stage of the disease and prevent irreversible damage to the retina.

¹  Wong WL et al. The Lancet Global Health. 2014;2(2):106-16. National Eye Institute – AMD. Friedman DS et al. Arch Ophthalmol. 2004;122.

   American Macular Degeneration Foundation.

² Maguire, M.G. et al. Ophthalmology 2016, 123(8), 1751 – 61.

³ Rofagha, S. et al. Ophthalmology 2013, 120(11):2292-9.