Corneal blindness, defined as visual acuity of 3/60 or less, can be caused by various factors, including scarring resulting from infections (such as herpes simplex), physical trauma, chemical injury, and genetic diseases. In North America and Europe, corneal blindness is treated through replacement of the damaged cornea with a corneal graft derived from human donor corneas. Despite the availability of immunosuppressive drugs, graft rejection remains a serious problem, with a graft failure rate in the U.S. of 35% within five years post-transplantation.
In some territories, such as China, donor corneas are scarce, and alternative sources of treatment for corneal blindness are needed. Although approximately four to five million patients in China are living with corneal blindness, with an incidence of at least 100,000 new cases of corneal blindness each year, the vast majority of cases go untreated. In 2007, for example, only about 3,000 corneal grafts were performed in China.
We believe FG-5200 may represent a therapeutic option that is more widely available and one with reduced risk of the immunogenicity associated with use of donor tissues.