The U.S. Food and Drug Administration has approved Apellis Pharmaceuticals Inc's drug to treat an advanced eye disorder that is one of the leading causes of blindness globally, the company said on Friday.

The drug, which would be sold under the brand name Syfovre, slowed down the progression of the eye disease geographic atrophy (GA), becoming the only FDA-approved treatment for the disorder.

Shares of the drugmaker rose 19.4% to $61.99 after market.

"Syfovre will be listed at $2,190 per vial, in line with recently approved anti-VEGF (vascular endothelial growth factor) therapies," the company told Reuters.

Anti-VEGF therapies block or regulate the formation and growth of blood vessels and are used as treatment for cancer and age-related macular degeneration.

GA is a chronic progressive condition that tends to occur in the late stage of age-related macular degeneration, where irreversible loss of retinal tissue can result in loss of vision. The disease affects 8 million patients globally, and about 20% of individuals with age-related macular degeneration.

The drug is already approved and sold under the brand name of Empaveli for the treatment of a rare blood disorder called paroxysmal nocturnal hemoglobinuria.

Apellis said the drug is expected to be available by the beginning of March through specialty distributors and specialty pharmacies in the United States.