Drug for rare, fatal genetic disorder receives FDA approval

SILVER SPRING, Md. — The Food and Drug Administration has approved a new treatment for a genetic disorder that affects about 500 people in the United States and 3,000 worldwide, the agency said Tuesday.

The FDA announced the approval of Procysbi (cysteamine bitartrate) delayed-release capsules, made by Novato, Calif.-based Raptor Pharmaceuticals, for cystinosis. Cystinosis causes buildup in every cell of the body of a protein building block called cystine, which can cause kidney problems and thus lead to excess loss of sugar, proteins and salts through the urine. Cystinosis may lead to slow body growth and small stature, weak bones and kidney failure and is fatal if not treated in early childhood. The most severe of the three types of the disease is nephropathic cystinosis, which causes severe kidney damage.

The FDA has approved two other drugs for cystinosis: Mylan's Cystagon (cysteamine bitartrate), approved in 1994; and Sigma-Tau Pharmaceuticals' Cystaran (cysteamine) ophthalmic solution eye drops, used to treat corneal cystine crystal accumulation, approved last year.