FDA approves Raptor's Procysbi for rare genetic condition; and Plan B One-Step

US drugmaker Raptor Pharmaceuticals (Nasdaq: RPTP) saw its share price rise 8.2% to $7.09 in mid-afternoon trading yesterday (April 30) after the US Food and Drug Administration approved its Procysbi (cysteamine bitartrate) for the management of nephropathic cystinosis, a rare genetic condition, in children and adults. Procysbi was granted orphan product designation because it is intended to treat a rare disease or condition.

Cystinosis affects an estimated 500 patients in the USA and about 3,000 patients worldwide. Fatal if not treated in early childhood, cystinosis causes a protein building block called cystine to build up in every cell of the body. Cystinosis may lead to slow body growth and small stature, weak bones and developing and worsening kidney failure. There are three types of cystinosis, the most severe being nephropathic cystinosis, which severely damages the kidneys.

Currently-approved cystinosis therapies are Cystagon and Cystaran