(Adds details, shares)
March 22 (Reuters) - Ultragenyx Pharmaceutical Inc said its drug to treat patients with seizures did not meet the main goal in a mid-stage study, sending its shares down 6.2 percent in after-market trading on Wednesday.
The company said the study did not show statistical significance in reducing the frequency of seizures among patients treated with the drug compared to a placebo, during a eight week treatment period.
Ultragenyx's experimental treatment for mucopolysaccharidosis — a rare genetic, metabolic disorder when the body is unable to breakdown GAGs, a kind of complex carbohydrate — is in its late stage.
The company's other rare and ultra-rare disease treatments are in its mid-stages. (Reporting by Akankshita Mukhopadhyay in Bengaluru; Editing by Shounak Dasgupta)