(Adds details, shares)
May 18 (Reuters) - Shire Plc, said successful late-stage data on its drug for hereditary angioedema (HAE) would form the basis of a U.S. marketing application for the treatment.
The company's U.S.-listed shares were up nearly 7 percent at $194.76 before the bell on Thursday.
Patients with HAE suffer from recurrent episodes of severe swelling and Shire's drug, lanadelumab, is being developed to prevent these attacks.
Shire said lanadelumab reduced the monthly attack rate by 87 percent versus a placebo in a late-stage study over 26 weeks in patients 12 years and older with the rare genetic disease.
HAE affects about 1 in 50,000 people, and the areas most commonly affected are the extremities, gastrointestinal tract, and upper airways.
In the United States, existing treatments include either injections for acute attacks or short-acting intravenous infusions administered twice a week, the company said.
"If approved, lanadelumab may offer patients a long-acting treatment option that significantly reduces HAE attacks when administered subcutaneously as infrequently as every four weeks," the study's lead investigator Aleena Banerji said.
Shire said it plans to submit a U.S. application to market the drug by late 2017 or early 2018.
(Reporting by Natalie Grover in Bengaluru; Editing by Martina D'Couto)