* Alexion data opens a new chapter - Barclays
* Expects to file for approval in U.S., EU, Japan in H2 2018
* Shares up 12.4 percent to $137.88 (Adds details on drug, analysts quotes, updates share price)
March 15 (Reuters) - Alexion Pharmaceuticals Inc said its experimental drug to treat a rare blood disorder showed in an eagerly awaited study that it was not inferior to its flagship drug, Soliris, paving the way for the company to establish a dominate position in the market as competition looms.
Alexion's shares rose as much as 12.4 percent to $137.88 in trading on Thursday.
The drugmaker has been under pressure from shareholder Elliott Management and is seeking to restore investor confidence following an exodus of top management and a sales practices scandal related to Soliris, its pricey rare disease treatment.
The company's future hinges on the successful development of ALXN1210, aimed at treating the same rare blood disorder as Soliris.
The drug could eat into Soliris sales as the experimental drug's dosing schedule is designed to reduce the number of times it needs to be administered to six per year from about 26 with Soliris.
But having two drugs to treat the rare illness could maintain the company's lock on the market for several years, ensuring solid revenue streams.
"We believe that these results open a new chapter in Alexion, moving the complement franchise beyond Soliris and reducing the threat of potential competition," Barclays analysts said in a note.
Analysts also said that the drug could be launched early enough to establish itself in the market ahead of any Soliris patent expiration.
ALXN1210 was being tested against Soliris in patients with Paroxysmal Nocturnal Hemoglobinuria (PNH) and demonstrated non-inferiority to Soliris on the main goal, as well as four of the key secondary goals.
"Reducing the treatment burden with significantly fewer injections is meaningful ... (and) should help establish ALXN1210 as the new standard-of-care," Yatin Suneja, SunTrust Robinson Humphrey analyst, wrote in a note.
The main goal of the 246-patient study was to reduce high levels of cell damage in the blood and lower the use of blood transfusions.
The drug was generally well tolerated with a safety profile that was consistent with that seen for Soliris, the company said.
Soliris, which brought in $3.14 billion in sales in 2017, is already approved for PNH and atypical hemolytic uremic syndrome, and an autoimmune disorder of progressive muscle weakness, generalized myasthenia gravis.
Alexion said it expects to file a marketing application for the drug in the United States, the European Union and Japan in the second half of 2018. (Reporting by Akankshita Mukhopadhyay in Bengaluru; Editing by Maju Samuel, Bernard Orr)