Biogen Idec Inc and Swedish Orphan Biovitrum said their experimental blood disorder drug was effective in treating children with hemophilia in a late-stage trial.
The drug, Eloctate, was able to maintain low bleeding rates in children with hemophilia A - a rare genetic disorder in which a person's blood does not clot properly due to missing or reduced levels of a protein called factor VIII.
The late-stage trial tested Eloctate in previously treated children under 12 years with severe hemophilia A.
The main goal of the study was to evaluate the frequency of antibody development that can interfere with the therapy and none were detected.
Eloctate is a long-acting hemophilia treatment that was given to patients as twice-weekly preventive injections.
Hemophilia drugs generally need to be infused every two or three days to prevent bleeding episodes.
Biogen and Swedish Orphan Biovitrum have also developed another hemophilia drug, Alprolix, that was approved by the U.S. Food and Drug Administration last month for treating hemophilia B. Hemophilia B is caused by the absence of the factor IX protein.
Biogen shares were up slightly at $300.92 in premarket trading. They closed at $300.68 on Wednesday on the Nasdaq.
(Reporting by Esha Dey in Bangalore; Editing by Saumyadeb Chakrabarty)