SHANGHAI, April 11 (Xinhua) -- China has approved its first gene therapy for hemophilia B, an inherited bleeding disorder caused by the deficiency of the clotting protein factor IX (FIX).The National Medical Products Administration has officially approved BBM-H901 (Dalnacogene Ponparvovec Injection) for the treatment of adult patients with moderate to severe hemophilia B, Belief BioMed and Takeda China jointly announced on Friday.