Hemophilia A and B are inherited bleeding disorders caused by the deficiency of blood clotting factor VIII (FVIII) or factor IX (FIX), respectively. Based on their combined incidence, it is expected that there are approximately 500,000 persons with hemophilia globally. Existing treatment consists of factor (VIII or IX) infusion products that are administered intravenously up to 3 times per week to maintain sufficient blood clotting activity to prevent spontaneous bleeding. Without treatment, severe hemophilia is crippling and fatal by late adolescence to early adulthood. Despite the life-saving benefit provided by factor infusion products, they are constrained by their short duration, high cost and limited global distribution. Currently, less than 30% of the global hemophilia population receives factor infusion therapy. Expression Therapeutics is developing novel therapies to overcome limitations to current factor infusion therapy for hemophilia. Our core technologies consist of genetic elements designed to improve factor expression in both gene therapy approaches and recombinant protein manufacturing. Our lead product candidates include a stem cell gene therapy product and a low cost recombinant FVIII product. Other products in earlier stage development include liver-directed gene therapies for hemophilia A and B and a bioengineered FVIII possessing improved pharmacological properties in the context of both gene therapy and protein replacement therapy.