Major Success for Gene Therapy for Factor IX Deficiency: near elimination of bleeding and factor use

Hemophilia B Gene Therapy with a High-Specific-Activity Factor IX Variant: the researchers infused a single-stranded adeno-associated viral (AAV) vector consisting of a bioengineered capsid, liver-specific promoter and factor IX Padua (factor IX–R338L) transgene in 10 men with hemophilia B who had factor IX coagulant activity of 2% or less of the normal value.

They found sustained therapeutic expression of factor IX coagulant activity after gene transfer in the 10 participants with hemophilia who received the same vector dose. Transgene-derived factor IX coagulant activity enabled the termination of baseline prophylaxis and the near elimination of bleeding and factor use.

More info here: http://www.nejm.org/doi/full/10.1056/NEJMoa1708538