The present inventors verified the coagulation promoting effect of multispecific antigen binding molecules, said molecules replacing the function of FVIII, using blood and plasma collected from patients with FIX abnormality. As a result, it is clarified that a multispecific antigen binding molecule replacing the function of FVIII is not only usable in a method for preventing and/or treating bleeding in hemophilia A, acquired hemophilia A, von Willebrand's disease and hemophilia C caused by the dysfunction of FVIII but also usable in a method for preventing and/or treating bleeding in FIX abnormality owing to the coagulation promoting activity thereof. It is also clarified that the effect of a FIX preparation can be enhanced by the combined use of the FIX preparation with the multispecific antigen binding molecule replacing the function of FVIII and this combined use appears promising as a combination therapy showing a stable hemostatic effect.本發明者們，使用源自FIX異常症患者的血液及血漿，檢證因替代FVIII功能之多特異性抗原結合分子所致之凝固促進作用。其結果，替代FVIII功能之多特異性抗原結合分子不僅顯示可作為針對起因於FVIII功能不全的血友病A、後天血友病A、溫韋伯氏症、及血友病C中的出血之預防法和/或治療法來利用，亦因其凝固促進活性可作為針對FIX異常症的出血之預防法和/或治療法來利用。再者，替代FVIII功能的多特異性抗原結合分子與FIX製劑併用時，可增強FIX製劑的效果，有望作為顯示安定的止血效果的併用療法。
