Inhibition of hybrid human/porcine FVIII by murine MoAb NMC-VIII/5. HB⁻ or hybrid FVIII was diluted into hemophilia A plasma to a final concentration of 0.8 to 1.2 U/mL and then incubated for 2 hours with the indicated dilutions of NMC-VIII/5 antibody. Residual FVIII activity was measured as described in Materials and Methods. (○) HB⁻; (•) HP20; (▿) HP23; (▾) HP24; (□) HP25; (▪) HP26; (▵) HP27; (▴) HP28.