Table 1.
Relative FVIII‐equivalence of bsAbs across assays and assay parameters
| Chromogenic | aPTT | TGA (FXIa trigger) | TGA (TF trigger) | |||
|---|---|---|---|---|---|---|
| Lag time | Peak | Lag time | Peak | |||
| rFVIII | ++++ | ++++ | ++++ | ++++ | ++++ | ++++ |
| SI‐Emia | ++++ | ++++++++ | +++++ | ++ | +++ | + |
| Anti‐FIXa homodimer | +++++ | ++++ | ++++ | + | Not determined | Not determined |
| Anti‐FX homodimer | + | + | + | + | Not determined | Not determined |
| BS‐027125b | + | ++++ | +++ | + | ++ | + |
| Anti‐FIXa homodimer | + | No activity | No activity | No activity | Not determined | Not determined |
| Anti‐FX homodimer | No activity | No activity | No activity | No activity | Not determined | Not determined |
Abbreviations: anti‐FIXa, anti‐factor IXa; anti‐FX, anti‐factor X; aPTT, activated partial thromboplastin time;bs‐Abs, bispecific antibodies; BS‐027125, anti‐FIXa and anti‐FX antibodies BS‐125 and BS‐027; rFVIII, recombinant factor VIII; SI‐Emi, sequence identical emicizumab; TF, tissue factor; TGA, thrombin generation assay.
a
Relative activity at concentrations achieved at steady state in patients on emicizumab prophylaxis.
b
Relative activity at concentrations giving peak activity.