Bispecific antibody mimicking factor VIIIa (FIX-FX bridging)

Emicizumab

Brand names: Hemlibra

Adult dose

Dose: Loading 3mg/kg SC weekly ×4; maintenance 1.5mg/kg weekly OR 3mg/kg q2w OR 6mg/kg q4w

Route: Subcutaneous

Frequency: Weekly–monthly

Clinical pearls

NICE TA577 / TA585: prophylaxis for haemophilia A with or without inhibitors
UKHCDO and BSH guidance
Affects aPTT-based assays — use chromogenic FVIII (bovine) for monitoring
Annualised bleed rate dramatically reduced vs FVIII prophylaxis

Contraindications

Hypersensitivity

Side effects

Injection-site reactions
Headache
Arthralgia
Thrombotic microangiopathy / thrombotic events when concurrent aPCC ≥100 units/kg/24h
Antibody development (rare)

Interactions

Activated prothrombin complex concentrate (FEIBA — avoid combination if possible; if used, doses ≤100 units/kg/24h)

Monitoring

Bleeding episodes
Inhibitor titre
ADAs
TMA signs

Reference: BNF; NICE TA577; NICE TA585; UKHCDO; BSH; SmPC; https://bnf.nice.org.uk/drugs/emicizumab/. Verify against your local formulary and the latest BNF before prescribing.

Curated clinical cross-links plus same-class fallbacks.

Calculators

Pathways