Pharmacokinetics and coagulation biomarkers in children and adults with hemophilia A receiving emicizumab prophylaxis every 1, 2, or 4 weeks

• Published in: Research and practice in thrombosis and haemostasis Vol. 8; no. 1; p. 102306
• Main Authors: Kiialainen, Anna, Adamkewicz, Joanne I., Petry, Claire, Oldenburg, Johannes, Pipe, Steven W., Young, Guy, Mahlangu, Johnny, Lehle, Michaela, Niggli, Markus, Castaman, Giancarlo, Jiménez-Yuste, Víctor, Shima, Midori, Négrier, Claude, Schmitt, Christophe
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.01.2024
• Subjects: biomarkers; emicizumab; hemophilia A; pharmacodynamics; pharmacokinetics; emicizumab; pharmacokinetics; hemophilia A; biomarkers; pharmacodynamics
• ISSN: 2475-0379; 2475-0379
• DOI: 10.1016/j.rpth.2023.102306

Emicizumab is a bispecific antibody that bridges activated factor (F)IX and FX, mimicking the function of missing activated FVIII and thus improving hemostasis in people with hemophilia A. The efficacy and safety of emicizumab were demonstrated in 4 phase III clinical trials (HAVEN 1-4). Here, we describe pharmacokinetics (PKs), pharmacodynamics (PDs), and exploratory safety biomarkers in HAVEN 1 to 4. Participants received emicizumab at a loading dose of 3 mg/kg weekly for 4 weeks, followed by maintenance doses of 1.5 mg/kg weekly, 3 mg/kg every 2 weeks, or 6 mg/kg every 4 weeks. PKs, PDs, and safety biomarkers were assessed in samples collected at regular intervals during the trials. Emicizumab plasma trough concentrations increased during the loading dose period, reaching a mean of 52.9 μg/mL (SD, 13.6 μg/mL) at week 5, and were sustained at 42.1 to 52.3 μg/mL thereafter with maintenance dosing. Activated partial thromboplastin time shortened following the first emicizumab dose. Mean FVIII-like activity and thrombin generation peak height increased to 25.2 IU/dL (SD, 6.9 IU/dL) and 115.2 nM (SD, 42.5 nM) at week 5, with levels sustained at 17 to 23 IU/dL and >116 nM thereafter, respectively. Emicizumab did not notably affect FIX or FX plasma antigen levels, prothrombin time, or concentrations of exploratory safety markers of coagulation activation (D-dimer, prothrombin fragment 1 + 2, and fibrinogen). In HAVEN 1 to 4, emicizumab demonstrated sustained PKs and PDs and improved coagulation parameters without affecting safety biomarkers. •The efficacy and safety of emicizumab were previously demonstrated in the HAVEN 1 to 4 trials.•Pharmacokinetics, pharmacodynamics, and safety biomarkers were evaluated in HAVEN 1 to 4.•Emicizumab demonstrated sustained pharmacokinetics and pharmacodynamics throughout the trials.•Factor IX/factor X plasma antigen levels, prothrombin time, and safety markers were not notably affected.