Marstacimab: prescribing and clinical use
Focused clinical detail for use alongside current product information, local policy and patient-specific assessment.
Marstacimab: clinical details
Prescribing considerations
- Initiate under a haemophilia specialist in a non-bleeding state after confirming severe congenital haemophilia A or B without the relevant factor inhibitor.
- Assess thrombotic and ischaemic history, prothrombotic conditions, immobility, obesity, smoking, cancer and acute severe illness.
- Establish a written breakthrough-bleeding plan; marstacimab is not an acute bleed treatment.
- Coordinate switching, major surgery and treatment interruption through the specialist service.
- Provide injection training and record the product name and batch number.
Contraindications and cautions
- Hypersensitivity to marstacimab or any excipient.
- Particular caution is required with thromboembolic risk factors or acute severe illness.
- Evidence is unavailable in moderate or severe renal or hepatic impairment.
- The licensed indication excludes children under 12 years, people below the specified body weight and haemophilia with factor inhibitors.
Monitoring
- Bleeding control and breakthrough bleeding
- Symptoms and changing risk factors for venous or arterial thrombosis
- Injection-site reactions, rash and hypersensitivity symptoms
- Blood pressure
- Clinical status during severe infection, sepsis, trauma, cancer or perioperative care
- PT and aPTT are not meaningful measures of marstacimab activity
Clinical pharmacology
Marstacimab is a recombinant human IgG1 antibody against the Kunitz-2 domain of TFPI. It has nonlinear, target-mediated disposition and is cleared predominantly by protein catabolism.
Formulation and product differences
- Preservative-free, single-use pre-filled pen containing a clear, colourless to light-yellow solution.
- Keep refrigerated in the original carton, protect from light and do not freeze or shake. Once stored at room temperature, it must not be returned to the refrigerator and must be used or discarded within the authorised storage period.
Marstacimab preparations and strengths
Injection
Route: Parenteral
Strengths: 150 mg
Marstacimab interactions
Formal interaction studies have not been conducted. Conventional metabolic interactions are considered unlikely because marstacimab is cleared mainly through protein catabolism.
Factor VIII or factor IX concentrates
These may be needed for breakthrough bleeding according to the individual haemophilia-team plan; do not substitute extra marstacimab.
Bypassing agents and other haemostatic treatments
Close exposure to additional haemostatic agents has been linked to thrombosis with other anti-TFPI products, so specialist coordination is required.
Other medicines injected under the skin
Use a different anatomical injection site where possible.
Sources
These sources were used to prepare and review this medicine page.
Prepared and reviewed by the iatroX editorial team.