Marstacimab
Marstacimab is a human monoclonal IgG1 antibody that inhibits Tissue Factor Pathway Inhibitor (TFPI), a key regulator of the coagulation cascade. By neutralizing TFPI activity, it promotes thrombin generation and enhances blood clotting. This medication is used for prophylactic treatment to prevent bleeding episodes in patients with hemophilia.
A monoclonal antibody that promotes blood clotting by blocking TFPI, used to prevent bleeding in hemophilia patients.
Key facts at a glance
- ATC
- B02BX11
- RxNorm
- 2697133
- Generic
- Marstacimab
- Class
- atc-b02
- Brands
- Hympavzi
- Availability
- rx
- Lactation
- unknown
- Routes
- —
- Forms
- prefilled syringe
- Regions
- US, EU, CN, JP
- Monitoring
- —
This page is for informational purposes only.
Do not use this information to diagnose yourself or to replace a physician's advice. Always consult a qualified healthcare provider before starting, stopping, or changing any medication. If you believe you are experiencing a medical emergency, call your local emergency number immediately.
Dosage and administration
- Usual dose
- 300mg loading dose followed by 300mg once weekly
- Maximum
- consult physician
- Frequency
- once weekly
- Instructions
- Follow physician instructions
- Duration limits
- as prescribed
- Monitoring
- standard
- Usual dose
- 300mg loading dose followed by 300mg once weekly
- Maximum
- consult physician
- Frequency
- once weekly (patients 12 years and older)
- Instructions
- Follow physician instructions
- Duration limits
- as prescribed
- Monitoring
- standard
- Usual dose
- 300mg loading dose followed by 300mg once weekly
- Maximum
- consult physician
- Frequency
- once weekly
- Instructions
- Follow physician instructions
- Duration limits
- as prescribed
- Monitoring
- standard
Overdose information
Special Populations
11 groupspregnancy
first trimesteravoid if possible
use only if benefits outweigh potential risks to fetus; consider discontinuation prior to conception if possible
regular fetal monitoring including ultrasound assessments
Use with caution and monitor for adverse effects.
pregnancy
second trimesteravoid if possible
use only if benefits outweigh potential risks; monitor closely
regular fetal monitoring
Use with caution and monitor for adverse effects.
pregnancy
third trimesteravoid if possible
consider discontinuation before delivery; discuss with hematologist
fetal monitoring and assessment of bleeding risk in newborn
Use with caution and monitor for adverse effects.
lactation
breastfeedingno adjustment needed
decide whether to discontinue breastfeeding or discontinue therapy based on benefit-risk assessment
monitor infant for signs of bleeding or infection
Use with caution and monitor for adverse effects.
pediatric_age
adolescents 12 to 17no adjustment needed
approved for patients 12 years and older with hemophilia A or B without inhibitors
regular monitoring of bleeding episodes and anti-drug antibodies
pediatric_age
children under 12not established
safety and efficacy not established in children under 12; use only in clinical trials or as directed by pediatric hematologist
close monitoring in clinical trial setting
geriatric
elderly over 65no adjustment needed
no specific dose adjustment required; monitor renal function
standard monitoring of bleeding episodes and adverse events
renal_impairment
mild to moderateno adjustment needed
no dose adjustment required for mild to moderate renal impairment
standard monitoring
renal_impairment
severeno adjustment needed
use with caution; limited data available
monitor for adverse effects
Use with caution and monitor for adverse effects.
hepatic_impairment
mild to moderateno adjustment needed
use with caution; limited data available
monitor liver function tests
Use with caution and monitor for adverse effects.
hepatic_impairment
severeavoid
not recommended in severe hepatic impairment due to limited data
close monitoring if used
Use of this medication in this population requires careful consideration of risks and benefits.
Statistics and clinical data
Drug class
Marstacimab is a monoclonal antibody that targets tissue factor pathway inhibitor (TFPI)
FDA approval year
FDA approval for hemophilia A and B treatment
Common uses
Indicated for routine prophylaxis to prevent or reduce the frequency of bleeding episodes in adults and pediatric patients with hemophilia A or B
Mechanism of action
Binds to the Kunitz domain of TFPI, inhibiting TFPI activity and promoting thrombin generation
Prevention of bleeding episodes in patients with hemophilia, including those with factor VIII or factor IX deficiencies. Used as prophylactic therapy to reduce bleeding risk.
Marstacimab targets and neutralizes the Kunitz domain 2 (K2) of Tissue Factor Pathway Inhibitor (TFPI), which is the primary inhibitor of the extrinsic coagulation pathway. By blocking TFPI, it removes the brake on thrombin generation, enhancing the body's natural clotting ability.
Administered via subcutaneous injection. As a monoclonal antibody, there is potential for immunogenic reactions. Patients should be monitored for signs of thrombotic events given the enhanced coagulation state. Not a substitute for factor replacement in acute bleeding situations. Treatment should be supervised by a hematologist.
Contraindications
Conditions and patient states where this medication should be avoided or used with caution.
Do not use (1)
Known allergy to this medication or its components
Use caution (1)
Consult healthcare provider for benefits vs risks assessment
Official drug label
WellAlly may earn a referral fee from linked resources at no extra cost to you. Editorial content is never influenced by commercial relationships.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed July 26, 2026. · Read our editorial policy