Emicizumab is a bispecific antibody drug used for preventing bleeding in patients with hemophilia A.

How to Use Emicizumab

Route of Administration

Emicizumab is for subcutaneous injection only and must not be administered intravenously.

The drug should be injected into the lateral upper arm, thigh, or any quadrant of the abdomen. A different anatomical site should be selected for each injection compared to the previous one.

The injection site should avoid moles, scars, and areas of skin that are sensitive, bruised, red, hardened, or damaged.

Injections into the lateral upper arm may only be performed by caregivers or healthcare professionals.

Preparation Before Medication Use

Before use, visually inspect the medicinal solution for particles and discoloration.

Emicizumab subcutaneous injection should be a colorless to slightly yellow solution. Do not use it if visible particles are found or the solution is discolored.

It is necessary to prepare a syringe, a transfer needle, and an injection needle to draw the medicinal solution from the vial and administer the subcutaneous injection.

Selection of Injection Devices

A 1mL syringe should be used for doses not exceeding 1mL; a 2mL or 3mL syringe should be used for doses greater than 1mL but not exceeding 2mL.

The transfer needle should be an 18-gauge needle with a length of 1½ inches, and the injection needle should be a 26-gauge needle with a maximum length of ½ inch.

All injection devices must be sterile, latex-free, pyrogen-free, and for single-use only.

Patient Self-Management

After receiving appropriate training on subcutaneous injection techniques under the guidance of healthcare professionals, patients may self-administer the injection or have it administered by a caregiver.

Self-administration is not recommended for children under 7 years of age.

After each injection, any unused residual medicinal solution in the single-dose vial should be discarded.

Routine Dosage Regimen

Administer 3mg/kg subcutaneously once weekly for the first 4 weeks, followed by 1.5mg/kg subcutaneously once weekly thereafter. This dosage regimen is applicable to adult, adolescent, and pediatric patients.

If a dose is missed on the scheduled date, administer the missed dose as soon as possible before the next scheduled dose, then resume the regular weekly dosing schedule. Do not double the dose to make up for a missed one.

In clinical trials, if the therapeutic effect is suboptimal (e.g., occurrence of ≥2 spontaneous and clinically significant bleeding episodes), the maintenance dose may be increased to 3mg/kg once weekly after 24 weeks of treatment. However, this adjustment should be made cautiously after evaluation by healthcare professionals.

Concomitant Use with Other Hemostatic Drugs

When patients need to use activated prothrombin complex concentrate (aPCC), special attention should be paid to the risks of thrombotic microangiopathy (TMA) and thromboembolism.

Clinical experience shows that patients receiving emicizumab prophylaxis may experience TMA and thrombotic events when the average cumulative dose of aPCC exceeds 100U/kg within 24 hours.

Emicizumab Use in Special Populations

Elderly Patients

Clinical studies of emicizumab did not include a sufficient number of patients aged 65 years and older; therefore, it is unknown whether the response of elderly patients differs from that of younger patients.

Close monitoring is required when administering emicizumab to elderly patients.

Pregnant Women

Currently, there are no data on the use of emicizumab in pregnant women to assess the risks of drug-related major birth defects and miscarriage.

Emicizumab should be used during pregnancy only if the potential benefit outweighs the potential risk to the fetus.

Women of childbearing age should use contraceptive measures while receiving emicizumab.

Lactating Women

It is unknown whether emicizumab is present in human milk, its effects on breastfed infants, or its effects on milk production.

The benefits of breastfeeding for infant development and health, the mother’s clinical need for emicizumab, and any potential adverse effects on the breastfed infant should be considered.