Marstacimab

US label section 2.1 — recommended dosage in adults and paediatric patients 12 years of age and older. DOSE ADJUSTMENT DURING TREATMENT: in patients weighing 50 kg or more, consider a dose adjustment to 300 mg subcutaneously weekly when control of bleeding events is judged to be inadequate by the healthcare provider. MISSED DOSES on 150 mg maintenance: administer as soon as possible before the day of the next scheduled dose, then resume the usual 150 mg weekly schedule; if more than 13 days have passed since the last dose, administer a 300 mg loading dose followed by resumption of 150 mg once weekly. MISSED DOSES on 300 mg maintenance: administer a dose as soon as possible, then resume the 300 mg weekly schedule. BREAKTHROUGH BLEEDS (section 2.5): factor VIII and factor IX products or bypassing agents (e.g. rFVIIa or aPCC) can be administered to treat breakthrough bleeds in patients receiving marstacimab — do not use additional doses of marstacimab to treat breakthrough bleeds. SURGERY (section 2.6): temporarily pause marstacimab at least 7 days before major surgery. ADMINISTRATION (section 2.3): may be removed from the refrigerator and allowed to warm at room temperature (up to 30 degrees C) in the carton for 15 to 30 minutes protected from direct sunlight — do not warm using a heat source such as hot water or a microwave; after proper instruction, a patient 12 years and older may self-inject or a caregiver may administer, if the healthcare provider determines it is appropriate. PAEDIATRIC 6 TO LESS THAN 12 YEARS (section 2.2): loading dose 150 mg (one 150 mg injection or two 75 mg injections) subcutaneously, then maintenance dosing of 75 mg every week by subcutaneous injection starting one week after the loading dose, on the same day each week at any time of day; in patients weighing 25 kg or more, consider a dose adjustment to 150 mg subcutaneously weekly if control of bleeding events is inadequate — safety and efficacy above 150 mg weekly have not been established in this age group. Missed doses on 75 mg maintenance: give as soon as possible before the day of the next scheduled dose then resume the weekly 75 mg schedule; if more than 13 days have passed, give a 150 mg loading dose then resume 75 mg weekly. This paediatric regimen is a fixed milligram dose rather than a per-kg dose, so no structured per-kg paediatric dose is given here. Safety and effectiveness have not been established in paediatric patients younger than 6 years of age. Verify all paediatric dosing against a children's formulary before prescribing. SOURCE: no UK SPC was fetched in this bundle — this draft is distilled from the US prescribing information and must be verified against the UK SPC.