Neonatal Fc receptor (FcRn) antagonist Pregnancy: There are limited data on use in pregnant women to inform a drug-associated risk. In pregnant monkeys given doses greater than clinical, increases in embryonic death, reduced body weight and impaired immune function were observed in the absence of maternal toxicity. A pregnancy exposure registry exists (US label §8.1).

Rozanolixizumab

Brand names: Rystiggo

Rozanolixizumab is a neonatal Fc receptor (FcRn) blocking monoclonal antibody used for generalised myasthenia gravis in adults who are anti-acetylcholine receptor or anti-MuSK antibody positive.

Auto-extracted from the source labelling — not yet independently clinician-verified. These values were distilled from the UK SPC (or the US label where noted) but have not had a clinician sign-off. Confirm against the current SmPC before prescribing.

Adult dose

Dose: Body-weight banded: less than 50 kg — 420 mg (3 mL); 50 kg to less than 100 kg — 560 mg (4 mL); 100 kg and above — 840 mg (6 mL)

Route: Subcutaneous infusion only, using an infusion pump at a rate of up to 20 mL/hour (abdominal site below the navel, lower right or lower left)

Frequency: Once weekly for 6 weeks (one treatment cycle)

Max: 840 mg per dose (patients weighing 100 kg and above)

SOURCE CAVEAT: no UK SPC posology was fetched in this bundle — the dose above is from the US FDA prescribing information for RYSTIGGO (generalised myasthenia gravis) and must be verified against the UK SPC. Administer subsequent treatment cycles based on clinical evaluation; the safety of initiating subsequent cycles sooner than 63 days from the start of the previous treatment cycle has not been established. Missed dose: may be administered up to 4 days after the scheduled time point, then resume the original schedule until the cycle is completed. Evaluate the need to administer age-appropriate vaccines according to immunisation guidelines BEFORE initiating a new treatment cycle; immunisation with live-attenuated or live vaccines is not recommended during treatment (transient reduction in IgG). Should only be prepared and infused by a healthcare provider. Administration setup: syringe pump occlusion alarm limits at maximum setting, administration tubing 61 cm or shorter, infusion set needle 26 gauge or larger. Allow vials to reach room temperature for approximately 30 minutes before use; do not shake; infuse within 4 hours of puncturing the vial and administer immediately after priming the infusion set. Monitor patients during administration and for 15 minutes after completion for signs and symptoms of hypersensitivity — discontinue and give supportive measures if a reaction occurs. Do not flush the infusion line at the end (volume already accounts for line losses). Single-use vials, no preservative — discard any remaining solution. Paediatric: safety and effectiveness in paediatric patients have not been established. Elderly: clinical studies did not include sufficient numbers of patients aged 65 and over.

Dose auto-extracted from US FDA prescribing information (openFDA / DailyMed) — cross-check; US labelling may differ from UK — not yet clinician-verified. Always confirm against the product SmPC and your local formulary before prescribing.

Contraindications

None stated — the US label §4 states 'None'

Side effects

Headache (>=10%)
Infections (>=10%) — delay administration in active infection; consider withholding if serious infection occurs
Diarrhoea (>=10%)
Pyrexia and nausea (>=10%)
Hypersensitivity reactions including angioedema and rash (>=10%); serious events of aseptic meningitis have been reported

Interactions

Medicines that bind to the human neonatal Fc receptor (FcRn) — e.g. immunoglobulin products, monoclonal antibodies, or antibody derivatives containing the human Fc domain of the IgG subclass — may have lower systemic exposure and reduced effectiveness; monitor closely, and where concomitant long-term use of such a medicine is essential consider discontinuing rozanolixizumab and using alternative therapy [US label §7.1]
Live and live-attenuated vaccines are not recommended during treatment; the safety of live/live-attenuated vaccination and the response to any vaccine are unknown

Clinical monograph

How it works

It binds FcRn and blocks the recycling of immunoglobulin G, accelerating the degradation of circulating IgG including the pathogenic autoantibodies that drive myasthenia gravis.

Prescribing in practice

Because it lowers total IgG, it increases susceptibility to infection, particularly of the respiratory and urinary tracts, and treatment should be deferred during active infection.
Aseptic meningitis and headache have been reported following administration and warrant prompt assessment.
Immunisation status should be reviewed before starting, and live vaccines are generally avoided during treatment.

Monitoring

Monitor for signs of infection during and after treatment cycles and assess clinical response in myasthenic symptoms and function.

Counselling the patient

Report symptoms of infection, such as fever or productive cough, promptly to your care team.
Seek urgent advice for a severe or persistent headache with neck stiffness, as meningitis-like reactions can occur.
Tell your clinician about planned vaccinations so timing can be optimised.

Evidence & guidelines

Rozanolixizumab's efficacy in generalised myasthenia gravis was demonstrated in the randomised placebo-controlled MycarinG trial.

Reference: NICE TA917; SmPC; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. The structured dose values shown have been reviewed by a clinician. Monograph status: clinician-reviewed (2026-07-04).

Curated clinical cross-links plus same-class fallbacks.

Calculators

Pathways