RYSTIGGO

Clinical safety rating: caution

Comprehensive clinical and safety monograph for RYSTIGGO (RYSTIGGO).

How it works

RYSTIGGO (rozanolixizumab) is a humanized monoclonal antibody that binds to the neonatal Fc receptor (FcRn), reducing the recycling of immunoglobulin G (IgG) and lowering circulating IgG levels, including pathogenic autoantibodies in generalized myasthenia gravis.

What the body does with it

Metabolism	Rozanolixizumab is a monoclonal antibody; it is expected to be degraded into small peptides and amino acids via catabolic pathways, not metabolized by cytochrome P450 enzymes.
Excretion	Rystiggo (rozanolixizumab) is eliminated primarily via catabolism into small peptides and amino acids. No specific renal or biliary excretion data are available; as a monoclonal antibody, it is not expected to be excreted unchanged in urine or feces.
Half-life	The terminal elimination half-life is approximately 5.3 days (range 4.5–6.1 days), supporting weekly subcutaneous dosing.
Protein binding	Rystiggo is a monoclonal antibody; protein binding is primarily to endogenous IgG (neonatal Fc receptor, FcRn). Specific percentage binding not defined; typical mAb binding is ~100% to target but no significant nonspecific binding.
Volume of Distribution	Approximately 0.06 L/kg (range 0.04–0.08 L/kg), indicating distribution primarily confined to the vascular and interstitial spaces.
Bioavailability	Subcutaneous bioavailability is approximately 73% (range 64–84%) relative to intravenous administration.
Onset of Action	Following subcutaneous administration, clinically meaningful reduction in activities of daily living (MG-ADL) scores is observed within 1 week.
Duration of Action	The therapeutic effect persists for the dosing interval of once weekly; after last dose, clinical effect wanes over several weeks consistent with its half-life.

Classification & Brands

Dosing & administration

Subcutaneous injection: 600 mg once weekly for 4 weeks, then 900 mg once weekly. Administered as two 1.5 mL (200 mg/mL) injections for 600 mg dose or three 1.5 mL injections for 900 mg dose.

Dosage form	INJECTABLE
Renal impairment	No dose adjustment recommended for mild to moderate renal impairment (eGFR ≥30 mL/min/1.73 m²). Not studied in severe renal impairment (eGFR <30 mL/min/1.73 m²) or on dialysis; use not recommended.
Liver impairment	Not studied in hepatic impairment; no specific dose adjustment guidelines available. Use with caution in patients with hepatic impairment.
Pediatric use	Safety and effectiveness in pediatric patients (<18 years) have not been established; no recommended dosing.
Geriatric use	No specific dose adjustment recommended for geriatric patients (>65 years). Clinical studies included limited number of elderly patients; no overall differences in safety or efficacy observed.

Use during pregnancy

1st trimester	Consult provider
2nd trimester	Consult provider
3rd trimester	Consult provider

Clinical note

Comprehensive clinical and safety monograph for RYSTIGGO (RYSTIGGO).

Breastfeeding	No data on presence in human milk, effects on breastfed infant, or milk production. RYSTIGGO is a monoclonal antibody; IgG is excreted in human milk in small amounts. Consider developmental and health benefits of breastfeeding along with maternal need for drug.
Teratogenic Risk	Insufficient human data; based on animal studies, no evidence of teratogenicity at clinically relevant doses. However, IgG antibodies can cross the placenta with increasing transfer during the second and third trimesters. Potential fetal risk cannot be excluded; use only if clearly needed after risk-benefit assessment.

Warnings & precautions

■ FDA Black Box Warning

No black box warning.

Side Effect Profile

Serious Effects

Absolute Contraindications

["Active meningococcal infection.","Known hypersensitivity to rozanolixizumab or any excipients."]

Clinical Precautions

Precautions

["Meningococcal infection: May increase risk of meningococcal infections; monitor and vaccinate if not previously vaccinated.","Hypersensitivity reactions: Infusion-related reactions including anaphylaxis may occur."]

Clinical Tips & Counseling

Drug interactions

Loading safety data…

RYSTIGGO

Clinical safety rating: caution

Comprehensive clinical and safety monograph for RYSTIGGO (RYSTIGGO).

How it works

What the body does with it

Metabolism	Rozanolixizumab is a monoclonal antibody; it is expected to be degraded into small peptides and amino acids via catabolic pathways, not metabolized by cytochrome P450 enzymes.
Excretion	Rystiggo (rozanolixizumab) is eliminated primarily via catabolism into small peptides and amino acids. No specific renal or biliary excretion data are available; as a monoclonal antibody, it is not expected to be excreted unchanged in urine or feces.
Half-life	The terminal elimination half-life is approximately 5.3 days (range 4.5–6.1 days), supporting weekly subcutaneous dosing.
Protein binding	Rystiggo is a monoclonal antibody; protein binding is primarily to endogenous IgG (neonatal Fc receptor, FcRn). Specific percentage binding not defined; typical mAb binding is ~100% to target but no significant nonspecific binding.
Volume of Distribution	Approximately 0.06 L/kg (range 0.04–0.08 L/kg), indicating distribution primarily confined to the vascular and interstitial spaces.
Bioavailability	Subcutaneous bioavailability is approximately 73% (range 64–84%) relative to intravenous administration.
Onset of Action	Following subcutaneous administration, clinically meaningful reduction in activities of daily living (MG-ADL) scores is observed within 1 week.
Duration of Action	The therapeutic effect persists for the dosing interval of once weekly; after last dose, clinical effect wanes over several weeks consistent with its half-life.

Classification & Brands

Dosing & administration

Subcutaneous injection: 600 mg once weekly for 4 weeks, then 900 mg once weekly. Administered as two 1.5 mL (200 mg/mL) injections for 600 mg dose or three 1.5 mL injections for 900 mg dose.

Dosage form	INJECTABLE
Renal impairment	No dose adjustment recommended for mild to moderate renal impairment (eGFR ≥30 mL/min/1.73 m²). Not studied in severe renal impairment (eGFR <30 mL/min/1.73 m²) or on dialysis; use not recommended.
Liver impairment	Not studied in hepatic impairment; no specific dose adjustment guidelines available. Use with caution in patients with hepatic impairment.
Pediatric use	Safety and effectiveness in pediatric patients (<18 years) have not been established; no recommended dosing.
Geriatric use	No specific dose adjustment recommended for geriatric patients (>65 years). Clinical studies included limited number of elderly patients; no overall differences in safety or efficacy observed.

Use during pregnancy

1st trimester	Consult provider
2nd trimester	Consult provider
3rd trimester	Consult provider

Clinical note

Comprehensive clinical and safety monograph for RYSTIGGO (RYSTIGGO).

Breastfeeding	No data on presence in human milk, effects on breastfed infant, or milk production. RYSTIGGO is a monoclonal antibody; IgG is excreted in human milk in small amounts. Consider developmental and health benefits of breastfeeding along with maternal need for drug.
Teratogenic Risk	Insufficient human data; based on animal studies, no evidence of teratogenicity at clinically relevant doses. However, IgG antibodies can cross the placenta with increasing transfer during the second and third trimesters. Potential fetal risk cannot be excluded; use only if clearly needed after risk-benefit assessment.

Warnings & precautions

■ FDA Black Box Warning

No black box warning.

Side Effect Profile

Serious Effects

Absolute Contraindications

["Active meningococcal infection.","Known hypersensitivity to rozanolixizumab or any excipients."]