Section 04 · Monograph

Satralizumab

Reviewed Nov 2026FDA label

EnspryngAnti-IL-6 receptor mAb

Indications

Neuromyelitis optica spectrum disorder (NMOSD) in adult patients who are anti-aquaporin-4 (AQP4) antibody positiveFDA-labeled

Humanized recombinant IgG2 monoclonal antibody directed against the interleukin-6 receptor (IL-6R)
Binds both soluble and membrane-bound IL-6 receptors, inhibiting IL-6-mediated signaling
IL-6 is implicated in NMOSD pathogenesis (AQP4-antibody production, blood-brain-barrier permeability); the precise mechanism underlying clinical benefit in NMOSD is not fully established
Uses recycling antibody engineering to extend half-life, enabling every-4-week subcutaneous maintenance dosing

Loading phase: 120 mg subcutaneous injection at Weeks 0, 2, and 4
Maintenance phase: 120 mg subcutaneously every 4 weeks thereafter
Pretreatment screening for hepatitis B, tuberculosis, and baseline liver transaminases is required before initiation
Assess for active infection before each dose; delay dosing if an active infection is present

No formal drug-drug interaction studies have been conducted with satralizumab-mwge
The impact of commonly used small-molecule drugs on satralizumab-mwge pharmacokinetics is inconclusive per labeling
Live and live-attenuated vaccines are not recommended during treatment
Use with other immunosuppressive therapies warrants close monitoring for additive infection risk

Screen for hepatitis B and tuberculosis before starting therapy
Monitor ALT/AST every 4 weeks for the first 3 months, then every 3 months for the remainder of the first year, then as clinically indicated; discontinue if ALT/AST exceed 5x the upper limit of normal
Monitor absolute neutrophil count 4-8 weeks after initiation, then at regular intervals; interrupt therapy if ANC falls below 1.0 x 10^9/L
Assess for signs/symptoms of infection before each dose; delay or withhold dosing during active infection

No adequate data on developmental risk in human pregnancies are available
Animal reproduction studies in cynomolgus monkeys at doses up to 50 mg/kg/week showed no adverse effects on embryo-fetal development
A pregnancy exposure registry monitors outcomes in women exposed to satralizumab-mwge during pregnancy (enrollment: 1-833-277-9338)
Presence of satralizumab-mwge in human milk is unknown; monoclonal IgG antibodies are excreted in monkey milk — weigh developmental/health benefits of breastfeeding against the mother's clinical need for therapy