Siponimod (Mayzent) is a sphingosine 1-phosphate (S1P) receptor modulator used for the treatment of relapsing forms of multiple sclerosis (MS) in adults, including clinically isolated syndrome, relapsing-remitting disease, and active secondary progressive disease.
How to Use Siponimod (Mayzent)
Dosing Regimen
Standard Dose: The maintenance dose is determined based on the CYP2C9 genotype. For patients with CYP2C9*1/*1, *1/*2, or *2/2 genotypes, the recommended maintenance dose is 2mg, taken orally once daily. For patients with CYP2C91/*3 or *2/*3 genotypes, the recommended maintenance dose is 1mg, taken orally once daily.
Dose Escalation: A 5-day escalation regimen is required to reach the 2mg maintenance dose (0.25mg on Day 1, 0.25mg on Day 2, 0.5mg on Day 3, 0.75mg on Day 4, 1.25mg on Day 5). Alternatively, a 4-day escalation regimen is used to reach the 1mg maintenance dose (0.25mg on Day 1, 0.25mg on Day 2, 0.5mg on Day 3, 0.75mg on Day 4).
Administration Method: Swallow the tablet whole; do not split, crush, or chew it.
Pre-Treatment Assessment
CYP2C9 genotype testing.
Electrocardiogram (ECG) to evaluate cardiac conduction function.
Complete blood count.
Liver function tests (performed within 6 months).
Ophthalmic examination including assessment of the macula.
Skin examination.
Varicella-zoster virus antibody testing (vaccination is required if there is no history of immunity).
Dose Adjustment of Siponimod (Mayzent)
Adjustment Based on Safety
Cardiac Monitoring: Patients with sinus bradycardia (heart rate <55 bpm), first-degree atrioventricular block, or second-degree (Mobitz Type I) atrioventricular block require 6-hour monitoring after the first dose.
Restart After Interruption: If treatment is interrupted for ≥4 days, the dose escalation regimen must be restarted.
Adjustment Based on Adverse Reactions
Infection: Initiation of treatment should be delayed in cases of severe active infection.
Hepatic Dysfunction: Discontinue treatment if ALT/AST >3× upper limit of normal (ULN) accompanied by symptoms.
Macular Edema: Consider discontinuing treatment if macular edema is confirmed.
Use in Special Populations for Siponimod (Mayzent)
Pregnancy and Lactation
Pregnancy: Animal data suggest potential fetal harm. Women of childbearing age must use effective contraception during treatment and for 10 days after discontinuing the medication.
Lactation: There are no human data available, but animal studies show that the drug is excreted in breast milk. A risk-benefit assessment is recommended.
Hepatic Impairment
No dose adjustment is needed for patients with mild to moderate hepatic impairment. Data on patients with severe hepatic impairment are limited, so caution is advised.
Renal Impairment
No dose adjustment is needed for patients with severe renal impairment (creatinine clearance 15-29 mL/min), but close monitoring is required.
