Ocrelizumab (Ocrevus) is a B-cell depleting antibody targeting CD20, used for the treatment of relapsing multiple sclerosis (RMS) and primary progressive multiple sclerosis (PPMS).

Ocrelizumab (Ocrevus) Medication Precautions

Contraindication Screening

Active Hepatitis B Virus (HBV) Infection: HBV screening (HBsAg and anti-HB tests) must be performed before medication administration. The drug is contraindicated in patients with positive results.

History of Severe Infusion Reactions: Contraindicated in patients who have experienced life-threatening infusion reactions to Ocrevus in the past.

Infection Status Assessment: If an active infection is present, medication administration should be delayed until the infection is fully controlled.

Pre-Medication Preparation

Immunoglobulin Testing: Serum immunoglobulin levels (IgG/IgA/IgM) must be tested at baseline. Patients with low levels require consultation with specialists.

Liver Function Testing: Levels of alanine transaminase (ALT), aspartate transaminase (AST), alkaline phosphatase, and bilirubin must be checked before medication administration.

Vaccination: Live vaccines must be administered 4 weeks before medication initiation; inactivated vaccines are recommended to be administered 2 weeks in advance.

Administration Regimen

Initial Dose: 300 mg via intravenous infusion, followed by another 300 mg 2 weeks later (total dose: 600 mg).

Maintenance Dose: A single 600 mg intravenous infusion every 6 months.

Pre-Infusion Prophylaxis: 30 minutes before each infusion, 100 mg of methylprednisolone (or an equivalent glucocorticoid) and an antihistamine (e.g., diphenhydramine) must be administered intravenously.

Ocrelizumab (Ocrevus) Medication Monitoring

Infusion Reaction Monitoring

Onset Time: 34-40% of patients experience infusion reactions, most occurring during the first infusion and potentially lasting up to 24 hours after the infusion.

Symptom Management: For mild reactions, reduce the infusion rate by 50% for at least 30 minutes.

Severe Reactions: Immediately discontinue the infusion and provide symptomatic support.

Life-Threatening Reactions: Permanently discontinue the medication.

Observation Requirements: Monitor the patient for at least 1 hour after each infusion, and inform the patient that delayed reactions may occur.

Infection Monitoring

Common Infection Types: Upper/lower respiratory tract infections (40-49%), skin infections (14%), and herpes virus infections (2.1-5%).

Special Infection Risks

Progressive Multifocal Leukoencephalopathy (PML): Immediately evaluate patients who develop neurological symptoms (e.g., cognitive impairment, unilateral weakness).

HBV Reactivation: Carriers require continuous monitoring of liver function.

Severe Herpes Infections: Including central nervous system (CNS) infections and intraocular infections.

Management Principle: If an infection occurs, suspend medication administration until the infection resolves completely.

Laboratory Monitoring

Immunoglobulins: Test IgG levels every 6-12 months. If levels remain low and are accompanied by severe infections, consider discontinuing the medication.

Liver Function: Discontinue the medication if unexplained ALT/AST levels exceed 3 times the upper limit of normal (ULN) along with elevated bilirubin.

Complete Blood Count (CBC): When neutrophils are < 1.0 × 10⁹/L, assess the risk of infection.