Multiple Sclerosis — Disease-Modifying Therapy Pregnancy: Contraindicated — animal data show foetal B-cell depletion and increased perinatal mortality; use effective contraception; discontinue 12 months before planned pregnancy

Ocrelizumab

Brand names: Ocrevus

Adult dose

Dose: 300 mg IV on day 1 and day 15 (first dose split); then 600 mg every 6 months

Route: IV infusion

Frequency: Every 6 months (after initial split dose)

Max: 600 mg per 6-month dose

Pre-medicate: methylprednisolone 100 mg IV + antihistamine + antipyretic 30–60 min before. First infusion: 300 mg over 2.5 hours. Subsequent 600 mg: over 3.5 hours. Do NOT give live vaccines within 4 weeks before or during treatment.

Paediatric dose

Dose: Seek specialist opinion N/A/kg

Route: IV

Frequency: N/A

Max: N/A

Not licensed in paediatrics; seek specialist paediatric neurology opinion

Dose adjustments

Renal

No dose adjustment required — monoclonal antibody

Hepatic

No dose adjustment required

Paediatric weight-based calculator

Patient weight (kg)

Not licensed in paediatrics; seek specialist paediatric neurology opinion

Clinical pearls

Mechanism: humanised anti-CD20 monoclonal antibody — depletes CD20-expressing B cells (including memory B cells) via antibody-dependent cellular cytotoxicity and complement-dependent cytotoxicity; B-cell reconstitution takes 12+ months after stopping
OPERA I & II (NEJM 2017): ocrelizumab vs interferon beta-1a in RRMS — 46–47% reduction in annualised relapse rate; 40% relative reduction in confirmed disability progression
ORATORIO trial (NEJM 2017): ocrelizumab vs placebo in primary progressive MS (PPMS) — FIRST disease-modifying therapy to show efficacy in PPMS; 24% relative risk reduction in confirmed disability progression; landmark trial
MHRA: licensed for RRMS and PPMS — the first therapy licensed for PPMS in the UK; NICE TA585 (RRMS) and TA586 (PPMS) both approved
Hepatitis B screening MANDATORY: screen all patients for HBsAg, anti-HBc, anti-HBs before starting; prophylactic antiviral therapy required if HBsAg+ or anti-HBc+ with anti-HBs below protective levels
COVID-19 vulnerability: B-cell depletion significantly impairs humoral COVID-19 vaccine response — pre-vaccination timing critical; vaccinate ideally 4+ weeks before next dose or when B cells returning

Contraindications

Active severe infections (including active hepatitis B — screen ALL patients before starting)
Immunocompromised state
Pregnancy (animal reproductive toxicity — B-cell depletion in neonate)
Live vaccines (contraindicated during treatment and until B-cell reconstitution)

Side effects

Infusion-related reactions (30% first infusion — flushing, fever, chills, urticaria, hypotension; reduced with premedication and slow infusion rate)
Infections (increased — upper and lower respiratory tract; urinary tract; COVID-19 severity increased)
Herpes virus reactivation (screen for hepatitis B, VZV status before start)
Progressive multifocal leukoencephalopathy (PML — JC virus; lower risk than natalizumab)
Hypogammaglobulinaemia (with prolonged treatment — check IgG levels)
Breast cancer risk signal (small — MHRA monitoring)

Interactions

Immunosuppressants (additive immunosuppression — avoid combination; washout period needed when switching DMTs)
Live vaccines (ABSOLUTE contraindication during treatment)
Chlorambucil, cyclophosphamide (additive B-cell depletion)

Monitoring

Hepatitis B serology pre-treatment (mandatory)
Full blood count (lymphocyte count)
Serum immunoglobulins (IgG annually — hypogammaglobulinaemia)
MRI brain with gadolinium (disease activity monitoring)
Infusion reactions during each infusion
JC virus antibody titre (PML risk monitoring)

Reference: BNFc; BNF 90; OPERA I/II NEJM 2017;376(3):209-220; ORATORIO NEJM 2017;376(3):221-234; NICE TA585/TA586; MHRA SPC. Verify against your local formulary and the latest BNF before prescribing.

Curated clinical cross-links plus same-class fallbacks.

Calculators

Drugs

Pathways