Anti-CD20 Monoclonal Antibody — CLL / Follicular Lymphoma Pregnancy: Avoid — IgG crosses placenta; potential for fetal B-cell depletion; effective contraception required during and for 18 months after treatment

Obinutuzumab

Brand names: Gazyvaro

Adult dose

Dose: CLL: cycle 1 — 100 mg day 1, 900 mg day 2, 1000 mg days 8 and 15; cycles 2–6 — 1000 mg day 1. Follicular lymphoma: 1000 mg days 1, 8, 15 (cycle 1); day 1 of cycles 2–6; then maintenance 1000 mg every 2 months × 2 years

Route: IV infusion

Frequency: Per treatment cycle schedule

Max: 1000 mg per infusion

Type II anti-CD20 glycoengineered mAb. More potent direct cell death and ADCC than rituximab. Combined with chlorambucil for CLL (first-line), or with bendamustine/CHOP for follicular lymphoma.

Paediatric dose

Dose: Seek specialist opinion mg/kg

Route: IV

Frequency: Per specialist protocol

Max: Not established in children

Not licensed in children

Dose adjustments

Renal

No dose adjustment required

Hepatic

No dose adjustment required in mild impairment; limited data in severe impairment

Paediatric weight-based calculator

Patient weight (kg)

Not licensed in children

Clinical pearls

CLL11 trial: obinutuzumab + chlorambucil significantly superior to rituximab + chlorambucil and chlorambucil monotherapy in treatment-naive CLL (PFS and OS benefit)
Type II vs Type I anti-CD20: obinutuzumab induces more direct cell death (homotypic adhesion, lysosomal pathway) and enhanced ADCC vs rituximab
Hepatitis B reactivation: screen ALL patients for HBsAg and anti-HBc before initiating; prophylactic antivirals for HBsAg+ or anti-HBc+ patients
Infusion-related reactions very common with first infusion — premedicate with corticosteroid, antihistamine, and paracetamol; split first dose (100 mg day 1, 900 mg day 2)
PML risk: avoid in active JC virus infection; monitor for new neurological symptoms — any suspicion → halt treatment, urgent neurology review
Tumour lysis syndrome prophylaxis: hydration + allopurinol or rasburicase before first infusion in high tumour burden

Contraindications

Active HBV infection (risk of HBV reactivation)
Hypersensitivity to obinutuzumab

Side effects

Infusion-related reactions (very common — especially first infusion)
Neutropenia
Thrombocytopenia
Anaemia
Progressive multifocal leukoencephalopathy (PML — rare)
HBV reactivation
Tumour lysis syndrome

Interactions

Vaccines — live vaccines contraindicated during and for 12 months after treatment
Antihypertensives — hold before infusion (hypotension risk during IRR)

Monitoring

FBC (before each cycle)
Hepatitis B serology (before treatment and during)
Infusion-related reaction monitoring
LFTs
Neurological symptoms (PML)

Reference: BNFc; BNF 90; CLL11 Trial (Goede et al. NEJM 2014); GALLIUM Trial (Marcus et al. NEJM 2017); NICE TA343; SPC Gazyvaro. Verify against your local formulary and the latest BNF before prescribing.

Curated clinical cross-links plus same-class fallbacks.

Calculators

Pathways