II. Indications: Leukemia and Lymphoma
- Non-Hodgkin's Lymphoma
- Large B cell Lymphoma
- Burkitt Lymphoma
-
Follicular Lymphoma
- Obinutuzumab
-
Chronic Lymphocytic Leukemia
- Rituximab
- Ofatumumab
- Acute Mature B Cell Leukemia
III. Indications: Non-Oncology
- Refractory Rheumatoid Arthritis
- Granulomatosis with Polyangiitis (formerly known as Wegener's Granulomatosis)
-
Multiple Sclerosis
- Ofatumumab
- Ocrelizumab (Ocrevus)
- Delgado (2024) J Neurol 271(4):1515-35 +PMID: 37906325 [PubMed]
IV. Contraindications
- Active Hepatitis BVirus Infection
- Screen before starting regimen
V. Mechanism
- See Monoclonal Antibody-Mediated Chemotherapy
- CD20 Antigens
- CD20 Antigens are phosphoproteins found only on the surface of B-Cells including Leukemia, Lymphoma (but not B-Cell precursors)
- Regulate transmembrane Calcium conductance
- Plays a role in B-Cell Activation and proliferation, as well as complement-dependent cytotoxicity
- Anti-CD20 Monoclonal Antibody
- Recombinant human Monoclonal Antibody directed against the CD20 Antigen cell surface marker
- Bind CD20 and triggers a cytotoxic immune response, depleting CD20 positive B Cells
VI. Medications: Anti-CD20
-
Rituximab (Rituxan)
- See Rituximab
- Used in Non-Hodgkin's Lymphoma (as well as several other Lymphomas and Leukemias)
- Also used in Refractory Rheumatoid Arthritis, Granulomatosis with Polyangiitis
- Risk of severe infusion reactions and severe mucocutaneous reactions
- Also risk of PML, Tumor Lysis Syndrome, Hepatitis B reactivation and Bowel Obstruction and perforation
- Also risk of Acute Kidney Injury, Cardiac Arrhythmia and severe cytopenia
- Ofatumumab (Arzerra, Kesimpta)
- Used in Chronic Lymphocytic Leukemia (Arzerra) and Multiple Sclerosis (Kesimpta)
- Risk of severe infusion reactions, Severe infections, Hepatitis B reactivation
- Obinutuzumab (Gazyva)
- Used in CLL, Follicular Lymphoma
- Risk of Hepatitis B reactivation, PML, DIC, Tumor Lysis Syndrome, infusion reactions, severe infections, cytopenias,
- Ocrelizumab (Ocrevus)
- Indicated for Multiple Sclerosis (relapsing, and primary progressive)
- First-line only in primary progresive MS (only one FDA approved in primary progressive MS)
- Pretreat doses with Methylprednisolone and Diphenhydramine (or other Antihistamine) 30 to 60 minutes before dose
- Adults with MS
- Load: 300 mg IV infusion over 3.5 hours for 2 doses, 2 weeks apart
- Maintenance: 600 mg IV infusion over 3.5 hours every 6 months
- Indicated for Multiple Sclerosis (relapsing, and primary progressive)
VII. Medications: Anti-CD20 with Cytotoxic Conjugates
- Ibritumomab tiuxetan (Zevalin)
- Used for Non-Hodgkin's Lymphoma
- Risk of severe infusion reactions, cytopenias and secondary malignancies
- Conjugate of CD20 Monoclonal Antibody (Ibritumomab) and a radioisotope chelation site (tiuxetan)
- Tiuxetan is bound to Iridium-111 or yttrium Y-90
- Delivers cytotoxic dose of radiation to B Cells with CD20 cell surface marker
- Tositumomab-Iodine 131 (Bexxar)
- Used for Non-Hodgkin's Lymphoma
- Risk of severe infusion reactions, cytopenia, secondary malignancy, Hypothyroidism
- Conjugate of CD20 Monoclonal Antibody (Tositumomab) and a radioisotope, Iodine-131
- Delivers cytotoxic dose of radiation to B Cells with CD20 cell surface marker
VIII. Dosing
- See other references for disease specific dosing protocols
IX. Adverse Effects
- Severe infusion reactions including Anaphylaxis (Rituximab, Ofatumumab, Ibritumomab, Obinutuzumab, Tositumomab)
- Severe mucocutaneous syndrome (Rituximab, Ibritumomab)
- Progressive Multifocal Leukoencephalopathy (Rituximab, Ofatumumab, Obinutuzumab)
- Tumor Lysis Syndrome (Rituximab, Obinutuzumab)
- Hepatitis B reactivation (Rituximab, Ofatumumab, Obinutuzumab)
- Acute Kidney Injury (Rituximab)
- Cardiac Arrhythmia (Rituximab)
- Severe cytopenia (Rituximab, Ofatumumab, Ibritumomab, Obinutuzumab, Tositumomab)
- Bowel Obstruction and perforation (Rituximab, Ofatumumab)
- Severe infections (Rituximab, Obinutuzumab)
- Hypothyroidism (Tositumomab-I131)
- Secondary malignancy (Ibritumomab-tiuxetan, Tositumomab-I131)
X. Safety
- Avoid in Lactation
- Avoid in pregnancy (all trimesters, Pregnancy category X)
- Use reliable Contraception
XI. Drug Interactions
-
Vaccines
- Give non-Live Vaccines at least 2 weeks prior to dosing
- Hold CD20 Monoclonal Antibody for 6 months before and 4-6 weeks after Live Vaccines
- Ideally, give Live Attenuated Vaccines at least 6 weeks before starting CD20 Monoclonal Antibodies