MabThera (Rituximab)
Monoclonal Antibody for Lymphoma, Leukaemia, Rheumatoid Arthritis and Vasculitis
Quick Facts About MabThera
Key Takeaways
- Rituximab is a monoclonal antibody that targets and depletes CD20-positive B-lymphocytes, used across oncology, rheumatology, and autoimmune conditions.
- Always administered by healthcare professionals in a clinical setting; pre-medication with antihistamines, paracetamol, and corticosteroids is given before each infusion to reduce reactions.
- Infusion reactions are the most common side effect, particularly during the first infusion, and can usually be managed by slowing or pausing the infusion.
- Patients with a history of hepatitis B must be screened and monitored, as reactivation can occur and may be fatal in rare cases.
- Live vaccines should be avoided during and for several months after treatment; effective contraception is required for 12 months after the last dose.
What Is MabThera and What Is It Used For?
MabThera contains rituximab, a type of protein known as a monoclonal antibody. It was one of the first monoclonal antibodies approved for cancer treatment and has since transformed the management of several B-cell-mediated diseases. Rituximab specifically binds to the CD20 antigen, a transmembrane protein found on the surface of pre-B and mature B-lymphocytes. When rituximab attaches to CD20, it triggers the destruction of these cells through multiple mechanisms including complement-dependent cytotoxicity (CDC), antibody-dependent cellular cytotoxicity (ADCC), and direct induction of apoptosis (programmed cell death).
Importantly, CD20 is not expressed on haematopoietic stem cells, pro-B cells, or plasma cells. This means that while rituximab effectively depletes the pool of mature B-cells, it preserves the ability of the bone marrow to produce new B-cells over time and does not directly affect antibody-producing plasma cells. B-cell recovery typically begins approximately 6 months after the last dose and returns to normal levels within 9 to 12 months.
Non-Hodgkin Lymphoma (NHL)
Rituximab has become a cornerstone of treatment for B-cell non-Hodgkin lymphoma, one of the most common types of blood cancer. NHL affects the lymphatic system, specifically the B-lymphocytes, and rituximab can be used as a single agent or in combination with chemotherapy regimens such as CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisolone). In adult patients who respond well to initial treatment, rituximab may be continued as maintenance therapy every two to three months for up to two years to prolong remission. In children and adolescents aged 6 months and older, rituximab is used in combination with chemotherapy for specific subtypes including diffuse large B-cell lymphoma (DLBCL), Burkitt lymphoma, and Burkitt leukaemia.
Chronic Lymphocytic Leukaemia (CLL)
CLL is the most common form of leukaemia in adults. It involves the accumulation of abnormal B-lymphocytes in the bone marrow, blood, and lymph nodes. Rituximab is used in combination with chemotherapy agents such as fludarabine and cyclophosphamide (the FC regimen) to destroy these abnormal cells. The combination of rituximab with chemotherapy (R-FC) has been shown to significantly improve progression-free survival and overall survival in CLL patients compared to chemotherapy alone.
Rheumatoid Arthritis (RA)
In rheumatoid arthritis, B-lymphocytes contribute to the chronic inflammation that damages joints. Rituximab is approved for the treatment of moderate to severe RA in patients who have had an inadequate response to, or cannot tolerate, other disease-modifying antirheumatic drugs (DMARDs) including at least one TNF inhibitor. It is always used in combination with methotrexate. Clinical trials have demonstrated that rituximab slows joint destruction, reduces signs and symptoms of RA, and improves physical function. The treatment is most effective in patients who are positive for rheumatoid factor (RF) and/or anti-cyclic citrullinated peptide (anti-CCP) antibodies.
Granulomatosis with Polyangiitis (GPA) and Microscopic Polyangiitis (MPA)
GPA (formerly known as Wegener's granulomatosis) and MPA are forms of anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis that primarily affect the lungs, kidneys, and other organs through inflammation of blood vessels. Rituximab is approved in combination with corticosteroids for the treatment of these conditions in adults and children aged 2 years and older. For adults who respond well to induction therapy, rituximab can be continued as maintenance treatment for at least two years and up to five years, depending on the clinical response.
Pemphigus Vulgaris
Pemphigus vulgaris is a rare, potentially life-threatening autoimmune blistering disease in which autoantibodies target desmoglein proteins, causing painful blisters on the skin, mouth, throat, nose, and genitals. Rituximab is approved for the treatment of moderate to severe pemphigus vulgaris and has shown significant efficacy in achieving and maintaining complete remission, often allowing patients to reduce or discontinue corticosteroid therapy.
What Should You Know Before Taking MabThera?
Contraindications
You must not receive MabThera if you are allergic to rituximab, other similar proteins (murine proteins), or any of the inactive ingredients. Additionally, treatment is contraindicated in patients with active, severe infections because rituximab depletes B-cells and can further impair the immune response. Patients with a severely compromised immune system should not receive this medication.
For patients being treated for rheumatoid arthritis, granulomatosis with polyangiitis, microscopic polyangiitis, or pemphigus vulgaris, MabThera is also contraindicated in the presence of severe heart failure (New York Heart Association Class IV) or severe, uncontrolled cardiovascular disease. This restriction exists because infusion reactions can include cardiovascular events such as hypotension, arrhythmias, and in rare cases, myocardial infarction.
Warnings and Precautions
Before starting MabThera, inform your doctor about your complete medical history. Special caution is needed in several situations:
- Infections: If you have any current infection, even a mild one such as a common cold, treatment should be delayed until the infection has resolved. The cells affected by rituximab play an important role in fighting infections, and treatment increases susceptibility to bacterial, viral, and fungal infections.
- Heart disease: Patients with a history of angina pectoris, heart palpitations, heart failure, or other cardiac conditions require careful monitoring, as infusion reactions can worsen these conditions.
- Respiratory problems: Patients with lung disease or a history of breathing difficulties should be closely monitored during infusion.
- History of recurrent or severe infections: Inform your doctor if you have experienced frequent or serious infections in the past, as rituximab may increase infection risk.
- Vaccinations: Certain vaccines, particularly live vaccines, should not be given during or for several months after rituximab treatment. Your doctor will review your vaccination status and complete any necessary immunisations at least 4 weeks before starting therapy. Inactivated vaccines may be given, but the immune response may be reduced.
Pregnancy and Breastfeeding
Rituximab can cross the placenta and may affect the developing baby, particularly during the second and third trimesters. Rituximab has been associated with transient B-cell depletion and lymphopenia in exposed neonates. If you are of childbearing potential, you and your partner must use effective contraception during treatment and for 12 months after the last dose of MabThera.
Breastfeeding is not recommended during treatment with MabThera. Although rituximab passes into breast milk in very small amounts, the long-term effects on breastfed infants are not known. As a precautionary measure, breastfeeding should be avoided during treatment and for at least 6 months after the last dose.
If you are pregnant, think you may be pregnant, or are planning to have a baby, tell your doctor before receiving MabThera. Your doctor will weigh the benefits of treatment against the potential risks to the unborn child and advise you accordingly.
How Does MabThera Interact with Other Drugs?
Drug interactions with rituximab are an important consideration, particularly because it is frequently used in combination with other potent medications such as chemotherapy agents and immunosuppressants. Always inform your doctor about all medications you are taking, including prescription drugs, over-the-counter medicines, and herbal supplements.
Major Interactions
The following interactions require special attention and may necessitate changes to your treatment plan:
| Interacting Drug/Class | Interaction | Clinical Significance |
|---|---|---|
| Antihypertensives | Hypotension may occur during infusion; combined effect may cause dangerous blood pressure drops | May need to withhold antihypertensives for 12 hours before infusion |
| Live vaccines (e.g. MMR, yellow fever, BCG) | Depleted B-cells cannot mount adequate immune response; risk of vaccine-related infection | Contraindicated during and for several months after treatment |
| TNF inhibitors (e.g. infliximab, etanercept, adalimumab) | Additive immunosuppression; significantly increased risk of serious infections | Avoid concurrent use; allow adequate washout period |
| Other immunosuppressants (e.g. ciclosporin, tacrolimus, mycophenolate) | Compounded immunosuppression | Increased risk of opportunistic infections; close monitoring required |
| Cisplatin | Potential additive renal toxicity | Monitor renal function closely when used in combination |
Minor Interactions
Inactivated vaccines (such as influenza or pneumococcal vaccines) may be administered during rituximab treatment, but the immune response is likely to be diminished. It may be advisable to complete any recommended vaccinations well before initiating rituximab therapy. Paracetamol and antihistamines are routinely co-administered as pre-medication and do not present clinically significant interactions.
There are limited data on formal drug interaction studies with rituximab. However, because rituximab is not metabolised by cytochrome P450 enzymes, pharmacokinetic interactions with medications cleared through this pathway are not expected. The primary concern is pharmacodynamic interactions with other immunomodulatory or immunosuppressive agents that may compound the risk of infection or impair immune recovery.
What Is the Correct Dosage of MabThera?
MabThera is always administered by a doctor or nurse experienced in the use of this treatment, in a clinical setting equipped to manage potential infusion reactions. Pre-medication with an analgesic/antipyretic (e.g. paracetamol), an antihistamine (e.g. diphenhydramine), and sometimes a corticosteroid is given before each infusion to reduce the risk and severity of infusion-related reactions.
Non-Hodgkin Lymphoma (NHL) – Adults
Monotherapy: 375 mg/m² body surface area, administered once weekly for 4 consecutive weeks. Retreatment courses are possible.
Combination with chemotherapy: 375 mg/m² on day 1 of each chemotherapy cycle, typically every 3 weeks for up to 8 cycles.
Maintenance: For patients who respond to induction therapy, 375 mg/m² every 2 or 3 months for up to 2 years.
Non-Hodgkin Lymphoma – Children and Adolescents (≥ 6 months)
375 mg/m² IV in combination with chemotherapy, given up to 6 times over a period of 3.5 to 5.5 months. Dosing schedules are determined by the specific chemotherapy protocol.
Chronic Lymphocytic Leukaemia (CLL)
Cycle 1: 375 mg/m² on day 0.
Cycles 2–6: 500 mg/m² on day 1 of each 28-day cycle.
Chemotherapy (e.g. fludarabine and cyclophosphamide) is administered after the rituximab infusion.
Rheumatoid Arthritis
Each treatment course consists of two 1000 mg IV infusions given 2 weeks apart. Retreatment courses may be given depending on clinical response, typically no sooner than 16 weeks (and often 24 weeks or longer) after the previous course. Rituximab is always used in combination with methotrexate.
GPA and MPA – Induction (Adults)
Four infusions of 375 mg/m² given once weekly for 4 consecutive weeks, in combination with IV corticosteroids.
Maintenance (adults ≥ 18 years): After remission induction, two 500 mg infusions 2 weeks apart, followed by 500 mg every 6 months for at least 2 years (up to 5 years based on clinical response).
GPA and MPA – Children (≥ 2 years)
375 mg/m² IV once weekly for 4 weeks, in combination with corticosteroids. Maintenance dosing in paediatric patients is determined by the treating specialist.
Pemphigus Vulgaris
Induction: Two 1000 mg infusions 2 weeks apart.
Maintenance: 500 mg at 12 months, 18 months, and then every 6 months as needed, based on clinical evaluation.
Missed Dose
Because MabThera is administered under medical supervision in a hospital or clinic, missed doses are managed by your healthcare team. If you miss a scheduled appointment, contact your doctor or treatment centre as soon as possible to reschedule. Dosing intervals and the total number of infusions may be adjusted at your doctor's discretion.
Overdose
There is limited clinical experience with overdose of rituximab. In clinical trials, doses up to 500 mg/m² have been evaluated. No dose-limiting toxicity was identified, though the rate and severity of infusion reactions may increase at higher doses. In the event of an overdose, the infusion should be stopped immediately, the patient closely monitored, and supportive treatment provided. No specific antidote exists for rituximab.
What Are the Side Effects of MabThera?
Like all medicines, MabThera can cause side effects, although not everybody gets them. Most side effects are mild to moderate and can be managed with appropriate medical intervention. However, some can be serious and may require immediate treatment. In rare cases, certain side effects have been fatal. The side effect profile varies depending on the condition being treated. Below is a summary of the most important side effects across all approved indications.
Infusion Reactions
Infusion-related reactions are the most common side effect of rituximab and typically occur during or within 24 hours of the first infusion. Symptoms may include fever, chills, rigors, nausea, fatigue, headache, difficulty breathing, elevated or low blood pressure, wheezing, throat swelling, itching, rash, flushing, and in rare cases, irregular heartbeats or heart attack. Pre-medication significantly reduces the risk and severity of these reactions. If infusion reactions occur, the infusion rate can be slowed or temporarily stopped. Reactions are generally less common with subsequent infusions.
Side Effects by Frequency – Oncology Indications (NHL/CLL)
Very Common
May affect more than 1 in 10 people
- Bacterial or viral infections, bronchitis
- Low white blood cell count (neutropenia), with or without fever
- Low platelet count (thrombocytopenia)
- Nausea
- Hair thinning, chills, headache
- Decreased immunoglobulin levels (IgG)
Common
May affect up to 1 in 10 people
- Blood infections (sepsis), pneumonia, shingles, urinary tract infections, sinus infections
- Anaemia (low red blood cells)
- Allergic reactions (hypersensitivity)
- High blood sugar, weight loss, facial and body swelling, elevated LDH
- Numbness, tingling, burning sensations in the skin
- Insomnia, restlessness, dizziness, anxiety
- Conjunctivitis, increased tear production
- Tinnitus, ear pain
- Heart problems including heart attack, irregular or rapid heart rate
- High or low blood pressure
- Bronchospasm, shortness of breath, nasal congestion
- Vomiting, diarrhoea, abdominal pain, mouth sores, difficulty swallowing
- Urticaria (hives), increased sweating, night sweats
- Muscle and joint pain, back and neck pain
- Fatigue, flu-like symptoms, tremor
Uncommon
May affect up to 1 in 100 people
- Blood clotting disorders, aplastic haemolytic anaemia
- Swollen or enlarged lymph nodes
- Depression, loss of interest in usual activities, nervousness
- Taste changes
- Decreased heart rate, chest pain (angina)
- Asthma, insufficient oxygenation of body organs
- Abdominal bloating
Very Rare / Rare
May affect up to 1 in 10,000 people or frequency unknown
- Transient increase in certain immunoglobulins (IgM)
- Tumour lysis syndrome (chemical disturbances from breakdown of cancer cells)
- Nerve damage in arms and legs, facial paralysis
- Heart failure
- Inflammation of blood vessels (vasculitis), including those causing skin symptoms
- Respiratory failure
- Intestinal perforation
- Severe blistering skin conditions (Stevens-Johnson syndrome, toxic epidermal necrolysis)
- Kidney failure, severe vision loss
- Progressive multifocal leukoencephalopathy (PML) – a rare, serious brain infection
- Enteroviral meningoencephalitis – a serious brain and meningeal infection
- Hearing loss
Side Effects – Rheumatoid Arthritis
Very Common
May affect more than 1 in 10 people
- Upper respiratory tract infections, urinary tract infections
- Infusion-related allergic reactions (blood pressure changes, nausea, rash, fever, itching, nasal symptoms, palpitations, fatigue)
- Headache
- Decreased immunoglobulin levels
Common
May affect up to 1 in 10 people
- Bronchitis, sinusitis
- Athlete's foot (tinea pedis)
- High cholesterol levels
- Numbness, tingling, sciatica, migraine, dizziness
- Hair loss, anxiety, depression
- Indigestion, acid reflux, diarrhoea, mouth and throat irritation
- Stomach, back, muscle, and/or joint pain
Side Effects – GPA and MPA
Very Common
May affect more than 1 in 10 people
- Respiratory and urinary tract infections, common colds, herpes infections
- Infusion-related allergic reactions
- Diarrhoea, cough or shortness of breath
- Nosebleeds, elevated blood pressure
- Joint or back pain, muscle twitching and weakness
- Dizziness, tremor (often in hands)
- Insomnia, swelling of hands or ankles
Common
May affect up to 1 in 10 people
- Indigestion, constipation
- Skin rash including acne, flushing or redness
- Fever, nasal congestion
- Muscle pain, pain in hands or feet
- Anaemia, low platelet count
- Elevated potassium levels, changes in heart rhythm
Side Effects – Pemphigus Vulgaris
Very Common
May affect more than 1 in 10 people
- Infusion-related allergic reactions
- Headache
- Upper respiratory tract infections
- Prolonged depression
- Hair loss
Common
May affect up to 1 in 10 people
- Common colds, herpes infections, eye infections, oral thrush, urinary tract infections
- Mood changes including irritability and depression
- Skin effects: itching, hives, benign lumps
- Fatigue, dizziness, fever
- Joint and back pain, muscle pain
- Increased heart rate
How Should You Store MabThera?
Because MabThera is a biologic medication administered in hospitals and clinics, storage is managed by trained pharmacy and healthcare professionals rather than by patients at home. Nevertheless, understanding proper storage conditions is important for ensuring drug quality and safety.
MabThera concentrate for solution for infusion must be stored in a refrigerator at 2°C to 8°C (36°F to 46°F). The product must not be frozen. The vials should be kept in the outer carton to protect from light, as rituximab is sensitive to light degradation. Unused or expired medication should not be disposed of via wastewater or household waste; healthcare facilities follow local regulations for the safe disposal of biologic medicines to protect the environment.
Once diluted for infusion, the prepared solution should be used immediately or may be stored for up to 24 hours at 2°C to 8°C and for a further 12 hours at room temperature, depending on local guidelines and the specific diluent used. Always check with your healthcare provider if you have questions about the handling of your medication.
What Does MabThera Contain?
The active substance in MabThera is rituximab, a chimeric mouse/human monoclonal antibody produced by mammalian cell culture (Chinese Hamster Ovary cells) using recombinant DNA technology. The intravenous formulation is a clear, colourless concentrate for solution for infusion with a concentration of 10 mg/ml.
Available Presentations
- 10 ml vial: Contains 100 mg rituximab (10 mg/ml) – supplied in packs of 2 vials
- 50 ml vial: Contains 500 mg rituximab (10 mg/ml) – supplied in packs of 1 vial
- Subcutaneous formulation: 1400 mg rituximab in 11.7 ml solution for injection (with recombinant human hyaluronidase) – for certain approved indications
Inactive Ingredients
The intravenous concentrate contains: sodium citrate, polysorbate 80, sodium chloride, sodium hydroxide, hydrochloric acid, and water for injections. The subcutaneous formulation additionally contains recombinant human hyaluronidase (rHuPH20), L-histidine, L-histidine hydrochloride monohydrate, trehalose dihydrate, L-methionine, and polysorbate 80.
The manufacturer of MabThera is Roche Pharma AG, Grenzach-Wyhlen, Germany, and it is marketed by F. Hoffmann-La Roche Ltd. The marketing authorisation holder in the EU is Roche Registration GmbH.
Frequently Asked Questions About MabThera
MabThera (rituximab) is a monoclonal antibody used to treat several conditions: non-Hodgkin lymphoma (NHL), chronic lymphocytic leukaemia (CLL), rheumatoid arthritis (in combination with methotrexate), granulomatosis with polyangiitis (GPA) and microscopic polyangiitis (MPA), and pemphigus vulgaris. It works by targeting and depleting CD20-positive B-lymphocytes, a type of white blood cell involved in these diseases.
MabThera is given as an intravenous infusion (drip) in a hospital or specialised clinic. A subcutaneous injection formulation (1400 mg) is also available for certain indications. Before each infusion, you receive pre-medication including paracetamol, an antihistamine, and sometimes corticosteroids to reduce the risk of infusion reactions. Each infusion typically takes several hours, and you will be monitored during and after the procedure.
The most serious potential side effects include severe infusion reactions (which can be life-threatening), progressive multifocal leukoencephalopathy (PML, a rare brain infection), hepatitis B reactivation, severe infections (including pneumonia and sepsis), severe skin reactions (Stevens-Johnson syndrome), and cardiac events. However, with appropriate pre-medication, screening, and monitoring, most patients tolerate rituximab well.
Live vaccines (such as MMR, yellow fever, BCG, or oral polio) must not be given during or for several months after rituximab treatment because the depleted immune system cannot mount a safe response. Inactivated vaccines (such as flu or COVID-19 vaccines) can be given but may produce a weaker immune response. Ideally, all necessary vaccinations should be completed at least 4 weeks before starting rituximab.
Rituximab has a terminal elimination half-life of approximately 22 days, but its biological effects are much longer-lasting. B-cell depletion typically lasts 6 to 9 months after the last infusion, and B-cells usually return to normal levels within 9 to 12 months. This is why effective contraception must be used for 12 months after the last dose, and breastfeeding should be avoided for at least 6 months after treatment completion.
Yes, several rituximab biosimilars have been approved by the EMA and FDA, including Truxima, Ruxience, Rixathon, and Riximyo. These biosimilars are highly similar to the reference product and have demonstrated equivalent efficacy, safety, and immunogenicity in clinical trials. Your healthcare provider can discuss whether a biosimilar is appropriate for your specific treatment needs.
References
- European Medicines Agency (EMA). MabThera (rituximab) – Summary of Product Characteristics. Available at: EMA MabThera EPAR. Accessed January 2026.
- Salles G, Barrett M, Foà R, et al. Rituximab in B-Cell Hematologic Malignancies: A Review of 20 Years of Clinical Experience. Adv Ther. 2017;34(10):2232-2273. doi:10.1007/s12325-017-0612-x
- Smolen JS, Landewé RBM, Bergstra SA, et al. EULAR recommendations for the management of rheumatoid arthritis with synthetic and biological disease-modifying antirheumatic drugs: 2022 update. Ann Rheum Dis. 2023;82(1):3-18.
- Stone JH, Merkel PA, Spiera R, et al. Rituximab versus cyclophosphamide for ANCA-associated vasculitis. N Engl J Med. 2010;363(3):221-232. doi:10.1056/NEJMoa0909905
- Joly P, Maho-Vaillant M, Prost-Squarcioni C, et al. First-line rituximab combined with short-term prednisone versus prednisone alone for the treatment of pemphigus (RITUX 3): a prospective, multicentre, parallel-group, open-label randomised trial. Lancet. 2017;389(10083):2031-2040.
- World Health Organization (WHO). WHO Model List of Essential Medicines – 23rd list (2023). Available at: WHO Essential Medicines.
- National Institute for Health and Care Excellence (NICE). Rituximab for the treatment of relapsed or refractory chronic lymphocytic leukaemia. Technology appraisal guidance [TA193]. Updated 2023.
- British National Formulary (BNF). Rituximab. Available at: bnf.nice.org.uk. Accessed January 2026.
Editorial Team
This article has been developed and reviewed by the iMedic Medical Editorial Team, comprising board-certified specialists in oncology, haematology, rheumatology, and clinical pharmacology.
Last reviewed: . This article follows the GRADE evidence framework and is reviewed according to international medical standards. No commercial funding or pharmaceutical sponsorship.