Drug Monograph
Rituxan (Rituximab)
rituximab — chimeric anti-CD20 monoclonal antibody
Pharmacokinetic Profile
Half-Life
NHL: ~22 d; CLL: ~32 d; RA: ~18 d; GPA/MPA: ~25 d
Metabolism
Proteolytic degradation + Fcγ-mediated endocytosis; target-mediated CL
Bioavailability
~100% (IV administration)
Volume of Distribution
3.1 L
Clinical Information
Drug Class
CD20-directed cytolytic antibody (chimeric IgG1 kappa)
Available Forms
100 mg/10 mL and 500 mg/50 mL single-dose vials (10 mg/mL)
Route
IV infusion only (never push or bolus)
Renal Adjustment
Not formally studied
Hepatic Adjustment
Not formally studied
Pregnancy
Can cause fetal B-cell lymphocytopenia; use contraception 12 months after last dose
Lactation
Do not breastfeed during treatment and for 6 months after last dose
Schedule
Prescription only (not scheduled)
Generic / Biosimilar
Yes — rituximab-abbs (Truxima), rituximab-pvvr (Ruxience), rituximab-arrx (Riabni)
Black Box Warning
Yes — Fatal infusion reactions, mucocutaneous reactions, HBV reactivation, PML
Approved Indications & Off-Label Uses
| Indication | Approved Population | Therapy Type | Status |
|---|---|---|---|
| Non-Hodgkin lymphoma (NHL) — multiple CD20+ B-cell subtypes | Adults (all subtypes); pediatric ≥6 months (mature B-cell NHL/B-AL) | Single agent or with chemotherapy; maintenance after response | FDA Approved |
| Chronic lymphocytic leukaemia (CLL) | Adults with CD20+ CLL (previously untreated or treated) | With fludarabine and cyclophosphamide (FC) | FDA Approved |
| Rheumatoid arthritis (RA) | Adults with moderately to severely active RA, inadequate response to ≥1 TNF antagonist | With methotrexate | FDA Approved |
| GPA (Wegener’s) and MPA | Adults and pediatric ≥2 years | With glucocorticoids (induction and follow-up) | FDA Approved |
| Pemphigus vulgaris (PV) | Adults with moderate to severe PV | With tapering glucocorticoids; maintenance therapy | FDA Approved |
Rituximab was the first monoclonal antibody approved for cancer treatment (1997) and has since become one of the most widely used biologics in medicine, spanning haematological oncology, rheumatology, nephrology, and dermatology. Its mechanism of CD20-directed B-cell depletion has proven therapeutically versatile. The RA indication specifically requires prior inadequate response to at least one TNF antagonist, positioning rituximab as a second-line biologic in RA management.
Notable Off-Label Uses
Membranous nephropathy: Widely used as first-line immunosuppressive therapy; supported by the MENTOR trial. Evidence quality: High.
Neuromyelitis optica spectrum disorder (NMOSD): First-line B-cell depleting therapy for AQP4-IgG seropositive disease. Evidence quality: High (NEOS/RIN-1 trials).
Immune thrombocytopenic purpura (ITP): Second-line therapy for chronic ITP refractory to corticosteroids. Evidence quality: Moderate.
Other autoimmune conditions: Used in lupus nephritis, myasthenia gravis, autoimmune haemolytic anaemia, and various vasculitides. Evidence quality: Moderate-Low (varies by indication).
Dosing by Clinical Scenario
Oncology Indications
| Clinical Scenario | Starting Dose | Maintenance Dose | Maximum Dose | Notes |
|---|---|---|---|---|
| Relapsed/refractory follicular or low-grade NHL — single agent | 375 mg/m² IV weekly × 4 doses | Retreatment: 375 mg/m² weekly × 4 | 8 weekly doses (initial) | Detectable in serum 3–6 months post-treatment B-cell recovery begins ~6 months; median normalisation ~12 months |
| Previously untreated follicular NHL — with first-line chemotherapy | 375 mg/m² IV Day 1 of each cycle, up to 8 doses | 375 mg/m² q8wk × 12 doses (single-agent maintenance) | Up to 20 total doses | Maintenance starts 8 weeks after completing combination therapy Only in patients achieving CR or PR |
| Non-progressing low-grade NHL — after first-line CVP | 375 mg/m² IV weekly × 4 doses | Repeat q6 months × up to 16 total doses | 16 doses | Following 6–8 cycles of CVP chemotherapy |
| Previously untreated DLBCL — with CHOP or anthracycline-based regimen | 375 mg/m² IV Day 1 of each cycle, up to 8 doses | N/A | 8 doses | 90-minute infusion available from Cycle 2 if no Grade 3–4 IRR in Cycle 1 Not for patients with cardiovascular disease or lymphocytes ≥5000/mm³ |
| CLL — with fludarabine and cyclophosphamide (FC) | 375 mg/m² IV Day 0 of Cycle 1 | 500 mg/m² IV Day 1 of Cycles 2–6 (q28d) | 6 cycles total | Note higher dose (500 mg/m²) from Cycle 2 onward PCP and herpes prophylaxis during + 12 months after treatment |
Autoimmune / Inflammatory Indications
| Clinical Scenario | Starting Dose | Maintenance Dose | Maximum Dose | Notes |
|---|---|---|---|---|
| RA — with methotrexate, after TNF antagonist failure | 1000 mg IV × 2 doses (Day 1 and Day 15) | Repeat course q24wk or per clinical evaluation | Not sooner than q16wk | Methylprednisolone 100 mg IV 30 min before each infusion Must have failed ≥1 TNF antagonist for approved use |
| GPA/MPA induction — adults, with glucocorticoids | 375 mg/m² IV weekly × 4 weeks | See follow-up dosing below | 4 doses per course | IV methylprednisolone 1000 mg/day × 1–3 days + oral prednisone taper Methylprednisolone 100 mg IV before each rituximab infusion |
| GPA/MPA follow-up — adults, after disease control achieved | 500 mg IV × 2 doses (Day 1 and Day 15) | 500 mg IV q6 months | Per clinical evaluation | Initiate within 24 weeks of last induction dose (or within 4 weeks of disease control if non-rituximab induction) PCP prophylaxis during + ≥6 months after last infusion |
| GPA/MPA — pediatric (≥2 yr) induction | 375 mg/m² IV weekly × 4 weeks | 250 mg/m² × 2 (2 wk apart), then 250 mg/m² q6mo | Per clinical evaluation | IV methylprednisolone 30 mg/kg (max 1 g/day) × 3 days before first infusion |
| Pemphigus vulgaris — with tapering glucocorticoids | 1000 mg IV × 2 doses (Day 1 and Day 15) | 500 mg IV at Month 12, then q6 months | Per clinical evaluation | Relapse: 1000 mg IV single dose; no sooner than 16 weeks from prior infusion Methylprednisolone 100 mg IV before each infusion. Consider PCP prophylaxis. |
Clinical Pearl: Premedication Is Essential
All patients require premedication with acetaminophen and an antihistamine before each infusion. For RA, GPA/MPA, and PV, add methylprednisolone 100 mg IV (or equivalent) 30 minutes prior. For NHL patients receiving 90-minute infusions, the glucocorticoid component of their chemotherapy regimen serves as premedication. Infusion-related reactions are most severe during the first infusion (80% of fatal reactions occurred with first infusion) and decrease with subsequent doses. First infusion starts at 50 mg/hr, increasing by 50 mg/hr every 30 minutes to a maximum of 400 mg/hr.
Pharmacology
Mechanism of Action
Rituximab is a genetically engineered chimeric murine/human IgG1-kappa monoclonal antibody (~145 kDa) that binds specifically to the CD20 antigen expressed on the surface of pre-B and mature B lymphocytes but not on haematopoietic stem cells, pro-B cells, normal plasma cells, or other normal tissues. Binding of rituximab to CD20 triggers B-cell destruction through multiple pathways: complement-dependent cytotoxicity (CDC), antibody-dependent cellular cytotoxicity (ADCC) mediated by Fc-receptor-bearing effector cells, and direct induction of apoptosis. Additionally, rituximab sensitises chemoresistant lymphoma cell lines to the cytotoxic effects of certain chemotherapeutic agents. CD20 is not shed from the cell surface and does not internalise upon antibody binding, making it an ideal therapeutic target. The resulting B-cell depletion is rapid and sustained, typically lasting 6 to 9 months, with B-cell recovery beginning around 6 months and returning to normal levels by approximately 12 months.
ADME Profile
| Parameter | Value | Clinical Implication |
|---|---|---|
| Absorption | IV only; ~100% bioavailability. Not administered SC (Rituxan Hycela is a separate SC formulation for NHL only). | Requires healthcare-setting infusion with monitoring for infusion reactions. First infusion typically 4–6 hours; subsequent infusions can be shortened to 90 minutes in select NHL patients. |
| Distribution | Vd: 3.1 L. Crosses the placenta. Detectable in serum 3–6 months after treatment. | Low Vd indicates distribution largely confined to the vascular compartment. Placental transfer results in neonatal B-cell depletion. Use contraception for 12 months after last dose. |
| Metabolism | Proteolytic degradation via reticuloendothelial system; Fcγ-mediated endocytosis. Target-mediated clearance (CD20 binding) contributes to nonlinear PK at low concentrations. | Clearance decreases with successive infusions as CD20+ B cells are depleted, explaining the increasing half-life from first (~3.2 days) to fourth infusion (~8.6 days) in the weekly NHL regimen. Higher tumour burden or B-cell count increases initial clearance. |
| Elimination | Terminal t½: NHL ~22 days (6–52); CLL ~32 days (14–62); RA ~18 days (5–78); GPA/MPA adults ~25 days (11–52). CL in RA: 0.335 L/day. | Long, variable half-life supports infrequent dosing (q2–4 weeks in oncology, q6 months in maintenance). Wide inter-patient variability driven by tumour burden, CD19+ counts, and BSA. Not eliminated renally or hepatically. |
Side Effects
≥10%Very Common (by indication)
| Adverse Effect | Incidence | Clinical Note |
|---|---|---|
| Infusion-related reactions | 77% (NHL, 1st infusion); decreasing thereafter | Fever, chills, rigours, urticaria, hypotension, bronchospasm. Most severe with first infusion (onset 30–120 min). Managed with rate reduction and symptomatic treatment. |
| Lymphopenia | 40% (Grade 3–4, NHL) | Expected pharmacologic effect of CD20-directed B-cell depletion; median duration 14 days. IgM/IgG decreased below normal in 14% of NHL patients. |
| Fever | ≥25% (NHL) | Usually infusion-related; resolves with antipyretics and rate reduction |
| Infection | ≥25% (NHL); ≥10% (RA) | URTI, nasopharyngitis, UTI, and bronchitis most common in RA. Serious infections possible with prolonged hypogammaglobulinaemia. |
| Neutropenia | ≥25% (CLL); 6% (Grade 3–4, NHL) | Prolonged and late-onset neutropenia more common with R-FC (CLL) than FC alone. Monitor CBC regularly. |
| Asthenia / fatigue | ≥25% (NHL) | Common across indications; usually mild to moderate |
1–10%Common
| Adverse Effect | Incidence | Clinical Note |
|---|---|---|
| Anaemia | 3% (Grade 3–4, NHL) | Monitor CBC; transfuse as clinically indicated |
| Thrombocytopenia | 2% (Grade 3–4, NHL) | Usually transient; may reflect marrow infiltration in NHL |
| Hypotension | ~10% (NHL) | Often infusion-related; manage with rate reduction and IV fluids |
| Nausea / diarrhea | ≥15% (GPA/MPA) | May reflect concurrent glucocorticoid therapy |
| Headache | ≥15% (GPA/MPA, PV) | Usually mild; distinguish from PML symptoms |
| Peripheral oedema | ≥15% (GPA/MPA) | Monitor volume status |
| Depression | ≥15% (PV) | Screen for mood changes; may also reflect underlying disease burden |
SeriousSerious Adverse Effects (Boxed Warning Level and Beyond)
| Adverse Effect | Estimated Frequency | Typical Onset | Required Action |
|---|---|---|---|
| Fatal infusion-related reactions | Rare; 80% with 1st infusion | 30–120 min of infusion start | Stop infusion immediately; administer epinephrine, glucocorticoids, bronchodilators, oxygen; permanently discontinue for severe reaction |
| Progressive multifocal leukoencephalopathy (PML) | Very rare; fatal cases reported | Most within 12 months of last infusion | Discontinue rituximab and reduce/discontinue concurrent immunosuppressants. Brain MRI + LP for JC virus PCR. No effective treatment. |
| Hepatitis B virus reactivation | Reported even in resolved HBV (anti-HBc+ only) | During or up to 24 months post-treatment | Screen all patients (HBsAg + anti-HBc) before initiation. If HBV evidence: hepatology consult + antiviral prophylaxis. Discontinue rituximab if reactivation occurs. |
| Severe mucocutaneous reactions (SJS, TEN, pemphigus) | Rare; fatal cases reported | Variable; reported from 1st day of exposure | Discontinue permanently; do not rechallenge |
| Tumour lysis syndrome (NHL/CLL) | Risk correlates with tumour burden (≥25,000 malignant cells/mm³) | 12–24 hours after first infusion | Aggressive IV hydration + allopurinol/rasburicase pre-treatment. Monitor K, Ca, phosphate, uric acid, creatinine. Dialysis if indicated. |
| Serious/fatal infections (bacterial, fungal, viral) | Varies by indication; risk with prolonged hypogammaglobulinaemia (>11 months) | During and following completion of therapy | Discontinue rituximab; initiate antimicrobials. Viral reactivation (CMV, HSV, VZV, parvovirus B19) reported. |
| Cardiac adverse reactions (MI, VF, cardiogenic shock) | Rare; higher risk with pre-existing cardiac disease | During infusion | Discontinue infusion for serious arrhythmias. Cardiac monitoring during and after infusion for high-risk patients. |
| Bowel obstruction and perforation (NHL) | Rare; mean onset 6 days (range 1–77) | Days after infusion | Evaluate urgently for abdominal pain or vomiting; surgical consultation |
DiscontinuationKey Discontinuation Triggers
| Reason | Incidence | Context |
|---|---|---|
| Severe infusion-related reaction | Varies; rate decreases after first infusion | Permanent discontinuation for Grade 3–4 reactions or life-threatening cardiac arrhythmias |
| PML diagnosis | Very rare | Immediate permanent discontinuation; reduce all concurrent immunosuppression |
| HBV reactivation | Uncommon but reported | Immediate discontinuation of rituximab and concomitant chemotherapy |
| Severe mucocutaneous reaction | Rare | Permanent discontinuation; safety of rechallenge not established |
Managing Infusion-Related Reactions: The Primary Safety Concern
Infusion-related reactions occur in up to 77% of NHL patients with the first infusion but decrease substantially with subsequent doses. Fatal reactions, though rare, occurred in approximately 0.04–0.07% of patients, with 80% of deaths associated with the first infusion. Risk factors include high circulating lymphocyte count (≥25,000/mm³) and high tumour burden. Management: stop or slow the infusion, administer glucocorticoids, epinephrine, bronchodilators, and oxygen as needed. Resume at 50% of the previous rate once symptoms resolve. The 90-minute accelerated infusion protocol is available only for previously untreated follicular NHL and DLBCL patients who tolerated the first standard-rate infusion without Grade 3–4 reactions.
Drug Interactions
Rituximab has no formal drug interaction studies. As a monoclonal antibody, it is not metabolised by CYP450 enzymes and does not influence hepatic enzyme activity. However, its profound B-cell depletion and immunosuppressive effects create clinically important pharmacodynamic interactions with other immunomodulatory agents.
MajorOther Biologic DMARDs (TNF inhibitors, abatacept, tocilizumab, anakinra)
MechanismCompounded immunosuppression during B-cell depletion
EffectSignificantly increased risk of serious and opportunistic infections; limited safety data
ManagementMonitor closely for infection if used; limited data on safety in patients with peripheral B-cell depletion
FDA PIMajorLive Viral Vaccines
MechanismB-cell depletion impairs humoral immune response to vaccination
EffectRisk of vaccine-strain infection; reduced immunogenicity. Response to pneumococcal vaccine 19% (vs 61% MTX alone); anti-KLH antibodies 47% (vs 93%)
ManagementComplete all live vaccinations before starting rituximab. Administer non-live vaccines ≥4 weeks before a course. Tetanus response preserved (39% vs 42%).
FDA PI (vaccine study)MajorCisplatin
MechanismAdditive renal toxicity
EffectSevere renal toxicity reported in NHL patients receiving combination
ManagementRituximab + cisplatin is not an approved combination. Monitor renal function closely if used together.
FDA PIModerateMethotrexate
MechanismNo PK interaction; concomitant use is the approved regimen for RA
EffectMTX does not alter rituximab PK; rituximab does not alter systemic MTX exposure
ManagementSafe to co-administer as approved. Additive immunosuppression requires infection vigilance.
FDA PIModerateFludarabine / Cyclophosphamide (FC)
MechanismNo PK interaction; approved combination for CLL
EffectRituximab does not alter FC exposure. Increased incidence of prolonged and late-onset neutropenia vs FC alone.
ManagementPCP and herpes prophylaxis during treatment and for 12 months after. Monitor CBC closely.
FDA PIMinorCHOP Chemotherapy
MechanismNo significant PK interaction
EffectRituximab PK is similar whether given with or without CHOP
ManagementStandard R-CHOP dosing; no dose adjustments needed for the interaction
FDA PIMonitoring
- HBV Screening (HBsAg, anti-HBc)Before initiating treatment
RoutineScreen ALL patients before first dose. If evidence of prior/current HBV: hepatology consult for antiviral prophylaxis. Monitor for HBV reactivation during and up to 24 months after treatment. Reactivation reported even in resolved HBV (HBsAg−, anti-HBc+, anti-HBs+). - CBC with Differential and PlateletsBefore first dose; then q2–4 months (RA/GPA/MPA); weekly-monthly with chemo
RoutineGrade 3–4 cytopenias in 48% of NHL patients (lymphopenia 40%, neutropenia 6%). Continue monitoring after final dose until resolution. Prolonged/late-onset neutropenia more frequent with R-FC. - Immunoglobulin Levels (IgG, IgM)Baseline; periodically during and after treatment
RoutineHypogammaglobulinaemia (>11 months post-rituximab) associated with increased serious infection risk. IgM/IgG decreased below normal in 14% of NHL patients. Consider IgG replacement if recurrent infections with low IgG. - Infusion Monitoring (vitals, O2 sat)During and for 1–2 hours post-infusion
RoutineMost severe reactions in first 30–120 minutes of first infusion. Have emergency medications available (epinephrine, glucocorticoids, bronchodilators, oxygen). Cardiac monitoring for patients with history of arrhythmia or angina. - Renal FunctionBefore and during treatment
RoutineMonitor for TLS (especially NHL with high tumour burden). Discontinue for rising creatinine or oliguria. Renal toxicity with cisplatin combination. - Neurological SymptomsOngoing clinical assessment
Trigger-basedNew-onset neurological manifestations warrant PML evaluation (neurology consult, brain MRI, lumbar puncture for JC virus). Most PML cases within 12 months of last infusion. - Mucocutaneous SymptomsOngoing clinical assessment
Trigger-basedMonitor for new skin lesions, oral ulcers, or mucosal involvement that may indicate SJS, TEN, or paraneoplastic pemphigus. Discontinue rituximab immediately if suspected.
Contraindications & Cautions
Absolute Contraindications
- None listed in the FDA PI — rituximab has no absolute contraindications per the current prescribing information
Relative Contraindications (Specialist Input Recommended)
- Active, severe infections — rituximab not recommended for use in patients with severe active infections
- Active HBV infection (HBsAg positive) — risk of fulminant reactivation; consult hepatology for antiviral prophylaxis before initiating
- Severe cardiopulmonary disease — infusion reactions can trigger MI, VF, cardiogenic shock; requires close cardiac monitoring
- High circulating malignant cell count (≥25,000/mm³) — increased risk of fatal infusion reactions and TLS
- Pregnancy — causes fetal B-cell lymphocytopenia; use effective contraception during and for 12 months after last dose
Use with Caution
- History of prior inadequate response to non-biologic DMARDs only (RA) — favourable risk-benefit not established; not recommended without prior TNF antagonist failure
- Elderly CLL patients (>70 years) — exploratory analyses suggest no benefit from adding rituximab to FC in this age group
- Patients with existing hypogammaglobulinaemia — prolonged B-cell depletion may further impair humoral immunity
FDA Boxed Warning
Fatal Infusion-Related Reactions, Severe Mucocutaneous Reactions, HBV Reactivation, and PML
RITUXAN administration can result in serious, including fatal, infusion-related reactions. Deaths within 24 hours of infusion have occurred; approximately 80% of fatal reactions occurred with the first infusion. Severe, including fatal, mucocutaneous reactions (SJS, TEN, paraneoplastic pemphigus) can occur. HBV reactivation, including fulminant hepatitis, hepatic failure, and death, can occur — screen all patients for HBV before treatment. Progressive multifocal leukoencephalopathy (PML), including fatal PML due to JC virus infection, can occur.
Patient Counselling
Purpose of Therapy
Rituximab targets a specific protein (CD20) on the surface of B cells to deplete them from the body. Depending on the condition, this either destroys cancerous B cells or reduces the autoimmune inflammation driven by B cells. It is given as an intravenous infusion in a healthcare setting where medical staff can monitor for reactions.
How to Take
Rituximab is given as a slow drip through a vein (IV infusion), always in a clinic or hospital. You will receive premedication (paracetamol/acetaminophen, an antihistamine, and sometimes a steroid) to reduce the risk of infusion reactions. The first infusion usually takes 4 to 6 hours; subsequent infusions may be shorter. Do not receive live vaccines during treatment or for a period after treatment ends.
Infusion Reactions
Tell patientReactions such as fever, chills, difficulty breathing, or dizziness are most likely during or within 24 hours of the first infusion and become less common with subsequent treatments. You will be closely monitored and premedicated to reduce risk.
Call prescriberDifficulty breathing, chest tightness, dizziness, swelling, or severe rash during or after infusion — alert the infusion team immediately.
Infection Risk
Tell patientThis medicine depletes B cells, which are part of your immune system. This increases your risk of infections, some of which can be serious. Practice good hygiene and avoid contact with sick individuals. You may be more vulnerable to infections for months after your last dose.
Call prescriberFever, persistent cough, burning urination, sore throat that does not resolve, any unusual illness, or signs of shingles (painful blistering rash).
Hepatitis B Risk
Tell patientIf you have had hepatitis B in the past (even if you were told it was cleared), this medicine can cause it to reactivate. You will be screened before treatment, and if necessary, placed on antiviral medication.
Call prescriberYellowing of skin or eyes, dark urine, right-sided abdominal pain, extreme fatigue, or loss of appetite.
Neurological Changes
Tell patientVery rarely, a serious brain infection called PML can occur. It is important to report any new neurological symptoms immediately, as early detection is critical.
Call prescriberConfusion, memory problems, difficulty walking, vision changes, weakness on one side of the body, or changes in personality or behaviour.
Pregnancy and Contraception
Tell patientRituximab can harm an unborn baby by depleting the baby’s B cells. Women of childbearing potential must use effective contraception during treatment and for 12 months after the last dose. Do not breastfeed during treatment and for 6 months after the last dose.
Call prescriberIf you become pregnant or suspect you may be pregnant during or within 12 months of treatment.
Sources
Regulatory (PI / SmPC)
- RITUXAN (rituximab) injection, for intravenous use. Full Prescribing Information. Genentech, Inc. Revised 12/2021. Genentech PIPrimary source for all approved indications, dosing across NHL/CLL/RA/GPA-MPA/PV, boxed warnings, adverse reactions, and PK data.
- European Medicines Agency. MabThera (rituximab) Summary of Product Characteristics. EMAEuropean regulatory reference with additional guidance on retreatment criteria and cardiovascular risk assessment.
Key Clinical Trials
- Coiffier B, Lepage E, Briere J, et al. CHOP chemotherapy plus rituximab compared with CHOP alone in elderly patients with diffuse large-B-cell lymphoma. N Engl J Med. 2002;346(4):235-242. doi:10.1056/NEJMoa011795Landmark GELA trial (n=399) establishing R-CHOP as standard of care for DLBCL with improved overall survival.
- Cohen SB, Emery P, Greenwald MW, et al. Rituximab for rheumatoid arthritis refractory to anti-tumor necrosis factor therapy: results of a multicenter, randomized, double-blind, placebo-controlled, phase III trial (REFLEX). Arthritis Rheum. 2006;54(9):2793-2806. doi:10.1002/art.22025Pivotal RA trial (n=520) demonstrating ACR20 superiority of rituximab+MTX vs placebo+MTX in anti-TNF refractory patients.
- Stone JH, Merkel PA, Spiera R, et al. Rituximab versus cyclophosphamide for ANCA-associated vasculitis (RAVE). N Engl J Med. 2010;363(3):221-232. doi:10.1056/NEJMoa0909905RAVE trial (n=197) establishing rituximab as non-inferior to cyclophosphamide for remission induction in GPA/MPA; superior for relapsing disease.
- 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). Lancet. 2017;389(10083):2031-2040. doi:10.1016/S0140-6736(17)30070-3Phase 3 trial (n=90) demonstrating superior complete remission with first-line rituximab + short prednisone vs prednisone alone for pemphigus (89% vs 34%).
- Guillevin L, Pagnoux C, Karras A, et al. Rituximab versus azathioprine for maintenance in ANCA-associated vasculitis (MAINRITSAN). N Engl J Med. 2014;371(19):1771-1780. doi:10.1056/NEJMoa1404231MAINRITSAN trial establishing rituximab maintenance superiority over azathioprine for sustaining remission in GPA/MPA (5% vs 29% relapse at month 28).
Guidelines
- Fraenkel L, Bathon JM, England BR, et al. 2021 American College of Rheumatology guideline for the treatment of rheumatoid arthritis. Arthritis Care Res. 2021;73(7):924-939. doi:10.1002/acr.24596Positions rituximab as an option after TNF antagonist failure in RA, with conditional recommendation.
- Chung SA, Langford CA, Maz M, et al. 2021 American College of Rheumatology/Vasculitis Foundation guideline for the management of ANCA-associated vasculitis. Arthritis Rheumatol. 2021;73(8):1366-1383. doi:10.1002/art.41773Recommends rituximab for both induction and maintenance of GPA/MPA, conditionally preferred over cyclophosphamide for induction in certain settings.
Mechanistic / Basic Science
- Reff ME, Carner K, Chambers KS, et al. Depletion of B cells in vivo by a chimeric mouse human monoclonal antibody to CD20. Blood. 1994;83(2):435-445. doi:10.1182/blood.V83.2.435.435Foundational preclinical study demonstrating CD20-targeted B-cell depletion by rituximab through CDC and ADCC mechanisms.
Pharmacokinetics / Special Populations
- Regazzi MB, Iacona I, Avanzini MA, et al. Pharmacokinetic behavior of rituximab: a study of different schedules of administration for heterogeneous clinical settings. Ther Drug Monit. 2005;27(6):785-792. doi:10.1097/01.ftd.0000184228.49517.a0PK study confirming two-compartment model; clearance 3.1–11.9 mL/hr/m; steady state after 6–8 weekly infusions.
- Li J, Zhi J, Wenger M, et al. Rituximab exhibits a long half-life based on a population pharmacokinetic analysis in non-Hodgkin’s lymphoma patients. Blood. 2007;110(11):2371. ASH AbstractPopulation PK analysis (n=298) establishing median terminal half-life of 22 days (range 6–52) with CD19+ count and tumour burden as key covariates.
- Keystone E, Fleischmann R, Emery P, et al. Safety and efficacy of additional courses of rituximab in patients with active rheumatoid arthritis. Arthritis Rheum. 2007;56(12):3896-3908. doi:10.1002/art.23059Long-term safety data supporting retreatment with rituximab in RA; mean half-life 18 days with consistent safety over multiple courses.