TABLE OF CONTENTS
Rituximab is a genetically engineered chimeric murine/human monoclonal IgG1 kappa antibody directed against the CD20 antigen. Rituximab has an approximate molecular weight of 145 kD. Rituximab has a binding affinity for the CD20 antigen of approximately 8.0 nM.
Rituximab is produced by mammalian cell (Chinese Hamster Ovary) suspension culture in a nutrient medium containing the antibiotic gentamicin. Gentamicin is not detectable in the final product. Rituximab is a sterile, clear, colorless, preservative-free liquid concentrate for intravenous administration. Rituximab is supplied at a concentration of 10 mg/mL in either 100 mg (10 mL) or 500 mg (50 mL) single-use vials. The product is formulated in 9 mg/mL sodium chloride, 7.35 mg/mL sodium citrate dihydrate, 0.7 mg/mL polysorbate 80, and Water for Injection. The pH is 6.5.
|2. INDICATIONS AND USAGE|
2.1 Non–Hodgkin’s Lymphoma (NHL)
Rituximab is indicated for the treatment of patients with:
• Relapsed or refractory, low–grade or follicular, CD20–positive, B–cell NHL as a single agent
• Previously untreated follicular, CD20–positive, B–cell NHL in combination with CVP chemotherapy
• Non–progressing (including stable disease), low–grade, CD20–positive, B–cell NHL, as a single agent, after first–line CVP chemotherapy
• Previously untreated diffuse large B–cell, CD20–positive NHL in combination with CHOP or other anthracycline–based chemotherapy regimens
2.2 Chronic Lymphocytic Leukemia (CLL)
Rituximab is indicated, in combination with fludarabine and cyclophosphamide (FC), for the treatment of patients with previously untreated and previously treated CD20-positive CLL.
2.3 Rheumatoid Arthritis (RA)
Rituximab in combination with methotrexate is indicated for the treatment of adult patients with moderately–to severely–active rheumatoid arthritis who have had an inadequate response to one or more TNF antagonist therapies.
2.4 Granulomatosis with Polyangiitis (GPA) (Wegener’s Granulomatosis) and Microscopic Polyangiitis (MPA)
Rituximab, in combination with glucocorticoids, is indicated for the treatment of adult patients with Wegener’s Granulomatosis (WG) and Microscopic Polyangiitis (MPA).
2.5 Limitations of Use
Rituximab is not recommended for use in patients with severe, active infections.
|3. DOSAGE AND ADMINISTRATION|
Administer Only as an Intravenous Infusion.
DO NOT ADMINISTER AS AN INTRAVENOUS PUSH OR BOLUS.
Premedicate before each infusion.
• First Infusion: Initiate infusion at a rate of 50 mg/hr. In the absence of infusion toxicity, increase infusion rate by 50 mg/hr increments every 30 minutes, to a maximum of 400 mg/hr.
• Subsequent Infusions:
Standard Infusion: Initiate infusion at a rate of 100 mg/hr. In the absence of infusion toxicity, increase rate by 100 mg/hr increments at 30-minute intervals, to a maximum of 400 mg/hr.
For previously untreated follicular NHL and DLBCL patients:
If patients did not experience a Grade 3 or 4 infusion related adverse event during Cycle 1, a 90-minute infusion can be administered in Cycle 2 with a glucocorticoid-containing chemotherapy regimen.
Initiate at a rate of 20% of the total dose given in the first 30 minutes and the remaining 80% of the total dose given over the next 60 minutes. If the 90-minute infusion is tolerated in Cycle 2, the same rate can be used when administering the remainder of the treatment regimen (through Cycle 6 or 8).
Patients who have clinically significant cardiovascular disease or who have a circulating lymphocyte count ≥5000/mm3 before Cycle 2 should not be administered the 90-minute infusion.
• Interrupt the infusion or slow the infusion rate for infusion reactions [see Boxed Warning, Warnings and Precautions]. Continue the infusion at one half the previous rate upon improvement of symptoms.
3.2 Recommended Dose for Non–Hodgkin’s Lymphoma (NHL)
The recommended dose is 375 mg/m2 as an IV infusion according to the following schedules:
• Relapsed or Refractory, Low–Grade or Follicular, CD20–Positive, B–Cell NHL
Administer once weekly for 4 or 8 doses.
• Retreatment for Relapsed or Refractory, Low–Grade or Follicular, CD20–Positive, B–Cell NHL
Administer once weekly for 4 doses.
• Previously Untreated, Follicular, CD20–Positive, B–Cell NHL
Administer on Day 1 of each cycle of CVP chemotherapy, for up to 8 doses. In patients with complete or partial response, initiate rituximab maintenance eight weeks following completion of rituximab in combination with chemotherapy. Administer rituximab as a single-agent every 8 weeks for 12 doses.
• Non–progressing, Low–Grade, CD20–Positive, B–cell NHL, after first–line CVP chemotherapy
Following completion of 6–8 cycles of CVP chemotherapy, administer once weekly for 4 doses at 6–month intervals to a maximum of 16 doses.
• Diffuse Large B–Cell NHL
Administer on Day 1 of each cycle of chemotherapy for up to 8 infusions.
3.3 Recommended Dose for Chronic Lymphocytic Leukemia (CLL)
The recommended dose is:
• 375 mg/m2 the day prior to the initiation of FC chemotherapy, then 500 mg/m2 on Day 1 of cycles 2-6 (every 28 days).
3.4 Recommended Dose as a Component of Zevalin®
• Infuse rituximab 250 mg/m2 within 4 hours prior to the administration of Indium–111–(In–111–) Zevalin and within 4 hours prior to the administration of Yttrium–90– (Y–90–) Zevalin.
• Administer rituximab and In–111–Zevalin 7–9 days prior to rituximab and Y–90– Zevalin.
• Refer to the Zevalin package insert for full prescribing information regarding the Zevalin therapeutic regimen.
3.5 Recommended Dose for Rheumatoid Arthritis (RA)
• Administer rituximab as two-1000 mg intravenous infusions separated by 2 weeks.
• Glucocorticoids administered as methylprednisolone 100 mg intravenous or its equivalent 30 minutes prior to each infusion are recommended to reduce the incidence and severity of infusion reactions.
• Subsequent courses should be administered every 24 weeks or based on clinical evaluation, but not sooner than every 16 weeks.
• Rituximab is given in combination with methotrexate.
3.6 Recommended Dose for Granulomatosis with Polyangiitis (GPA) (Wegener’s Granulomatosis) and Microscopic Polyangiitis (MPA)
• Administer rituximab as a 375 mg/m2 intravenous infusion once weekly for 4 weeks.
• Glucocorticoids administered as methylprednisolone 1000 mg intravenously per day for 1 to 3 days followed by oral prednisone 1 mg/kg/day (not to exceed 80 mg/day and tapered per clinical need) are recommended to treat severe vasculitis symptoms. This regimen should begin within 14 days prior to or with the initiation of rituximab and may continue during and after the 4 week course of rituximab treatment.
• Safety and efficacy of treatment with subsequent courses of rituximab have not been established [see Warnings and Precautions].
3.7 Recommended Concomitant Medications
Premedicate before each infusion with acetaminophen and an antihistamine. For patients administered rituximab according to the 90-minute infusion rate, the glucocorticoid component of their chemotherapy regimen should be administered prior to infusion.
For RA patients, methylprednisolone 100 mg intravenously or its equivalent is recommended 30 minutes prior to each infusion.
For GPA and MPA patients, glucocorticoids are given in combination with rituximab [see Dosage and Administration].
Pneumocystis jiroveci pneumonia (PCP) and anti-herpetic viral prophylaxis is recommended for patients with CLL during treatment and for up to 12 months following treatment as appropriate.
PCP prophylaxis is also recommended for patients with GPA and MPA during treatment and for at least 6 months following the last rituximab infusion.
3.8 Preparation for Administration
Use appropriate aseptic technique. Parenteral drug products should be inspected visually for particulate matter and discoloration prior to administration. Do not use vial if particulates or discoloration is present. Withdraw the necessary amount of rituximab and dilute to a final concentration of 1 to 4 mg/mL in an infusion bag containing either 0.9% Sodium Chloride, USP, or 5% Dextrose in Water, USP. Gently invert the bag to mix the solution. Do not mix or dilute with other drugs. Discard any unused portion left in the vial.
|5. MECHANISM OF ACTION|
Rituximab binds specifically to the antigen CD20 (human B-lymphocyte-restricted differentiation antigen, Bp35), a hydrophobic transmembrane protein with a molecular weight of approximately 35 kD located on pre–B and mature B lymphocytes. The antigen is expressed on >90% of B–cell non–Hodgkin’s lymphomas (NHL), but the antigen is not found on hematopoietic stem cells, pro-Bcells, normal plasma cells or other normal tissues. CD20 regulates an early step(s) in the activation process for cell cycle initiation and differentiation, and possibly functions as a calcium ion channel. CD20 is not shed from the cell surface and does not internalize upon antibody binding. Free CD20 antigen is not found in the circulation.
B cells are believed to play a role in the pathogenesis of rheumatoid arthritis (RA) and associated chronic synovitis. In this setting, B cells may be acting at multiple sites in the autoimmune/inflammatory process, including through production of rheumatoid factor (RF) and other autoantibodies, antigen presentation, T–cell activation, and/or pro–inflammatory cytokine production.
Mechanism of Action: The Fab domain of rituximab binds to the CD20 antigen on B lymphocytes, and the Fc domain recruits immune effector functions to mediate B-cell lysis in vitro. Possible mechanisms of cell lysis include complement-dependent cytotoxicity (CDC) and antibody-dependent cell mediated cytotoxicity (ADCC). The antibody has been shown to induce apoptosis in the DHL-4 human B-cell lymphoma line.
Normal Tissue Cross-reactivity: Rituximab binding was observed on lymphoid cells in the thymus, the white pulp of the spleen, and a majority of B lymphocytes in peripheral blood and lymph nodes. Little or no binding was observed in the non-lymphoid tissues examined.
|6. USE IN SPECIFIC POPULATIONS|
6.1 Usage in Pregnancy
Pregnancy Category C
There are no adequate and well–controlled studies of rituximab in pregnant women. Postmarketing data indicate that B–cell lymphocytopenia generally lasting less than six months can occur in infants exposed to rituximab in–utero. Rituximab was detected postnatally in the serum of infants exposed in–utero.
Non–Hodgkin’s lymphoma and moderate–severe rheumatoid arthritis are serious conditions that require treatment. Rituximab should be used during pregnancy only if the potential benefit to the mother justifies the potential risk to the fetus.
Reproduction studies in cynomolgus monkeys at maternal exposures similar to human therapeutic exposures showed no evidence of teratogenic effects. However, B–cell lymphoid tissue was reduced in the offspring of treated dams. The B–cell counts returned to normal levels, and immunologic function was restored within 6 months of birth.
6.2 Nursing Mothers
It is not known whether rituximab is secreted into human milk. However, rituximab is secreted in the milk of lactating cynomolgus monkeys, and IgG is excreted in human milk. Published data suggest that antibodies in breast milk do not enter the neonatal and infant circulations in substantial amounts. The unknown risks to the infant from oral ingestion of rituximab should be weighed against the known benefits of breastfeeding.
6.3 Pediatric Use
FDA has not required pediatric studies in polyarticular juvenile idiopathic arthritis (PJIA) patients ages 0 to 16 due to concerns regarding the potential for prolonged immunosuppression as a result of B cell depletion in the developing juvenile immune system. The safety and effectiveness of rituximab in pediatric patients have not been established.
6.4 Geriatric Use
Diffuse Large B-Cell NHL
Among patients with DLBCL evaluated in three randomized, active-controlled trials, 927 patients received rituximab in combination with chemotherapy. Of these, 396 (43%) were age 65 or greater and 123 (13%) were age 75 or greater. No overall differences in effectiveness were observed between these patients and younger patients. Cardiac adverse reactions, mostly supraventricular arrhythmias, occurred more frequently among elderly patients. Serious pulmonary adverse reactions were also more common among the elderly, including pneumonia and pneumonitis.
Low–Grade or Follicular Non–Hodgkin’s Lymphoma
Clinical studies of rituximab in low–grade or follicular, CD20–positive, B–cell NHL did not include sufficient numbers of patients aged 65 and over to determine whether they respond differently from younger subjects.
Chronic Lymphocytic Leukemia
Among patients with CLL evaluated in two randomized active-controlled trials, 243 of 676 rituximab-treated patients (36%) were 65 years of age or older; of these, 100 rituximab-treated patients (15%) were 70 years of age or older.
In exploratory analyses defined by age, there was no observed benefit from the addition of rituximab to fludarabine and cyclophosphamide among patients 70 years of age or older in Study 9 or in Study 10; there was also no observed benefit from the addition of rituximab to fludarabine and cyclophosphamide among patients 65 years of age or older in Study 10. Patients 70 years or older received lower dose intensity of fludarabine and cyclophosphamide compared to younger patients, regardless of the addition of rituximab. In Study 9, the dose intensity of rituximab was similar in older and younger patients, however in Study 10 older patients received a lower dose intensity of rituximab.
The incidence of Grade 3 and 4 adverse reactions was higher among patients receiving R-FC who were 70 years or older compared to younger patients for neutropenia [44% vs. 31% (Study 9); 56% vs. 39% (Study 10)], febrile neutropenia [16% vs. 6% (Study 9)], anemia [5% vs. 2% (Study 9); 21% vs. 10% (Study 10)], thrombocytopenia [19% vs. 8% (Study 10)], pancytopenia [7% vs. 2% (Study 9); 7% vs. 2% (Study 10)] and infections [30% vs. 14% (Study 10)].
Among the 2578 patients in global RA studies completed to date, 12% were 65–75 years old and 2% were 75 years old and older. The incidences of adverse reactions were similar between older and younger patients. The rates of serious adverse reactions, including serious infections, malignancies, and cardiovascular events were higher in older patients.
|7. WARNINGS AND PRECAUTIONS|
7.1 Infusion Reactions
Rituximab can cause severe, including fatal, infusion reactions. Severe reactions typically occurred during the first infusion with time to onset of 30–120 minutes. Rituximab–induced infusion reactions and sequelae include urticaria, hypotension, angioedema, hypoxia, bronchospasm, pulmonary infiltrates, acute respiratory distress syndrome, myocardial infarction, ventricular fibrillation, cardiogenic shock, anaphylactoid events, or death.
Premedicate patients with an antihistamine and acetaminophen prior to dosing. For RA patients, methylprednisolone 100 mg IV or its equivalent is recommended 30 minutes prior to each infusion. Institute medical management (e.g. glucocorticoids, epinephrine, bronchodilators, or oxygen) for infusion reactions as needed. Depending on the severity of the infusion reaction and the required interventions, temporarily or permanently discontinue rituximab. Resume infusion at a minimum 50% reduction in rate after symptoms have resolved. Closely monitor the following patients: those with pre–existing cardiac or pulmonary conditions, those who experienced prior cardiopulmonary adverse reactions, and those with high numbers of circulating malignant cells ( ≥ 25,000/mm3). [See Boxed Warning, Adverse Reactions.]
7.2 Tumor Lysis Syndrome (TLS)
Acute renal failure, hyperkalemia, hypocalcemia, hyperuricemia, or hyperphosphatemia from tumor lysis, some fatal, can occur within 12–24 hours after the first infusion of rituximab in patients with NHL. A high number of circulating malignant cells (≥ 25,000/mm3) or high tumor burden, confers a greater risk of TLS. Administer aggressive intravenous hydration and anti-hyperuricemic therapy in patients at high risk for TLS. Correct electrolyte abnormalities, monitor renal function and fluid balance, and administer supportive care, including dialysis as indicated. [See Boxed Warning].
7.3 Severe Mucocutaneous Reactions
Mucocutaneous reactions, some with fatal outcome, can occur in patients treated with rituximab. These reactions include paraneoplastic pemphigus, Stevens–Johnson syndrome, lichenoid dermatitis, vesiculobullous dermatitis, and toxic epidermal necrolysis. The onset of these reactions has varied from 1–13 weeks following rituximab exposure. Discontinue rituximab in patients who experience a severe mucocutaneous reaction. The safety of readministration of rituximab to patients with severe mucocutaneous reactions has not been determined. [See Boxed Warning, Adverse Reactions.]
7.4 Progressive Multifocal Leukoencephalopathy (PML)
JC virus infection resulting in PML and death can occur in rituximab–treated patients with hematologic malignancies or with autoimmune diseases. The majority of patients with hematologic malignancies diagnosed with PML received rituximab in combination with chemotherapy or as part of a hematopoietic stem cell transplant. The patients with autoimmune diseases had prior or concurrent immunosuppressive therapy. Most cases of PML were diagnosed within 12 months of their last infusion of rituximab.
Consider the diagnosis of PML in any patient presenting with new–onset neurologic manifestations. Evaluation of PML includes, but is not limited to, consultation with a neurologist, brain MRI, and lumbar puncture. Discontinue rituximab and consider discontinuation or reduction of any concomitant chemotherapy or immunosuppressive therapy in patients who develop PML. [See Boxed Warning, Adverse Reactions.]
7.5 Hepatitis B Virus (HBV) Reactivation
Hepatitis B virus (HBV) reactivation with fulminant hepatitis, hepatic failure, and death can occur in patients with hematologic malignancies treated with rituximab. The median time to the diagnosis of hepatitis was approximately 4 months after the initiation of rituximab and approximately one month after the last dose.
Screen patients at high risk of HBV infection before initiation of rituximab. Closely monitor carriers of hepatitis B for clinical and laboratory signs of active HBV infection for several months following rituximab therapy. Discontinue rituximab and any concomitant chemotherapy in patients who develop viral hepatitis, and institute appropriate treatment including antiviral therapy. Insufficient data exist regarding the safety of resuming rituximab in patients who develop hepatitis subsequent to HBV reactivation. [See Adverse Reactions.]
Serious, including fatal, bacterial, fungal, and new or reactivated viral infections can occur during and following the completion of rituximab-based therapy. Infections have been reported in some patients with prolonged hypogammaglobulinemia (defined as hypogammaglobulinemia >11 months after rituximab exposure). New or reactivated viral infections included cytomegalovirus, herpes simplex virus, parvovirus B19, varicella zoster virus, West Nile virus, and hepatitis B and C. Discontinue rituximab for serious infections and institute appropriate anti-infective therapy. [See Adverse Reactions.]
Discontinue infusions for serious or life–threatening cardiac arrhythmias. Perform cardiac monitoring during and after all infusions of rituximab for patients who develop clinically significant arrhythmias, or who have a history of arrhythmia or angina. [See Adverse Reactions.]
Severe, including fatal, renal toxicity can occur after rituximab administration in patients with NHL. Renal toxicity has occurred in patients who experience tumor lysis syndrome and in patients with NHL administered concomitant cisplatin therapy during clinical trials. The combination of cisplatin and rituximab is not an approved treatment regimen. Monitor closely for signs of renal failure and discontinue rituximab in patients with a rising serum creatinine or oliguria. [See Warnings and Precautions.]
7.9 Bowel Obstruction and Perforation
Abdominal pain, bowel obstruction and perforation, in some cases leading to death, can occur in patients receiving rituximab in combination with chemotherapy. In postmarketing reports, the mean time to documented gastrointestinal perforation was 6 (range 1–77) days in patients with NHL. Perform a thorough diagnostic evaluation and institute appropriate treatment for complaints of abdominal pain. [See Adverse Reactions.]
The safety of immunization with live viral vaccines following rituximab therapy has not been studied and vaccination with live virus vaccines is not recommended.
For RA patients, physicians should follow current immunization guidelines and administer non–live vaccines at least 4 weeks prior to a course of rituximab.
The effect of rituximab on immune responses was assessed in a randomized, controlled study in patients with RA treated with rituximab and methotrexate (MTX) compared to patients treated with MTX alone.
A response to pneumococcal vaccination (a T–cell independent antigen) as measured by an increase in antibody titers to at least 6 of 12 serotypes was lower in patients treated with rituximab plus MTX as compared to patients treated with MTX alone (19% vs. 61%). A lower proportion of patients in the rituximab plus MTX group developed detectable levels of anti–keyhole limpet hemocyanin antibodies (a novel protein antigen) after vaccination compared to patients on MTX alone (47% vs. 93%).
A positive response to tetanus toxoid vaccine (a T–cell dependent antigen with existing immunity) was similar in patients treated with rituximab plus MTX compared to patients on MTX alone (39% vs. 42%). The proportion of patients maintaining a positive Candida skin test (to evaluate delayed type hypersensitivity) was also similar (77% of patients on rituximab plus MTX vs. 70% of patients on MTX alone).
Most patients in the rituximab–treated group had B–cell counts below the lower limit of normal at the time of immunization. The clinical implications of these findings are not known.
7.11 Laboratory Monitoring
In patients with lymphoid malignancies, during treatment with rituximab monotherapy, obtain complete blood counts (CBC) and platelet counts prior to each rituximab course. During treatment with rituximab and chemotherapy, obtain CBC and platelet counts at weekly to monthly intervals and more frequently in patients who develop cytopenias [see Adverse Reactions]. In patients with RA obtain CBC and platelet counts at two to four month intervals during rituximab therapy. The duration of cytopenias caused by rituximab can extend months beyond the treatment period.
7.12 Concomitant Use with Biologic Agents and DMARDS other than Methotrexate in RA, GPA and MPA
Limited data are available on the safety of the use of biologic agents or DMARDs other than methotrexate in RA patients exhibiting peripheral B-cell depletion following treatment with rituximab. Observe patients closely for signs of infection if biologic agents and/or DMARDs are used concomitantly. Use of concomitant immunosuppressants other than corticosteroids has not been studied in GPA or MPA patients exhibiting peripheral B-cell depletion following treatment with rituximab.
7.13 Use in RA Patients Who Have Not Had Prior Inadequate Response to Tumor Necrosis Factor (TNF) Antagonists
While the efficacy of rituximab was supported in four controlled trials in patients with RA with prior inadequate responses to non–biologic DMARDs, and in a controlled trial in MTX–naïve patients, a favorable risk–benefit relationship has not been established in these populations. The use of rituximab in patients with RA who have not had prior inadequate response to one or more TNF antagonists is not recommended.
7.14 Retreatment in Patients with Granulomatosis with Polyangiitis (GPA) (Wegener’s Granulomatosis) and Microscopic Polyangiitis (MPA)
Limited data are available on the safety and efficacy of subsequent courses of rituximab in patients with GPA and MPA. The safety and efficacy of retreatment with rituximab have not been established [see Dosage and Administration, Adverse Reactions].
|8. ADVERSE REACTIONS|
The following serious adverse reactions are discussed in greater detail in other sections of the labeling:
• Infusion reactions [see Warnings and Precautions]
• Tumor lysis syndrome [see Warnings and Precautions]
• Mucocutaneous reactions [see Warnings and Precautions]
• Progressive multifocal leukoencephalopathy [see Warnings and Precautions]
• Hepatitis B reactivation with fulminant hepatitis [see Warnings and Precautions]
• Infections [see Warnings and Precautions]
• Cardiac arrhythmias[see Warnings and Precautions]
• Renal toxicity[see Warnings and Precautions]
• Bowel obstruction and perforation [see Warnings and Precautions]
The most common adverse reactions of rituximab (incidence ≥ 25%) observed in clinical trials of patients with NHL were infusion reactions, fever, lymphopenia, chills, infection, and asthenia.
The most common adverse reactions of rituximab (incidence ≥ 25%) observed in clinical trials of patients with CLL were: infusion reactions and neutropenia.
8.1 Clinical Trials Experience in Lymphoid Malignancies
Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice.
The data described below reflect exposure to rituximab in 2282 patients, with exposures ranging from a single infusion up to 6-8 months. Rituximab was studied in both single-agent and active-controlled trials (n = 356 and n = 1926). The population included 679 patients with low-grade follicular lymphoma, 927 patients with DLBCL, and 676 patients with CLL. Most NHL patients received rituximab as an infusion of 375 mg/m2 per infusion, given as a single agent weekly for up to 8 doses, in combination with chemotherapy for up to 8 doses, or following chemotherapy for up to 16 doses. CLL patients received rituximab 375 mg/m2 as an initial infusion followed by 500 mg/m2 for up to 5 doses, in combination with fludarabine and cyclophosphamide. Seventy-one percent of CLL patients received 6 cycles and 90% received at least 3 cycles of rituximab-based therapy.
In the majority of patients with NHL, infusion reactions consisting of fever, chills/rigors, nausea, pruritus, angioedema, hypotension, headache, bronchospasm, urticaria, rash, vomiting, myalgia, dizziness, or hypertension occurred during the first rituximab infusion.
Infusion reactions typically occurred within 30 to 120 minutes of beginning the first infusion and resolved with slowing or interruption of the rituximab infusion and with supportive care (diphenhydramine, acetaminophen, and intravenous saline). The incidence of infusion reactions was highest during the first infusion (77%) and decreased with each subsequent infusion. [See Boxed Warning, Warnings and Precautions.]
Serious infections (NCI CTCAE Grade 3 or 4), including sepsis, occurred in less than 5% of patients with NHL in the single–arm studies. The overall incidence of infections was 31% (bacterial 19%, viral 10%, unknown 6%, and fungal 1%). [See Warnings and Precautions.]
In randomized, controlled studies where rituximab was administered following chemotherapy for the treatment of follicular or low–grade NHL, the rate of infection was higher among patients who received rituximab. In diffuse large B–cell lymphoma patients, viral infections occurred more frequently in those who received rituximab.
Cytopenias and hypogammaglobulinemia
In patients with NHL receiving rituximab monotherapy, NCI–CTC Grade 3 and 4 cytopenias were reported in 48% of patients. These included lymphopenia (40%), neutropenia (6%), leukopenia (4%), anemia (3%), and thrombocytopenia (2%). The median duration of lymphopenia was 14 days (range, 1–588 days) and of neutropenia was 13 days (range, 2–116 days). A single occurrence of transient aplastic anemia (pure red cell aplasia) and two occurrences of hemolytic anemia following rituximab therapy occurred during the single–arm studies.
In studies of monotherapy, rituximab–induced B–cell depletion occurred in 70% to 80% of patients with NHL. Decreased IgM and IgG serum levels occurred in 14% of these patients.
Relapsed or Refractory, Low-Grade NHL
Adverse reactions in Table 1 occurred in 356 patients with relapsed or refractory, low–grade or follicular, CD20–positive, B–cell NHL treated in single–arm studies of rituximab administered as a single agent. Most patients received rituximab 375 mg/m2 weekly for 4 doses.
Table 1: Incidence of Adverse Reactions in ≥ 5% of Patients with Relapsed or Refractory, Low–Grade or Follicular NHL, Receiving Single–agent Rituximab (N=356)a,b
a Adverse reactions observed up to 12 months following rituximab.
b Adverse reactions graded for severity by NCI–CTC criteria.
In these single-arm rituximab studies, bronchiolitis obliterans occurred during and up to 6 months after rituximab infusion.
Previously Untreated, Low-Grade or Follicular, NHL
In Study 4, patients in the R-CVP arm experienced a higher incidence of infusional toxicity and neutropenia compared to patients in the CVP arm. The following adverse reactions occurred more frequently (≥5%) in patients receiving R-CVP compared to CVP alone: rash (17% vs. 5%), cough (15% vs. 6%), flushing (14% vs. 3%), rigors (10% vs. 2%), pruritus (10% vs. 1%), neutropenia (8% vs. 3%), and chest tightness (7% vs. 1%).
In Study 5, detailed safety data collection was limited to serious adverse reactions, Grade ≥ 2 infections, and Grade ≥ 3 adverse reactions. In patients receiving rituximab as single-agent maintenance therapy following rituximab plus chemotherapy, infections were reported more frequently compared to the observation arm (37% vs. 22%). Grade 3-4 adverse reactions occurring at a higher incidence (≥ 2%) in the rituximab group were infections (4% vs. 1%) and neutropenia (4% vs. < 1%).
In Study 6, the following adverse reactions were reported more frequently (≥5%) in patients receiving rituximab following CVP compared to patients who received no further therapy: fatigue (39% vs. 14%), anemia (35% vs. 20%), peripheral sensory neuropathy (30% vs. 18%), infections (19% vs. 9%), pulmonary toxicity (18% vs. 10%), hepato-biliary toxicity (17% vs. 7%), rash and/or pruritus (17% vs. 5%), arthralgia (12% vs. 3%), and weight gain (11% vs. 4%). Neutropenia was the only Grade 3 or 4 adverse reaction that occurred more frequently (≥2%) in the rituximab arm compared with those who received no further therapy (4% vs. 1%).
In Studies 7 and 8, the following adverse reactions, regardless of severity, were reported more frequently (≥5%) in patients age ≥60 years receiving R-CHOP as compared to CHOP alone: pyrexia (56% vs. 46%), lung disorder (31% vs. 24%), cardiac disorder (29% vs. 21%), and chills (13% vs. 4%). Detailed safety data collection in these studies was primarily limited to Grade 3 and 4 adverse reactions and serious adverse reactions.
In Study 8, a review of cardiac toxicity determined that supraventricular arrhythmias or tachycardia accounted for most of the difference in cardiac disorders (4.5% for R-CHOP vs. 1.0% for CHOP).
The following Grade 3 or 4 adverse reactions occurred more frequently among patients in the R-CHOP arm compared with those in the CHOP arm: thrombocytopenia (9% vs. 7%) and lung disorder (6% vs. 3%). Other Grade 3 or 4 adverse reactions occurring more frequently among patients receiving R-CHOP were viral infection (Study 8), neutropenia (Studies 8 and 9), and anemia (Study 9).
The data below reflect exposure to rituximab in combination with fludarabine and cyclophosphamide in 676 patients with CLL in Study 11 or Study 12. The age range was 3083 years and 71% were men. Detailed safety data collection in Study 11 was limited to Grade 3 and 4 adverse reactions and serious adverse reactions.
Infusion-related adverse reactions were defined by any of the following adverse events occurring during or within 24 hours of the start of infusion: nausea, pyrexia, chills, hypotension, vomiting, and dyspnea.
In Study 11, the following Grade 3 and 4 adverse reactions occurred more frequently in R-FC-treated patients compared to FC-treated patients: infusion reactions (9% in R-FC arm), neutropenia (30% vs. 19%), febrile neutropenia (9% vs. 6%), leukopenia (23% vs. 12%), and pancytopenia (3% vs. 1%).
In Study 12, the following Grade 3 or 4 adverse reactions occurred more frequently in R-FC-treated patients compared to FC-treated patients: infusion reactions (7% in R-FC arm), neutropenia (49% vs. 44%), febrile neutropenia (15% vs. 12%), thrombocytopenia (11% vs. 9%), hypotension (2% vs. 0%), and hepatitis B (2% vs. < 1%). Fifty-nine percent of R-FC-treated patients experienced an infusion reaction of any severity.
8.2 Clinical Trials Experience in Rheumatoid Arthritis
Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice.
The data presented below reflect the experience in 2578 RA patients treated with rituximab in controlled and long-term studies with a total exposure of 5014 patient-years.
Among all exposed patients, adverse reactions reported in greater than 10% of patients include infusion-related reactions, upper respiratory tract infection, nasopharyngitis, urinary tract infection, and bronchitis.
In placebo-controlled studies, patients received 2 x 500 mg or 2 x 1000 mg intravenous infusions of rituximab or placebo, in combination with methotrexate, during a 24-week period. From these studies, 938 patients treated with rituximab (2 x 1000 mg) or placebo have been pooled (see Table 2). Adverse reactions reported in ≥ 5% of patients were hypertension, nausea, upper respiratory tract infection, arthralgia, pyrexia and pruritus (see Table 2). The rates and types of adverse reactions in patients who received rituximab 2 x 500 mg were similar to those observed in patients who received rituximab 2 x 1000 mg.
Table 2*: Incidence of All Adverse Reactions** Occurring in ≥ 2% and at Least 1% Greater than Placebo Among Rheumatoid Arthritis Patients in Clinical Studies Up to Week 24 (Pooled)
* These data are based on 938 patients treated in Phase 2 and 3 studies of rituximab (2 x 1000 mg) or placebo administered in combination with methotrexate.
** Coded using MedDRA.
In the rituximab RA pooled placebo-controlled studies, 32% of rituximab-treated patients experienced an adverse reaction during or within 24 hours following their first infusion, compared to 23% of placebo-treated patients receiving their first infusion. The incidence of adverse reactions during the 24-hour period following the second infusion, rituximab or placebo, decreased to 11% and 13%, respectively. Acute infusion reactions (manifested by fever, chills, rigors, pruritus, urticaria/rash, angioedema, sneezing, throat irritation, cough, and/or bronchospasm, with or without associated hypotension or hypertension) were experienced by 27% of rituximab-treated patients following their first infusion, compared to 19% of placebo-treated patients receiving their first placebo infusion. The incidence of these acute infusion reactions following the second infusion of rituximab or placebo decreased to 9% and 11%, respectively. Serious acute infusion reactions were experienced by <1% of patients in either treatment group. Acute infusion reactions required dose modification (stopping, slowing, or interruption of the infusion) in 10% and 2% of patients receiving rituximab or placebo, respectively, after the first course. The proportion of patients experiencing acute infusion reactions decreased with subsequent courses of rituximab. The administration of intravenous glucocorticoids prior to rituximab infusions reduced the incidence and severity of such reactions, however, there was no clear benefit from the administration of oral glucocorticoids for the prevention of acute infusion reactions. Patients in clinical studies also received antihistamines and acetaminophen prior to rituximab infusions.
In the pooled, placebo-controlled studies, 39% of patients in the rituximab group experienced an infection of any type compared to 34% of patients in the placebo group. The most common infections were nasopharyngitis, upper respiratory tract infections, urinary tract infections, bronchitis, and sinusitis.
The incidence of serious infections was 2% in the rituximab-treated patients and 1% in the placebo group.
In the experience with rituximab in 2578 RA patients, the rate of serious infections was 4.31 per 100 patient years. The most common serious infections (≥ 0.5%) were pneumonia or lower respiratory tract infections, cellulitis and urinary tract infections. Fatal serious infections included pneumonia, sepsis and colitis. Rates of serious infection remained stable in patients receiving subsequent courses. In 185 rituximab-treated RA patients with active disease, subsequent treatment with a biologic DMARD, the majority of which were TNF antagonists, did not appear to increase the rate of serious infection. Thirteen serious infections were observed in 186.1 patient years (6.99 per 100 patient years) prior to exposure and 10 were observed in 182.3 patient years (5.49 per 100 patient years) after exposure.
Cardiac Adverse Reactions
In the pooled, placebo-controlled studies, the proportion of patients with serious cardiovascular reactions was 1.7% and 1.3% in the rituximab and placebo treatment groups, respectively. Three cardiovascular deaths occurred during the double-blind period of the RA studies including all rituximab regimens (3/7690.4%) as compared to none in the placebo treatment group (0/389).
In the experience with rituximab in 2578 RA patients, the rate of serious cardiac reactions was 1.93 per 100 patient years. The rate of myocardial infarction (MI) was 0.56 per 100 patient years (28 events in 26 patients), which is consistent with MI rates in the general RA population. These rates did not increase over three courses of rituximab.
Since patients with RA are at increased risk for cardiovascular events compared with the general population, patients with RA should be monitored throughout the infusion and rituximab should be discontinued in the event of a serious or life-threatening cardiac event.
Hypophosphatemia and hyperuricemia
In the pooled, placebo-controlled studies, newly-occurring hypophosphatemia (< 2.0 mg/dl) was observed in 12% (67/540) of patients on rituximab versus 10% (39/398) of patients on placebo. Hypophosphatemia was more common in patients who received corticosteroids. Newly-occurring hyperuricemia (>10 mg/dl) was observed in 1.5% (8/540) of patients on rituximab versus 0.3% (1/398) of patients on placebo.
In the experience with rituximab in RA patients, newly-occurring hypophosphatemia was observed in 21% (528/2570) of patients and newly-occurring hyperuricemia was observed in 2% (56/2570) of patients. The majority of the observed hypophosphatemia occurred at the time of the infusions and was transient.
Retreatment in Patients with RA
In the experience with rituximab in RA patients, 2578 patients have been exposed to rituximab and have received up to 10 courses of rituximab in RA clinical trials, with 1890, 1043, and 425 patients having received at least two, three, and four courses, respectively. Most of the patients who received additional courses did so 24 weeks or more after the previous course and none were retreated sooner than 16 weeks. The rates and types of adverse reactions reported for subsequent courses of rituximab were similar to rates and types seen for a single course of rituximab.
In RA Study 2, where all patients initially received rituximab, the safety profile of patients who were retreated with rituximab was similar to those who were retreated with placebo [see Dosage and Administration].
8.3 Clinical Trials Experience in Granulomatosis with Polyangiitis (GPA) (Wegener’s Granulomatosis) and Microscopic Polyangiitis (MPA)
Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice.
The data presented below reflect the experience in 197 patients with GPA and MPA treated with rituximab or cyclophosphamide in a single controlled study, which was conducted in two phases: a 6 month randomized, double-blind, double-dummy, active-controlled remission induction phase and an additional 12 month remission maintenance phase. In the 6-month remission induction phase, 197 patients with GPA and MPA were randomized to either rituximab 375 mg/ m2 once weekly for 4 weeks plus glucocorticoids, or oral cyclophosphamide 2 mg/kg daily (adjusted for renal function, white blood cell count, and other factors) plus glucocorticoids to induce remission. Once remission was achieved or at the end of the 6 month remission induction period, the cyclophosphamide group received azathioprine to maintain remission. The rituximab group did not receive additional therapy to maintain remission. The primary analysis was at the end of the 6 month remission induction period and the safety results for this period are described below.
Adverse reactions presented below in Table 3 were adverse events which occurred at a rate of greater than or equal to 10% in the rituximab group. This table reflects experience in 99 GPA and MPA patients treated with rituximab, with a total of 47.6 patient-years of observation and 98 GPA and MPA patients treated with cyclophosphamide, with a total of 47.0 patient-years of observation. Infection was the most common category of adverse events reported (47-62%) and is discussed below.
Table 3: Incidence of All Adverse Reactions Occurring in ≥ 10% of Rituximab-treated GPA and MPA Patients in the Clinical Study Up to Month 6*
* The study design allowed for crossover or treatment by best medical judgment, and 13 patients in each treatment group received a second therapy during the 6 month study period.
Infusion-related reactions in the active-controlled, double-blind study were defined as any adverse event occurring within 24 hours of an infusion and considered to be infusion-related by investigators. Among the 99 patients treated with rituximab, 12% experienced at least one infusion related reaction, compared with 11% of the 98 patients in the cyclophosphamide group. Infusion-related reactions included cytokine release syndrome, flushing, throat irritation, and tremor. In the rituximab group, the proportion of patients experiencing an infusion related reaction was 12%, 5%, 4%, and 1% following the first, second, third, and fourth infusions, respectively. Patients were pre-medicated with antihistamine and acetaminophen before each rituximab infusion and were on background oral corticosteroids which may have mitigated or masked an infusion reaction; however, there is insufficient evidence to determine whether premedication diminishes the frequency or severity of infusion reactions.
In the active-controlled, double-blind study, 62% (61/99) of patients in the rituximab group experienced an infection of any type compared to 47% (46/98) patients in the cyclophosphamide group by Month 6. The most common infections in the rituximab group were upper respiratory tract infections, urinary tract infections, and herpes zoster.
The incidence of serious infections was 11% in the rituximab-treated patients and 10% in the cyclophosphamide treated patients, with rates of approximately 25 and 28 per 100 patient-years, respectively. The most common serious infection was pneumonia.
Hypogammaglobulinemia (IgA, IgG or IgM below the lower limit of normal) has been observed in patients with GPA and MPA treated with rituximab. At 6 months, in the rituximab group, 27%, 58% and 51% of patients with normal immunoglobulin levels at baseline, had low IgA, IgG and IgM levels, respectively compared to 25%, 50% and 46% in the cyclophosphamide group.
Retreatment in Patients with GPA and MPA
In the active-controlled, double-blind study, subsequent courses of rituximab were allowed for patients experiencing a relapse of disease. The limited data preclude any conclusions regarding the safety of subsequent courses of rituximab with GPA and MPA [see Dosage and Administration (2.6), and Warnings and Precautions].
As with all therapeutic proteins, there is a potential for immunogenicity. The observed incidence of antibody (including neutralizing antibody) positivity in an assay is highly dependent on several factors including assay sensitivity and specificity, assay methodology, sample handling, timing of sample collection, concomitant medications, and underlying disease. For these reasons, comparison of the incidence of antibodies to rituximab with the incidence of antibodies to other products may be misleading.
Using an ELISA assay, anti–human anti–chimeric antibody (HACA) was detected in 4 of 356 (1.1%) patients with low–grade or follicular NHL receiving single–agent rituximab. Three of the four patients had an objective clinical response.
A total of 273/2578 (11%) patients with RA tested positive for HACA at any time after receiving rituximab. HACA positivity was not associated with increased infusion reactions or other adverse reactions. Upon further treatment, the proportions of patients with infusion reactions were similar between HACA positive and negative patients, and most reactions were mild to moderate. Four HACA positive patients had serious infusion reactions, and the temporal relationship between HACA positivity and infusion reaction was variable. The clinical relevance of HACA formation in rituximab–treated patients is unclear.
8.3 Postmarketing Experience
The following adverse reactions have been identified during post–approval use of rituximab in hematologic malignancies. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure. Decisions to include these reactions in labeling are typically based on one or more of the following factors: (1) seriousness of the reaction, (2) frequency of reporting, or (3) strength of causal connection to rituximab.
• Hematologic: prolonged pancytopenia, marrow hypoplasia, and late–onset neutropenia, hyperviscosity syndrome in Waldenstrom’s macroglobulinemia.
• Cardiac: fatal cardiac failure.
• Immune/Autoimmune Events: uveitis, optic neuritis, systemic vasculitis, pleuritis, lupus–like syndrome, serum sickness, polyarticular arthritis, and vasculitis with rash.
• Infection: viral infections, including progressive multifocal leukoencephalopathy (PML), increase in fatal infections in HIV–associated lymphoma, and a reported increased incidence of Grade 3 and 4 infections in patients with previously treated lymphoma without known HIV infection.
• Neoplasia: disease progression of Kaposi’s sarcoma.
• Skin: severe mucocutaneous reactions.
• Gastrointestinal: bowel obstruction and perforation.
• Pulmonary: fatal bronchiolitis obliterans and fatal interstitial lung disease.
• Nervous system: Posterior Reversible Encephalopathy Syndrome (PRES) / Reversible Posterior Leukoencephalopathy Syndrome (RPLS).
There has been no experience with overdosage in human clinical trials. Single doses of up to 500 mg/m2 have been administered in clinical trials.
|10. DRUG INTERACTIONS|
Formal drug interaction studies have not been performed with rituximab. In patients with CLL, rituximab did not alter systemic exposure to fludarabine or cyclophosphamide. In clinical trials of patients with RA, concomitant administration of methotrexate or cyclophosphamide did not alter the pharmacokinetics of rituximab.
Non-Hodgkins Lymphoma (NHL)
Pharmacokinetics were characterized in 203 NHL patients receiving 375 mg/m2 rituximab weekly by IV infusion for 4 doses. Rituximab was detectable in the serum of patients 3 to 6 months after completion of treatment.
The pharmacokinetic profile of rituximab when administered as 6 infusions of 375 mg/m2 in combination with 6 cycles of CHOP chemotherapy was similar to that seen with rituximab alone.
Based on a population pharmacokinetic analysis of data from 298 NHL patients who received rituximab once weekly or once every three weeks, the estimated median terminal elimination half life was 22 days (range, 6.1 to 52 days). Patients with higher CD19–positive cell counts or larger measurable tumor lesions at pretreatment had a higher clearance. However, dose adjustment for pretreatment CD19 count or size of tumor lesion is not necessary. Age and gender had no effect on the pharmacokinetics of rituximab. Pharmacokinetics were characterized in 21 patients with CLL receiving rituximab according to the recommended dose and schedule. The estimated median terminal half-life of rituximab was 32 days (range, 14 to 62 days).
Following administration of 2 doses of rituximab in patients with RA, the mean (± S.D.; % CV) concentrations after the first infusion (Cmax first) and second infusion (Cmax second) were 157 (± 46; 29%) and 183 (± 55; 30%) mcg/mL, and 318 (± 86; 27%) and 381 (± 98; 26%) mcg/mL for the 2 × 500 mg and 2 × 1000 mg doses, respectively.
Based on a population pharmacokinetic analysis of data from 2005 RA patients who received rituximab, the estimated clearance of rituximab was 0.335 L/day; volume of distribution was 3.1 L and mean terminal elimination half life was 18.0 days (range, 5.17 to 77.5 days). Age, weight and gender had no effect on the pharmacokinetics of rituximab in RA patients.
Granulomatosis with Polyangiitis (GPA) (Wegener’s Granulomatosis) and Microscopic Polyangiitis
Based on the population pharmacokinetic analysis of data in 97 GPA and MPA patients who received 375 mg/m2 rituximab once weekly by intravenous infusion for four weeks, the estimated median terminal elimination half-life was 23 days (range, 9 to 49 days). Rituximab mean clearance and volume of distribution were 0. 312 L/day (range, 0.115 to 0.728 L/day) and 4.50 L (range, 2.21 to 7.52 L) respectively. Male patients and patients with higher BSA or positive HACA levels have higher clearance. However, further dose adjustment based on gender or HACA status is not necessary.
The pharmacokinetics of rituximab have not been studied in children and adolescents. No formal studies were conducted to examine the effects of either renal or hepatic impairment on the pharmacokinetics of rituximab.
|12. HOW SUPPLIED/STORAGE AND HANDLING|
1) How Available:
a) Brand name: RITUXAN, by Biogen Idec Inc. and Genentech.
b) Generic drugs: None.
2) How Supplied:
Rituxan vials [100 mg/10 mL (NDC 50242–051–21) and 500 mg/50 mL (NDC 50242–053–06)].
Store at 2°C — 8°C (36°F — 46°F). Do not use beyond expiration date stamped on carton. Rituxan vials should be protected from direct sunlight. Do not freeze or shake.
Rituxan solutions for infusion may be stored at 2°C — 8°C (36°F — 46°F) for 24 hours. Rituxan solutions for infusion have been shown to be stable for an additional 24 hours at room temperature. However, since Rituxan solutions do not contain a preservative, diluted solutions should be stored refrigerated (2°C — 8°C).
No incompatibilities between Rituxan and polyvinylchloride or polyethylene bags have been observed.