Riabni

Indications and Usage, Pemphigus Vulgaris (PV) ( 1.5 ) 6/2025 Dosage and Administration, Recommended Dose for (PV) ( 2.7 ) 6/2025 Dosage and Administration, Recommended Dose for Premedication and Prophylactic Medications ( 2.8 ) 6/2025 Warnings and Precautions, Infusion Related Reactions ( 5.1 ) 6/2025 Warnings and Precautions ( 5.12 ) 6/2025

1 INDICATIONS AND USAGE RIABNI is a CD20-directed cytolytic antibody indicated for the treatment of: Adult patients with Non-Hodgkin's Lymphoma (NHL) ( 1.1 ). 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 first line chemotherapy and, in patients achieving a complete or partial response to a rituximab product in combination with chemotherapy, as single-agent maintenance therapy. Non-progressing (including stable disease), low-grade, CD20-positive, B-cell NHL as a single agent after first-line cyclophosphamide, vincristine, and prednisone (CVP) chemotherapy. Previously untreated diffuse large B-cell, CD20-positive NHL in combination with cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) or other anthracycline-based chemotherapy regimens. Adult patients with Chronic Lymphocytic Leukemia (CLL) ( 1.2 ). Previously untreated and previously treated CD20-positive CLL in combination with fludarabine and cyclophosphamide (FC). Rheumatoid Arthritis (RA) in combination with methotrexate in adult patients with moderately- to-severely- active RA who have inadequate response to one or more TNF antagonist therapies ( 1.3 ). Granulomatosis with Polyangiitis (GPA) (Wegener's Granulomatosis) and Microscopic Polyangiitis (MPA) in adult patients in combination with glucocorticoids ( 1.4 ). Moderate to severe Pemphigus Vulgaris (PV) in adult patients ( 1.5 ). 1.1 Non-Hodgkin's Lymphoma (NHL) RIABNI is indicated for the treatment of adult 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 first line chemotherapy and, in patients achieving a complete or partial response to a rituximab product in combination with chemotherapy, as single-agent maintenance therapy. Non-progressing (including stable disease), low-grade, CD20-positive, B-cell NHL as a single agent after first-line cyclophosphamide, vincristine, and prednisone (CVP) chemotherapy. Previously untreated diffuse large B-cell, CD20-positive NHL in combination with cyclophosphamide, doxorubicin, vincristine, prednisone (CHOP) or other anthracycline-based chemotherapy regimens. 1.2 Chronic Lymphocytic Leukemia (CLL) RIABNI, in combination with fludarabine and cyclophosphamide (FC), is indicated for the treatment of adult patients with previously untreated and previously treated CD20-positive CLL. 1.3 Rheumatoid Arthritis (RA) RIABNI, 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. 1.4 Granulomatosis with Polyangiitis (GPA) (Wegener's Granulomatosis) and Microscopic Polyangiitis (MPA) RIABNI, in combination with glucocorticoids, is indicated for the treatment of adult patients with Granulomatosis with Polyangiitis (GPA) (Wegener's Granulomatosis) and Microscopic Polyangiitis (MPA). 1.5 Pemphigus Vulgaris (PV) RIABNI is indicated for the treatment of adult patients with moderate to severe pemphigus vulgaris.

2 DOSAGE AND ADMINISTRATION Administer only as an intravenous infusion ( 2.1 ). Do not administer as an intravenous push or bolus ( 2.1 ). RIABNI should only be administered by a healthcare professional with appropriate medical support to manage severe infusion-related reactions that can be fatal if they occur ( 2.1 ). The dose for adult B-cell NHL is 375 mg/m 2 ( 2.2 ). The dose for CLL is 375 mg/m 2 in the first cycle and 500 mg/m 2 in cycles 2–6, in combination with FC, administered every 28 days ( 2.3 ). The dose as a component of Zevalin ® (ibritumomab tiuxetan) Therapeutic Regimen is 250 mg/m 2 ( 2.4 ). The dose for RA in combination with methotrexate is two-1,000 mg intravenous infusions separated by 2 weeks (one course) every 24 weeks or based on clinical evaluation, but not sooner than every 16 weeks. Methylprednisolone 100 mg intravenous or equivalent glucocorticoid is recommended 30 minutes prior to each infusion ( 2.5 ). The induction dose for adult patients with active GPA and MPA in combination with glucocorticoids is 375 mg/m 2 once weekly for 4 weeks. The follow up dose for adult patients with GPA and MPA who have achieved disease control with induction treatment, in combination with glucocorticoids is two 500 mg intravenous infusions separated by two weeks, followed by a 500 mg intravenous infusion every 6 months thereafter based on clinical evaluation ( 2.6 ). The dose for PV is two-1,000 mg intravenous infusions separated by 2 weeks in combination with a tapering course of glucocorticoids, then a 500 mg intravenous infusion at Month 12 and every 6 months thereafter or based on clinical evaluation. Dose upon relapse is a 1,000 mg intravenous infusion with considerations to resume or increase the glucocorticoid dose based on clinical evaluation. Subsequent infusions may be no sooner than 16 weeks after the previous infusion ( 2.7 ). Methylprednisolone 100 mg intravenous or equivalent glucocorticoid is recommended 30 minutes prior to each infusion ( 2.8 ). 2.1 Important Dosing Information Administer only as an intravenous infusion [see Dosage and Administration (2.8) ] . Do not administer as an intravenous push or bolus. RIABNI should only be administered by a healthcare professional with appropriate medical support to manage severe infusion-related reactions that can be fatal if they occur [see Warnings and Precautions (5.1) ]. Premedicate before each infusion [see Dosage and Administration (2.8) ] . Prior to First Infusion Screen all patients for HBV infection by measuring HBsAg and anti-HBc before initiating treatment with RIABNI [see Warnings and Precautions (5.3) ] . Obtain complete blood counts (CBC) including platelets prior to the first dose. During RIABNI Therapy In patients with lymphoid malignancies during treatment with RIABNI monotherapy, obtain complete blood counts (CBC) with differential and platelet counts prior to each RIABNI course. During treatment with RIABNI and chemotherapy, obtain CBC with differential and platelet counts at weekly to monthly intervals and more frequently in patients who develop cytopenias [see Adverse Reactions (6.1) ]. In patients with RA, GPA or MPA, obtain CBC with differential and platelet counts at two to four month intervals during RIABNI therapy. Continue to monitor for cytopenias after final dose and until resolution. First Infusion : Standard Infusion : Initiate infusion at a rate of 50 mg/hour. In the absence of infusion toxicity, increase infusion rate by 50 mg/hour increments every 30 minutes, to a maximum of 400 mg/hour. Subsequent Infusions: Standard Infusion: Initiate infusion at a rate of 100 mg/hour. In the absence of infusion toxicity, increase rate by 100 mg/hour increments at 30-minute intervals, to a maximum of 400 mg/hour. For Previously Untreated Follicular NHL and DLBCL Adult 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 glucocortic …

3 DOSAGE FORMS AND STRENGTHS Injection: 100 mg/10 mL (10 mg/mL) and 500 mg/50 mL (10 mg/mL) as a clear to slightly opalescent, colorless to slightly yellow solution in a single-dose vial. Injection: 100 mg/10 mL (10 mg/mL) and 500 mg/50 mL (10 mg/mL) solution in single-dose vials ( 3 )

4 CONTRAINDICATIONS None. None ( 4 )

6 ADVERSE REACTIONS The following clinically significant adverse reactions are discussed in greater detail in other sections of the labeling: Infusion-related reactions [see Warnings and Precautions (5.1) ] Severe mucocutaneous reactions [see Warnings and Precautions (5.2) ] Hepatitis B reactivation with fulminant hepatitis [see Warnings and Precautions (5.3) ] Progressive multifocal leukoencephalopathy [see Warnings and Precautions (5.4) ] Tumor lysis syndrome [see Warnings and Precautions (5.5) ] Infections [see Warnings and Precautions (5.6) ] Cardiovascular adverse reactions [see Warnings and Precautions (5.7) ] Renal toxicity [see Warnings and Precautions (5.8) ] Bowel obstruction and perforation [see Warnings and Precautions (5.9) ] Most common adverse reactions in clinical trials were: NHL (greater than or equal to 25%): infusion-related reactions, fever, lymphopenia, chills, infection, and asthenia ( 6.1 ). CLL (greater than or equal to 25%): infusion-related reactions and neutropenia ( 6.1 ). RA (greater than or equal to 10%): upper respiratory tract infection, nasopharyngitis, urinary tract infection, and bronchitis (other important adverse reactions include infusion-related reactions, serious infections, and cardiovascular events) ( 6.1 ). GPA and MPA (greater than or equal to 15%): infections, nausea, diarrhea, headache, muscle spasms, anemia, peripheral edema, infusion-related reactions ( 6.1 ). PV (greater than or equal to 15%): infusion-related reactions, depression, upper respiratory tract infection/ nasopharyngitis, headache (other important adverse reactions include infections) ( 6.1 ). To report SUSPECTED ADVERSE REACTIONS, contact Amgen, Inc. at 1-800-77-AMGEN (1-800-772-6436) or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch . 6.1 Clinical Trials Experience 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 clinical practice. B-Cell Malignancies The data described below reflect exposure to rituximab in 3,092 patients, with exposures ranging from a single infusion up to 2 years. Rituximab was studied in both single-arm and controlled trials (n = 356 and n = 2,427). The population included 1,180 patients with low grade or follicular lymphoma, 927 patients with DLBCL, 676 patients with CLL, and 309 patients with another indication. Most NHL patients received rituximab as an infusion of 375 mg/m 2 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/m 2 as an initial infusion followed by 500 mg/m 2 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. The most common adverse reactions of rituximab (incidence greater than or equal to 25%) observed in clinical trials of patients with NHL were infusion-related reactions, fever, lymphopenia, chills, infection, and asthenia. The most common adverse reactions of rituximab (incidence greater than or equal to 25%) observed in clinical trials of patients with CLL were: infusion-related reactions and neutropenia. Infusion-Related Reactions In the majority of patients with NHL, infusion-related 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-related 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-related …

7 DRUG INTERACTIONS Formal drug interaction studies have not been performed with rituximab products. 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. Renal toxicity when used in combination with cisplatin ( 5.8 ).

8 USE IN SPECIFIC POPULATIONS Lactation : Advise not to breastfeed ( 8.2 ). Geriatric Use : In CLL patients older than 70 years of age, exploratory analyses suggest no benefit with the addition of rituximab to FC ( 8.5 ). 8.1 Pregnancy Risk Summary Based on human data, rituximab products can cause adverse developmental outcomes including B-cell lymphocytopenia in infants exposed in utero ( see Clinical Considerations ). In animal reproduction studies, intravenous administration of rituximab to pregnant cynomolgus monkeys during the period of organogenesis caused lymphoid B-cell depletion in the newborn offspring at doses resulting in 80% of the exposure (based on AUC) of those achieved following a dose of 2 grams in humans. Advise pregnant women of the risk to a fetus. Adverse outcomes in pregnancy occur regardless of the health of the mother or the use of medications. The background risk of major birth defects and miscarriage for the indicated populations is unknown. The estimated background risk in the U.S. general population of major birth defects is 2%-4% and of miscarriage is 15%-20% of clinically recognized pregnancies. Clinical Considerations Fetal/Neonatal Adverse Reactions Observe newborns and infants for signs of infection and manage accordingly. Data Human Data Postmarketing data indicate that B-cell lymphocytopenia generally lasting less than 6 months can occur in infants exposed to rituximab in utero . Rituximab was detected postnatally in the serum of infants exposed in utero . Animal Data An embryo-fetal developmental toxicity study was performed on pregnant cynomolgus monkeys. Pregnant animals received rituximab via the intravenous route during early gestation (organogenesis period; post coitum Days 20 through 50). Rituximab was administered as loading doses on post coitum (PC) Days 20, 21 and 22, at 15, 37.5 or 75 mg/kg/day, and then weekly on PC Days 29, 36, 43 and 50, at 20, 50 or 100 mg/kg/week. The 100 mg/kg/week dose resulted in 80% of the exposure (based on AUC) of those achieved following a dose of 2 grams in humans. Rituximab crosses the monkey placenta. Exposed offspring did not exhibit any teratogenic effects but did have decreased lymphoid tissue B cells. A subsequent pre-and postnatal reproductive toxicity study in cynomolgus monkeys was completed to assess developmental effects including the recovery of B cells and immune function in infants exposed to rituximab in utero . Animals were treated with a loading dose of 0, 15, or 75 mg/kg every day for 3 days, followed by weekly dosing with 0, 20, or 100 mg/kg dose. Subsets of pregnant females were treated from PC Day 20 through postpartum Day 78, PC Day 76 through PC Day 134, and from PC Day 132 through delivery and postpartum Day 28. Regardless of the timing of treatment, decreased B cells and immunosuppression were noted in the offspring of rituximab-treated pregnant animals. The B-cell counts returned to normal levels, and immunologic function was restored within 6 months postpartum. 8.2 Lactation There are limited data on the presence of rituximab in human milk and the effect on the breastfed child, and there are no data on the effect on milk production. Rituximab is detected in the milk of lactating cynomolgus monkeys, and maternal IgG is present in human breast milk. Rituximab has also been reported to be excreted at low concentrations in human breast milk. Given that the clinical significance of this finding for children is not known, advise women not to breastfeed during treatment with RIABNI and for 6 months after the last dose due to the potential of serious adverse reactions in breastfed children. 8.3 Females and Males of Reproductive Potential Rituximab products can cause fetal harm when administered to a pregnant woman [see Use in Specific Populations (8.1) ] . Pregnancy Testing Verify pregnancy status in females of reproductive potential prior to initiating RIABNI. Contraception Females Advise females of reproductive potential to use ef …

12.1 Mechanism of Action Rituximab-arrx is a monoclonal antibody. Rituximab products target the CD20 antigen expressed on the surface of pre-B and mature B-lymphocytes. Upon binding to CD20, rituximab products mediate B-cell lysis. Possible mechanisms of cell lysis include complement dependent cytotoxicity (CDC) and antibody dependent cell mediated cytotoxicity (ADCC). 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 proinflammatory cytokine production.

11 DESCRIPTION Rituximab-arrx is a genetically engineered chimeric murine/human monoclonal IgG1 kappa antibody directed against the CD20 antigen. Rituximab-arrx has an approximate molecular weight of 145 kD. Rituximab-arrx is produced in a mammalian cell (Chinese Hamster Ovary) suspension culture in a nutrient medium. RIABNI (rituximab-arrx) injection is a sterile, preservative-free, clear to slightly opalescent, colorless to slightly yellow solution for intravenous infusion. RIABNI is supplied at a concentration of 10 mg/mL in either 100 mg/10 mL or 500 mg/50 mL single-dose vials. Each mL of solution contains 10 mg rituximab-arrx, polysorbate 80 (0.7 mg), sodium chloride (9 mg), sodium citrate dihydrate (7.35 mg), and Water for Injection, USP. Hydrochloric acid is used to adjust the buffer solution pH. The pH is 6.5.

16 HOW SUPPLIED/STORAGE AND HANDLING RIABNI (rituximab-arrx) injection is a sterile, clear to slightly opalescent, colorless to slightly yellow preservative free solution for intravenous use supplied as a carton containing one 100 mg/10 mL (10 mg/mL) single dose vial (NDC 55513-224-01, 55513-224-21) and a carton containing one 500 mg/50 mL (10 mg/mL) single dose vial (NDC 55513-326-01, 55513-326-21). Store RIABNI vials refrigerated at 2°C to 8°C (36°F to 46°F). Protect RIABNI vials from direct sunlight. Do not freeze or shake.