Elrexfio

Dosage and Administration, Recommended Dosage ( 2.2 ) 7/2025 Dosage and Administration, Restarting ELREXFIO After Dosage Delay ( 2.4 ) 7/2025 Dosage and Administration, Preparation and Administration Instructions ( 2.6 ) 7/2025

1 INDICATIONS AND USAGE ELREXFIO is indicated for the treatment of adult patients with relapsed or refractory multiple myeloma who have received at least four prior lines of therapy, including a proteasome inhibitor, an immunomodulatory agent, and an anti-CD38 monoclonal antibody. This indication is approved under accelerated approval based on response rate and durability of response [see Clinical Studies (14) ] . Continued approval for this indication may be contingent upon verification of clinical benefit in a confirmatory trial(s). ELREXFIO is a bispecific B-cell maturation antigen (BCMA)-directed CD3 T‐cell engager indicated for the treatment of adult patients with relapsed or refractory multiple myeloma who have received at least four prior lines of therapy including a proteasome inhibitor, an immunomodulatory agent, and an anti-CD38 monoclonal antibody. This indication is approved under accelerated approval based on response rate and durability of response. Continued approval for this indication may be contingent upon verification of clinical benefit in a confirmatory trial(s). ( 1 )

2 DOSAGE AND ADMINISTRATION ELREXFIO Dosing Schedule ( 2.2 ) Dosing Schedule Day ELREXFIO Dose Step-up Dosing Schedule Day 1 Step-up dose 1 12 mg Day 4 Step-up dose 2 32 mg Day 8 First treatment dose 76 mg Weekly Dosing Schedule One week after first treatment dose and weekly thereafter through week 24 Subsequent treatment doses 76 mg Biweekly (Every 2 Week) Dosing Schedule Responders only week 25 onward. Week 25 and every 2 weeks thereafter through week 48 Subsequent treatment doses 76 mg Every 4 Week Dosing Schedule In patients who have maintained the response following 24 weeks of treatment at the biweekly dosing schedule. Week 49 and every 4 weeks thereafter Subsequent treatment doses 76 mg • Patients should be hospitalized for 48 hours after administration of the first step-up dose, and for 24 hours after administration of the second step-up dose. ( 2.1 ) • For subcutaneous injection only. ( 2.2 ) • Administer pre-treatment medications as recommended. ( 2.3 ) • See Full Prescribing Information for instructions on preparation and administration. ( 2.6 ) 2.1 Important Dosing Information Administer ELREXFIO subcutaneously according to the step-up dosing schedule to reduce the incidence and severity of cytokine release syndrome (CRS). Administer pre-treatment medications prior to each dose in the ELREXFIO step-up dosing schedule, which includes step-up dose 1, step-up dose 2, and the first treatment dose as recommended [see Dosage and Administration (2.2 , 2.3 )] . ELREXFIO should only be administered by a qualified healthcare professional with appropriate medical support to manage severe reactions such as CRS and neurologic toxicity, including ICANS [see Warnings and Precautions (5.1 , 5.2 )] . Due to the risk of CRS, patients should be hospitalized for 48 hours after administration of the first step-up dose, and for 24 hours after administration of the second step-up dose. 2.2 Recommended Dosage For subcutaneous injection only. The recommended dosing schedule for ELREXFIO is provided in Table 1. The recommended dosages of ELREXFIO subcutaneous injection are: step-up dose 1 of 12 mg on Day 1, step-up dose 2 of 32 mg on Day 4, followed by the first treatment dose of 76 mg on Day 8, and then 76 mg weekly thereafter through week 24. For patients who have received at least 24 weeks of treatment with ELREXFIO and have achieved a response [partial response (PR) or better] and maintained this response for at least 2 months, the dose interval should transition to an every two-week schedule. For patients who have received at least 24 weeks of treatment with ELREXFIO at the every two-week dosing schedule and have maintained the response, the dose interval should transition to an every four-week schedule. Continue treatment with ELREXFIO until disease progression or unacceptable toxicity. Administer pre-treatment medications prior to each dose in the ELREXFIO step-up dosing schedule, which includes step-up dose 1, step-up dose 2, and the first treatment dose as recommended [see Dosage and Administration (2.3) ] . Table 1. ELREXFIO Dosing Schedule Note: See Table 2 for recommendations on restarting ELREXFIO after dose delays. Dosing Schedule Day ELREXFIO Dose Step-up Dosing Schedule Day 1 Administer pre-treatment medications prior to each dose in the ELREXFIO step-up dosing schedule, which includes step-up dose 1, step-up dose 2, and the first treatment dose [see Dosage and Administration (2.3) ] . Step-up dose 1 12 mg Day 4 A minimum of 2 days should be maintained between step-up dose 1 (12 mg) and step-up dose 2 (32 mg). Step-up dose 2 32 mg Day 8 A minimum of 3 days should be maintained between step-up dose 2 (32 mg) and the first treatment (76 mg) dose. First treatment dose 76 mg Weekly Dosing Schedule One week after first treatment dose and weekly thereafter A minimum of 6 days should be maintained between treatment doses. through week 24 Subsequent treatment doses 76 mg Biweekly (Every 2 Week) Dosing Schedule *Responders only week …

3 DOSAGE FORMS AND STRENGTHS ELREXFIO injection is a clear to slightly opalescent, and colorless to pale brown liquid solution available as: • 76 mg/1.9 mL (40 mg/mL) in a single-dose vial • 44 mg/1.1 mL (40 mg/mL) in a single-dose vial Injection : • 76 mg/1.9 mL (40 mg/mL) in a single-dose vial. ( 3 ) • 44 mg/1.1 mL (40 mg/mL) in a single-dose vial. ( 3 )

4 CONTRAINDICATIONS None. None. ( 4 )

6 ADVERSE REACTIONS The following adverse reactions are discussed elsewhere in labeling: • Cytokine Release Syndrome [see Warnings and Precautions (5.1) ] . • Neurologic Toxicity, Including ICANS [see Warnings and Precautions (5.2) ] . • Infections [see Warnings and Precautions (5.4) ] . • Neutropenia [see Warnings and Precautions (5.5) ] . • Hepatotoxicity [see Warnings and Precautions (5.6) ] . Most common adverse reactions (incidence ≥20%) are CRS, fatigue, injection site reaction, diarrhea, upper respiratory tract infection, musculoskeletal pain, pneumonia, decreased appetite, rash, cough, nausea, and pyrexia. The most common Grade 3 to 4 laboratory abnormalities (≥30%) are decreased lymphocytes, decreased neutrophils, decreased hemoglobin, decreased white blood cells, and decreased platelets. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Pfizer Inc. at 1-800-438-1985 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 practice. Relapsed/Refractory Multiple Myeloma MagnetisMM-3 The safety of ELREXFIO was evaluated in MagnetisMM-3 [see Clinical Studies (14) ]. The safety population described (n = 183) includes patients who received the recommended dosage regimen of 12 mg subcutaneously on Day 1, 32 mg on Day 4, and 76 mg once weekly starting on Day 8. Among patients who received ELREXFIO, 42% were exposed for 6 months or longer and 9% were exposed for one year or longer. The median age of patients who received ELREXFIO was 68 years (range: 36 to 88 years); 48% were female; 61% were White, 10% were Hispanic/Latino, 9% were Asian, and 6% were Black or African American. Serious adverse reactions occurred in 68% of patients who received ELREXFIO at the recommended dosing schedule. Serious adverse reactions in >2% of patients included pneumonia (25%), sepsis (13%), CRS (13%), upper respiratory tract infection (4.4%), acute kidney injury (3.8%), urinary tract infection (3.3%), COVID-19 (3.3%), encephalopathy (3.3%), pyrexia (2.2%), and febrile neutropenia (2.2%). Fatal adverse reactions occurred in 10% of patients including pneumonia (3.3%), sepsis (2.7%), acute respiratory distress syndrome (0.5%), cardio-respiratory arrest (0.5%), cardiogenic shock (0.5%), cardiopulmonary failure (0.5%), COVID-19 (0.5%), failure to thrive (0.5%), and pulmonary embolism (0.5%). Permanent discontinuations of ELREXFIO due to an adverse reaction occurred in 17% of patients. Adverse reactions which resulted in permanent discontinuation of ELREXFIO in >2% of patients included septic shock (2.2%). Dosage interruptions of ELREXFIO due to an adverse reaction occurred in 73% of patients. Adverse reactions which resulted in dose interruptions of ELREXFIO in >5% of patients included neutropenia, pneumonia, COVID-19, upper respiratory tract infection, thrombocytopenia, and anemia. The most common adverse reactions (≥20%) were CRS, fatigue, injection site reaction, diarrhea, upper respiratory tract infection, musculoskeletal pain, pneumonia, decreased appetite, rash, cough, nausea, and pyrexia. The most common Grade 3 to 4 laboratory abnormalities (≥30%) were decreased lymphocytes, decreased neutrophils, decreased hemoglobin, decreased white blood cells, and decreased platelets. Table 8 summarizes adverse reactions in MagnetisMM-3. Table 8. Adverse Reactions (≥10%) in Patients with Relapsed or Refractory Multiple Myeloma Who Received ELREXFIO in MagnetisMM-3 Adverse reactions were graded based on CTCAE Version 5.0, with the exception of CRS, which was graded based on the ASTCT 2019 criteria. System Organ Class Preferred Term ELREXFIO N = 183 All Grades (%) Grade 3 or 4 (%) Immune system disorders Cytokine release syndrome 58 0.5 Only grade 3 adverse reactions occurred. Hy …

7 DRUG INTERACTIONS For certain CYP substrates, minimal changes in the concentration may lead to serious adverse reactions. Monitor for toxicity or drug concentrations of such CYP substrates when co-administered with ELREXFIO. ELREXFIO causes release of cytokines [see Clinical Pharmacology (12.2) ] that may suppress activity of cytochrome P450 (CYP) enzymes, resulting in increased exposure of CYP substrates. Increased exposure of CYP substrates is more likely to occur after the first dose of ELREXFIO Day 1 and up to 14 days after the 32 mg dose on Day 4 and during and after CRS [see Warnings and Precautions (5.1) ].

8 USE IN SPECIFIC POPULATIONS Lactation : Advise not to breastfeed. ( 8.2 ) 8.1 Pregnancy Risk Summary Based on the mechanism of action, ELREXFIO may cause fetal harm when administered to a pregnant woman [see Clinical Pharmacology (12.1) ] . There are no available data on the use of ELREXFIO in pregnant women to evaluate for a drug associated risk. No animal reproductive or developmental toxicity studies have been conducted with ELREXFIO. Elranatamab-bcmm causes T-cell activation and cytokine release; immune activation may compromise pregnancy maintenance. In addition, based on the finding of B-cell depletion in non-pregnant animals, elranatamab-bcmm can cause B-cell lymphocytopenia in infants exposed to elranatamab-bcmm in-utero. Human immunoglobulin (IgG) is known to cross the placenta after the first trimester of pregnancy; therefore, elranatamab-bcmm has the potential to be transmitted from the mother to the developing fetus. Advise women of the potential risk to the fetus. ELREXFIO is associated with hypogammaglobulinemia, therefore, assessment of immunoglobulin levels in newborns of mothers treated with ELREXFIO should be considered. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2% to 4% and 15% to 20%, respectively. 8.2 Lactation Risk Summary There are no data on the presence of elranatamab-bcmm in human milk, the effects on the breastfed child, or the effects on milk production. Maternal IgG is known to be present in human milk. Because of the potential for serious adverse reactions in a breastfed child, advise women not to breastfeed during treatment with ELREXFIO and for 4 months after the last dose. 8.3 Females and Males of Reproductive Potential ELREXFIO may cause fetal harm when administered to a pregnant woman [see Use in Specific Populations (8.1) ] . Pregnancy Testing Verify the pregnancy status of females of reproductive potential prior to initiating treatment with ELREXFIO. Contraception Females Advise females of reproductive potential to use effective contraception during treatment and for 4 months after the last dose of ELREXFIO. 8.4 Pediatric Use The safety and effectiveness of ELREXFIO in pediatric patients have not been established. 8.5 Geriatric Use Of the 183 patients with relapsed or refractory multiple myeloma treated with ELREXFIO in MagnetisMM-3 at the recommended dosage, 62% were 65 years of age or older, and 19% were 75 years of age or older. No overall differences in safety or effectiveness were observed in patients 65-74 years of age compared to younger patients. Clinical studies did not include sufficient numbers of patients 75 years of age or older to determine whether they respond differently from younger patients.

12.1 Mechanism of Action Elranatamab-bcmm is a bispecific B-cell maturation antigen (BCMA)-directed T-cell engaging antibody that binds BCMA on plasma cells, plasmablasts, and multiple myeloma cells and CD3 on T-cells leading to cytolysis of the BCMA-expressing cells. Elranatamab-bcmm activated T-cells, caused proinflammatory cytokine release, and resulted in multiple myeloma cell lysis.

11 DESCRIPTION Elranatamab-bcmm is a bispecific B-cell maturation antigen (BCMA)-directed CD3 T-cell engager. It is a bispecific, humanized immunoglobulin 2-alanine (IgG2Δa) kappa antibody derived from two monoclonal antibodies (mAbs), an anti-BCMA mAb and an anti-CD3 mAb. Each of these mAbs contributes one distinct heavy (H) chain and one distinct light (L) chain to the bispecific elranatamab-bcmm. The resulting 4-chain bispecific antibody is covalently linked via five inter-chain disulfide bonds. Elranatamab-bcmm is produced using two recombinant Chinese hamster ovary (CHO) cell lines, one that contains the DNA encoding the sequence for anti-BCMA monoclonal antibody (mAb) and one that contains the sequence for anti-CD3 mAb, which are grown separately in suspension culture using chemically-defined (CD), animal-derived component-free (ACF) media. The molecular weight of elranatamab-bcmm is approximately 148.5 kDa. ELREXFIO ® (elranatamab-bcmm) injection is a sterile, preservative-free, clear to slightly opalescent, and colorless to pale brown liquid solution for subcutaneous administration. ELREXFIO (elranatamab-bcmm) is supplied at a concentration of 40 mg/mL in either 76 mg/1.9 mL or 44 mg/1.1 mL single-dose vials. Each mL of solution contains 40 mg elranatamab-bcmm, edetate disodium (0.045 mg), histidine (1.12 mg), L-histidine hydrochloride monohydrate (2.67 mg), polysorbate 80 (0.2 mg), sucrose (85 mg) and Water for Injection. The pH is 5.8.

16 HOW SUPPLIED/STORAGE AND HANDLING How Supplied ELREXFIO ® (elranatamab-bcmm) injection is a sterile, preservative-free, clear to slightly opalescent, and colorless to pale brown liquid solution supplied as follows: • One 76 mg/1.9 mL (40 mg/mL) single-dose vial in a carton. NDC: 0069-4494-02 • One 44 mg/1.1 mL (40 mg/mL) single-dose vial in a carton. NDC: 0069-2522-02 ELREXFIO is supplied in a single-dose glass vial sealed with a rubber stopper (not made of natural rubber latex) and an aluminum seal with a flip-off cap. Storage and Handling Store refrigerated at 2 °C to 8 °C (36 °F to 46 °F) in the original carton until time of use to protect from light. Do not freeze or shake the vial or carton.