Ropeginterferon Alfa-2b

1 INDICATIONS AND USAGE BESREMi is an interferon alfa-2b indicated for: • The treatment of adults with essential thrombocythemia. ( 1.1 ) • The treatment of adults with polycythemia vera. ( 1.2 ) 1.1 Essential Thrombocythemia BESREMi is indicated for the treatment of adults with essential thrombocythemia. 1.2 Polycythemia Vera BESREMi is indicated for the treatment of adults with polycythemia vera.

12.1 Mechanism of Action Interferon alfa belongs to the class of type I interferons, which exhibit their cellular effects in polycythemia vera and essential thrombocythemia in the bone marrow by binding to a transmembrane receptor termed interferon alfa receptor (IFNAR). Binding to IFNAR initiates a downstream signaling cascade through the activation of kinases, in particular Janus kinase 1 (JAK1) and tyrosine kinase 2 (TYK2) and activator of transcription (STAT) proteins. Nuclear translocation of STAT proteins controls distinct gene-expression programs and exhibits various cellular effects. The actions involved in the therapeutic effects of interferon alfa in polycythemia vera and essential thrombocythemia are not fully elucidated.

2 DOSAGE AND ADMINISTRATION Essential thrombocythemia: • The recommended dose of BESREMi is: a starting dose of 250 mcg by subcutaneous injection, at 2 weeks, increase the dose to 350 mcg by subcutaneous injection, at 4 weeks, increase to the maintenance dosage of 500 mcg by subcutaneous injection every 2 weeks. Maintain an every 2‑week schedule throughout treatment unless dose modification is required for safety or tolerability. Consider dose re-escalation in case of prior dose reduction, recovery, and lack of hematologic response. ( 2.2 , 2.3 , 5 ) Polycythemia vera: • The recommended dose of BESREMi is: a starting dosage of 100 mcg by subcutaneous injection every 2 weeks (50 mcg if receiving hydroxyurea). Increase the dose by 50 mcg every 2 weeks (up to a maximum of 500 mcg) until hematological parameters are stabilized ( 2.1 ). Interrupt or discontinue dosing if certain adverse reactions occur. Dose re-increase to be considered in case of prior dose reduction, recovery, and lack of hematologic response. ( 2.2 , 2.3 , 5 ) 2.1 Pre-Treatment Testing Obtain a pregnancy test in females of reproductive potential prior to initiating treatment with BESREMi [see Use in Specific Populations ( 8.3 )] . 2.2 Recommended Dosage Essential Thrombocythemia : • The recommended dose of BESREMi is: • A starting dose of 250 mcg by subcutaneous injection. • At 2 weeks, increase the dose to 350 mcg by subcutaneous injection. • At 4 weeks, increase to the maintenance dosage of 500 mcg by subcutaneous injection every 2 weeks. • Maintain an every 2-week schedule throughout treatment unless dose modification is required for safety or tolerability. • Consider dose re-escalation in case of prior dose reduction, recovery, and lack of hematologic response (platelets less than 400 × 10 9 /L and leukocytes less than 10 × 10 9 /L). • Monitor complete blood counts every 2 weeks during titration and every 3 to 6 months during maintenance. Polycythemia Vera: Patients Not Already on Hydroxyurea • The recommended BESREMi starting dosage for patients not on hydroxyurea is 100 mcg by subcutaneous injection every two weeks. • Increase the dose by 50 mcg every two weeks (up to a maximum of 500 mcg), until the hematological parameters are stabilized (hematologic response: hematocrit less than 45%, platelets less than 400 × 10 9 /L, and leukocytes less than 10 × 10 9 /L). • Consider dose re-escalation in case of prior dose reduction, recovery, and lack of hematologic response. Patients Transitioning from Hydroxyurea • When transitioning to BESREMi from hydroxyurea, start BESREMi at 50 mcg by subcutaneous injection every two weeks in combination with hydroxyurea. • Gradually taper off the hydroxyurea by reducing the total biweekly dose by 20-40% every two weeks during Weeks 3-12. • Increase the dose of BESREMi by 50 mcg every two weeks (up to a maximum of 500 mcg), until the hematological parameters are stabilized (hematocrit less than 45%, platelets less than 400 × 10 9 /L, and leukocytes less than 10 × 10 9 /L). • Discontinue hydroxyurea by Week 13. Maintain the two-week dosing interval of BESREMi at which hematological stability is achieved for at least 1 year. After achievement of hematological stability for at least 1 year on a stable dose of BESREMi, the dosing interval may be expanded to every 4 weeks. Monitor patients closely especially during the titration phase. Perform complete blood counts (CBC) regularly, every 2 weeks during the titration phase and every 3-6 months during the maintenance phase (after the patient’s optimal dose is established). Monitor CBC more frequently if clinically indicated. Phlebotomy as rescue treatment to normalize blood hyperviscosity may be necessary during the titration phase [see Clinical Pharmacology ( 12.2 )] . 2.3 Dose Modifications Essential Thrombocythemia: If dose interruption occurs, resume dosing at previously attained levels. If drug-related toxicities arise, reduce the dose to the next lower level or interrupt in acc

6 ADVERSE REACTIONS The following clinically significant adverse reactions are described elsewhere in the labeling. • Depression and Suicide [see Warnings and Precautions ( 5.1 )] • Endocrine Toxicity [see Warnings and Precautions ( 5.2 )] • Cardiovascular Toxicity [see Warnings and Precautions ( 5.3 )] • Hematologic and Hemorrhagic Disorders [see Warnings and Precautions ( 5.4 )] • Hypersensitivity Reactions [see Warnings and Precautions ( 5.5 )] • Pancreatitis [see Warnings and Precautions ( 5.6 )] • Colitis [see Warnings and Precautions ( 5.7 )] • Pulmonary Toxicity [see Warnings and Precautions ( 5.8 )] • Ophthalmologic Toxicity [see Warnings and Precautions ( 5.9 )] • Hyperlipidemia [see Warnings and Precautions ( 5.10 )] • Hepatotoxicity [see Warnings and Precautions ( 5.11 )] • Renal Toxicity [see Warnings and Precautions ( 5.12 )] • Dental and Periodontal Toxicity [see Warnings and Precautions ( 5.13 )] • Dermatologic Toxicity [see Warnings and Precautions ( 5.14 )] • Driving and Operating Machinery [see Warnings and Precautions ( 5.15 )] • Embryo-Fetal Toxicity [see Warnings and Precautions ( 5.16 )] • Essential thrombocythemia: The most common adverse reactions reported in >20% of patients were transaminase elevations, anemia, pyrexia, beta 2 microglobulin urine increased, bacterial infection, pruritus, and weight decreased. ( 6 ) • Polycythemia vera: The most common adverse reactions reported in >40% of patients were influenza-like illness, arthralgia, fatigue, pruritus, nasopharyngitis, and musculoskeletal pain. ( 6 ) To report SUSPECTED ADVERSE REACTIONS, contact PharmaEssentia at 1-800-999-2449 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. Essential Thrombocythemia The pooled safety population described in the Warnings and Precautions section reflects exposure to BESREMi as monotherapy for the treatment of essential thrombocythemia dosed every 2 weeks in 182 patients in an open-label trial [P1101 ET, SURPASS ET] and a single-arm trial [A22-301, EXCEED ET]. The mean age was 56 years (range: 21 to 84 years). There were 104 (57%) women, 78 (43%) men, and 93 (51%) Asian, 76 (42%) Caucasian, 5 (2.7%) Black or African American, 5 (2.7%) Other, and 3 (1.6%) Hispanic patients were included in the studies. Among 182 patients who received BESREMi, 70 (39%) patients were exposed for >56 weeks (>14 months). The mean (SD) dose of BESREMi was 394.9 (98.4) mcg during the treatment period. In this pooled safety population, the most common adverse reactions in ≥10% of BESREMi-treated patients were aspartate aminotransferase increased (44%), alanine aminotransferase increased (43%), fatigue (31%), anemia (24%), white blood cell count decreased (23%), neutrophil count decreased (22%), pruritus (17%), gamma-glutamyltransferase increased (16%), alopecia (16%), headache (15%), diarrhea (13%), nausea (13%), beta 2 microglobulin urine increased (12%), influenza like illness (11%), and myalgia (11%). The safety findings described below reflect exposure to BESREMi as monotherapy for the treatment of essential thrombocythemia in 91 patients in the SURPASS ET study [see Clinical Studies ( 14 )] . Among the 91 patients receiving BESREMi, 55% were exposed for 9 to 13 months and 36% were exposed for more than 13 months. Serious adverse reactions were reported in 2.2% of patients treated with BESREMi in the SURPASS ET study and included vascular headache and drug eruption. Adverse reactions requiring permanent discontinuation of patients treated with BESREMi occurred in 1.1% patient each and included aspartate aminotransferase increased, alanine aminotransferase increased, gamma-glutamyltransferase increased, pneumonitis, pulmonary hypertension, thyr

5 WARNINGS AND PRECAUTIONS • Depression and Suicide: Monitor for symptoms and need for treatment. ( 5.1 ) • Endocrine Toxicity: Discontinue if endocrine disorders occur that cannot be medically managed. ( 5.2 ) • Cardiovascular Toxicity: Avoid use in patients with severe or unstable cardiovascular disease. Monitor patients with history of cardiovascular disorders more frequently. ( 5.3 ) • Hematologic and Hemorrhagic Disorders: Perform blood counts at baseline, every 2 weeks during titration, and at least every 3-6 months during maintenance treatment. ( 5.4 ) • Hypersensitivity Reactions: Stop treatment and immediately manage reaction. ( 5.5 ) • Pancreatitis: Consider discontinuation if confirmed pancreatitis. ( 5.6 ) • Colitis: Discontinue if signs or symptoms of colitis. ( 5.7 ) • Pulmonary Toxicity: Discontinue if pulmonary infiltrates or pulmonary function impairment. ( 5.8 ) • Ophthalmologic Toxicity: Monitor for ocular toxicity. Promptly evaluate eye symptoms and discontinue if new or worsening eye disorders. ( 5.9 ) • Hyperlipidemia: Monitor serum triglycerides before BESREMi treatment and intermittently during therapy and manage when elevated. ( 5.10 ) • Hepatotoxicity: Monitor liver enzymes and hepatic function at baseline and during treatment. Reduce dose or discontinue depending on severity. ( 5.11 ) • Renal Toxicity: Monitor serum creatinine at baseline and during therapy. Discontinue if severe renal impairment develops. ( 5.12 ) • Dental and Periodontal Toxicity: Advise on good oral hygiene and regular dental examinations. ( 5.13 ) • Dermatologic Toxicity: Consider discontinuing if clinically significant dermatologic toxicity. ( 5.14 ) • Driving and Operating Machinery: Advise patients to avoid driving or using machinery if they experience dizziness, somnolence, or hallucination. ( 5.15 ) • Embryo-Fetal Toxicity: Can cause fetal harm. ( 5.16 ) 5.1 Depression and Suicide Life-threatening or fatal neuropsychiatric reactions have occurred in patients receiving interferon alfa products, including BESREMi. These reactions may occur in patients with and without previous psychiatric illness. Psychiatric reactions have been observed in 10% of BESREMi-treated patients with essential thrombocythemia including depression, adjustment disorder with depressed mood, and depressed mood. Serious neuropsychiatric reactions have been observed in 3% of BESREMi-treated patients with polycythemia vera, including depression, depressive symptoms, depressed mood, and listlessness. Of these cases, 3.4% of the patients recovered with temporary drug interruption and 2.8% stopped BESREMi treatment. Other central nervous system effects, including suicidal ideation, attempted suicide, aggression, bipolar disorder, mania and confusion have been observed with other interferon alfa products. BESREMi is contraindicated in patients with a history of severe psychiatric disorders, particularly severe depression, suicidal ideation, or suicide attempt [see Contraindications ( 4 )] . Closely monitor patients for any symptoms of psychiatric disorders and consider psychiatric consultation and treatment if such symptoms emerge. If psychiatric symptoms worsen, it is recommended to discontinue BESREMi therapy. 5.2 Endocrine Toxicity Endocrine toxicity has occurred in patients receiving interferon alfa products, including BESREMi. These toxicities may include worsening hypothyroidism and hyperthyroidism. Autoimmune thyroiditis and hyperglycemia, including new onset type 1 diabetes, have been reported in patients receiving interferon alfa-2b products. Endocrine toxicities included hyperthyroidism (1.1%), hypothyroidism (1.1%), autoimmune thyroiditis (0.5%), and thyroiditis (0.5%) in BESREMi-treated patients with essential thrombocythemia. Endocrine toxicities included hyperthyroidism (4.5%), hypothyroidism (3.9%), and autoimmune thyroiditis/thyroiditis (2.8%) in BESREMi-treated patients with polycythemia vera. Do not use BESREMi in patients with active serious

4 CONTRAINDICATIONS BESREMi is contraindicated in patients with: • Existence of, or history of severe psychiatric disorders, particularly severe depression, suicidal ideation, or suicide attempt. • Hypersensitivity to interferons including interferon alfa-2b or any of the inactive ingredients of BESREMi. • Moderate (Child-Pugh B) or severe (Child-Pugh C) hepatic impairment. • History or presence of active serious or untreated autoimmune disease. • Immunosuppressed transplant recipients. BESREMi is contraindicated in patients with: • Existence of, or history of severe psychiatric disorders, particularly severe depression, suicidal ideation or suicide attempt ( 4 ) • Hypersensitivity to interferons or to any of the inactive ingredients in BESREMi ( 4 ) • Hepatic impairment (Child-Pugh B or C) ( 4 ) • History or presence of active serious or untreated autoimmune disease ( 4 ) • Immunosuppressed transplant recipients ( 4 )

10 OVERDOSAGE Overdosage of BESREMi may result in influenza-like symptoms or other adverse reactions. There is no antidote to BESREMi overdosage. In case of an overdose, frequently monitor signs and symptoms for adverse reactions. Consider contacting the Poison Help line (1-800-222-1222) or a medical toxicologist for additional overdose management recommendations.