CYANOCOBALAMIN

Cyanocobalamin is a synthetic form of vitamin B 12 . The chemical name is 5,6-dimethyl-benzimidazolyl cyanocobamide. The cobalt content is 4.35%. The molecular formula is C 63 H 88 CoN 14 O 14 P, which corresponds to a molecular weight of 1355.38 and the following structural formula: Figure 1. Cyanocobalamin Nasal Spray Chemical Structure Cyanocobalamin occurs as dark red crystals or orthorhombic needles or crystalline red powder. It is very hygroscopic in the anhydrous form, and sparingly to moderately soluble in water (1:80). Its pharmacologic activity is destroyed by heavy metals (iron) and strong oxidizing or reducing agents (vitamin C), but not by autoclaving for short periods of time (15-20 minutes) at 121°C. The vitamin B 12 coenzymes are very unstable in light. Cyanocobalamin Nasal Spray is a solution of cyanocobalamin, USP (vitamin B 12 ) for administration as a spray to the nasal mucosa. Each unit dose device of Cyanocobalamin Nasal Spray contains 0.125 mL of a 500 mcg/0.1 mL solution of cyanocobalamin with benzalkonium chloride in purified water, citric acid, glycerin and sodium citrate. The spray solution has a pH between 4.5 and 5.5. Each spray delivers an average of 500 mcg of cyanocobalamin per actuation. chemical structure image

Cyanocobalamin Nasal Spray is indicated for: • Vitamin B 12 maintenance therapy in adult patients with pernicious anemia who are in remission following intramuscular vitamin B 12 therapy and who have no nervous system involvement • Treatment of adult patients with dietary, drug-induced, or malabsorption-related vitamin B 12 deficiency not due to pernicious anemia • Prevention of vitamin B 12 deficiency in adult patients with vitamin B 12 requirements in excess of normal Limitations of Use • Cyanocobalamin Nasal Spray should not be used for the vitamin B 12 absorption test (Schilling test). • In patients with correctible or temporary causes of vitamin B 12 deficiency, the benefit of continued long-term use of Cyanocobalamin Nasal Spray following adequate correction of vitamin B 12 deficiency and underlying disease has not been established. • The effectiveness of Cyanocobalamin Nasal Spray in patients with active symptoms of nasal congestion, allergic rhinitis or upper respiratory infection has not been determined. Treatment with Cyanocobalamin Nasal Spray should be deferred until symptoms have subsided. Cyanocobalamin Nasal Spray is a vitamin B 12 indicated for: • Vitamin B 12 maintenance therapy in adult patients with pernicious anemia who are in remission following intramuscular vitamin B 12 therapy and who have no nervous system involvement ( 1 ) • Treatment of adult patients with dietary, drug-induced, or malabsorption-related vitamin B 12 deficiency not due to pernicious anemia ( 1 ) • Prevention of vitamin B 12 deficiency in adult patients with vitamin B 12 requirements in excess of normal ( 1 ) Limitations of Use: • Should not be used for the vitamin B 12 absorption test (Schilling test). ( 1 ) • In patients with correctible or temporary causes of vitamin B 12 deficiency the benefit of continued long-term use following correction of vitamin B 12 deficiency and underlying disease has not been established. ( 1 ) • In patients with active symptoms of nasal congestion, allergic rhinitis or upper respiratory infection effectiveness has not been established. ( 1 )

• Prior to treatment, obtain hematocrit, reticulocyte count, vitamin B 12 , folate, and iron levels. ( 2.1 ) • The recommended initial dose is one spray (500 mcg) in one nostril once weekly. ( 2.2 ) • Administer at least one hour before or one hour after ingestion of hot foods or liquids. ( 2.2 ) • Monitor serum B 12 levels periodically. Obtain a serum B 12 level and peripheral blood count one month after treatment initiation, then subsequently at intervals of 3 to 6 months. ( 2.3 ) • If serum levels of B 12 decline after one month of treatment, consider increasing the dose. Assess serum B 12 level one month after each dose adjustment. If serum B 12 levels are persistently low, consider alternative therapy (e.g., intramuscular or subcutaneous vitamin B 12 therapy). ( 2.3 ) • See Full Prescribing Information to see what other therapies should be administered with Cyanocobalamin Nasal Spray. ( 2.4 ) 2.1 Testing and Other Considerations Prior to Dosing Prior to treatment, obtain hematocrit, reticulocyte count, vitamin B 12 , folate, and iron levels [see Dosage and Administration (2.4) ] . Consider the potential for concomitant drugs to interfere with vitamin B 12 and folate diagnostic blood assays [see Drug Interactions (7) ] . In patients with suspected cobalamin hypersensitivity, consider administering an intradermal test dose of parenteral vitamin B 12 prior to use of Cyanocobalamin Nasal Spray [see Warnings and Precautions (5.2) ] . 2.2 Recommended Dosage The recommended initial dose of Cyanocobalamin Nasal Spray is one spray (500 mcg) administered in ONE nostril once weekly. Administer Cyanocobalamin Nasal Spray at least one hour before or one hour after ingestion of hot foods or liquids since hot foods may cause nasal secretions and a resulting loss of medication. Defer use of Cyanocobalamin Nasal Spray in patients with nasal congestion, allergic rhinitis, or upper respiratory infections until after symptoms have subsided. 2.3 Monitoring, Dosage Modifications, and Treatment Duration Monitoring for Response and Safety Monitor serum B 12 levels periodically during therapy to establish adequacy of therapy. Obtain a serum B 12 level and peripheral blood count one month after treatment initiation, then subsequently at intervals of 3 to 6 months [see Warnings and Precautions (5.3)]. Dosage Modifications If serum levels of B 12 decline after one month of treatment with Cyanocobalamin Nasal Spray, consider increasing the dose. Assess serum B 12 level one month after each dose adjustment. If serum B 12 levels are persistently low, consider alternative therapy (e.g., intramuscular or subcutaneous vitamin B 12 therapy). Treatment Duration In patients whose underlying cause of vitamin B 12 deficiency has been corrected and are deemed no longer at risk for vitamin B 12 deficiency, discontinue Cyanocobalamin Nasal Spray. The safety and effectiveness of continued long-term use in these individuals has not been established. In patients with pernicious anemia, continue appropriate vitamin B 12 treatment indefinitely. 2.4 Administration of Cyanocobalamin Nasal Spray with Other Therapy Cyanocobalamin Nasal Spray should be administered with other therapy(ies) in: - Patients with concurrent folate and vitamin B 12 deficiency: Administer folic acid in addition to Cyanocobalamin Nasal Spray - Patients with concurrent iron and vitamin B 12 deficiency: Administer iron in addition to Cyanocobalamin Nasal Spray - Patients with correctible causes of vitamin B 12 deficiency: Consider measures to treat the underlying condition associated with vitamin B 12 deficiency in addition to treatment with Cyanocobalamin Nasal Spray

Cyanocobalamin Nasal Spray is contraindicated in patients with hypersensitivity to cobalt and/or vitamin B 12 or any of its excipients [see Warnings and Precautions (5.2) ] . Anaphylactic shock and death have been reported after parenteral vitamin B 12 administration in sensitive patients. • Hypersensitivity to cobalt, vitamin B 12 or any excipients ( 4 )

The following serious adverse reactions are described elsewhere in the labeling: • Severe Optic Atrophy in Patients with Leber’s Disease [see Warnings and Precautions (5.1) ] . • Anaphylactic Reactions [see Warnings and Precautions (5.2) ] . • Hypokalemia and Thrombocytosis Due to Intense Treatment of Megaloblastic Anemia [see Warnings and Precautions (5.4) ] . The most common adverse reactions (≥ 4%) were infection, headache, glossitis, paresthesia, asthenia, nausea and rhinitis ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Padagis ® at 1-866-634-9120 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. The adverse reactions described in Table 1 below are based on data from an eight week cross over trial in which vitamin B 12 deficient patients in hematologic remission received one vitamin B 12 intramuscular injection (N=25) and then received once weekly intranasal administration of another nasal cyanocobalamin formulation (N=24) for 4 weeks. Table 1. Adverse Reactions Following Intranasal or Intramuscular Administration of Cyanocobalamin In Vitamin B 12 Deficient Patients in Hematologic Remission Adverse Reaction Number of Patients (%) Another Cyanocobalamin Nasal Formulation, 500 mcg (n=24) Intramuscular Cyanocobalamin*, 100 mcg (n=25) Infection a 3 (13) 3 (12) Headache 1 (4) 5 (20) Asthenia 1 (4) 4 (16) Nausea 1 (4) 1 (4) Glossitis 1 (4) 0 (0) Paresthesia 1 (4) 1 (4) Rhinitis 1 (4) 2 (8) a Sore throat, common cold * The data are not an adequate basis for comparison of rates between the study drug and the active control

Chloramphenicol may decrease the efficacy of Cyanocobalamin Nasal Spray when used for treatment of anemia. If Cyanocobalamin Nasal Spray is used for the treatment of anemia concomitantly with chloramphenicol, monitor for reduced efficacy and if needed, consider an alternative therapy.