MESNA

1 INDICATIONS AND USAGE Mesna is indicated as a prophylactic agent in reducing the incidence of ifosfamide-induced hemorrhagic cystitis. Limitation of Use: Mesna is not indicated to reduce the risk of hematuria due to other pathological conditions such as thrombocytopenia. Mesna is a cytoprotective agent indicated as a prophylactic agent in reducing the incidence of ifosfamide-induced hemorrhagic cystitis. ( 1 ) Limitation of Use: Mesna is not indicated to reduce the risk of hematuria due to other pathological conditions such as thrombocytopenia. ( 1 )

2 DOSAGE AND ADMINISTRATION Mesna may be given as a fractionated dosing schedule of a single bolus injection followed by two oral administrations of mesna tablets as outlined below. The dosing schedule should be repeated on each day that ifosfamide is administered. When the dosage of ifosfamide is adjusted, the ratio of mesna to ifosfamide should be maintained. ( 2 ) Intravenous and Oral Dosing Schedule: 0 Hours 2 Hours 6 Hours Ifosfamide 1.2 g/m 2 -- -- MESNEX Injection 240 mg/m 2 -- -- Mesna Tablets -- 480 mg/m 2 480 mg/m 2 Maintain sufficient urinary output, as required for ifosfamide treatment, and monitor urine for the presence of hematuria. ( 2.3 ) 2.2 Intravenous and Oral Dosing Mesna may be given on a fractionated dosing schedule of a single bolus injection followed by two oral administrations of mesna tablets as outlined below. MESNEX injection is given as intravenous bolus injections in a dosage equal to 20% of the ifosfamide dosage (w/w) at the time of ifosfamide administration. Mesna tablets are given orally in a dosage equal to 40% of the ifosfamide dose 2 and 6 hours after each dose of ifosfamide. The total daily dose of mesna is 100% of the ifosfamide dose. The recommended dosing schedule is outlined in Table 2 . Table 2. Recommended Intravenous and Oral Dosing Schedule 0 Hours 2 Hours 6 Hours Ifosfamide 1.2 g/m 2 – – MESNEX Injection The dosing schedule should be repeated on each day that ifosfamide is administered. When the dosage of ifosfamide is increased or decreased, the ratio of mesna to ifosfamide should be maintained. 240 mg/m 2 – – Mesna Tablets – 480 mg/m 2 480 mg/m 2 The efficacy and safety of this ratio of intravenous and oral mesna has not been established as being effective for daily doses of ifosfamide higher than 2 g/m 2 . Patients who vomit within two hours of taking oral mesna should repeat the dose or receive intravenous MESNEX. 2.3 Monitoring for Hematuria Maintain adequate hydration and sufficient urinary output, as required for ifosfamide treatment, and monitor urine for the presence of hematuria. If severe hematuria develops when mesna is given according to the recommended dosage schedule, dosage reductions or discontinuation of ifosfamide therapy may be required.

5 WARNINGS AND PRECAUTIONS Hypersensitivity reactions: Anaphylactic reactions have been reported. Less severe hypersensitivity reactions may also occur. Monitor patients. If a reaction occurs, discontinue mesna and provide supportive care. ( 5.1 ) Dermatologic toxicity: Skin rash with eosinophilia and systemic symptoms, Stevens-Johnson syndrome, and toxic epidermal necrolysis have occurred. Skin rash, urticaria, and angioedema have also been seen. Monitor patients. If a reaction occurs, discontinue mesna and provide supportive care. ( 5.2 ) Benzyl alcohol toxicity: Serious and fatal adverse reactions can occur in premature neonates and low-birth weight infants treated with benzyl alcohol-preserved drugs, including MESNEX injection. Avoid use in premature neonates and low-birth weight infants. ( 5.3 ) Laboratory test alterations: False positive tests for urinary ketones and interference with enzymatic CPK activity tests have been seen. ( 5.4 ) 5.1 Hypersensitivity Reactions Mesna may cause systemic hypersensitivity reactions, including anaphylaxis. These reactions may include fever, cardiovascular symptoms (hypotension, tachycardia), acute renal impairment, hypoxia, respiratory distress, urticaria, angioedema, laboratory signs of disseminated intravascular coagulation, hematological abnormalities, increased liver enzymes, nausea, vomiting, arthralgia, and myalgia. These reactions may occur with the first exposure or after several months of exposure. Monitor for signs or symptoms. Discontinue mesna and provide supportive care. 5.2 Dermatologic Toxicity Drug rash with eosinophilia and systemic symptoms and bullous and ulcerative skin and mucosal reactions, consistent with Stevens-Johnson syndrome or toxic epidermal necrolysis have occurred. Mesna may cause skin and mucosal reactions characterized by urticaria, rash, erythema, pruritus, burning sensation, angioedema, periorbital edema, flushing and stomatitis. These reactions may occur with the first exposure or after several months of exposure. Discontinue mesna and provide supportive care. 5.3 Benzyl Alcohol Toxicity Serious adverse reactions including fatal reactions and the “gasping syndrome” occurred in premature neonates and low-birth weight infants who received benzyl alcohol dosages of 99 to 234 mg/kg/day (blood levels of benzyl alcohol were 0.61 to 1.378 mmol/L). Symptoms associated with “gasping syndrome” and other potential adverse reactions include gradual neurological deterioration, seizures, intracranial hemorrhage, hematological abnormalities, skin breakdown, hepatic and renal failure, hypotension, bradycardia, and cardiovascular collapse. Premature neonates and low-birth weight infants may be more likely to develop these reactions because they may be less able to metabolize benzyl alcohol. The minimum amount of benzyl alcohol at which toxicity may occur is not known. MESNEX injection contains 10.4 mg/mL of the preservative benzyl alcohol. Avoid use of MESNEX injection in premature neonates and low-birth weight infants. Mesna tablets do not contain benzyl alcohol [see Use in Specific Populations (8.4) ]. 5.4 Laboratory Test Interferences False-Positive Urine Tests for Ketone Bodies A false positive test for urinary ketones may arise in patients treated with mesna when using nitroprusside sodium-based urine tests (including dipstick tests). The addition of glacial acetic acid can be used to differentiate between a false positive result (cherry-red color that fades) and a true positive result (red-violet color that intensifies). False-Negative Tests for Enzymatic CPK Activity Mesna may interfere with enzymatic creatinine phosphokinase (CPK) activity tests that use a thiol compound (e.g., N-acetylcysteine) for CPK reactivation. This may result in a falsely low CPK level. False-Positive Tests for Ascorbic Acid Mesna may cause false-positive reactions in Tillman’s reagent-based urine screening tests for ascorbic acid. 5.5 Use in Patients with a History of Adverse Reactio…

4 CONTRAINDICATIONS Mesna is contraindicated in patients known to be hypersensitive to mesna or to any of the excipients [see Warnings and Precautions (5.1) ]. Known hypersensitivity to mesna or to any of the excipients in mesna tablets and MESNEX injection, including benzyl alcohol. ( 4 )

7 DRUG INTERACTIONS No clinical drug interaction studies have been conducted with mesna.

8.1 Pregnancy Risk Summary Mesna is used in combination with ifosfamide or other cytotoxic agents. Ifosfamide can cause fetal harm when administered to a pregnant woman. Refer to the ifosfamide prescribing information for more information on use during pregnancy. MESNEX injection contains the preservative benzyl alcohol. Because benzyl alcohol is rapidly metabolized by a pregnant woman, benzyl alcohol exposure in the fetus is unlikely [see Warnings and Precautions (5.3) and Use in Specific Populations (8.4) ]. The estimated background risk of major birth defects and miscarriage for the indicated populations are unknown. All pregnancies have a background risk of birth defect, loss, or other adverse outcomes. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2-4% and 15-20%, respectively. Data Animal Data Mesna is used in combination with ifosfamide or other cytotoxic agents. Ifosfamide can cause fetal harm including embryo-fetal lethality. Refer to the ifosfamide prescribing information for more information on use during pregnancy. In embryo-fetal development studies, oral administration of mesna to pregnant rats (500, 1000, 1500, and 2000 mg/kg) and rabbits (500 and 1000 mg/kg) during the period of organogenesis revealed no adverse developmental outcomes at doses approximately 10 times the maximum recommended total daily human equivalent dose based on body surface area.

6 ADVERSE REACTIONS The following are discussed in more detail in other sections of the labeling. • Hypersensitivity Reactions [see Warnings and Precautions (5.1) ] • Dermatological Toxicity [see Warnings and Precautions (5.2) ] • Benzyl Alcohol Toxicity [see Warnings and Precautions (5.3) ] • Laboratory Test Interferences [see Warnings and Precautions (5.4) ] • Use in Patients with a History of Adverse Reactions to Thiol Compounds [see Warnings and Precautions (5.5) ] The most common adverse reactions (> 10%) when mesna is given with ifosfamide are nausea, vomiting, constipation, leukopenia, fatigue, fever, anorexia, thrombocytopenia, anemia, granulocytopenia, diarrhea, asthenia, abdominal pain, headache, alopecia, and somnolence. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Ingenus Pharmaceuticals, LLC at 1-877-748-1970 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. Mesna adverse reaction data are available from four Phase 1 studies in which single oral doses of 600-2400 mg of mesna tablets were administered to a total of 82 healthy volunteers. In two Phase 1 multiple-dose studies where healthy volunteers received mesna tablets alone or intravenous MESNEX followed by repeated doses of mesna tablets, flatulence and rhinitis were reported. Additional adverse reactions in healthy volunteers receiving mesna alone included abdominal pain/colic, epigastric pain/burning, mucosal irritation, lightheadedness, back pain, arthralgia, myalgia, conjunctivitis, nasal congestion, rigors, paresthesia, photophobia, fatigue, lymphadenopathy, extremity pain, malaise, chest pain, dysuria, pleuritic pain, dry mouth, dyspnea, and hyperhidrosis. In healthy volunteers, mesna was commonly associated with a rapid (within 24 hours) decrease in lymphocyte count, which was generally reversible within one week of administration. Because mesna is used in combination with ifosfamide or ifosfamide-containing chemotherapy regimens, it is difficult to distinguish the adverse reactions which may be due to mesna from those caused by the concomitantly administered cytotoxic agents. Adverse reactions reasonably associated with mesna administered orally in four controlled studies in which patients received ifosfamide or ifosfamide-containing regimens are presented in Table 3 . Table 3: Adverse Reactions in ≥5% of Patients Receiving Mesna in combination with Ifosfamide-containing Regimens Mesna Regimen Intravenous-Oral-Oral Intravenous dosing of ifosfamide and MESNEX followed by oral doses of mesna according to the applicable dosage schedule [see Dosage and Administration (2) ] . N exposed 119 (100%) Incidence of AEs 106 (89.1%) Nausea 64 (53.8) Vomiting 45 (37.8) Constipation 21 (17.6) Leukopenia 21 (17.6) Fatigue 24 (20.2) Fever 18 (15.1) Anorexia 19 (16.0) Thrombocytopenia 16 (13.4) Anemia 21 (17.6) Granulocytopenia 15 (12.6) Asthenia 21 (17.6) Abdominal Pain 18 (15.1) Alopecia 13 (10.9) Dyspnea 11 (9.2) Chest Pain 11 (9.2) Hypokalemia 11 (9.2) Diarrhea 17 (14.3) Dizziness 5 (4.2) Headache 13 (10.9) Pain 10 (8.4) Sweating Increased 2 (1.7) Back Pain 6 (5.0) Hematuria 7 (5.9) Injection Site Reaction 10 (8.4) Edema 9 (7.6) Edema Peripheral 8 (6.7) Somnolence 12 (10.1) Anxiety 4 (3.4) Confusion 6 (5.0) Face Edema 5 (4.2) Insomnia 11 (9.2) Coughing 10 (8.4) Dyspepsia 6 (5.0) Hypotension 6 (5.0) Pallor 6 (5.0) Dehydration 7 (5.9) Pneumonia 8 (6.7) Tachycardia 7 (5.9) Flushing 6 (5.0) 6.2 Postmarketing Experience The following adverse reactions have been reported in the postmarketing experience of patients receiving mesna in combination with ifosfamide or similar drugs, making it difficult to distinguish the adverse reactions which may be due to mesna from those cau…