MESNA

Mesna, USP is a detoxifying agent to inhibit the hemorrhagic cystitis induced by ifosfamide. The active ingredient mesna, USP is a synthetic sulfhydryl compound designated as sodium-2-mercaptoethane sulfonate with a molecular formula of C 2 H 5 NaO 3 S 2 and a molecular weight of 164.18. Its structural formula is as follows: Mesna tablets USP are white to off white, modified capsule shaped, biconvex film-coated tablets, scored on one side and debossed with “I354” on the other side. They contain 400 mg mesna, USP. The excipients are lactose monohydrate, dibasic calcium phosphate, cornstarch, povidone, microcrystalline cellulose, magnesium stearate, hydroxypropyl methylcellulose, polyethylene glycol, and titanium dioxide. FDA approved dissolution test specifications differ from USP. Structural Formula

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 )

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.

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 )

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 caused by the concomitantly administered cytotoxic agents. Because these reactions are reported from a population of unknown size, precise estimates of frequency cannot be made. Cardiovascular : Hypertension Gastrointestinal : Dysgeusia Hepatobiliary : Hepatitis Nervous System : Convulsion Respiratory : Hemoptysis

No clinical drug interaction studies have been conducted with mesna.