Amifostine

ETHYOL is a cytoprotective agent indicated for: – reduction of cumulative renal toxicity associated with repeated administration of cisplatin in patients with advanced ovarian cancer. ( 1.1 ) – reduction of the incidence of moderate to severe xerostomia in patients undergoing post-operative radiation treatment for head and neck cancer, where the radiation port includes a substantial portion of the parotid glands. ( 1.2 ) Limitation of Use Avoid the use of ETHYOL in settings where chemotherapy can produce a significant survival benefit or cure, or in patients receiving definitive radiotherapy. ( 1 , 5.1 , 5.2 )

1.1 Reduction of Cumulative Renal Toxicity with Chemotherapy ETHYOL (amifostine) is indicated to reduce the cumulative renal toxicity associated with repeated administration of cisplatin in patients with advanced ovarian cancer [see Clinical Studies (14.1) ] .

1.2 Reduction of Moderate to Severe Xerostomia from Radiation of the Head and Neck ETHYOL is indicated to reduce the incidence of moderate to severe xerostomia in patients undergoing post-operative radiation treatment for head and neck cancer, where the radiation port includes a substantial portion of the parotid glands [see Clinical Studies (14.2) ] . Limitation of Use Do not use ETHYOL in other settings where chemotherapy can produce a significant survival benefit or cure [see Warnings and Precautions (5.1) ] , or in patients receiving definitive radiotherapy [see Warnings and Precautions (5.2) ] , except in the context of a clinical study.

For Injection: sterile lyophilized white powder in 10 mL single-dose vials. Each vial contains 500 mg of amifostine on the anhydrous basis. – For injection: sterile lyophilized powder in 10 mL single-dose vials. – Each vial contains 500 mg of amifostine on the anhydrous basis.

ETHYOL is contraindicated in patients with known hypersensitivity to aminothiol compounds. ETHYOL is contraindicated in patients with known hypersensitivity to aminothiol compounds. ( 4 )

– Hypotension and Cardiovascular Events: Patients who are hypotensive or dehydrated should not receive ETHYOL. If interruption of antihypertensive therapy is possible, interrupt antihypertensive therapy 24 hours prior to ETHYOL administration. Monitor blood pressure during infusion; interrupt and restart infusion if decrease in systolic blood pressure is observed. Do not administer ETHYOL to hypotensive patients who are taking antihypertensive therapy that cannot be stopped for 24 hours prior to ETHYOL administration. ( 5.3 ) – Severe Cutaneous Reactions: Monitor patients prior to, during, and weeks after administration for severe cutaneous reactions. Discontinue for cutaneous reactions or lesions appearing outside of the injection site/radiation port or on the palms or soles. ( 5.4 ) – Hypersensitivity: Discontinue for severe acute allergic reactions. Administer treatment for serious allergic events. ( 5.5 ) – Nausea and Vomiting: Administer antiemetic medication prior to and in conjunction with ETHYOL. Monitor fluid balance when administered with highly emetogenic chemotherapy. ( 5.6 ) – Hypocalcemia: Monitor serum calcium levels in patients at risk of hypocalcemia. If necessary, administer calcium supplements. ( 5.7 ) – Embryo-Fetal Toxicity: ETHYOL can cause fetal harm. Advise patients of the potential risk to a fetus ( 5.8 , 8.1 , 8.3 ). Also, refer to the cisplatin full prescribing information for pregnancy and contraception information.

5.1 Effectiveness of the Chemotherapy Regimen ETHYOL may interfere with the antitumor activity of chemotherapy regimens. Do not use ETHYOL in patients receiving chemotherapy for other malignancies in which chemotherapy can produce a significant survival benefit or cure (e.g., certain malignancies of germ cell origin), except in the context of a clinical study. Limited data are currently available regarding interference with antitumor efficacy when ETHYOL is administered prior to cisplatin therapy in settings other than advanced ovarian cancer.

5.2 Effectiveness of Radiotherapy ETHYOL may interfere with the antitumor activity of the radiotherapy regimens. Do not use ETHYOL in patients receiving definitive radiotherapy, except in the context of a clinical trial, since there are insufficient data to exclude a tumor-protective effect in this setting. ETHYOL was studied with standard fractionated radiotherapy and when ≥75% of both parotid glands were exposed to radiation. The safety and efficacy of ETHYOL on the incidence of xerostomia in the setting of combined chemotherapy and radiotherapy, and in the setting of accelerated or hyperfractionated therapy, have not been established.

5.3 Hypotension and Cardiovascular Events Severe hypotension with serious sequelae have been reported in clinical studies and post-marketing experience in patients treated with ETHYOL. Severe hypotension events included apnea, dyspnea, hypoxia, chest pain, tachycardia, bradycardia, extrasystoles, supraventricular tachycardia, atrial fibrillation/flutter, myocardial ischemia, myocardial infarction, unconsciousness, syncope, seizure, renal failure, and respiratory and cardiac arrest. In the WR-1 study of patients with ovarian cancer dosing ETHYOL at 910 mg/m 2 , transient hypotension was observed in 62% of the patients treated, with 8% of the patients experiencing ≥ Grade 3 hypotension. The mean time of onset was 14 minutes after initiation of the ETHYOL infusion, the mean duration of hypotension was 6 minutes, and blood pressure returned to normal within 15 minutes after the onset of hypotension in most cases. Approximately 3% of patients permanently discontinued ETHYOL due to severe hypotension. In the WR-38 study of patients with head and neck cancer administering ETHYOL at a dose of 200 mg/m 2 prior to radiotherapy, hypotension was observed in 15% of patients treated, with 3% of the patients experiencing ≥ Grade 3 hypotension. Before administration of ETHYOL, verify that patients are not hypotensive or dehydrated. Adequately hydrate patients prior to initiating ETHYOL infusion. Patients receiving ETHYOL at doses recommended for chemotherapy should have antihypertensive therapy interrupted 24 hours preceding administration of ETHYOL. Patients receiving ETHYOL at doses recommended for chemotherapy who are taking antihypertensive therapy that cannot be stopped for 24 hours preceding ETHYOL treatment should avoid treatment with ETHYOL. During and after ETHYOL infusion, closely monitor the blood pressure of patients whose antihypertensive medication has been interrupted since hypertension may be exacerbated by discontinuation of antihypertensive medication or other causes such as intravenous hydration. During ETHYOL infusion, keep patients in a supine position and monitor blood pressure every 5 minutes during the infusion, and thereafter as clinically indicated. For infusion durations less than 5 minutes, blood pressure should be monitored at least before and immediately after the infusion, and thereafter as clinically indicated. It is important that the duration of the 910 mg/m 2 infusion does not exceed 15 minutes, as administration of ETHYOL as a longer infusion is associated with a higher incidence of adverse reactions. If hypotension occurs, place patients in the Trendelenburg position and give an infusion of normal saline using a separate intravenous line. If the blood pressure returns to normal within 5 minutes and the patient is asymptomatic, the infusion may be restarted, so that the full dose of ETHYOL can be administered. Guidelines for interrupting and restarting ETHYOL infusion if a decrease in systolic blood pressure should occur are provided [see Dosage and Administration (2.1) ] .

5.4 Severe Cutaneous Reactions Fatal and severe cutaneous reactions have been reported in clinical studies and post-marketing experience in patients treated with ETHYOL. Severe cutaneous reactions include erythema multiforme, Stevens- Johnson syndrome, toxic epidermal necrolysis, toxicoderma, exfoliative dermatitis and drug reaction with biopsy-confirmed eosinophilia and systemic symptoms (DRESS). These reactions have been reported more frequently when ETHYOL is used as a radioprotectant [see Adverse Reactions (6) ] . Severe cutaneous reactions may develop weeks after initiation of ETHYOL administration. Monitor patients carefully prior to, during, and after ETHYOL administration. Discontinue ETHYOL for cutaneous reactions or mucosal lesions appearing outside of the injection site or radiation port and for erythematous, edematous or bullous lesions on the palms or soles.

5.5 Hypersensitivity Hypersensitivity reactions, including anaphylaxis, have been reported in clinical studies and post-marketing experience with ETHYOL administration. Hypersensitivity and anaphylactic reactions observed during or after ETHYOL administration have included pyrexia, chills, dyspnea, hypoxia, chest discomfort, cutaneous eruptions, pruritus, urticaria, and laryngeal edema. Epinephrine and other appropriate measures should be available for treatment of serious infusion-related reactions when administering ETHYOL. When severe allergic reactions occur, immediately and permanently discontinue ETHYOL.

5.6 Nausea and Vomiting Nausea and/or vomiting occur frequently after ETHYOL infusion and may be severe. In the WR-1 study of patients with ovarian cancer dosing ETHYOL at 910 mg/m 2 , vomiting was observed in 96% of the patients treated, with severe nausea/vomiting on day 1 of cyclophosphamide-cisplatin chemotherapy in 19% of patients. In the WR-38 study of patients with head and neck cancer administering ETHYOL at a dose of 200 mg/m 2 prior to radiotherapy, vomiting was observed in 53% of patients treated, with severe nausea/vomiting in 8% of patients. Administer antiemetic medication(s) prior to and in conjunction with ETHYOL [see Dosage and Administration (2.1) ] . […]

The following serious adverse reactions are discussed in greater detail in other sections of the labeling: – Hypotension and Cardiovascular Events [see Warnings and Precautions (5.3) ] – Severe Cutaneous Reactions [see Warnings and Precautions (5.4) ] – Hypersensitivity [see Warnings and Precautions (5.5) ] – Nausea and Vomiting [see Warnings and Precautions (5.6) ] – Hypocalcemia [see Warnings and Precautions (5.7) ] Most common adverse reactions are hypotension, nausea and vomiting. ( 6 ) To report SUSPECTED ADVERSE REACTIONS, contact Legacy Pharma Inc. at 1-800-727-7151 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch .

6.1 Clinical Trial 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. ETHYOL was administered to patients receiving chemotherapeutic agents for advanced ovarian cancer (WR-1 study) or who were receiving standard fractionated radiotherapy for head and neck cancer (WR-38 study) [see Clinical Studies (14) ] . In the WR-38 study of patients with head and neck cancer, 17% (26/150) discontinued ETHYOL due to adverse reactions. All but one of these patients continued to receive radiation treatment until completion. Table 2 summarizes adverse reactions reported in patients from the WR-1 and WR-38 clinical trials. Table 2: Incidence of Common Adverse Reactions in Patients Receiving ETHYOL Ovarian Cancer (WR-1 Trial) 910 mg/m 2 Head and Neck Cancer (WR-38 Trial) 200 mg/m 2 Per Patient Per Infusion Per Patient Per Infusion Nausea/Vomiting ≥Grade 3 36/122 (30%) 53/592 (9%) 12/150 (8%) 13/4314 (<1%) All Grades 117/122 (96%) 520/592 (88%) 80/150 (53%) 233/4314 (5%) Hypotension ≥Grade 3 10/122 (8%) 4/150 (3%) All Grades 75/122 (62%) 159/592 (27%) 22/150 (15%) 46/4314 (1%) Other clinically relevant adverse reactions reported in patients in the WR-1 and WR-38 trials include the following: Infusion-related Reactions: flushing/feeling of warmth, chills/feeling of coldness, malaise, pyrexia, rash, dizziness, somnolence, hiccups, diarrhea, sneezing, diplopia and blurred vision. These effects have not generally precluded the completion of therapy. Injection site reactions (including rash/erythema, pruritus, urticaria, pain, inflammation, bruising and local swelling) were also observed.

6.2 Post-Marketing Experience The following adverse reactions have been identified during post-approval use of ETHYOL. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure. The following reported post-marketing adverse reactions are described elsewhere in the labeling: – Hypotension and Cardiovascular Events [see Warnings and Precautions (5.3) ] – Severe Cutaneous Reactions [see Warnings and Precautions (5.4) ] – Hypersensitivity [see Warnings and Precautions (5.5) ] Adverse reactions associated with the use of ETHYOL that have been identified in other clinical trials and/or post-marketing reports are described below: Immune system disorders: Hypersensitivity reactions including pruritus, urticaria, laryngeal edema, anaphylactic reactions, anaphylactoid reactions. Nervous system disorders: Seizure. Cardiac disorders: Myocardial ischemia, myocardial infarction, cardiac arrest, arrhythmias including tachycardia, bradycardia, atrial fibrillation/ flutter, supraventricular tachycardia, extrasystoles. Vascular disorders: Transient hypertension and exacerbations of preexisting hypertension. Respiratory, thoracic and mediastinal disorders: Apnea, dyspnea, hypoxia, respiratory arrest. Skin and subcutaneous tissue disorders: Erythema multiforme, dermatitis exfoliative, Stevens-Johnson syndrome, toxic epidermal necrolysis. Renal and urinary disorders: Renal failure. General disorders and administration site conditions: Chest discomfort and chest pain.

Closely monitor patients receiving anti-hypertensive medications or other drugs that could cause or potentiate hypotension. – Closely monitor patients receiving anti-hypertensive medications or other drugs that could cause or potentiate hypotension. ( 7 )

– – Advise not to breastfeed. ( 8.2 ) See 17 for PATIENT COUNSELING INFORMAITON.

8.1 Pregnancy Risk Summary When ETHYOL is used in combination with cisplatin, refer to the cisplatin full prescribing information for pregnancy information. Based on findings in animals, ETHYOL can cause fetal harm when administered to a pregnant woman. There are no available data on ETHYOL use in pregnant women to evaluate for a drug-associated risk of major birth defects, miscarriage or adverse maternal or fetal outcomes. In animal reproduction studies, intravenous administration of ETHYOL to pregnant rabbits during organogenesis was embryotoxic at doses approximately sixty percent of the recommended dose in humans based on body surface area (see Data) . Advise pregnant women and females of reproductive potential of the potential risk to a fetus. The background risk of major birth defects and miscarriage for the indicated population is unknown. However, the estimated background risk of major birth defects is 2-4% and of miscarriage is 15-20% of clinically recognized pregnancies in the U.S. general population. Data Animal Data ETHYOL has been shown to be embryotoxic in rabbits at intravenous doses of 50 mg/kg, approximately sixty percent of the recommended dose in humans on a body surface area basis.

8.2 Lactation Risk Summary When ETHYOL is used in combination with cisplatin, refer to the cisplatin full prescribing information for lactation information. There are no data on the presence of amifostine or its metabolites in human milk, the effects on the breastfed child, or the effects on milk production. Because of the potential for serious adverse reactions in a breastfed child, advise lactating women not to breastfeed during treatment with ETHYOL.

8.3 Females and Males of Reproductive Potential When ETHYOL is used in combination with cisplatin, refer to the cisplatin full prescribing information for contraception and infertility information. Pregnancy Testing Verify pregnancy status in females of reproductive potential prior to initiating ETHYOL. Infertility Males Based on findings from animal studies, ETHYOL may impair fertility in males of reproductive potential [see Nonclinical Toxicology (13.1) ] .

8.4 Pediatric Use The safety and effectiveness in pediatric patients have not been established.

8.5 Geriatric Use The clinical studies did not include sufficient number of subjects aged 65 and over to determine whether they respond differently from younger subjects. Other reported clinical experience has not identified differences in responses between elderly and younger patients. In general, dose selection for an elderly patient should be cautious, reflecting the greater frequency of decreased hepatic, renal, or cardiac function and of concomitant disease or other drug therapy in elderly patients.

ETHYOL is a prodrug that is dephosphorylated by alkaline phosphatase in tissues to a pharmacologically active free thiol metabolite. This metabolite is believed to be responsible for the reduction of the cumulative renal toxicity of cisplatin and for the reduction of the toxic effects of radiation on normal oral tissues. The ability of ETHYOL to differentially protect normal tissues is attributed to the higher capillary alkaline phosphatase activity, higher pH and better vascularity of normal tissues relative to tumor tissue, which results in a more rapid generation of the active thiol metabolite as well as a higher rate constant for uptake into cells. The higher concentration of the thiol metabolite in normal tissues is available to bind to, and thereby detoxify, reactive metabolites of cisplatin. This thiol metabolite can also scavenge reactive oxygen species generated by exposure to either cisplatin or radiation.