NITYR

1 INDICATIONS AND USAGE NITYR ® is indicated for the treatment of adult and pediatric patients with hereditary tyrosinemia type 1 (HT-1) in combination with dietary restriction of tyrosine and phenylalanine. NITYR is a hydroxyphenyl-pyruvate dioxygenase inhibitor indicated for the treatment of adult and pediatric patients with hereditary tyrosinemia type 1 (HT-1) in combination with dietary restriction of tyrosine and phenylalanine. ( 1 )

2 DOSAGE AND ADMINISTRATION The recommended starting dosage is 0.5 mg/kg (actual body weight) administered orally twice daily. ( 2.1 ) Administer NITYR with or without food. ( 2.1 ) Maintain dietary restriction of tyrosine and phenylalanine when administering NITYR. ( 2.1 ) The recommended maintenance dosage of NITYR in patients 5 years of age and older who have undetectable serum and urine succinylacetone concentrations after a minimum of 4 weeks on a stable dosage of nitisinone, is 1 to 2 mg/kg once daily. ( 2.1 ) See the full prescribing information for dosage titration and monitoring. ( 2.2 ) See the full prescribing information for preparation and administration instructions. ( 2.2 ) 2.1 Recommended Dosage The recommended starting dosage of NITYR is 0.5 mg/kg (actual body weight) administered orally twice daily. Titrate the dose in each individual patient based on biochemical and/or clinical response. Administer NITYR with or without food [see Clinical Pharmacology ( 12.3 )] . Maintain dietary restriction of tyrosine and phenylalanine when administering NITYR. Maintenance Dosage The recommended maintenance dosage of NITYR in patients 5 years of age and older who have undetectable serum and urine succinylacetone concentrations after a minimum of 4 weeks on a stable dosage of nitisinone, is 1 to 2 mg/kg once daily [see Clinical Pharmacology ( 12.2 )] . A maximum total daily dosage of 2 mg/kg may be needed based on the evaluation of all biochemical parameters. Missed Dose If a dose of NITYR is missed, do not administer two doses at once to make up for a missed dose. Take the next dose at the scheduled time. 2.2 Dosage Titration and Monitoring Monitor plasma and/or urine succinylacetone concentrations, liver function parameters and alpha-fetoprotein levels. Monitor all biochemical parameters more closely (i.e. plasma and/or urine succinylacetone, urine 5-aminolevulinate (ALA), and erythrocyte porphobilinogen (PBG)-synthase activity during initiation of therapy, when switching from twice daily to once daily dosing, or if there is a deterioration in the patient’s condition. If succinylacetone is still detectable in blood or urine 4 weeks after the start of nitisinone treatment, increase the NITYR dosage to 0.75 mg/kg twice daily. If the biochemical response is satisfactory (undetectable blood and/or urine succinylacetone), the dosage should be adjusted only according to body weight gain and not according to plasma tyrosine levels. Maintain plasma tyrosine levels below 500 micromol/L by dietary restriction of tyrosine and phenylalanine intake [see Warnings and Precautions ( 5.1 )] . In patients who develop plasma tyrosine levels above 500 micromol/L, assess dietary tyrosine and phenylalanine intake. Do not adjust the NITYR dosage in order to lower the plasma tyrosine concentration. 2.3 Preparation and Administration Instructions For patients who have difficulty swallowing intact tablets, disintegrate NITYR in water and administer using an oral syringe. For patients who can swallow semi-solid foods, NITYR tablets can be crushed and mixed with applesauce. Administration of NITYR with other liquids or foods has not been studied and is not recommended. Preparation and Administration of NITYR with Water in an Oral Syringe: Do not prepare more than two tablets at once within the same oral syringe. If patient’s dosage requires more than two tablets, follow the steps below using multiple oral syringes and prescribed number of tablets to achieve the required dose. One Tablet 1. Remove the plunger from the 5-mL oral syringe and insert a single, intact tablet. 2. Replace the plunger and draw up 2.6 mL of room temperature water. 3. Cap the oral syringe and leave the oral syringe for at least the length of time below: • 15 minutes for a 2 mg tablet • 60 minutes for a 5 mg or 10 mg tablet 4. Turn the oral syringe up and down for at least 30 seconds to suspend the material. 5. Inspect the syringe to ensure the tablet has fully disintegrated. If the tablet is not fully disintegrated, leave the oral syringe for an additional 10 minutes. Do not administer unless the tablet has fully disintegrated. Before administration of the suspension, turn the oral syringe up and down for 30 seconds to ensure the particles are suspended. 6. Uncap the oral syringe and administer all the suspension into the patient's mouth. To facilitate full administration, avoid depressing the plunger to the end of the oral syringe and leave a gap between the plunger and the oral syringe. 7. Fill the oral syringe by drawing up 2 mL of water. Shake well and administer while this time fully depressing the plunger. If particles are still present in the syringe, repeat this step. Two Tablets 1. Remove the plunger from the 5-mL oral syringe and insert two intact tablets. 2. Replace the plunger and draw up 5 mL of room temperature water. 3. Cap the oral syringe and leave it for at least the length of time below: • 15 minutes for 2 mg tablets • 60 minutes for 5 mg or 10 mg tablets 4. Turn the oral syringe up and down for at least 30 seconds to suspend the material. 5. Inspect the syringe to ensure the tablets have fully disintegrated. If the tablet is not fully disintegrated, leave the oral syringe for an additional 10 minutes. Do not administer unless the tablet has fully disintegrated. Before administration of the suspension, turn the oral syringe up and down for 30 seconds to ensure the particles are suspended. 6. Uncap the oral syringe and administer all the suspension into the patient's mouth. To facilitate full administration, avoid depressing the plunger to the end of the oral syringe and leave a gap between the plunger and the oral syringe. 7. Fill the oral syringe by drawing up 2 mL of water. Shake well and administer while this time fully depressing the plunger. If particles are still present in the syringe, repeat this step. Storage Instructions for the NITYR with water in an Oral Syringe The suspension can be stored at room temperature in the capped oral syringe, protected from direct sunlight for up to 24 hours after adding water to the tablets. Discard after 24 hours. Preparation and Administration of NITYR Mixed in Applesauce For patients who can swallow semi-solid food, NITYR can be crushed and mixed with applesauce. 1. Measure approximately one teaspoon of applesauce and transfer it into a clean container (e.g., clean glass). 2. Crush only 1 tablet at a time between two teaspoons forming a fine powder. Repeat this step if more than 1 tablet is needed. 3. Transfer the powder to the applesauce container ensuring all the powder is transferred and no powder residue remains on the teaspoon. 4. Mix the powder into the applesauce until the powder is well dispersed. 5. Administer the entire NITYR-applesauce mixture to the patient immediately or within 2 hours of mixing. 6. To ensure that there is not any remaining NITYR-applesauce mixture, add approximately one teaspoon of applesauce to the same container and administer to the patient. Storage Instructions for NITYR Mixed in Apple Sauce The mixture can be stored at room temperature, out of direct sunlight, for up to 2 hours after adding the crushed tablets to the applesauce. Discard after 2 hours.

4 CONTRAINDICATIONS None. None. ( 4 )

5 WARNINGS AND PRECAUTIONS Ocular Symptoms, Developmental Delay and Hyperkeratotic Plaques Due To Elevated Plasma Tyrosine Levels: Inadequate restriction of tyrosine and phenylalanine intake can lead to elevations in plasma tyrosine and levels above 500 micromol/L may lead to ocular signs and symptoms, intellectual disability and developmental delay, or painful hyperkeratotic plaques on the soles and palms. ( 5.1 ) Do not adjust NITYR dosage in order to lower the plasma tyrosine concentration. ( 5.1 ) Obtain slit-lamp examination prior to treatment and regularly thereafter. Reexamine patients if symptoms develop or tyrosine levels are > 500 micromol/L. Assess plasma tyrosine levels in patients with an abrupt change in neurologic status. ( 5.1 ) Leukopenia and Severe Thrombocytopenia: Monitor platelet and white blood cell counts. ( 5.2 ) 5.1 Ocular Symptoms, Developmental Delay and Hyperkeratotic Plaques Due To Elevated Plasma Tyrosine Levels Treatment with NITYR may cause elevated plasma tyrosine levels in patients with HT-1. Inadequate restriction of tyrosine and phenylalanine intake can lead to elevations in plasma tyrosine levels and levels greater than 500 micromol/L may lead to the following: Ocular signs and symptoms including corneal ulcers, corneal opacities, keratitis, conjunctivitis, eye pain, and photophobia. All of which have been reported in patients treated with nitisinone [see Adverse Reactions ( 6.1 )] . In a clinical study in a non HT-1 population without dietary restriction and reported tyrosine levels > 500 micromol/L both symptomatic and asymptomatic keratopathies have been observed. Therefore, perform a baseline ophthalmologic examination including slit-lamp examination prior to initiating NITYR treatment and regularly thereafter. Patients who develop photophobia, eye pain, or signs of inflammation such as redness, swelling, or burning of the eyes or tyrosine levels are > 500 micromol/L during treatment with NITYR should undergo slit-lamp reexamination and immediate measurement of the plasma tyrosine concentration. Variable degrees of intellectual disability and developmental delay. In patients treated with NITYR who exhibit an abrupt change in neurologic status, perform a clinical laboratory assessment including plasma tyrosine levels. Painful hyperkeratotic plaques on the soles and palms. Maintain concomitant reduction in dietary tyrosine and phenylalanine while on NITYR treatment. In patients with HT-1 who are treated with NITYR and dietary restriction and develop elevated plasma tyrosine levels, assess dietary tyrosine and phenylalanine intake. Do not adjust NITYR dosage in order to lower the plasma tyrosine concentration. Maintain plasma tyrosine levels below 500 micromol/L. 5.2 Leukopenia and Severe Thrombocytopenia In clinical trials, patients treated with another oral formulation of nitisinone and dietary restriction developed reversible leukopenia (3%), thrombocytopenia (3%), or both (1.5%) [see Adverse Reactions ( 6.1 )] . No patients developed infections or bleeding as a result of the episodes of leukopenia and thrombocytopenia. Monitor platelet and white blood cell counts during NITYR therapy.

7 DRUG INTERACTIONS CYP2C9 Substrates : Increased systemic exposure of these co-administered drugs; reduce the dosage. Additional dosage adjustments may be needed to maintain therapeutic drug concentrations for narrow therapeutic index drugs. ( 7 ) OAT1/OAT3 Substrates : Increased systemic exposure of these co-administered drugs; monitor for potential adverse reactions. ( 7 ) Nitisinone is a moderate CYP2C9 inhibitor, a weak CYP2E1 inducer and an inhibitor of OAT1/OAT3. TABLE 2 includes drugs with clinically significant drug interactions when administered concomitantly with NITYR and instructions for preventing or managing them. TABLE 2. Clinically Significant Interactions Affecting Co-Administered Drugs Sensitive CYP2C9 Substrates (e.g., celecoxib, tolbutamide) or CYP2C9 Substrates with a Narrow Therapeutic Index (e.g., phenytoin, warfarin) Clinical Impact Increased exposure of the co-administered drugs metabolized by CYP2C9. [see Clinical Pharmacology ( 12.3 )] Prevention or Management Reduce the dosage of the co-administered drugs metabolized by CYP2C9 drug by half. Additional dosage adjustments may be needed to maintain therapeutic drug concentrations for narrow therapeutic index drugs. See prescribing information for those drugs. OAT1/OAT3 Substrates (e.g., adefovir, ganciclovir, methotrexate) Clinical Impact Increased exposure of the interacting drug. [see Clinical Pharmacology ( 12.3 )] Prevention or Management Monitor for potential adverse reactions related to the co-administered drug.

6 ADVERSE REACTIONS Most common adverse reactions (>1%) are elevated tyrosine levels, thrombocytopenia, leukopenia, conjunctivitis, corneal opacity, keratitis, photophobia, eye pain, blepharitis, cataracts, granulocytopenia, epistaxis, pruritus, exfoliative dermatitis, dry skin, maculopapular rash and alopecia. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Cycle Pharmaceuticals Ltd. at 1-855-831-5413 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. Serious and or clinically significant adverse reactions described elsewhere in labeling include: Ocular Symptoms, Developmental Delay and Hyperkeratotic Plaques Due To Elevated Plasma Tyrosine Levels [see Warnings and Precautions ( 5.1 )] Leukopenia and Severe Thrombocytopenia [see Warnings and Precautions ( 5.2 )] 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 safety of NITYR has been established based on studies of another oral formulation of nitisinone in patients with HT-1 [see Clinical Studies ( 14 )] . Below is a display of the adverse reactions of nitisinone in these studies. Nitisinone was studied in one open-label, uncontrolled study of 207 patients with HT-1, ages 0 to 22 years at enrollment (median age 9 months), who were diagnosed with HT-1 by the presence of succinylacetone in the urine or plasma. The starting dose of nitisinone was 0.3 to 0.5 mg/kg twice daily, and the dose was increased in some patients to 1 mg/kg twice daily based on weight, biochemical, and enzyme markers. The recommended starting dosage of NITYR is 0.5 mg/kg twice daily [see Dosage and Administration ( 2.1 ) ]. Median duration of treatment was 22 months (range 0.1 to 80 months). The most serious adverse reactions reported during nitisinone treatment were thrombocytopenia, leukopenia, porphyria, and ocular/visual complaints associated with elevated tyrosine levels [see Warnings and Precautions ( 5.1 , 5.2 )] . Fourteen patients experienced ocular/visual events. The duration of the symptoms varied from 5 days to 2 years. Six patients had thrombocytopenia, three of which had platelet counts 30,000/microL or lower. In 4 patients with thrombocytopenia, platelet counts gradually returned to normal (duration up to 47 days) without change in the nitisinone dose. No patients developed infections or bleeding as a result of the episodes of leukopenia and thrombocytopenia. Patients with HT-1 are at increased risk of developing porphyric crises, hepatic neoplasms, and liver failure requiring liver transplantation. These complications of HT-1 were observed in patients treated with nitisinone for a median of 22 months during the clinical trial (liver transplantation 13%, liver failure 7%, malignant hepatic neoplasms 5%, benign hepatic neoplasms 3%, porphyria 1%). The most common adverse reactions reported in the clinical trial are summarized in TABLE 1. *reported in at least 1% of patients; ** another oral formulation of nitisinone TABLE 1 Most Common Adverse Reactions * in Patients with HT-1 Treated with Nitisinone ** Elevated tyrosine levels >10% Leukopenia 3% Thrombocytopenia 3% Conjunctivitis 2% Corneal Opacity 2% Keratitis 2% Photophobia 2% Eye Pain 1% Blepharitis 1% Cataracts 1% Granulocytopenia 1% Epistaxis 1% Pruritus 1% Exfoliative Dermatitis 1% Dry Skin 1% Maculopapular Rash 1% Alopecia 1% Adverse reactions reported in less than 1% of the patients, included death, seizure, brain tumor, encephalopathy, hyperkinesia, cyanosis, abdominal pain, diarrhea, enanthema, gastrointestinal hemorrhage, melena, elevated hepatic enzymes, liver enlargement, hypoglycemia, septicemia, and bronchitis.

8.1 Pregnancy Risk Summary Limited available data with nitisinone use in pregnant women are not sufficient to determine a drug-associated risk of adverse developmental outcomes. Animal reproduction studies have been conducted for nitisinone. In these studies, nitisinone was administered to mice and rabbits during organogenesis with oral doses of nitisinone up to 20 and 8-times respectively, the recommended initial dose of 1 mg/kg/day. In mice, nitisinone caused incomplete skeletal ossification of fetal bones and decreased pup survival at doses 0.4 times the recommended initial dose, and increased gestational length at doses 4 times the recommended initial dose. In rabbits, nitisinone caused maternal toxicity and incomplete skeletal ossification of fetal bones at doses 1.6 times the recommended initial dose ( see Data ) . The background risk of major birth defects and miscarriage for the indicated population are unknown. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2 to 4% and 15 to 20%, respectively. Data Animal Data Reproduction studies have been performed in mice at oral doses of about 0.4, 4 and 20 times the recommended initial dose (1 mg/kg/day) and in rabbits at oral doses of about 1.6, 4 and 8 times the recommended initial dose based on the body surface area. In mice, nitisinone has been shown to cause incomplete skeletal ossification of fetal bones at 0.4, 4 and 20 times the recommended initial dose, increased gestational length at 4 and 20 times the recommended initial dose, and decreased pup survival at 0.4 times the recommended initial dose based on the body surface area. In rabbits, nitisinone caused incomplete skeletal ossification of fetal bones at 1.6, 4 and 8 times the recommended initial dose based on the body surface area.