NITISINONE: 752 Adverse Event Reports & Safety Profile

ORFADIN contains nitisinone, which is a hydroxyphenyl-pyruvate dioxygenase inhibitor indicated as an adjunct to dietary restriction of tyrosine and phenylalanine in the treatment of hereditary tyrosinemia type 1 (HT-1). Nitisinone occurs as white to yellowish-white, crystalline powder. It is practically insoluble in water, soluble in 2M sodium hydroxide and in methanol, and sparingly soluble in alcohol. Chemically, nitisinone is 2-(2-nitro-4-trifluoromethylbenzoyl) cyclohexane-1,3-dione, and the structural formula is: Figure 1. The molecular formula is C 14 H 10 F 3 NO 5 with a relative mass of

329.23 Capsules: Hard, white-opaque capsule, marked as 2 mg, 5 mg, 10 mg or 20 mg strengths of nitisinone, intended for oral administration. Each capsule contains 2 mg, 5 mg, 10 mg or 20 mg nitisinone, plus pre-gelatinized starch. The capsule shell is gelatin and titanium dioxide and the imprint is an iron oxide. Oral suspension: 4 mg/mL, a white, slightly viscous opaque suspension. The inactive ingredients are hydroxypropyl methylcellulose, glycerol, polysorbate 80, sodium benzoate, citric acid monohydrate, trisodium citrate dihydrate, strawberry aroma (artificial) and purified water. Glycerol: Each mL contains 500 mg. Sodium: Each mL contains 0.7 mg (0.03 mEq).

Figure

1

HIGHLIGHTS OF PRESCRIBING INFORMATION These highlights do not include all the information needed to use NITISINONE CAPSULES safely and effectively. See full prescribing information for NITISINONE CAPSULES.

Nitisinone

Capsules, for oral use Initial U.S. Approval: 2002 1.

Indications And Usage

Nitisinone Capsules 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. Nitisinone is a hydroxy-phenylpyruvate 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.

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 <span class="opacity-50 text-xs">[see Clinical Pharmacology ( 12.3 )]</span> . 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 <span class="opacity-50 text-xs">[see Warnings and Precautions ( 5.1 )]</span> . 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.

None. None. ( 4 )

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 <span class="opacity-50 text-xs">[see Clinical Studies ( 14 )]</span> . 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 <span class="opacity-50 text-xs">[see Dosage and Administration ( 2.1 ) ]</span>. 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 <span class="opacity-50 text-xs">[see Warnings and Precautions ( 5.1 , 5.2 )]</span> . 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.

AND PRECAUTIONS Elevated Plasma Tyrosine Levels, Ocular Symptoms, Developmental Delay and Hyperkeratotic Plaques : Inadequate restriction of tyrosine and phenylalanine intake can lead to elevations in plasma tyrosine, which at levels above 500 micromol/L can result in symptoms, intellectual disability and developmental delay or painful hyperkeratotic plaques on the soles and palms; do not adjust ORFADIN dosage in order to lower the plasma tyrosine concentration. Obtain slit-lamp examination prior to treatment, regularly during treatment; 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 ) Risk of Adverse Reactions Due to Glycerol Content of ORFADIN Oral Suspension : Doses of 20 mL of ORFADIN oral suspension may cause headache, upset stomach and diarrhea due to the glycerol content. Consider switching patients to ORFADIN capsules. ( 5.3 )

5.1 Elevated Plasma Tyrosine Levels, Ocular Symptoms, Developmental Delay and Hyperkeratotic Plaques Nitisinone is an inhibitor of 4-hydroxyphenyl-pyruvate dioxygenase, an enzyme in the tyrosine metabolic pathway <span class="opacity-50 text-xs">[see Clinical Pharmacology ( 12.1 )]</span> . Therefore, treatment with ORFADIN may cause an increase in plasma tyrosine levels in patients with HT-1. Maintain concomitant reduction in dietary tyrosine and phenylalanine while on ORFADIN treatment. Do not adjust ORFADIN dosage in order to lower the plasma tyrosine concentration. Maintain plasma tyrosine levels below 500 micromol/L. 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 have been reported in patients treated with ORFADIN <span class="opacity-50 text-xs">[see Adverse Reactions ( 6.1 )]</span> . In a clinical study in a non HT-1 population without dietary restriction and reported tyrosine levels &gt;500 micromol/L both symptomatic and asymptomatic keratopathies have been observed. Therefore, perform a baseline ophthalmologic examination including slit-lamp examination prior to initiating ORFADIN 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 &gt; 500 micromol/L during treatment with ORFADIN 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 ORFADIN 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 In patients with HT-1 treated with dietary restrictions and ORFADIN who develop elevated plasma tyrosine levels, assess dietary tyrosine and phenylalanine intake.

5.2 Leukopenia and Severe Thrombocytopenia In clinical trials, patients treated with ORFADIN and dietary restriction developed transient leukopenia (3%), thrombocytopenia (3%), or both (1.5%) <span class="opacity-50 text-xs">[see Adverse Reactions ( 6.1 )]</span> . No patients developed infections or bleeding as a result of the episodes of leukopenia and thrombocytopenia. Monitor platelet and white blood cell counts during ORFADIN therapy.

5.3 Risk of Adverse Reactions Due to Glycerol Content of ORFADIN Oral Suspension Oral doses of glycerol of 10 grams or more have been reported to cause headache, upset stomach and diarrhea. ORFADIN oral suspension contains 500 mg/mL of glycerol. Patients receiving more than 20 mL of ORFADIN oral suspension (10 grams glycerol) as a single dose are at increased risk of these adverse reactions. Consider switching patients who are unable to tolerate the oral suspension to ORFADIN capsules.

INTERACTIONS Nitisinone is a moderate CYP2C9 inhibitor, a weak CYP2E1 inducer and an inhibitor of OAT1/OAT3.

Table

2 includes drugs with clinically important drug interactions when administered concomitantly with nitisinone and instructions for preventing or managing them.

Table

2: Clinically Relevant 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 )]

Intervention

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 )]

Intervention

Monitor for potential adverse reactions related to the co-administered drug. 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 ) Additional pediatric use information is approved for Swedish Orphan Biovitrum AB PUBL's Orfadin (nitisinone) capsules. However, due to Swedish Orphan Biovitrum AB PUBL's marketing exclusivity rights, this drug product is not labeled with that pediatric information.