4-Hydroxyphenyl-Pyruvate Dioxygenase Inhibitor

Nityr

Approved 26 Jul 2017OralTablet

The FDA lists this product in 3 strengths and forms.

Indications

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 )

Contraindications

None. None. ( 4 )

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.

Indications

Warnings and precautions

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 )]

6.1Clinical 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.

Nityr

Indications

Contraindications

Warnings and precautions

Two medicines in one question?

Nityr

Indications

Contraindications

Warnings and precautions

Two medicines in one question?

5.2Leukopenia and Severe Thrombocytopenia

Interactions

Pregnancy and breastfeeding

8.1Pregnancy Risk Summary

Adverse reactions

6.1Clinical Trials Experience

Composition

Strengths and forms

Official product information

At a glance