Nitisinone (NTBC) In Different Age Groups Of Patients With Alkaptonuria

Summary

Nitisinone is a potent inhibitor of the enzyme that catalyzes the formation of homogentisic acid, and should be an even more logical treatment for alkaptonuria than for tyrosinemia, for which it has been approved by the FDA.The objective of this research is to explore reported age related differences in toxicity of nitisinone and its pharmacokinetic underpinnings and to develop an optimal therapeutic requirement for a targeted population of presymptomatic patients. The additional effect of mixtures of amino acids excluding tyrosine will be explored to take advantage of protein synthesis to avoid elevations of tyrosine that would otherwise limit the optimal dosage of nitisinone. The study is designed to treat patients and find the optimal dosage of nitisinone to obtain maximal reduction in levels of homogentisic acid and maintain safe levels of tyrosine. The long term objective in the target population of pre-symptomatic patients is the prevention of the characteristic effects on joint cartilage and tendons.

Timeline

Start

2011-01

Primary completion

2016-06

Completion

2016-07

Publications

• Background Suwannarat P, O'Brien K, Perry MB, Sebring N, Bernardini I, Kaiser-Kupfer MI, Rubin BI, Tsilou E, Gerber LH, Gahl WA. Use of nitisinone in patients with alkaptonuria. Metabolism. 2005 Jun;54(6):719-28. doi: 10.1016/j.metabol.2004.12.017.
• Background Introne WJ, Perry MB, Troendle J, Tsilou E, Kayser MA, Suwannarat P, O'Brien KE, Bryant J, Sachdev V, Reynolds JC, Moylan E, Bernardini I, Gahl WA. A 3-year randomized therapeutic trial of nitisinone in alkaptonuria. Mol Genet Metab. 2011 Aug;103(4):307-14. doi: 10.1016/j.ymgme.2011.04.016. Epub 2011 May 6.
• Background Phornphutkul C, Introne WJ, Perry MB, Bernardini I, Murphey MD, Fitzpatrick DL, Anderson PD, Huizing M, Anikster Y, Gerber LH, Gahl WA. Natural history of alkaptonuria. N Engl J Med. 2002 Dec 26;347(26):2111-21. doi: 10.1056/NEJMoa021736.
• Background Gertsman I, Gangoiti JA, Nyhan WL, Barshop BA. Perturbations of tyrosine metabolism promote the indolepyruvate pathway via tryptophan in host and microbiome. Mol Genet Metab. 2015 Mar;114(3):431-7. doi: 10.1016/j.ymgme.2015.01.005. Epub 2015 Jan 29.
• Results Gertsman I, Barshop BA, Panyard-Davis J, Gangoiti JA, Nyhan WL. Metabolic Effects of Increasing Doses of Nitisinone in the Treatment of Alkaptonuria. JIMD Rep. 2015;24:13-20. doi: 10.1007/8904_2014_403. Epub 2015 Feb 10.

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Indications