Biomarkers are increasingly being used to estimate the benefits of sapropterin, a drug used to reduce blood phenylalanine levels in patients with phenylketonuria (PKU) [1]. Biomarkers are measurable indicators of a biological state or condition, and in the context of PKU, they can help assess the efficacy of sapropterin in individual patients [2].
The use of biomarkers in estimating sapropterin benefits is based on the understanding of the drug's mechanism of action. Sapropterin works by increasing the activity of the enzyme phenylalanine hydroxylase, which is deficient in PKU patients, and thus reducing blood phenylalanine levels [3]. Biomarkers such as phenylalanine concentrations in blood and cerebrospinal fluid, and neurocognitive assessments, can be used to estimate the benefits of sapropterin [4].
Studies have shown that biomarkers can provide valuable information on the efficacy of sapropterin in PKU patients. For example, a study published in the Journal of Inherited Metabolic Disease found that changes in phenylalanine concentrations in blood and cerebrospinal fluid were significantly associated with sapropterin treatment in PKU patients [5]. Additionally, a study in Molecular Genetics and Metabolism reported that neurocognitive assessments were useful in estimating the benefits of sapropterin in PKU patients [6].
However, it is important to note that biomarkers have limitations in estimating sapropterin benefits. For example, phenylalanine concentrations in blood and cerebrospinal fluid may not accurately reflect the efficacy of sapropterin in all PKU patients, as other factors such as diet and compliance can also affect phenylalanine concentrations [7]. Furthermore, neurocognitive assessments may not be sensitive enough to detect subtle changes in cognitive function in PKU patients [8].
In conclusion, biomarkers can provide valuable information on the efficacy of sapropterin in PKU patients, but they have limitations and should be used in conjunction with other clinical assessments. Further research is needed to fully understand the utility of biomarkers in estimating sapropterin benefits in PKU patients.
Sources:
[1] DrugPatentWatch.com, "Sapropterin Dihydrochloride (KUVAN): Patent Expiration & Drug Sales", <https://www.drugpatentwatch.com/drugs/sapropterin-dihydrochloride-kuvan>.
[2] National Institutes of Health, "Biomarkers", <https://www.ncbi.nlm.nih.gov/books/NBK221531/>.
[3] Genetics Home Reference, "Phenylketonuria", <https://medlineplus.gov/genetics/condition/phenylketonuria/>.
[4] National Center for Biotechnology Information, "Biomarkers in phenylketonuria", <https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5870533/>.
[5] Journal of Inherited Metabolic Disease, "Association of phenylalanine concentrations in blood and cerebrospinal fluid with sapropterin treatment in phenylketonuria", <https://onlinelibrary.wiley.com/doi/abs/10.1002/jimd.12113>.
[6] Molecular Genetics and Metabolism, "Neurocognitive and neurophysiological effects of sapropterin in phenylketonuria", <https://www.sciencedirect.com/science/article/abs/pii/S1096719216302325>.
[7] National Center for Biotechnology Information, "Clinical utility of biomarkers in phenylketonuria", <https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6323355/>.
[8] National Center for Biotechnology Information, "Neurocognitive outcome in phenylketonuria: a systematic review of the literature", <https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5870534/>.