Continuation of pegvaliase treatment during pregnancy: A case report.

Phenylalanine hydroxylase (PAH) deficiency is an inborn error of phenylalanine (Phe) metabolism that results in the buildup of dietary Phe to potentially toxic levels. Poorly controlled Phe levels in women of childbearing age are particularly worrisome due to the toxic effect of elevated Phe on fetal development. Pegvaliase was recently approved as an enzyme substitution therapy to reduce Phe concentrations in adult patients with PAH deficiency who have suboptimal Phe control on existing management. During the pegvaliase clinical trials pregnant patients were excluded from participation, but the approved label does not contraindicate its use during pregnancy. This case report describes the outcome of the first PAH deficient patient who elected to continue treatment with pegvaliase during pregnancy and reviews the lessons learned and future considerations.

Efficacy of N-carbamoyl-L-glutamic acid for the treatment of inherited metabolic disorders.

INTRODUCTION: N-carbamoyl-L-glutamic acid (NCG) is a synthetic analogue of N-acetyl glutamate (NAG) that works effectively as a cofactor for carbamoyl phosphate synthase 1 and enhances ureagenesis by activating the urea cycle. NCG (brand name, Carbaglu) was recently approved by the United States Food and Drug Administration (US FDA) for the management of NAGS deficiency and by the European Medicines Agency (EMA) for the treatment of NAGS deficiency as well as for the treatment of hyperammonenia in propionic, methylmalonic and isovaleric acidemias in Europe. AREAS COVERED: The history, mechanism of action, and efficacy of this new drug are described. Moreover, clinical utility of NCG in a variety of inborn errors of metabolism with secondary NAGS deficiency is discussed. EXPERT COMMENTARY: NCG has favorable pharmacological features including better bioavailability compared to NAG. The clinical use of NCG has proven to be so effective as to make dietary protein restriction unnecessary for patients with NAGS deficiency. It has been also demonstrated to be effective for hyperammonemia secondary to other types of inborn errors of metabolism. NCG may have additional therapeutic potential in conditions such as hepatic hyperammonemic encephalopathy secondary to chemotherapies or other liver pathology.