Plecanatide

Absorption

Plecanatide is minimally absorbed with negligible systemic availability following oral administration. Concentrations of plecanatide and its active metabolite in plasma are below the limit of quantitation after an oral dose of 3 mg. Therefore, standard pharmacokinetic parameters such as AUC, maximum concentration (Cmax), and half-life (t?) cannot be calculated.

Toxicity

Single oral doses of plecanatide at 0.5 mg/kg and 10 mg/kg caused mortality in young juvenile mice on postnatal days 7 and 14, respectively (human age equivalent of approximately 1 month to less than 2 years).

The Uses of Plecanatide

Plecanatide is used in the treatment of chronic idiopathic constipation and irritable bowel syndrome with constipation. It works as a laxative by drawing water in to the gastrointestinal tract thereby softening stool and encouraging its natural passage.

Indications

Plecanatide is indicated for the treatment of chronic idiopathic constipation (CIC) and irritable bowel syndrome with constipation (IBS-C) in adult patients.

Background

Plecanatide is a drug approved in January 2017 by the FDA for the treatment of chronic idiopathic constipation (CIC). It should not be used in children less than six years of age, and should be avoided in patients six years to 18 years of age

Pharmacokinetics

Food Effect Subjects who received either a low-fat, low calorie (LF-LC) meal or a high fat, high calorie (HF-HC) meal reported looser stools than fasted subjects up to 24 hours after a single dose of 9 mg (3 times the recommended dose). In clinical studies, Plecanatide was administered with or without food.

Enzyme inhibitor

This uroguanylin analogue (FW = 1681.90 g/mol; CAS 467426-54-6), also known by the codename SP-304, binds to and activates guanylate cyclase-C (GC-C) receptors (EC50 ≈ 0.3 μM) expressed on the epithelial cells lining turn sequentially activates protein kinase G-II and the chloride channel known as the Cystic Fibrosis Transmembrane-conductance Regulator (CFTR) to regulate ion and fluid transport, to promote epithelial cell homeostasis, and to maintain barrier function in the GI mucosa. Plecanatide is a hexadecapeptide that is structurally identical to uroguanylin, except for an glutamate substitution at position-3. Oral treatment with plecanatide at a dose range between 0.05-2.5 mg/kg per day is as effective as once-daily treatment with 5-amino salicylic acid (100 mg/kg) or sulfasalazine (80 mg/kg). Amelioration of colitis by the treatment with plecanatide or dolcanatide was not dose-dependent, most likely due to saturation of available GC-C receptors.

Metabolism

Plecanatide is metabolized in the GI tract to an active metabolite by loss of the terminal leucine moiety. Both plecanatide and the metabolite are proteolytically degraded within the intestinal lumen to smaller peptides and naturally occurring amino acids.