Pharmacological and clinical profiles of a novel calcimimetic, evocalcet (ORKEDIA<sup>®</sup>)

Calcimimetics allosterically activate the calcium receptor (CaR) and inhibit the secretion of parathyroid hormone (PTH). Cinacalcet hydrochloride (cinacalcet) has been approved as the first calcimimetic drug for the treatment of secondary hyperparathyroidism (SHPT) in patients with hemodialysis. Cinacalcet improved the achievement of target serum PTH and Ca levels and helped drastically reduce the number of parathyroidectomies. However, cinacalcet has side effects involving the gastrointestinal tract, such as nausea and vomiting, which makes it difficult to increase the dose and may result in reduced compliance. Evocalcet has been developed to improve defects of cinacalcet for management of SHPT. Evocalcet acts as an allosteric modulator of CaR, just like cinacalcet. However, its metabolic pathway is different from that of cinacalcet. The metabolism of evocalcet by cytochrome P450 is very low, so evocalcet has higher bioavailability. As a result, its pharmacologically effective dose for the inhibition of PTH secretion is lower than that of cinacalcet. Evocalcet had less of an effect on the gastrointestinal tract than cinacalcet because of the reduced dose required. In a clinical trial with a randomized, double-blind, head-to-head comparison study, it was also confirmed that the incidence of gastrointestinal-related adverse events was lower in the evocalcet group than in the cinacalcet group. Evocalcet may thus be a potent option for the management of SHPT.