ext608

EXT608 is a long-acting derivative of parathyroid hormone (PTH), developed by Extend Biosciences using their proprietary D-VITylation platform. It is designed as a subcutaneously administered therapy to mimic the physiological effects of endogenous PTH, aiming to restore and maintain normal serum calcium and phosphate levels in patients with hypoparathyroidism. The drug acts as an agonist at the parathyroid hormone receptor type 1 (PTHR1) and demonstrates prolonged activity, allowing for once-weekly dosing. Clinical studies have shown that EXT608 increases serum calcium without increasing urinary calcium, suppresses endogenous PTH as expected, and has been well tolerated in early trials with no serious adverse events reported. The compound received Orphan Drug Designation from the FDA in 2022[1][3][5][7].