ZT-01: A novel somatostatin receptor 2 antagonist for restoring the glucagon response to hypoglycaemia in type 1 diabetes.

Aim: To evaluate the pharmacokinetics and efficacy of a novel somatostatin receptor 2 antagonist, ZT-01, to stimulate glucagon release in rats with type 1 diabetes (T1D).

Methods: The pharmacokinetics of ZT-01 and PRL-2903 were assessed following intraperitoneal or subcutaneous dosing at 10 mg/kg. We compared the efficacy of ZT-01 with PRL-2903 to prevent hypoglycaemia during an insulin bolus challenge and under hypoglycaemic clamp conditions.

Results: Within 1 hour after intraperitoneal administration, ZT-01 achieved more than 10-fold higher plasma Cmax compared with PRL-2903. Twenty-four hour exposure was 4.7× and 11.3× higher with ZT-01 by the intraperitoneal and subcutaneous routes, respectively. The median time to reach hypoglycaemia of more than 3.0 mmol/L was 60, 70, and 125 minutes following vehicle, PRL-2903, or ZT-01 administration, respectively. Furthermore, rats receiving ZT-01 had significantly higher glucose nadirs following insulin administration compared with PRL-2903- and vehicle-treated rats. During the hypoglycaemic clamp, ZT-01 increased peak glucagon responses by ~4-fold over PRL-2903.

Conclusions: We conclude that ZT-01 may be effective in restoring glucagon responses and preventing the onset of hypoglycaemia in patients with T1D.