26-OR: A Novel Drug That Normalizes Hyperglycemia in Type 1 Diabetes

Abstract

Treatment of hyperglycemia in patients with type 1 diabetes (T1D) depends on insulin injections, which risk hypoglycemia and represent an unfavorable route of administration. Inhibition of EphA4 signaling in α-cells reduces glucagon hypersecretion, which suggests an alternative approach for the treatment of hyperglycemia in T1D. We have designed and synthesized a novel EphA4 agonist (Ki = 0.1 µM), termed WCDD301, that dose-dependently suppresses glucagon secretion (p<0.001) from mouse islets and dispersed α-cells at high glucose levels. Co-treatment of the EphA4 competitive inhibitor, Rhyncophylline (2.5µM) and WCDD301 (2.5µM or 5µM) substantially or partially, respectively, abolishes WCDD301 effects. Further, WCDD301 reduces glucagon secretion from nondiabetic human donor islet cells following 1h (p<0.05), 3h (p<0.01) and 6h (p<0.001) exposure. WCDD301 suppresses glucagon secretion (p<0.001) from isolated islets and dispersed islet cells from T1D subjects, comparable to the natural EphA4 ligand ephrinA5. Similar to ephrinA5 treatment, WCDD301 increases F-actin density in both human and mouse α-cells. WCDD301 exhibits good plasma (>289 and 105 min) and microsomal (>145 and 93.6 min) stability in human and mouse, respectively. In STZ-induced diabetic mice (initial blood glucose <300mg/dL, n=6), oral administration of WCDD301 (daily 10 mg/kg) substantially reduces blood glucose levels (140±31 mg/dL after four weeks). In diabetic NOD mice (initial blood glucose 249.6±13.1 mg/dL; n=7), oral administration of WCDD301 (daily 10 mg/kg) normalizes glucose (105±2.6 mg/dL after 3 weeks), which remains constant for >3 months (experiments on-going) accompanied by reduced plasma glucagon (16.6±7.9 pg/mL) compared to diabetic control (328.5±18.7 pg/ml). The data support our hypothesis that oral administration of WCDD301 suppresses glucagon secretion by an EphA4-dependent pathway. The recovery of euglycemia in T1D mouse models is promising for further evaluation towards potential treatment of T1D. Disclosure F. Asadi: None. S.C. Gunawardana: None. D.W. Piston: None. Funding The Leona M. and Harry B. Helmsley Charitable Trust (2305-06050); National Institutes of Health (R01DK123301, P30DK020579)