1676-P: A Novel GLP1R/GCGR Dual Agonist, DA-1726 Elicits Weight Loss Superior to Semaglutide in Diet-Induced Obese Rats

DA-1726 showed superior weight loss efficacy compared to Semaglutide (SEMA) in DIO mice. In this following study, a dose-response of DA-1726 was evaluated to determine the maximum efficacy in DIO rats that are known to have good translatability to human studies. The half-life of DA-1726 was longer in rats compared to mice, however the in vitro activity of DA-1726 against rat glucagon receptor was less potent than in the mouse, and plasma protein binding was approximately 10-fold higher in rats. Therefore, we set the effective dose for rats higher than for mice. DA-1726 was injected twice a week for about 4 weeks, a dose-dependent and significant weight loss effect was observed. The minimum effective dose in DIO rats was found to be 250 nmol/kg. Then, the maximum body weight loss effects of DA-1726 (500 and 1000 nmole/kg) and SEMA were compared in the DIO rat. In this study, DA-1726 showed an excellent weight loss effect than SEMA (32.6% for DA-1726 at a high dose vs. 24.0% for SEMA, p<0.05). The low-dose DA-1726 group showed a similar effect compared to SEMA even though they consumed more food. The high-dose DA-1726 group showed similar food intake as SEMA, but led to a higher weight loss effect. After repeated dosing, the high-dose DA-1726 significantly increased the expression of energy metabolism-related genes (Ucp1, Ppargc1a) in white adipose tissues (WAT), supporting increased energy expenditure. So then, in order to confirm whether this increased gene change was a direct effect leading to weight loss or an indirect effect caused by weight loss, we assessed the changes in gene expression after single dosing. DA-1726 (250 and 500 nmol/kg) induced small but significant weight loss 3 days after a single injection (-7.6% and -9.5% vs. control). However, the genes expression (Ucp1, Ppargc1a) in WAT was significantly increased only in the 500 nmol/kg-treated group suggesting a direct effect. Therefore, DA-1726 is expected to elicit excellent weight loss effects in humans with a new mechanism.