AOD-9604 vs GW-0742

Metabolic

Metabolic

Research Only

Research Only

The original preclinical hypothesis was that hGH(177-191) retains a lipolytic activity via a non-GH-receptor pathway, with some rodent data implicating β3-adrenoceptor expression and cAMP signaling in adipocytes. This mechanism is disputed and has not been robustly reproduced in controlled human studies — Phase 2 trials showed no significant effect on body weight versus placebo. AOD-9604 does not measurably raise serum IGF-1 and does not impair glucose tolerance in human safety studies, which is consistent with lack of GH-receptor agonism but does not establish clinical lipolytic efficacy.

GW-0742 is a high-affinity, highly selective agonist of human PPARδ (EC50 = 1.1 nM for hPPARδ transactivation vs ~1.1 µM for hPPARα and ~2 µM for hPPARγ), conferring ~1000-fold selectivity for PPARδ over the other PPAR subtypes. Upon activation, PPARδ heterodimerizes with RXR and binds PPAR-response elements (PPREs) to alter transcription of genes governing fatty-acid oxidation, glucose utilization, and inflammatory signaling. In mice, however, GW-0742-induced hepatomegaly, hepatic/skeletal-muscle peroxisome proliferation, and skeletal myopathy were shown to be predominantly mediated by off-target PPARα cross-activation rather than PPARδ—a mechanism-based toxicity concern at animal-study exposures.

Short; reported plasma half-life on the order of minutes in preclinical work. Well-characterized human PK data are limited.