Rapid generation of a novel DPP-4 inhibitor with long-acting properties: SAR study and PK/PD evaluation

Drug compliance is critical for patients with chronic diseases such as diabetes. In our continuous effort to find better glucose-lowering agents, an exploration for long-acting DPP-4 inhibitors had been launched. Based on our previously reported compounds bearing a pyrrolopyrimidine scaffold, the lead compound 4a (IC₅₀ = 2.3 nM, t_1/2(rat) = 5.46 h) with pharmacokinetic superiority was rapidly determined. Further SAR study indicated that the pyrrole ring was generally tolerable for variation, in which a β-substitution gave a better DPP-4 affinity. In depth evaluation of the pyrrole ring β position identified a highly potent compound 12a (IC₅₀ = 0.76 nM, t_1/2(rat) = 7.89 h). In vivo pharmacodynamics tests demonstrated similar or even slightly better sustained DPP-4 inhibition for compounds 4a and 12a compared with the first marketed once-weekly drug trelagliptin in this category, indicating that improvements to DPP-4 inhibitory activity or pharmacokinetic profile might be feasible ways to rapidly generate long-acting DPP-4 inhibitors.