The primary objective of the trial was to evaluate the tolerability of ascending doses of the investigational product as determined by the incidence and severity of reported adverse events. Secondary endpoints included pharmacokinetic parameters of plasma GLP-1 (glucagon-like peptide) and pharmacodynamic parameters of plasma insulin and glucose.
GLP-1 plasma concentrations peaked very quickly, with a mean Tmax occurring less than three minutes after inhalation. In the group that received 1.5mg of MKC253, the mean Cmax of total GLP-1 was 507pmol/L, with active GLP-1 reaching a Cmax of 310pmol/L. At all dose levels, MKC253 was well tolerated.
In these healthy subjects, GLP-1-induced insulin release occurred within six minutes of inhalation of MKC253. The insulin response was dose-dependent. The release of insulin from the pancreas was confirmed by corresponding significant increases in the levels of C-peptide. In subjects that received 1.5mg of MKC253, blood glucose concentrations were observed to decrease for a period of approximately 20 minutes after inhalation. All subjects were fasted prior to the administration of MKC253.