Objective: The safety, tolerability, pharmacokinetics and preliminary pharmacodynamics of single rising doses of a novel GLP-1 analog, CJC-1131, was evaluated.
Methods: CJC-1131 was subcutaneously injected in 8 groups (1.5 - 20.5 microg/kg) of healthy subjects (each group of six subjects included 1 placebo per dose level). CJC-1131 was also injected subcutaneously in 6 groups (1.5 - 12 microg/kg) of Type 2 diabetic patients after a 9-day washout period from their own anti-diabetic medication. Each group of 8 patients included 2 placebo-treated patients. Seven blood glucose measurements were taken daily, and meal tolerance tests were performed on the day before dosing and on Day 3.
Results: CJC-1131 was quickly absorbed from the subcutaneous space, and a less than dose-proportional increase was found in Cmax. The half-life of CJC-1131 varied from 8.9 - 14.7 days in healthy subjects and from 9.1 - 13.8 days in patients. The maximum tolerated dose in healthy subjects was established at 12 microg/kg with nausea and vomiting being the dose-limiting events. These events occurred generally in the morning after dosing. Blood glucose levels in patients decreased on Day 1 in proportion with dose, with a maximum average decrease of 4.1 mmol/l in the highest dose group. Higher doses appeared to be related to a slight weight loss in patients.
Conclusions: Conjugation to albumin led to a major prolongation of the half-life of GLP-1. The tolerability of this potential antidiabetic drug seems to be limited only by gastrointestinal complaints.