Prolonged Stimulation of Growth Hormone and IGF-1 Secretion by CJC-1295, a Long-acting Analogue of Growth Hormone-Releasing Hormone, in Healthy Adults
Sam L. Teichman, Ann Neale, Betty Lawrence, Catherine Gagnon, Jean-Paul Castaigne, and Lawrence A. Frohman*
WinPharm Associates, San Ramon CA.; ConjuChem, Inc., Montréal, Québéc, Canada; Section of Endocrinology, Department of Medicine, University of Illinois at Chicago, Chicago IL
Context: Therapeutic use of growth hormone-releasing hormone (GHRH) to enhance GH secretion is limited by its short duration of action.
Objective: To examine the pharmacokinetic profile, pharmacodynamic effects, and safety of CJC-1295, a long-acting GHRH analog.
Design: Two randomized, placebo-controlled, double-blind, ascending dose trials with durations of 28 and 49 days.
Setting: Two investigational sites.
Participants: Healthy subjects, ages 21 to 61 yr.
Interventions: sc administration of CJC-1295 or placebo in one of 4 ascending single doses in the first study and in 2 – 3 weekly or biweekly doses in the second study.
Main Outcome Measures: Peak concentrations and area under the curve (AUC) of GH and IGF-1; standard pharmacokinetic parameters for CJC-1295.
Results: After a single injection of CJC-1295, there were dose-dependent increases in mean plasma GH concentrations by 2-10 fold for 6 days and in mean plasma IGF-1 concentrations by 1.5- to 3-fold for 9 – 11 days. The estimated half-life of CJC-1295 was 5.8 – 8.1 days. After multiple CJC-1295 doses, mean IGF-1 levels remained above baseline for up to 28 days. No serious adverse reactions were reported.
Conclusions: sc administration of CJC-1295 resulted in sustained, dose-dependent increases in GH and IGF-1 levels in healthy adults and was safe and relatively well-tolerated, particularly at doses of 30 µg/kg or 60 µg/kg. There was evidence of a cumulative effect after multiple doses. These data support the potential utility of CJC-1295 as a therapeutic agent.
Another readers digest version. This study is fairly relevant as it was done on men 20-40 years old. It also gives the dosage per kg of body weight used.
Bottom line if you don’t want to read the thing GH pulse frequency and peak levels were not increased but base line GH level was increased which obviously increased total GH and IGF levels.
Pulsatile Secretion of Growth Hormone (GH) Persists During Continuous Stimulation by CJC-1295, a Long-Acting GHRH Analog
Madalina Ionescu and Lawrence A. Frohman*
Section of Endocrinology, Metabolism, and Diabetes, University of Illinois at Chicago, Chicago, IL 60608
Context: Pulsatile GH secretion is considered important for many of the hormone’s physiologic effects. Short-term GHRH infusions enhance GH pulsatility and increase IGF-1, but the short GHRH half-life limits its therapeutic use. A synthetic GHRH analog (CJC-1295) that binds permanently to endogenous albumin after injection (t1/2 = 8 d) stimulates GH and IGF-1 secretion in several animal species and in normal human subjects and enhances growth in rats.
Objective: To assess GH pulsatility after a single injection of CJC-1295 and determine which GH secretion parameters correlated to the increase in IGF-1 production.
Methods: GH pulsatility was assessed by 20-minute blood sampling during an overnight 12 h period in healthy 20-40 yr old men before and one week after injection of either 60 or 90 µg/kg CJC-1295.
Results: GH secretion was increased after CJC-1295 administration with preserved pulsatility. The frequency and magnitude of GH secretory pulses were unaltered. However, basal (trough) GH levels was markedly increased (7.5 fold; P < 0.0001) and contributed to an overall increase in GH secretion (mean GH levels: 46%; P < 0.01) and IGF-1 levels (45%; P < 0.001). No significant differences were observed between the responses to the two drug doses. The IGF-1 increases did not correlate with any parameters of GH secretion.
Conclusions: CJC-1295 increased trough and mean GH secretion and IGF-1 production with preserved GH pulsatility. The marked enhancement of trough GH levels by continuous GHRH stimulation implicates the importance of this effect on increasing IGF-1. Long-acting GHRH preparations may have clinical utility in patients with intact pituitary GH secretory capability.
Kevin
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