Activation of the GH/IGF-1 axis by CJC-1295 – a long-acting GHRH analog

Source: Sackmann-Sala L. et al., Growth Hormone & IGF Research, 2009, 10.1016/j.ghir.2009.02.004


Research Objective

To evaluate the effect of CJC-1295 – a long-acting Growth Hormone Releasing Hormone (GHRH) analog – on the activity of the GH/IGF-1 axis and related biomarkers in humans.

CJC-1295 is a modified GHRH peptide with an extended plasma half-life that stimulates endogenous secretion of growth hormone (GH) and insulin-like growth factor-1 (IGF-1). The study aimed to determine whether the peptide provides sustained activation of the GH/IGF-1 axis and whether serum biomarkers of the hormonal response can be identified.


Study Design

  • Type: clinical, experimental study in humans

  • Participants: healthy volunteers (men and women)

  • Interventions:

    • Single subcutaneous injection of CJC-1295

    • Control group with no treatment

  • Doses: 30–60 µg/kg (single administration)

  • Follow-up duration: up to 14 days post-injection

  • Measured parameters:

    • Serum levels of GH and IGF-1

    • Proteomic changes (plasma biomarkers)

    • Signatures of GH/IGF-1 activation


Key Results

Activation of the GH/IGF-1 axis

  • CJC-1295 caused a significant and prolonged increase in GH and IGF-1.

  • GH peaks were observed within 2–6 hours post-injection, and IGF-1 remained above baseline levels for up to 10–14 days.

  • The increase was dose-dependent and showed extended action compared to standard GHRH analogs.

Proteomic changes

  • Serum proteins whose expression changed after CJC-1295 administration were identified.

  • Biomarkers of GH/IGF-1 activity suitable for monitoring therapeutic effect were identified.

Biochemical parameters

  • No clinically significant changes in glucose, insulin, or liver enzymes were observed.

  • The hormonal response was physiological and controlled.

Tolerability

  • CJC-1295 was very well tolerated.

  • No serious side effects or signs of systemic toxicity were observed.


Conclusions

  • CJC-1295 activates the GH/IGF-1 axis in a sustained and dose-dependent manner.

  • It significantly increases GH and IGF-1 within weeks after a single administration.

  • It provides extended action and less frequent dosing compared to conventional GHRH peptides.

  • Suitable for research purposes related to hormonal activation and anabolic processes.


Limitations

  • Small number of participants.

  • Short follow-up period – lack of long-term data.

  • Patients with GH deficiency or metabolic disorders were not included.


Practical Significance

  • CJC-1295 is a promising long-acting GHRH analog.

  • Suitable for scientific research on the GH/IGF-1 axis, models of GH deficiency, and studies of muscle regeneration.

  • Can be used in controlled laboratory settings for pharmacodynamic studies.