In a randomized double-blind crossover trial, the oral ghrelin receptor agonist MK-0677 increased IGF-1 levels by 65% compared to placebo in hemodialysis patients with no serious adverse effects.
65% greater IGF-1 increaseMK-0677 produced a statistically significant 65% greater increase in IGF-1 compared to placebo (p<0.001) in hemodialysis patients over a 3-month crossover trial
What the researchers found
MK-0677 produced a 1.76-fold increase in geometric mean IGF-1 levels (95% CI 1.48–2.10; p < 0.001) in hemodialysis patients, compared to only a 1.07-fold change with placebo (95% CI 0.89–1.27; p = 0.718). After adjusting for baseline IGF-1, MK-0677 produced a 65% greater increase in IGF-1 compared to placebo (ratio of geometric means 1.65; 95% CI 1.33–2.04; p < 0.001).
No serious adverse effects were attributed to MK-0677 during the 3-month study period. This is the first study of MK-0677 in dialysis patients and demonstrates that the drug's ability to increase IGF-1 — previously shown in healthy subjects — is preserved in this critically ill population.
Why it matters
Protein-energy wasting affects a large proportion of dialysis patients and is strongly linked to increased morbidity and mortality. Current treatment options are limited — growth hormone injections require subcutaneous administration and produce unnatural GH secretion patterns. MK-0677 offers the advantage of oral dosing while maintaining normal GH secretion physiology, making it a more practical potential treatment. This study establishes safety and IGF-1 efficacy in the target population, a necessary step before larger clinical trials.
How the study worked
This was a randomized, crossover, double-blind, placebo-controlled study. Twenty-six hemodialysis patients enrolled and 22 completed the 3-month crossover design, receiving both MK-0677 and placebo in alternating periods. The primary outcome was change in serum IGF-1 levels. Statistical analysis used geometric means with 95% confidence intervals, adjusted for pre-intervention IGF-1 concentrations.
What this study cannot tell us
The study had a small sample size (22 completers from 26 enrolled). While IGF-1 increased significantly, the study did not measure clinical outcomes like lean body mass, muscle strength, nutritional status, or survival — only a surrogate biomarker. The 3-month duration may be too short to detect long-term safety concerns or clinical benefits. The study was designed as a preliminary safety/efficacy assessment, not a definitive clinical trial.
How to read the evidence
This is a randomized, double-blind, placebo-controlled crossover trial in humans — a strong study design. However, the small sample size (22 completers), short duration, and use of a surrogate endpoint (IGF-1 rather than clinical outcomes) limit the evidence strength. It serves as a well-designed proof-of-concept study.
When this study was published
Published in 2018, this study remains relevant as interest in ghrelin receptor agonists for wasting conditions continues to grow. Longer-term clinical outcome trials in dialysis patients have yet to be published.
The bigger picture
This study connects two important fields: ghrelin/growth hormone biology and nephrology supportive care. MK-0677 (ibutamoren) has been studied primarily in aging and growth hormone deficiency, but this is among the first applications in chronic kidney disease. The results support the broader concept that targeting the ghrelin-GH-IGF-1 axis through oral peptide mimetics could improve outcomes in catabolic conditions where muscle wasting drives mortality.
Questions still open
- Does the 65% increase in IGF-1 translate to improvements in lean body mass, physical strength, and nutritional status in dialysis patients?
- What is the long-term safety profile of MK-0677 in patients with end-stage renal disease, particularly regarding glucose metabolism?
- Could MK-0677 reduce mortality associated with protein-energy wasting in larger, longer clinical trials?
Common questions
What is MK-0677 and how does it work?
Why is protein-energy wasting dangerous for dialysis patients?
Read the original research
Oral ghrelin receptor agonist MK-0677 increases serum insulin-like growth factor 1 in hemodialysis patients: a randomized blinded study.
Nephrology, dialysis, transplantation : official publication of the European Dialysis and Transplant Association - European Renal Association, 33(3), 523-530
Citation
Campbell, Garland A; Patrie, James T; Gaylinn, Bruce D; Thorner, Michael O; Bolton, Warren K. (2018). Oral ghrelin receptor agonist MK-0677 increases serum insulin-like growth factor 1 in hemodialysis patients: a randomized blinded study.. Nephrology, dialysis, transplantation : official publication of the European Dialysis and Transplant Association - European Renal Association, 33(3), 523-530. https://doi.org/10.1093/ndt/gfw474