Purpose: The aim of this study was to evaluate the therapeutic effects of Anamorelin on patients with cancer anorexia-cachexia syndrome (CACS) based on a meta-analysis of published randomized trials.
Methods: We searched PubMed, Embase, Medline, and the Cochrane Central Register of Controlled Trials databases. Data from each selected study were evaluated individually. All continuous outcomes were calculated by the mean difference or standardized mean difference with 95% confidence interval for each study. Heterogeneity was assessed by using the Chi2 test at a significance level of P < 0.1, in addition to the I 2 statistic (I 2 > 50% indicated substantial heterogeneity).
Result: At last, four studies were included from 284 records. In three studies, lean body mass was reported and there was a significant difference between placebo and Anamorelin groups (P < 0.00001), without significant heterogeneity (I 2 = 0%). All the four studies reported the body weight change from baseline, and there was significant difference between placebo and Anamorelin groups (P = 0.007), but with high heterogeneity (I 2 = 97%). Two studies reported Anderson Symptom Assessment Scale (ASAS) score, and Anamorelin significantly increased the total ASAS score of CACS patients (P < 0.00001), without any heterogeneity (I 2 = 0%). Three studies reported non-dominant handgrip strength, and there was no significant difference between Anamorelin and placebo groups (P = 0.16). Three studies reported insulin-like growth factor-1 level, and there was significant difference between Anamorelin and placebo groups (P = 0.02), but with high heterogeneity (I 2 = 96%). Three studies reported IGF binding protein-3 concentration. Anamorelin significantly increased such concentration compared with placebo did (P < 0.00001). However, there was still higher heterogeneity (I 2 = 59%). All the included studies reported adverse events. Compared with placebo, Anamorelin induced fewer adverse events, but there was no significant difference between the two groups (RR = 0.07, P = 0.35).
Conclusion: In the included studies, Anamorelin had some positive effects to relieve the symptoms and improved the quality of life. However, the heterogeneity was apparent, so the clinical effects of Anamorelin should be further validated by increasing the sample size, varying the range of doses during treatment, and observing other outcomes. We are still confident for the future application of Anamorelin in phase III clinical trials.
Keywords: Anamorelin; Cancer anorexia-cachexia syndrome; Ghrelin receptor agonist; Meta-analysis; Randomized controlled trial.