Anamorelin, a highly selective ghrelin receptor agonist, enhances appetite and increases lean body mass in patients with cancer cachexia. However, the predictors of its therapeutic effectiveness are uncertain. This study aimed to investigate the association between the Glasgow prognostic score (GPS), used for classifying the severity of cancer cachexia, the therapeutic effectiveness of anamorelin, and the feasibility of early treatment based on cancer types. A retrospective analysis included patients with gastric, pancreatic, colorectal, and non-small-cell lung cancer treated with anamorelin between May 2021 and July 2022. The endpoints were the response rate for increased appetite within 3 weeks of treatment initiation and the time to treatment failure (TTF) due to therapeutic failure of anamorelin. Multivariate logistic regression model and Fine and Gray’s model were used for analysis. Of the 137 patients in this analysis, 51% of patients had a GPS of 0 or 1, and 49% of those had a GPS of 2. Patients with a GPS of 2 showed a lower response for increased appetite than those with a GPS of 0 or 1 (adjusted odds ratio 0.29 [95% CI 0.12–0.72], P = 0.007). Additionally, TTF was shorter in patients with a GPS of 2 with a GPS of 0 or 1 (adjusted subdistribution hazard ratio 2.22 [95% CI 1.22–4.03], P = 0.009). Anamorelin could be more effective in improving appetite and prolonging the duration of treatment effect in patients with a GPS of 0 or 1 than those with a GPS of 2.
