Impact of the Timing of Initial Anamorelin Administration in Advanced Gastrointestinal Cancer With Cancer Cachexia

Cachexia is a multifactorial syndrome that adversely affects the prognosis of patients with gastrointestinal cancer. Although anamorelin has been shown to improve appetite and body weight, the optimal timing of its initiation remains unclear. This study evaluated the effects of the timing of anamorelin initiation on nutritional recovery and clinical outcomes in patients with gastrointestinal cancer cachexia.

We retrospectively reviewed 42 patients with gastric (n=17) or colorectal cancer (n=25) complicated by cachexia who received 100 mg of anamorelin once daily between August 2021 and December 2024. Changes in body weight, food intake, and nutritional status were assessed before and after anamorelin administration, and overall survival was analyzed according to the type of cancer.

Initially, patients had experienced a mean body weight loss of 15.9±1.7% relative to the pre-diagnosis baseline. After four weeks, mean body weight increased by 2.9% (p<0.001), food intake improved significantly from 30.5%±0.3% to 57.1%±0.5% (p<0.001), and the Patient-Generated Subjective Global Assessment short form (PG-SGA SF) score decreased from 12.3±0.4 to 10.3±0.9 (p=0.003). The median overall survival was 17.9 months for gastric cancer and 36.8 months for colorectal cancer, with no significant difference between the two groups (p=0.089).

Anamorelin improved body weight, food intake, and nutritional status in patients with advanced gastrointestinal cancer cachexia. However, the modest degree of recovery suggests that earlier administration, before substantial weight and muscle loss, may maximize therapeutic benefits, support treatment continuity, and potentially improve survival outcomes. Therefore, early intervention should be considered in the clinical management of cancer cachexia.