Anamorelin in the Management of Cancer Cachexia: Clinical Efficacy, Challenges, and Future Directions

Cancer cachexia, a systemic multifactorial syndrome that affects survival prognosis, occurs in 80% of patients with advanced cancer. Patients with cancer cachexia experience progressive functional disability and persistent loss of skeletal muscle mass associated with reduced quality of life. Cancer cachexia requires multidisciplinary early intervention, including drugs, exercise, nutrition, and psychotherapy. Anamorelin is an oral drug with ghrelin-like effects, including significant appetite stimulation, increase in food intake and weight, and stimulation of growth hormone secretion. This review provides an overview of basic drug information and clinical trial data on anamorelin, focusing on its role in the treatment of cancer cachexia, with the aim of achieving more effective anamorelin administration. In several randomized, double-blind, placebo-controlled clinical trials, anamorelin significantly improved lean body mass and appetite in patients with cancer cachexia. However, no improvement was observed in motor function (handgrip strength and 6-minute walk test). Clinical trials of anamorelin have shown approximately consistent trends in efficacy, but decisions on whether or not to approve anamorelin vary internationally. The treatment of cancer cachexia, including with anamorelin, requires consideration of the selection of target patients, burden of treatment on patients, and assessment tools used by healthcare providers that may affect treatment outcomes. Based on several retrospective datasets, the initiation of anamorelin at earlier stages of cancer cachexia, combined with nutritional and exercise therapy, should be considered. However, current evidence is insufficient, and results of future studies are awaited.