Abstract
BACKGROUND: Anamorelin is expected to improve cancer cachexia by increasing lean body mass (LBM) due to increased appetite and protein synthesis. However, the effect of anamorelin on cancer cachexia in real-world practice is unclear. The purpose of this study was to evaluate the efficacy and safety of anamorelin and to identify predictors of efficacy on treatment with anamorelin. METHODS: We retrospectively analyzed data from patients with cancer cachexia treated with chemotherapy between May 2021 and August 2022. Efficacy of anamorelin was evaluated using LBM, with "12-week sustained effective response" to anamorelin treatment defined as maintenance or an increase in LBM for 12 weeks. We examined factors associated with "12-week sustained effective response" to anamorelin treatment using a multivariable logistic model that included controlling nutritional status (CONUT) score, an objective assessment of nutritional disorders, and the modified Glasgow prognostic score (mGPS), which scores the cachexia status of cancer patients. To assess patient subjective quality of life (QOL) changes related to eating after starting anamorelin treatment, we used a questionnaire (QOL-ACD appetite-related items: Q8, 9, 11). Adverse events were evaluated in accordance with the Common Terminology Criteria for Adverse Events (CTCAE) Version 5.0. RESULTS: On analysis of data from 40 patients, 23 patients showed a 12-week sustained effective response to anamorelin (57.5%). At 12 weeks, LBM significantly increased by 1.63 ± 3.73 kg (mean ± SD). Multivariable logistic analysis revealed that a low CONUT score was significantly associated with "12-week sustained effective response" to anamorelin treatment (adjusted odds ratio: 13.5, 95% confidence intervals: 2.2-84.2, P = 0.004). QOL assessment showed a trend toward increased appetite and enjoyment of meals after anamorelin initiation. Five patients (12.5%) had an increase in HbA1c of more than 1.0% during the 12 weeks after the start of anamorelin. No patient had QT interval prolongation or grade 3 or higher hepatic transaminase elevation. CONCLUSION: Anamorelin may maintain or increase LBM with tolerable safety in patients with cancer cachexia undergoing chemotherapy. A low CONUT score, despite meeting criteria for cancer cachexia, is suggested as a predictor for the efficacy of anamorelin, indicating that patients with a low CONUT score may benefit from early introduction of anamorelin.