The Optimal Timing for Initiating Anamorelin in the Treatment of Cancer Cachexia

Objective In 2021, anamorelin, an orally active ghrelin receptor selective antagonist, was approved for the treatment of cachexia in patients with non-small cell lung cancer, gastric cancer, pancreatic cancer, and colon cancer. Cancer cachexia is classified into three stages: pre-cachexia, cachexia, and refractory cachexia, with the pre-cachexia and cachexia stages considered reversible with a combination of nutritional therapy, pharmacotherapy, and exercise therapy. In addition, treatment of cachexia requires early intervention, but diagnosis and early detection of cachexia are difficult. We hypothesized that the initiation of anamorelin treatment may be delayed in clinical practice and explored the appropriate timing of treatment initiation. Methods The data of patients with cachexia who received anamorelin at our hospital from June 2021 to July 2023 were retrospectively reviewed. Anamorelin was administered to 201 patients, of whom 134 were included in the study. Survival time and duration of medication were compared based on the number of objective criteria for anamorelin prescription (C-reactive protein [CRP] >0.5 mg/dL, hemoglobin <12 g/dL, albumin <3.2 g/dL). Multivariate analysis was used to determine the factors associated with continuation of anamorelin treatment for 12 weeks. Results Patients with a higher number of objective criteria for anamorelin prescription (CRP >0.5 mg/dL, hemoglobin <12 g/dL, albumin <3.2 g/dL) had shorter anamorelin treatment duration and survival. In multivariate analysis, 12 weeks of anamorelin treatment was associated with CRP. Comparing CRP ≤0.5 mg/dL vs. CRP >0.5 mg/dL, survival was significantly longer for CRP ≤0.5 mg/dL (p < 0.01). Conclusions Initiating anamorelin treatment with close attention to CRP and ensuring that prescribing criteria are met may be helpful in treating cachexia.