Aponermin () is a recombinant circularly permuted human tumour necrosis factor-related apoptosis-inducing ligand (TRAIL) developed by Beijing Sunbio Biotech (a wholly owned subsidiary of Wuhan Hiteck Biological Pharma CO., LTD) for the treatment of multiple myeloma. Aponermin binds to and activates the death receptors 4 and/or 5 on tumour cells, triggering intracellular caspase reactions and inducing apoptosis, thereby exerting antitumor effects. In November 2023, aponermin in combination with thalidomide and dexamethasone received its first approval in China for the treatment of patients with relapsed or refractory multiple myeloma who have received at least two prior therapies. This article summarizes the milestones in the development of aponermin leading to this first approval for relapsed or refractory multiple myeloma.