Real World Study of Oxycodone/Naloxone Sustained-Release Tablets (Mimeixin) for Patients With Severe Cancer Pain

Cancer remains a significant health concern globally, with rising incidence and mortality rates. In 2022, there were 19.96 million new cancer cases and 9.74 million cancer deaths worldwide, including 4.8 million new cases and 2.6 million deaths in China. Cancer patients often experience pain during treatment, with 40% of patients reporting persistent pain, particularly moderate to severe pain, occurring in 40%-80% of cases. Unrelieved pain can exacerbate symptoms such as anxiety, depression, fatigue, insomnia, and loss of appetite, significantly impacting patients' quality of life. Opioids, represented by morphine and oxycodone, are widely used for the treatment of moderate to severe cancer pain. Long-term opioid use often leads to gastrointestinal adverse events, with opioid-induced constipation (OIC) being the most common, significantly affecting patients' quality of life and treatment compliance. Although some guidelines recommend laxatives as prophylactic and first-line treatment for OIC, approximately half of the patients do not experience adequate symptom improvement. The mechanism of OIC primarily involves the activation of intestinal μ-opioid receptors, which is difficult to address solely with laxatives. The key to treating OIC lies in blocking the stimulation of μ-opioid receptors in the gastrointestinal tract while maintaining the analgesic effect of opioid receptors in the central nervous system. Oxycodone/naloxone sustained-release tablets, a combination of the opioid receptor agonist oxycodone and the antagonist naloxone, effectively provide analgesia while improving OIC. Foreign studies have demonstrated that this medication significantly improves OIC while maintaining good analgesic effects, with good long-term tolerability. Mimeixin® is an oxycodone/naloxone sustained-release tablet developed with reference to the foreign-listed drug Targin®. It was approved by the National Medical Products Administration of China in June 2024 for the treatment of severe pain in adults that requires opioid analgesics for adequate control. However, clinical validation has not been conducted among Chinese cancer pain patients. Therefore, a prospective, single-arm, multicenter, real-world study is planned to evaluate the effect in bowel function, analgesic effect, quality of life, and safety of Mimeixin® in Chinese patients with severe cancer pain in real-world clinical practice.