We are developing novel analgesics to relieve intractable pain for cancer patients. We are also working on drug repositioning study to expand the indications of present drugs. Treatment with anticancer drugs frequently causes oral stomatitis with severe pain in cancer patients. Patients can eat and get adequate nutrition energy if the pain is relieved when eating. For cancer patients, orally taking nutrients is essential for maintaining and improving activities of daily living and quality of life. Lidocaine, a local anesthetic that inhibits all sensory neuronal activities, has been used as a pain-killer. However, lidocaine causes impaired taste and texture to the patients. 
We discovered a novel analgesic Compound X based on the voice of cancer patients. With support from Japan Agency for Medical Research and Development (AMED), we developed Compound X as a novel drug for stomatitis having a long-lasting pain-relieving effect without changing texture and taste. 
On the other hand, there are patients who need urgent supportive palliative care, and such patients cannot wait for future novel drugs. In this regard, we focused on the Japanese herbal medicine hangeshashinto to relieve pain and cure oral stomatitis. We proved hangeshashinto accelerates healing of stomatitis with a pain-killer activity.