Gastrointestinal Mucositis

This study aims to see if a single intravenous infusion of a cell therapy called Amimestrocel injection can help prevent severe mouth sores (oral mucositis) in patients receiving a stem cell transplant. Patients getting a stem cell transplant often receive strong chemotherapy (with radiation and/or a drug called melphalan) that can cause painful mouth and gut sores, making eating difficult and increasing infection risk. Amimestrocel injection is made from human umbilical cord cells that may help reduce inflammation and promote healing. About 22 adult patients scheduled for this type of transplant at one hospital in China will receive the infusion 1-2 days before their stem cell transplant. Researchers will closely check for mouth sores, pain, and side effects for the first 28 days, and continue safety monitoring for 100 days. The main goal is to see if the treatment lowers the rate of severe (Grade 3-4) mouth sores. The study will also track pain levels, need for pain medication, diarrhea, time for blood counts to recover, and overall safety.