Study on the Safety and Efficacy of Intratympanic Injection of Small Extracellular Vesicles Derived From Mesenchymal Stem Cells in Severe and Profound Sudden Sensorineural Hearing Loss

The goal of this clinical trial is to learn if small extracellular vesicles derived from mesenchymal stem cells work to treat severe and above sudden sensorineural hearing loss. It will also learn about the safety of small extracellular vesicles. The main questions it aims to answer are: 1. Does small extracellular vesicles combined with traditional drug treatment improve hearing even better in severe and above sudden deafness participants? 2. What medical problems do participants have with intratympanic injection of small extracellular vesicles? Researchers will compare small extracellular vesicles to dexamethasone to see if small extracellular vesicles work to treat severe and above sudden sensorineural hearing loss. In clinical Phase I trial, the investigators will complete the safety check and dose exploration. Participants will: 1. Receive traditional drug treatment in accordance with the "Guidelines for the Diagnosis and Treatment of Sudden Deafness (2015) 2. Receive small extracellular vesicles or a placebo tympanic injection additionally 3. Visit the clinic once every 2 weeks for checkups and tests 4. Receive tympanic injections of small extracellular vesicles ranging from low concentration to high concentration 5. Be evaluated for any adverse reactions In clinical Phase II trial, participants were randomly divided into a control group and an experimental group. Participants will: 6. Received intratympanic injections of small extracellular vesicles 3 times together with traditional drug treatment in experimental group 7. Received intratympanic injections of 5mg dexamethasone 3 times together with traditional drug treatment in control group, also for a total of 3 times Visit the clinic once 7 days , 1month and 3 months after treatment for checkups and tests of pure tone audiometry, speech audiometry, tinnitus disability scale and visual analogue scale assessment

NCT Number	NCT07404709
Lead Sponsor	The Affiliated Hospital of Qingdao University
Conditions	Sudden Hearing Loss, Extracellular Vesicles
Enrollment	9 participants
Start Date	2026-02-28
Primary Completion	2027-12-31 (estimated)
Study Completion	2028-12-31 (estimated)
Updated on ClinicalTrials.gov	2026-03-25