Regeneron Pharmaceuticals has released preliminary data from the first two patients treated with the investigational gene therapy DB-OTO. At the American Society for Gene and Cell Therapy (ASGCT) annual meeting in May, the company disclosed that, during the CHORD clinical trial, designed to evaluate safety and tolerability, the gene therapy improved hearing in two children with profound genetic deafness due to a mutation in the otoferlin gene. In one child, first dosed at age 11 months, DB-OTO improved hearing to normal levels within 24 weeks. The second child, age 4, saw initial hearing improvements after 6 weeks. The trial is still recruiting children from the United Kingdom, Spain and the United States with otoferlin-related deafness.

The new drug, DB-OTO, is designed to treat children whose hearing loss is caused by mutations in the OTOF gene, which encodes the otoferlin involved in synaptic vesicle fusion in the inner ear. Lack of a functional OTOF gene can cause congenital deafness by interfering with sound transmission from sensory cells in the inner ear to the auditory nerve. The gene therapy delivers a working copy of the otoferlin gene using a neutralized adeno-associated virus that is injected into the inner ear under general anesthesia, in a procedure similar to the one used for cochlear implantation.

Regeneron Pharmaceuticals 发布了首批两名接受研究性基因疗法 DB-OTO 治疗的患者的初步数据。在5月的美国基因与细胞治疗学会（ASGCT）年会上，该公司披露，在旨在评估安全性和耐受性的CHORD临床试验中，基因疗法改善了两名患有严重遗传性耳聋的儿童的听力。 otoferlin 基因突变。一名儿童在 11 个月大时首次接受给药，DB-OTO 在 24 周内将听力提高到正常水平。第二个孩子 4 岁，六周后听力有了初步改善。该试验仍在招募来自英国、西班牙和美国的患有奥托弗林相关耳聋的儿童。

这种新药 DB-OTO 旨在治疗因 OTOF 基因突变引起的听力损失儿童，该基因编码参与内耳突触小泡融合的 otoferlin。缺乏功能性 OTOF 基因会干扰从内耳感觉细胞到听神经的声音传输，从而导致先天性耳聋。基因疗法使用中和的腺相关病毒传递耳铁素基因的工作副本，在全身麻醉下将其注射到内耳，过程类似于人工耳蜗植入。