PackGene Biotech Empowers Gene Therapy, Opening a New Chapter of Life for Children with Rett Syndrome

On February 14, 2025, in the research ward of the Zengcheng Campus of Guangzhou Women and Children’s Medical Center, the father of Xixi, a child with Rett syndrome (RTT) from Shanxi Province, was filled with relief. Over the past few years, Xixi had suffered greatly from the disease. Today, however, encouraging changes have emerged—she is now able to actively express her needs by crying. Behind this progress are the positive results from the first investigator-initiated clinical study of RTT gene therapy in Central and South China, jointly conducted by the team of Professor Zhou Wenhao, President of Guangzhou Women and Children’s Medical Center, and the team of Professor Qiu Zilong from the Songjiang Institute of Shanghai Jiao Tong University School of Medicine. PackGene Biotech is honored to have supported the IIT project from R&D through clinical translation.

Gene Therapy Brings New Hope to Children with RTT

Xixi is six years old this year. Her parents recalled that at around one year of age, she was still able to say simple words such as “Dad” and “Mom.” In 2021, Xixi began to show obvious signs of regression: frequent hand-wringing, teeth grinding, and the gradual loss of her previously acquired abilities to walk and speak. Her parents took her to multiple hospitals over the course of two years, and she was eventually diagnosed with RTT through genetic testing at a hospital in Beijing.

RTT is an ultra-rare disease with an incidence of only 1 in 10,000 to 1 in 15,000, and was once regarded as an “incurable disease.” The condition primarily affects females. In the early stage of onset, patients may present with intellectual regression, loss of language and motor abilities, and stereotypic hand movements, severely affecting normal development and growth. Since the first confirmed RTT case in China in 1988, patients have long faced a situation in which no effective treatment was available. Conventional rehabilitation training has limited efficacy, and although drugs have been approved overseas, they are expensive and difficult for patients in China to access.

Facing such a difficult reality, Xixi’s parents spent nearly two years after her diagnosis seeking experts and traveling from place to place, hoping to find a chance of survival for their daughter. In 2024, they finally saw hope—on February 14, 2024, Xixi became the first child in Central and South China to receive gene therapy for RTT.

After one month of follow-up, Xixi showed significant improvements in motor ability, feeding ability, and the ability to actively express her needs. The gene therapy clinical study uses nearly 20 years of scientific research accumulated by Professor Qiu Zilong’s team at the Songjiang Institute of Shanghai Jiao Tong University School of Medicine. The therapy adopts a self-developed adeno-associated virus (AAV) vector carrying a normal MECP2 gene, which is precisely delivered into the patient’s brain through a single intrathecal injection.

Leveraging its professional capabilities and extensive project experience in the field of gene therapy, PackGene Biotech provided high-quality AAV vector services for this study, supporting the smooth advancement of the gene therapy program. Figuratively speaking, the AAV vector acts like a fire truck that can quickly reach the “accident site.” The drug enters the cerebrospinal fluid directly through the intrathecal spinal route and, after “traveling” to the brain, precisely delivers the normal MECP2 gene to damaged neurons. By supplementing the missing or abnormal gene and repairing neuronal function, the therapy helps alleviate symptoms of neurodevelopmental disorders in affected children.

This Research-Oriented Clinical Trial Will Enroll Six Children

“With a single injection, the therapy may provide long-term benefits, greatly reducing the economic and treatment burden on patients’ families,” said Professor Qiu Zilong. In previous animal studies, the MECP2 gene therapy drug RETT-001 demonstrated efficacy and safety superior to comparable products in China and abroad, with significantly prolonged animal survival and marked improvement in motor function.

This research-oriented clinical trial plans to enroll six children with RTT aged 4 to 10 years. Guangzhou Women and Children’s Medical Center has established a research ward integrating ethics review, risk monitoring, and standardized operating procedures. Through close multidisciplinary collaboration among intensive care, pediatrics, neurology, and other departments, the center provides comprehensive real-time monitoring to ensure the safety and standardization of treatment.

Professor Zhou Wenhao stated that the research team will continue to track Xixi’s changes in language, cognition, behavior, and other aspects, while also conducting multiple assessments such as electroencephalography and immune indicators. At the same time, the team plans to expand the scale of the clinical trial, striving to establish a more mature and accessible treatment approach as soon as possible, so that more children with RTT can benefit.

As a CRO & CTDMO deeply engaged in the CGT delivery field for more than a decade, PackGene Biotech is honored to witness more and more patient families regaining hope for life through the joint efforts and collaboration of multiple parties. Looking ahead, PackGene Biotech will continue to deepen its presence in the CGT delivery field, continuously improve its technical capabilities and service quality, and provide strong support for more gene therapy studies, fulfilling its mission of “making gene therapy affordable and accessible to the public.”