News
September 12, 2025
Capsida's gene therapy trial paused upon first patient's death
Two months after starting the phase I/II Synrgy trial with its gene therapy, CAP-002, enrolling 12 pediatric patients with rare disease STXBP1 encephalopathy, Capsida Biotherapeutics paused the study following the death of the trial’s first patient.
**Capsida Biotherapeutics Halts Gene Therapy Trial After Patient Death**
Capsida Biotherapeutics has temporarily suspended its Phase I/II clinical trial for CAP-002, a gene therapy designed to treat STXBP1 encephalopathy, following the death of the first patient enrolled in the study. The trial, known as Synrgy, was initiated just two months prior and aimed to assess the safety and efficacy of CAP-002 in twelve pediatric patients suffering from the rare and debilitating genetic disorder.
STXBP1 encephalopathy is a severe neurological condition caused by mutations in the STXBP1 gene, which is crucial for proper brain function. Children with this disease often experience a range of symptoms, including seizures, developmental delays, movement disorders, and intellectual disability. Currently, there is no cure for STXBP1 encephalopathy, and treatment focuses on managing the symptoms.
CAP-002, Capsida’s investigational gene therapy, seeks to address the underlying genetic cause of the disease by delivering a functional copy of the STXBP1 gene to the brain cells. The hope is that this will restore normal brain function and alleviate the symptoms of the disease.
The Synrgy trial was designed as an open-label study, meaning that both the researchers and the participants knew that the patient was receiving the experimental gene therapy. This allows for closer monitoring of the effects of the treatment.
While the company has not released specific details regarding the patient's death, the decision to pause the trial demonstrates a commitment to patient safety. Capsida Biotherapeutics has stated that it is working closely with independent experts and regulatory authorities, including the Food and Drug Administration (FDA), to thoroughly investigate the event and determine the cause of death.
The company plans to analyze all available data from the trial participant to understand whether the death was related to the gene therapy or to the underlying disease. Once the investigation is complete and the cause of death is determined, Capsida will assess the future of the CAP-002 program and determine whether the clinical trial can be safely resumed.
The news is undoubtedly disheartening for families affected by STXBP1 encephalopathy, who are eagerly awaiting potential treatments for this devastating condition. Gene therapy holds significant promise for treating genetic diseases, but the field is still relatively new, and careful research and monitoring are essential to ensure patient safety. The outcome of Capsida’s investigation will be closely watched by the medical
Capsida Biotherapeutics has temporarily suspended its Phase I/II clinical trial for CAP-002, a gene therapy designed to treat STXBP1 encephalopathy, following the death of the first patient enrolled in the study. The trial, known as Synrgy, was initiated just two months prior and aimed to assess the safety and efficacy of CAP-002 in twelve pediatric patients suffering from the rare and debilitating genetic disorder.
STXBP1 encephalopathy is a severe neurological condition caused by mutations in the STXBP1 gene, which is crucial for proper brain function. Children with this disease often experience a range of symptoms, including seizures, developmental delays, movement disorders, and intellectual disability. Currently, there is no cure for STXBP1 encephalopathy, and treatment focuses on managing the symptoms.
CAP-002, Capsida’s investigational gene therapy, seeks to address the underlying genetic cause of the disease by delivering a functional copy of the STXBP1 gene to the brain cells. The hope is that this will restore normal brain function and alleviate the symptoms of the disease.
The Synrgy trial was designed as an open-label study, meaning that both the researchers and the participants knew that the patient was receiving the experimental gene therapy. This allows for closer monitoring of the effects of the treatment.
While the company has not released specific details regarding the patient's death, the decision to pause the trial demonstrates a commitment to patient safety. Capsida Biotherapeutics has stated that it is working closely with independent experts and regulatory authorities, including the Food and Drug Administration (FDA), to thoroughly investigate the event and determine the cause of death.
The company plans to analyze all available data from the trial participant to understand whether the death was related to the gene therapy or to the underlying disease. Once the investigation is complete and the cause of death is determined, Capsida will assess the future of the CAP-002 program and determine whether the clinical trial can be safely resumed.
The news is undoubtedly disheartening for families affected by STXBP1 encephalopathy, who are eagerly awaiting potential treatments for this devastating condition. Gene therapy holds significant promise for treating genetic diseases, but the field is still relatively new, and careful research and monitoring are essential to ensure patient safety. The outcome of Capsida’s investigation will be closely watched by the medical
Category:
Technology