To the STXBP1 Community:
The team at Capsida is very aware that the STXBP1 community is anxious to learn more about the unexpected and devastating loss of the first patient dosed in our SYNRGY trial for STXBP1 Related DEE.
Although our investigation is not complete, we wanted to provide you with an update about our ongoing work to understand what happened in the study, which is currently on clinical hold. We have been carefully examining all available information and, while we have not yet identified a root cause, we continue to investigate this unexpected and tragic event.
Here is what we know so far:
- We have reviewed all available medical records with the investigator and safety committee. We have concluded that the trial was conducted in-line with the protocol and there is no evidence of any clinical trial error
- We have reviewed all records related to the manufacturing, handling and dosing of the product and have concluded that the materials were appropriately manufactured, handled and dosed.
- We recently received a report of the autopsy and submitted a copy of the report to the FDA. The autopsy confirms that the cause of death was cerebral edema, but did not conclusively establish the underlying cause of the cerebral edema. Cerebral edema was an unexpected outcome that was not observed in this program’s safety studies that supported the trial.
We have requested access to patient tissue samples that we understand were collected during the autopsy by the site. If we receive these samples, we will be able to perform or assist in performing additional evaluations to help identify the root cause of the cerebral edema, including the distribution and presence of the drug product in the patient.
Meanwhile, our work towards understanding the cause of this event continues, and will include appropriate consultation with the relevant experts and agencies, as well as additional preclinical studies.
We recognize that this update will not answer all the outstanding questions. Our team is working with urgency to gather additional information and find more clarifying answers to identify the root cause. We strongly believe in the power of gene therapy to positively transform the lives of patients, and we will continue to work closely with our partners, other industry leaders, relevant experts and the FDA and will continue to provide updates to this community as we have information to share.
Sincerely,
The entire Capsida Biotherapeutics team