We are deeply saddened to learn of the passing of a subject enrolled in Rocket Pharmaceuticals’ Phase 2 clinical trial of RP-A501 to treat Danon disease. On behalf of the California Institute for Regenerative Medicine (CIRM), which is partly funding the clinical trial, I extend our heartfelt condolences to the patient’s family, loved ones, and the dedicated medical team who cared for them during this challenging time. 

Danon disease is a rare and devastating genetic disorder that leads to heart failure and early death for many affected individuals. The subject’s participation in this trial was a courageous step toward advancing potential treatments for this condition. We honor the patient’s bravery and the contribution he made to science and to others living with this devastating disease who may benefit in the future. 

Rocket has informed us that the patient experienced a serious medical complication during the trial. While the condition—known as capillary leak syndrome—is being closely studied, Rocket is actively working to understand exactly what happened and is conducting a comprehensive root cause analysis. The FDA has since placed a clinical hold on the trial to allow for further evaluation. 

To learn more, visit the official announcement on Rocket’s website. 

As patient safety remains CIRM’s highest priority, we are closely monitoring the investigation and will continue to work with Rocket to ensure the highest standards of safety and ethics are upheld in this research. 

CIRM remains committed to supporting innovative research aimed at treating rare and life-threatening diseases. We will continue to prioritize patient safety and transparency as we move forward. 

Jonathan Thomas, PhD, JD
President & CEO
California Institute for Regenerative Medicine (CIRM)