Rocket Pharmaceuticals announces serious adverse event in RP-A501 trial

Rocket Pharmaceuticals (RCKT) announced an update related to RP-A501, its investigational gene therapy for Danon disease. A patient participating in the Phase 2 pivotal trial of RP-A501 experienced an unexpected serious adverse event. The SAE involved clinical complications related to a capillary leak syndrome. Rocket is conducting a comprehensive root cause analysis and remains in active dialogue with the FDA and other key stakeholders, with the current focus being on the recent introduction of a novel immune suppression agent to the pre-treatment regimen that had been implemented to mitigate complement activation observed in some patients. This novel agent was specific to the AAV9-Danon program. Upon learning of the initial event, Rocket voluntarily paused further dosing in the study. On May 23, the FDA placed a clinical hold on the trial to allow for further evaluation. Rocket reported that this patient has since passed away after an acute systemic infection. Rocket is working with the FDA, the Independent Data Safety Monitoring Committee, clinical investigators, and scientific experts, and is committed to ensuring the safety of all study patients while resuming the trial as expeditiously as possible. While the clinical hold remains in place, the company is unable to provide guidance on the anticipated timing for completion of the Phase 2 trial.