Pfizer to resume Duchenne gene therapy trials

April 29, 2022

Pfizer is set to resume its late-stage clinical trial CIFFREO, evaluating a treatment for Duchenne muscular dystrophy in ambulatory patients after stopping in December because of a clinical hold.

The U.S. FDA originally paused all studies after the death of a patient in the non-ambulatory cohort of the phase 1b study. The patient’s death in the phase 1b study was ultimately linked to a more advanced disease with an underlying cardiac dysfunction, said Pfizer. 

CIFFREO is a global study investigating the use of fordadistrogene movaparvovec, a gene therapy treatment, in ambulatory patients with DMD. DMD is a genetic disorder that causes progressive muscle degeneration. As of right now, there is no treatment for the disease. 

Following the patient's death in the Phase 1b study, CIFFREO was paused in all 11 countries. The pause led to a protocol amendment for Pfizer. Patients in the study will now be closely monitored with a seven-day hospitalization stay after they are dosed. Now, the company is set to resume in the United Kingdom, Canada, Taiwan, Spain and Belgium. The pharma giant expects to have all sites back up and running by the end of June. 

The pharma titan has not said if it will restart the treatment for non-ambulatory DMD patients. Pfizer said it will continue working with expert advisors before moving forward.