Pfizer pauses phase 3 CIFFREO crossover trial for DMD
After a patient death in the phase 2 DAYLIGHT study, Pfizer has decided to pause the phase 3 CIFFREO crossover trial for DMD.
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- On May 7, 2024, Pfizer published a letter announcing its plans to discontinue the CIFFREO trial, a phase 3 placebo-controlled crossover trial for Duchenne muscular dystrophy (DMD). According to the letter, a patient participating in the phase 2 sister study, DAYLIGHT for DMD, has passed away. While the company maintains that the cause of death has not been identified, it is pausing the other study out of caution.
Based on the trial submission information to clinicaltrials.gov, the DAYLIGHT study is a phase 2 clinical trial assessing fordadistrogene movaparvovec gene therapy to treat DMD. DAYLIGHT recruited 10 male DMD patients between two and four years old.
Fordadistrogene movaparvovec gene therapy is an adeno-associated virus serotype 9 (AAV) capsid that carries and delivers a modified version of the human dystrophin gene, absent in DMD patients. With the control of the human muscle-specific promoter, researchers hope that patients treated with this gene therapy can produce dystrophin proteins to keep muscles intact.
According to reports from Endpoints News, the trial participant in the DAYLIGHT trial died of cardiac arrest on May 3, 2024.
“We do not yet have complete information and are actively working with the trial site investigator to understand what happened. The patient received the investigational gene therapy, fordadistrogene movaparvovec, in early 2023,” Pfizer stated in its public letter.
Out of caution, the company has decided to discontinue dosing in its phase 3 CIFFREO trial. The CIFFREO trial also recruits patients with DMD for treatment with fordadistrogene movaparvovec gene therapy. However, CIFFREO is focused on treating boys with DMD between four and eight years old.
“We have decided to pause dosing associated with the crossover portion of CIFFREO, and we are working with regulators and the independent external Data Monitoring Committee as we learn more about this event. Other than this pause in dosing, trial activities are continuing as scheduled,” the company added.
Since this trial is in the middle of dosing, Pfizer notes that it will pause dosing in this study; however, other studies have already completed dosing and will not be paused.
