Pfizer initiates Phase III programme for Spark’s haemophilia B gene therapy

Pfizer and Spark Therapeutics have announced that the Phase III programme for the investigational haemophilia B gene therapy is to be initiated by Pfizer.

The Phase III open-label, multicentre, lead-in study will evaluate the efficacy and safety of factor IX prophylaxis replacement therapy in the usual care setting. The results of this lead-in study will serve as the within-subject control group for patients that enrol into the next part of the Phase III study, which will evaluate the investigational gene therapy fidanacogene elaparvovec for the treatment of haemophilia B.

Fidanacogene elaparvovec is a novel, investigational vector that contains a bio-engineered adeno-associated virus (AAV) capsid (protein shell) and a high-activity human coagulation factor IX gene. It is hoped that, once treated, patients will be able to produce factor IX themselves, rather than having to regularly inject factor IX.

“With the lead-in study now open and actively recruiting patients, we are excited to begin our Phase III programme evaluating fidanacogene elaparvovec for the treatment of haemophilia B,” stated Dr Brenda Cooperstone, senior vice president and chief development officer, Rare Disease, PfizerGlobal Product Development. “The current data suggest immense promise for the use of this potential one-time treatment option. We look forward to the opportunity to continue the progress achieved by Spark Therapeutics for patients living with haemophilia B.”

“We are pleased to have transitioned fidanacogene elaparvovec to Pfizer following the positive results of the ongoing Phase I/II clinical trial,” added Dr Katherine A. High, president and head of Research & Development, Spark Therapeutics. “The initiation of the Phase III programme marks an important milestone toward our goal of one day potentially freeing patients with haemophilia B of the need for regular infusions, while potentially eliminating spontaneous bleeding.”

Initiation of this Phase III programme has followed from the transfer of responsibility of Spark Therapeutics’ haemophilia B gene therapy programme to Pfizer.