Pfizer and Spark Therapeutics have announced the initiation of a Phase III open-label, multi-center, lead-in study for the evaluation of efficacy and safety of current factor IX prophylaxis replacement therapy for hemophilia B in the usual care setting.
The initiation of this program follows the transfer of responsibility for Spark’s hemophilia B gene therapy program to Pfizer. The efficacy data gathered in the lead in study for factor IX prophylaxis will serve as the within-subject control group for patients enrolling in the next stage of the Phase III study, evaluating the investigational gene therapy fidanacogene elaparvovec (previously known as SPK-9001 and PF-06838435) for hemophilia B.. Patients who have previously completed at least six months in the lead-in study will be enrolled in the interventional portion of the upcoming Phase II program.
Fidanacogene elaparvovec is a novel, investigational vector containing a bio-engineered adeno-associated virus (AAV) capsid and a high-activity human coagulation factor IX gene. Once treated, researchers hope that the patients will be able to produce factor IX themselves, instead of the current common treatment of self-injection of plasma-derived or recombinant factor IX.
In May 2018, Pfizer and Spark released data for 15 patients in the ongoing fidanacogene elaparvovec phase I/II clinical trial for the treatment of severe/moderately severe haemophilia B. This data demonstrated all 15 patients had discontinued routine infusions of factor IX concentrates, and there were no reported serious adverse events or thrombotic events as of the data cut off of May 7th.
“We are pleased to have transitioned fidanacogene elaparvovec to Pfizer following the positive results of the ongoing Phase 1/2 clinical trial,” commented Katherine A. High, MD, President and Head of Research & Development, Spark Therapeutics. “The initiation of the Phase 3 program marks an important milestone toward our goal of one day potentially freeing patients with hemophilia B of the need for regular infusions, while potentially eliminating spontaneous bleeding.”
Source: Pfizer Initiates Pivotal Phase 3 Program for Investigational Hemophilia B Gene Therapy Press Release