Pfizer starts Phase III study of gene therapy fidanacogene elaparvovec for haemophilia B

Pfizer has initiated a Phase III lead-in study of the investigational gene therapy fidanacogene elaparvovec for the treatment of haemophilia B, the company and partner Spark Therapeutics announced Monday. Brenda Cooperstone, chief development officer of rare diseases for Pfizer Global Product Development, commented "the current data suggest immense promise for the use of this potential one-time treatment option."

The drugmakers stated that the trial was initiated after Spark transferred responsibility of the haemophilia B gene therapy programme to Pfizer. They explained that the lead-in study will assess the efficacy and safety of current factor IX prophylaxis replacement therapy in the usual care setting. Efficacy data obtained in the lead-in study will then "serve as the within-subject control group for those patients that enroll into the next part of the Phase III study, which will evaluate…fidanacogene elaparvovec for the treatment of haemophilia B," the companies said, noting that the interventional portion of the trial will involve patients who have completed at least six months in the lead-in study.

Fidanacogene elaparvovec, which consists of a bio-engineered adeno-associated virus carrying a high-activity human coagulation factor IX gene, is designed to allow patients to produce factor IX themselves, rather than having to regularly inject it, the companies added.

FirstWord Reports: Providing insight, analysis and expert opinion on important Pharma trends and challenging issues <Click here>

Earlier this year, Pfizer and Spark unveiled results from an ongoing Phase I/II study illustrating that fidanacogene elaparvovec, previously known as SPK-9001, had lowered the annualised bleeding rate in 15 patients with severe or moderately severe haemophilia B by 98 percent, to an annual rate of 0.2 bleeds per participant. Results also showed that all patients had discontinued routine infusions of factor IX concentrates, with no serious adverse reactions or thrombotic events as of the data cut-off date.

For related analysis, see ViewPoints: Spark easily holds its haemophilia lead, with competition gathering in the distance.

To read more Top Story articles, click here.