Research Studies

As technology advances and provides electronic tools for enhancing communication by phone and computer, health care providers are finding ways to adapt these tools into patient care. Telehealth is the use of electronic information and telecommunications technologies to support long-distance clinical health care. For patients with hemophilia who experience a bleed in the home setting, telehealth has the potential to help the patient, family, and health care provider assess what is going on and develop the best plan of care, all while the patient stays in the home setting. In this clinical project, we will use the telehealth resources available at our institution to partner with patients and families with severe hemophilia with a high risk of bleeding episode who also have a home computer with a camera and internet access. We want to find out more about how many patients have these home resources, how to use video-conferencing when managing a bleed and what patients, families, and health care staff think about using video conferencing. This will help us plan future research using telehealth video-conferencing for a larger group of hemophilia patients.

Objective:

Safety and efficacy of long-lasting recombinant factor IX Fc fusion protein (rFIXFc), currently being developed to provide extended protection from bleeding in hemophilia B patients, were demonstrated in the phase 3 B-LONG study, where a half-life of 82 hours was observed. Here we describe how patients in B-LONG who were on prophylaxis with FIX prior to study entry were treated with rFIXFc and their clinical outcomes during B- LONG.

Methods:

Patients who were on prophylaxis with FIX prior to study entry were identified. Patients’ self-reported FIX dosing regimen and bleeding rates pre-study were compared to their rFIXFc dosing regimen and annualized bleeding rates on study. All patients were monitored for safety, including inhibitor formation.

Summary:

Of 123 patients enrolled, 48 received prophylaxis with FIX pre-study: 33 in Arm 1 (weekly prophylaxis: rFIXFc 50 IU/kg once weekly, dose adjusted based on FIX activity); 15 in Arm 2 (individualized dosing interval: rFIXFc 100 IU/kg every 10 days, interval adjusted based on FIX activity). The most common pre-study dosing intervals were twice weekly (67%), thrice weekly (18%), and once weekly (13%). The 21 patients in Arm 1 reporting twice weekly dosing pre-study had a median pre-study dose of 36.4 IU/kg per injection (total weekly dose: 72.7 IU/kg); in their last 3 months on-study, these patients received a median dose of 36.4 IU/kg rFIXFc once weekly. The 9 patients in Arm 2 reporting twice-weekly dosing pre-study had a median pre-study dose of 37.9 IU/kg per injection (total weekly dose: 75.9 IU/kg); in their last 3 months on-study, these patients received a median dose of 103 IU/kg rFIXFc at a median interval of once every 13.5 days. Overall, Arm 1 patients on prophylaxis pre-study reported a bleeding rate of 2.5 in the 12 months prior to study entry; on-study, they had an annualized bleeding rate of 2.1. Arm 2 patients on prophylaxis pre-study reported a bleeding rate of 2.0 in the 12 months prior to study entry; on-study they had an annualized bleeding rate of 0.0. Based on population pharmacokinetic modelling, approximately 95% of people with hemophilia B receiving 50 IU/kg rFIXFc once weekly were predicted to maintain FIX trough levels above 1% at all times. In the B-LONG study, rFIXFc was well tolerated and no inhibitor development was detected.

Conclusions:

Prophylaxis with rFIXFc may provide patients who are currently on prophylaxis the option for dosing every 1-2 weeks with low bleeding rates.