Patient-Reported Outcomes in Hemophilia B Patients Treated with IB1001 [Coagulation Factor IX (recombinant)]

INTRODUCTION. Hemophilia B is a rare bleeding disorder caused by missing or defective factor IX, a clotting protein in the coagulation cascade. Patients with hemophilia B are treated with infusion of concentrated factor IX to replace the deficiency. As a chronic disease, patient quality of life and treatment satisfaction is a fundamental component of overall patient care in hemophilia B. Anecdotal evidence has suggested that some patients experience improved clinical outcomes and increased satisfaction when treated with IB1001, approved in the US as IXINITY^®, [coagulation factor IX (recombinant)] (current factor treatment) as compared to their previous treatment. The objective of this study was to undertake a systematic assessment of IB1001 patient responses to measures of clinical care and quality of life that are relevant in hemophilia B in order to provide a more comprehensive description. METHODS. This was a cross-sectional study of hemophilia B patients in the United States currently being treated with IB1001. The study protocol was reviewed and approved by a central IRB. A survey was developed to capture patient-reported responses to clinical and quality of life questions of interest, including demographic characteristics, disease status, bleeding events, treatment, quality of life, and patient satisfaction. Where possible, patients were asked to compare responses on current factor treatment to those while on previous treatment with other available products. Patients were invited to complete the survey online. This was a pilot study to generate a descriptive analysis of patient experience. RESULTS. A total of 17 patients completed the survey. Most patients were male (76.5%) with a mean age of 43.8 years (range 16-73), and had been taking IB1001 for a mean 18 months at the time of this study. The elements most important for patient treatment choice were a high recovery rate, 24-hour half-life, no inhibitor development, and few side effects. Fewer annualized bleeding events were reported with the current factor treatment (mean 3.3 vs 6.7). Joint bleeds were most commonly reported, and most patients stated their bleed frequency was less (41%) or about the same (35%) on their current factor treatment compared to their previous treatment. Most patients reported their activity level as either 'very active' (23%), or 'somewhat active' (53%), and 47% of patients indicated they are more active now than on prior treatment. Overall, patients were either 'very satisfied' (76%) or 'somewhat satisfied' (12%) with their current factor treatment, compared with 12% and 23%, respectively, on prior treatment. Patients reported more mobility (29%), less pain (41%), and less anxiety or depression (18%) now than on prior treatment. CONCLUSIONS. In this study, we showed the utility of an online, survey-based instrument in characterizing patient experience with factor replacement products in hemophilia B. This study quantified the details of the patient experience that may have been driving the anecdotes of improved patient satisfaction and quality of life with IB1001. Overall, patients reported increased satisfaction, and improved clinical outcomes on their current factor treatment compared to products they had used in the past. While the data from this pilot study are encouraging, further study is warranted such as linking patient-reported outcomes to medical chart data to validate the clinical response and to better understand the variables that most influence patient satisfaction and quality of life.