Final results of the PUPs B-LONG study: Evaluating safety and efficacy of rFIXFc in previously untreated patients with hemophilia B

Beatrice Nolan, Anna Klukowska, Amy Shapiro, Antoine Rauch, Michael Recht, Margaret Ragni, Julie Curtin, Sriya Gunawardena, Sutirtha Mukhopadhyay, Deepthi Jayawardene, Bent Winding, Kathelijn Fischer, Raina Liesner

Research output: Contribution to journalArticlepeer-review

Abstract

PUPs B-LONG evaluated the safety and efficacy of recombinant factor IX Fc fusion protein (rFIXFc) in previously untreated patients (PUPs) with hemophilia B. In this openlabel, phase 3 study, male PUPs (age ,18 years) with hemophilia B (≤2 IU/dL of endogenous factor IX [FIX]) were to receive treatment with rFIXFc. Primary end point was occurrence of inhibitor development, with a secondary end point of annualized bleed rate (ABR). Of 33 patients who received ≥1 dose of rFIXFc, 26 (79%) were age ,1 year at study entry and 6 (18%) had a family history of inhibitors. Twenty-eight patients (85%) received prophylaxis; median dosing interval was 7 days, with an average weekly dose of 58 IU/kg. Twenty-seven patients (82%) completed the study. Twenty-one (64%), 26 (79%), and 28 patients (85%) had ≥50, ≥20, and ≥10 exposure days (EDs) to rFIXFc, respectively. One patient (3.03%; 95% confidence interval, 0.08% to 15.76%) developed a low-titer inhibitor after 11 EDs; no high-titer inhibitors were detected. Twenty-three patients (70%) had 58 treatment-emergent serious adverse events; 2 were assessed as related (FIX inhibition and hypersensitivity in 1 patient, resulting in withdrawal). Median ABR was 1.24 (interquartile range, 0.00-2.49) for patients receiving prophylaxis. Most (.85%) bleeding episodes required only 1 infusion for bleed resolution. In this first study reporting results with rFIXFc in pediatric PUPs with hemophilia B, rFIXFc was well tolerated, with the adverse event profile as expected in a pediatric hemophilia population. rFIXFc was effective, both as prophylaxis and in the treatment of bleeding episodes.

Original languageEnglish (US)
Pages (from-to)2732-2739
Number of pages8
JournalBlood Advances
Volume5
Issue number13
DOIs
StatePublished - Jul 13 2021

ASJC Scopus subject areas

  • Hematology

Fingerprint

Dive into the research topics of 'Final results of the PUPs B-LONG study: Evaluating safety and efficacy of rFIXFc in previously untreated patients with hemophilia B'. Together they form a unique fingerprint.

Cite this