PB1249 - Prospective, Observational Study of the Clinical Characteristics of Adults and Adolescents With Severe Hemophilia A

Tuesday, June 27, 2023

18:30 – 19:30 ET

Room: Exhibition

Presenting Author(s)

PC

Pratima Chowdary, MD

Consultant Haematologist
Katharine Dormandy Haemophilia and Thrombosis Centre, Royal Free London NHS Foundation Trust, London, United Kingdom
London, England, United Kingdom

Co-Author(s)

LK

Liane Khoo

Director
Haemophilia Treatment Centre, Royal Prince Alfred Hospital, NSW Health Pathology, Sydney, Australia
Sydney, New South Wales, Australia
MW

Michael Wang

Center Co-Director
Hemophilia and Thrombosis Center, University of Colorado Anschutz Medical Campus, Colorado USA
Aurora, Colorado, United States
HC

Hervé Chambost

Professor and Head of the Comprehensive Care Centre for Congenital Bleeding Disorders
AP-HM, Department of Pediatric Hematology Oncology, Children Hospital La Timone & Aix Marseille University, INSERM, INRA, C2VN, Marseille, France
Marseille, Provence-Alpes-Cote d'Azur, France
Anthony KC. Chan, MBBS

Professor
McMaster University, McMaster Children’s Hospital, Hamilton, Canada
Hamilton, Ontario, Canada
AM

Angel Moryusef

Director of Clinical Research
Sanofi, Cambridge, MA, USA
Cambridge, Massachusetts, United States
AW

Annemieke Willemze

Global Project Head, Efanesoctocog alfa (BIVV001), Rare Blood Disorders Development
Sanofi, Amsterdam, Netherlands
Amsterdam, Noord-Holland, Netherlands
Johannes Oldenburg, MD (he/him/his)

Professor, Chairman and Director
University Clinic Bonn AöR, Institute of Experimental Haematology and Transfusion Medicine, Bonn, Germany
Bonn, Nordrhein-Westfalen, Germany

Background: Severe hemophilia A is typically treated with factor VIII (FVIII) prophylaxis or non-factor therapy, with the aim of preventing bleeds and subsequent joint and musculoskeletal disease.

Aims: To collect real-world prospective treatment and outcome data in previously treated patients ≥12 years of age with severe hemophilia A, without a history of inhibitors, treated with marketed FVIII-replacement products.

Methods: In this global, observational study, data were collected from November 2019 for ≤12 months. The primary endpoint was annualized bleed rates (ABRs; spontaneous and traumatic). Additional endpoints included factor use, bleed treatment, hemophilia joint health score (HJHS), safety, Haemophilia Quality of Life Questionnaire (Haem-A-QoL), and Patient-Reported Outcomes Measurement Information System (PROMIS) Pain Intensity. A subset of participants in this study were included in the Phase 3 XTEND-1 trial of efanesoctocog alfa (NCT04161495).

Results: One hundred fifty-seven patients received ≥1 FVIII injection during the study (prophylaxis n=139, on-demand n=19, both n=1). Table 1 lists patient demographics and hemophilia-related medical history. Mean (standard deviation [SD]) duration of the observational period was 42.3 (14.1) and 46.7 (8.4) weeks for patients on prophylaxis and on-demand, respectively. Mean (SD) number of routine prophylaxis injections/week was 2.2 (1.07).

Median (quarter [Q]1, Q3) ABRs for patients on prophylaxis and on-demand, respectively: overall, 2.0 (0.0, 5.7) and 29.1 (8.4, 40.0); spontaneous, 0.0 (0.0, 3.0) and 14.7 (7.7, 30.1); traumatic, 1.0 (0.0, 2.1) and 4.8 (0.0, 8.7). HJHS and QoL outcomes are shown in Table 2.

Five patients experienced ≥1 serious treatment-emergent adverse event; one was fatal (post-procedural hemorrhage). No adverse events were related to FVIII-replacement therapy as assessed by the investigator.

Conclusion(s): Despite receiving prophylaxis with currently marketed FVIII-replacement therapies, patients in this real-world study demonstrated suboptimal control of bleeds and no improvements in health-related QoL and pain outcomes over time, suggesting the need for treatment optimization.

Funded by Sanofi and Sobi.