Efficacy and Safety of Valoctocogene Roxaparvovec 4 Years After Gene Transfer in GENEr8-1

Highlights From the ISTH 2024 Congress

Efficacy and Safety of Valoctocogene Roxaparvovec 4 Years After Gene Transfer in GENEr8-1

Presenting Author: Johnny Mahlangu, BSc, MBBCh, MMed, FCPath

Leavitt A,¹ Mahlangu J,² Raheja P,³ Symington E,⁴ Quon D,⁵ Giermasz A,⁵ Kenet G,⁶ Lowe G,⁷ Key N,⁸ Millar C,⁹ Pipe S,¹⁰ Madan B,¹¹ Chou S,¹² Klamroth R,¹³ Mason J,¹⁴ Chambost H,¹⁵ Peyvandi F,¹⁶ Yu H,¹⁷ Robinson T,¹⁸ Ozelo M,¹⁹

Adult Hemophilia Treatment Center, University of California San Francisco, California, United States
Department of Molecular Medicine and Haematology, University of the Witwatersrand, National Health Laboratory Service, and Charlotte Maxeke Johannesburg Academic Hospital, South Africa
Barts Health NHS Trust, London, United Kingdom
Cambridge University Hospitals NHS Foundation Trust, Cambridge, United Kingdom
Orthopaedic Hemophilia Treatment Center at Orthopaedic Institute for Children Los Angeles, California, United States
Division of Hematology/Oncology, Hemophilia Treatment Center, University of California Davis, Davis, California
National Hemophilia Center Sheba Medical center, Tel Hashomer & Amalia Biron Research Institute of Thrombosis & Hemostasis, Tel Aviv University, Israel
West Midlands Adult Haemophilia Comprehensive Care Centre, University Hospitals Birmingham NHS Foundation Trust
Division of Hematology, Department of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States
Imperial College Healthcare NHS Trust & Imperial College London, United Kingdom
University of Michigan, Ann Arbor, Michigan, United States
Guy's & St. Thomas' NHS Foundation Trust, Birmingham, United Kingdom
Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan
Vivantes Klinikum, Friedrichshain, Berlin, Germany
Queensland Haemophilia Centre, Cancer Care Services, Royal Brisbane and Women’s Hospital, Herston, Australia
AP-HM, Department of Pediatric Hematology Oncology, Children's Hospital La Timone & Aix Marseille University, INSERM, INRA, C2VN, Marseille, France
Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, Angelo Bianchi Bonomi Hemophilia and Thrombosis Center, Università degli Studi di Milano, Department of Pathophysiology and Transplantation, Milan, Italy
BioMarin Pharmaceutical Inc., San Rafael, California, United States
BioMarin Pharmaceuticals Inc., San Rafael, California, United States
Hemocentro UNICAMP, Department of Internal Medicine, School of Medical Sciences, University of Campinas, Campinas, Brazil

Figure 1: FVIII Activity Between Years 3 and 4

The following graphic shows FVIII activity between years 3 and 4 in patients who received valoctogene roxaparvovec gene transfer therapy. Using a one-stage chromogenic assay, participants maintained FVIII activity in the mild hemophilia range 4 years after receiving gene transfer therapy.

Figure 2: Sustained Reduction in Annualized Bleeding Rate (ABR)

Figure 2: Annualized Bleeding Rate (ABR)

The following figure shows the annualized bleed rates (ABR) of participants 4 years after receiving valoctogene roxaparvovec gene transfer therapy. ABR for treated bleeds decreased > 80% from baseline during the post-prophylaxis period, and 70% of patients did not have treated bleeds in year 4.