{ "abstract": "The Efanesoctocog Compassionate Hemophilia study (Méthodologie de Référence-004, number DEC24-269) provides a real-world evaluation of efanesoctocog alfa (efa), a first-in-class ultralong-acting factor VIII (FVIII) concentrate, within the French compassionate access authorization (CAA) framework. It aims to characterize the unmet medical needs leading to CAA requests and evaluate the hemostatic efficacy and biological monitoring of efa prophylaxis. This multicenter study included 50 patients with hemophilia A (84% severe; median age, 31 years), including 9 with inhibitor history. Although 54% of patients switched from FVIII prophylaxis, 46% of patients transitioned from emicizumab because of persistent breakthrough bleeding (88%) and complex multifactorial scenarios (76%). Over a median follow-up of 9 months, weekly efa prophylaxis resulted in a significant 89% reduction in treated bleeds (P < .001) and an 85% reduction in joint bleeds (P < .001) in the total population. This clinical benefit remained consistent across exploratory subgroups, including patients who were previously on emicizumab. No new-onset inhibitors occurred. Biologically, the median centralized day-7 trough level was 7 IU/dL using a drug-calibrated bovine chromogenic substrate assay (CSA, n = 31). However, a significant discrepancy was observed in paired comparisons (n = 18), where local 1-stage assays (OSAs) yielded a median trough level of 14 IU/dL, compared with a centralized CSA median of 7 IU/dL (P < .001). Notably, this divergence occurred across various local reagents considered acceptable alternatives to Actin FSL for efa monitoring. In conclusion, efa effectively addresses complex unmet needs, including those of emicizumab-treated patients. However, the discrepancy between results of local OSAs and drug-calibrated CSA highlights challenges in laboratory monitoring.", "abstract_shown": true, "affiliations": [ "Hematology and Transfusion Department, INSERM U1011, Centre Hospitalier Universitaire de Lille, Institut Pasteur de Lille, Université de Lille, Lille, France", "Hôpital Bicêtre, Assistance Publique – Hôpitaux de Paris, Université Paris-Saclay, Le Kremlin-Bicêtre, France", "Haemophilia Treatment Centre and French Reference Centre on Haemophilia, Louis Pradel Hospital, Hospices Civils de Lyon, Bron, France", "Haemophilia Treatment Centre, University Hospital of Besançon, Besançon, France", "Assistance Publique–Hôpitaux de Marseille, Haemophilia Treatment Centre, Children Hospital La Timone & Aix-Marseille University, Centre d'Études et de Recherche sur les Services de Santé et la Qualité de Vie, Health Services and Quality of Life Research, Research Unit 3279, Marseille, France", "Haemophilia Treatment Centre, University Hospital of Strasbourg, Strasbourg, France", "Haemophilia Treatment Centre, University Hospital of Reims, Reims, France", "Haemophilia Treatment Centre, University Hospital of Nancy, Nancy, France", "Haemophilia Treatment Centre, University Hospital of Limoges, Limoges, France", "Haemophilia Treatment Centre, University Hospital of Caen, Caen, France", "Haemophilia Treatment Centre, University Hospital of Rennes, Rennes, France", "Haemophilia Treatment Centre, University Hospital of Bordeaux, Bordeaux, France", "Haemophilia Treatment Centre, University Hospital of Brest, Brest, France", "Haemophilia Treatment Centre, Hôpital Cochin (Assistance Publique – Hôpitaux de Paris), Paris, France", "Haemophilia Treatment Centre, University Hospital of Montpellier, Montpellier, France", "Haemophilia Treatment Centre, University Hospital of Nantes, Nantes, France", "Haemophilia Treatment Centre, University Hospital of Dijon, Dijon, France", "Pharmaceutical Unit, Louis Pradel Hospital, Hospices Civils de Lyon, Bron, France", "Haemophilia Treatment Centre, University Hospital of Tours, Tours, France", "Department of Biostatistics, Centre Hospitalier Universitaire Lille, University of Lille, Lille, France" ], "article_type": "research article", "arxiv": null, "author_total": 28, "authors": [ { "affs": [ 0 ], "name": "Antoine Rauch" }, { "affs": [ 1 ], "name": "Hortense Maynadié" }, { "affs": [ 2 ], "name": "Stéphanie Desage" }, { "affs": [ 3 ], "name": "Alexandra Fournel" }, { "affs": [ 4 ], "name": "Audrey Petit" }, { "affs": [ 5 ], "name": "Dominique Desprez" }, { "affs": [ 6 ], "name": "Valérie Proulle" }, { "affs": [ 7 ], "name": "Birgit Frotscher" }, { "affs": [ 8 ], "name": "Marie-Celeste Laroque" }, { "affs": [ 2 ], "name": "Sandrine Meunier" }, { "affs": [ 9 ], "name": "Yohann Repesse" }, { "affs": [ 10 ], "name": "Sophie Bayart" }, { "affs": [ 11 ], "name": "Sabine Castet" }, { "affs": [ 12 ], "name": "Brigitte Pan-Petesch" }, { "affs": [ 13 ], "name": "Valérie Roussel-Robert" }, { "affs": [ 14 ], "name": "Alexandre Theron" }, { "affs": [ 15 ], "name": "Marc Trossaert" }, { "affs": [ 16 ], "name": "Fabienne Volot" }, { "affs": [ 2, 17 ], "name": "Valérie Chamouard" }, { "affs": [ 2, 17 ], "name": "Laura Tourvielle" }, { "affs": [ 18 ], "name": "Claire Pouplard" }, { "affs": [ 19 ], "name": "Julien Labreuche" }, { "affs": [ 0 ], "name": "Mélanie Y. Daniel" }, { "affs": [ 0 ], "name": "Emmanuelle Jeanpierre" }, { "affs": [ 0 ], "name": "Sophie Susen" }, { "affs": [ 2 ], "name": "Yesim Dargaud" }, { "affs": [ 1 ], "name": "Roseline D’Oiron" }, { "affs": [ 2 ], "name": "Christophe Nougier" } ], "bibtex": "https://research.draconitic.com/paper/29ds1yckd37e4.bib", "cited_by": 0, "doi": "10.1182/bloodadvances.2026020401", "fulltext_url": "https://pmc.ncbi.nlm.nih.gov/articles/PMC13734903/", "id": "29ds1yckd37e4", "issns": [ "2473-9529", "2473-9537" ], "landing_url": "https://doi.org/10.1182/bloodadvances.2026020401", "language": "en", "licence": "CC-BY-NC-ND-4.0", "licence_label": "CC BY-NC-ND 4.0", "licence_source": "article", "licence_url": "https://creativecommons.org/licenses/by-nc-nd/4.0/", "metadata_licence": null, "native_subjects": [ [ "heading", "Thrombosis and Hemostasis" ], [ "openalex", "2720|Hemophilia Treatment and Research" ] ], "openalex": "W7168282414", "pdf_url": "https://ashpublications.org/bloodadvances/article-pdf/doi/10.1182/bloodadvances.2026020401/2533856/bloodadvances.2026020401.pdf", "pmcid": "PMC13734903", "pmid": "42448323", "published": "2026-07-16", "publisher": "The American Society of Hematology", "ris": "https://research.draconitic.com/paper/29ds1yckd37e4.ris", "sources": [ { "first_seen": "2026-11-09T12:20:42Z", "native_id": "PMC13734903", "source": "pmc", "url": "https://doi.org/10.1182/bloodadvances.2026020401" } ], "subjects": [ { "field": "medicine", "origin": "openalex:2720|Hemophilia Treatment and Research", "subfield": "general" } ], "title": "Unmet needs despite standard-of-care prophylaxis in hemophilia A: improved outcomes after switching to efanesoctocog alfa", "title_text": "Unmet needs despite standard-of-care prophylaxis in hemophilia A: improved outcomes after switching to efanesoctocog alfa", "type": "peer-reviewed", "updated_at": "2026-11-09T12:20:42Z", "url": "https://research.draconitic.com/paper/29ds1yckd37e4", "venue": "Blood Advances", "versions": [] }