Abstract Number: OC 30.3
Meeting: ISTH 2022 Congress
Background: Haemophilia is associated with significant treatment burden. Concizumab, an anti-tissue factor pathway inhibitor antibody in clinical development as a subcutaneous, prophylactic treatment, aims to improve patient experience by reducing treatment burden. explorer4 and explorer5 (NCT03196284/NCT03196297) investigated daily concizumab prophylaxis in patients with haemophilia A/B with inhibitors (HAwI/HBwI), and severe HA, respectively. Haemophilia Treatment Experience Measure (Hemo-TEM), a 26-item questionnaire with five domains developed to measure treatment burden in haemophilia patients, was used to investigate the value of subcutaneous prophylaxis with concizumab.
Aims: Assess impact of concizumab subcutaneous prophylaxis on treatment burden.
Methods: explorer4 and 5 comprised main (≤24 weeks) and extension parts (≤94 and ≤102 weeks, respectively). In explorer4, HAwI/HBwI patients were randomised 2:1 to concizumab prophylaxis or bypassing agent on-demand. On-demand patients switched to concizumab prophylaxis in the extension. In explorer5, all patients received concizumab. Hemo-TEM was completed at baseline, 24 and ≥76 weeks. Scores range from 0–100; lower scores indicate lower treatment burden. Individual domain and total scores are calculated. Hemo-TEM development and validation are presented separately.
Results: Twenty-five and 29 patients completed explorer4 and 5, respectively. In explorer4, mean baseline Hemo-TEM total scores were similar between concizumab (25.0) and on-demand arms (26.2). After 24 weeks of treatment, the concizumab arm demonstrated change from baseline in mean Hemo-TEM total score of -15.3, indicating lower treatment burden versus baseline, with no change in the on-demand arm (Table 1). Similarly, change in mean Hemo-TEM total score from baseline (21.9) was -12.8 for patients in explorer5 after 24 weeks (Table 2). Improved scores were observed for all Hemo-TEM domains, with sustained improvements at last observational visit in both trials (Table 1, 2).
Conclusion(s): Hemo-TEM scores improved after ≥24 weeks of concizumab subcutaneous prophylaxis during explorer4 and explorer5, in patients with and without inhibitors, illustrating the potential value of concizumab in reducing treatment burden.
To cite this abstract in AMA style:Mancuso M, Skov Neergaard J, Cepo K, Porstmann T. Treatment Experience in Hemophilia Patients With and Without Inhibitors on Concizumab Prophylaxis: Hemo-TEM results from the phase 2 explorer4 & 5 studies [abstract]. https://abstracts.isth.org/abstract/treatment-experience-in-hemophilia-patients-with-and-without-inhibitors-on-concizumab-prophylaxis-hemo-tem-results-from-the-phase-2-explorer4-5-studies/. Accessed November 29, 2023.
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