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Thank you for attending THSNA 2026. The virtual meeting is now closed.
Presentation Details
| Sixth Interim Analysis of the HEM-POWR Study: Evaluating Real-World Effectiveness and Safety of Damoctocog Alfa Pegol in Patients With Severe and Nonsevere Hemophilia A in the United States Mark T Reding1, Beng Fuh2, Vanessa Salinas3, Maissaa Janbain4. 1Center for Bleeding and Clotting Disorders, University of Minnesota, Minneapolis, MN, USA.2East Carolina University, Greenville, NC, USA.3Center for Inherited Blood Disorders, Orange, CA, USA.4Tulane School of Medicine, New Orleans, LA, USA |
Abstract
Background: Damoctocog alfa pegol is an extended half-life factor VIII (FVIII) product approved in the US since 2018 for previously treated patients (PTPs) aged ≥12 years with hemophilia A; recent approval was received for children ≥7 years. The ongoing, open-label, multinational, prospective HEM-POWR study (NCT03932201) is evaluating long-term damoctocog alfa pegol use in real-world settings, with prior interim analyses demonstrating its effectiveness and safety. Objectives: To describe the effectiveness and safety of damoctocog alfa pegol among a subgroup of PTPs from US study sites in this sixth interim analysis of the HEM-POWR study. Methods: HEM-POWR assessed PTPs with severe or nonsevere hemophilia A receiving damoctocog alfa pegol prophylactically or on demand. The full analysis set (FAS) included patients with a documented study dose, ≥1 documented infusion during the observation period, and bleeding data. The modified FAS (mFAS) consisted of the patients in the FAS with ≥90 days of documentation in the patient diary. The safety analysis set (SAF) included those who received ≥1 study dose during the observation period and provided signed consent. The primary endpoint was annualized bleeding rate (ABR), evaluated in the mFAS; safety was a secondary endpoint, assessed in the SAF. Data were collected from patient diaries and physician records. Statistical analyses were explorative and descriptive. Results: At the data cutoff (June 5, 2025), 31 PTPs from the US were included in the SAF and 27 in the FAS. The median observation period was approximately 3 years (Table). In the FAS, median (quartile [Q]1, Q3) age was 39.0 (22.0, 50.0) years, and 88.9% patients were aged 18–<65 years. Most patients (63.0%) had severe disease, and 25.9% had mild/moderate (data missing n=3). Prior to enrollment, 24 (88.9%) patients were treated prophylactically (missing n=1). The most common dosing regimens with previous FVIII product prior to damoctocog alfa pegol were every 2 days (40.7%) and twice weekly (14.8%; missing n=12). The most common regimen was twice weekly at baseline of the observation period with damoctocog alfa pegol (44.0%; N=25) and at 6-month (45.8%; N=24) and 12-month follow up (45.8%; N=24). In the mFAS (N=25), the mean (SD) total ABR was 5.5 (9.7) with previous FVIII product prior to damoctocog alfa pegol initiation and 4.9 (9.2) with damoctocog alfa pegol during the observation period (Figure). Differences in ABR were –0.5 (11.6) for total bleeds, –1.9 (4.7) for spontaneous bleeds, –0.6 (11.6) for joint bleeds, and –1.7 (5.0) for spontaneous joint bleeds. In the SAF, 21 (67.7%) patients reported treatment-emergent adverse events (TEAEs); 9 (29.0%) patients had serious TEAEs. A change of treatment regimen occurred in 3 (9.7%) patients, which was considered serious for 2 (6.5%) patients. No new inhibitor development or deaths were reported. Conclusions: This subgroup analysis of PTPs from the US in the HEM-POWR study continues to support the favorable effectiveness and safety profile of damoctocog alfa pegol in PTPs with severe and nonsevere hemophilia A. The findings provide insights into real-world clinical practice and can help to inform US stakeholders. Funded by Bayer.
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No part of this publication may be reproduced, distributed, or transmitted in any form or by any means, including photocopying, recording, or other electronic or mechanical methods, without the prior written permission of the author.