Abstract Number: PB0570
Meeting: ISTH 2021 Congress
Background: Damoctocog alfa pegol (BAY 94-9027) is an extended–half-life PEGylated recombinant factor VIII product, approved for use in previously-treated patients (PTPs) aged ≥12 years with hemophilia A.
Aims: HEM-POWR (NCT03932201) is a multicenter, non-interventional, open-label, prospective phase IV trial investigating routine clinical use of damoctocog alfa pegol. Planned enrollment is ≥200 PTPs with mild, moderate, or severe hemophilia A. The 6-month interim safety analysis is presented.
Methods: Eligible patients include all PTPs receiving damoctocog alfa pegol on-demand or as prophylaxis, according to local label who provided informed consent. Primary outcomes include total bleeding events and annualized bleeding rate. Secondary outcomes include long-term safety, joint health, and patient-reported outcomes. Analyses will be exploratory, stratified by prophylaxis regimen and hemophilia severity. Ethical approval was obtained for all sites.
Results: At data cut-off (21 October), 39 PTPs were enrolled; 38 patients comprised the safety analysis set (one patient withdrew consent), including 8 mild/moderate patients (Table 1). Most patients (n=32) had received damoctocog alfa pegol within 12 months of baseline for variable time periods (mean [SD]=354.6 [614.02] days). Median (Q1;Q3) dose was 3000 (2000;3650) IU/infusion; the most common dosing regimen being twice-weekly prophylaxis (44%). 26/32 patients provided information about Factor VIII treatment within 12 months prior to initiation of damoctocog alfa pegol. In this group, the most common dosing frequency was three times weekly (data available for 24 patients). A group of six damoctocog alfa pegol-naïve patients had a comparatively worse bleeding history (Table 2). There were no study-drug-related treatment-emergent adverse events, nor inhibitor development. Two patients discontinued. Remote follow-up visits were made due to Covid-19; initial visits may now be conducted remotely.
|Patients in SAF (n)||38|
|Region /country of recruitment (n, %)
Europe / Japan / United States of America
5 (13.2%) / 20 (52.6%) / 13 (34.2%)
|Age at signing informed consent (median; Q1, Q3, y)||36.5 (23.0, 47.0)|
|History of inhibitors (n, %)||2 (5.3%)|
|Severe / moderate / mild hemophilia at diagnosis (n, %)||30 (79.0%) / 6 (15.8%) / 2 (5.3%)|
|Patients with at least one concomitant disease (n, %)
Hemarthrosis / pain / psychiatric disorders
3 (7.9%) / 7 (18.4%) / 5 (13.2%)
|Patients with at least one concomitant medication (n, %)||33 (86.84%)|
|Observation days (mean, SD, range)||72.7 (99.26, 1–298)|
|SAF, safety analysis set; SD, standard deviation; 1 patient excluded (missed dose).|
|Number of reported bleeds within 12 months prior to enrollment (median, Q1, Q3)
||Naïve to damoctocog alfa pegol
damoctocog alfa pegol
|Total bleeds||4 (2.0, 10.0)||0.0 (0.0, 1.0)||0.0 (0.0, 4.0)|
|Spontaneous||3.5 (1.0, 10.0)||0.0 (0.0, 0.0)||0.0 (0.0, 1.0)|
|Trauma||0.0 (0.0, 1.0)||0.0 (0.0, 0.0)||0.0 (0.0, 1.0)|
|Joint||3.5 (1.0, 10.0)||0.0 (0.0, 1.0)||0.0 (0.0, 2.0)|
|Spontaneous joint||3.0 (1.0, 10.0)||0.0 (0.0, 1.0)||0.0 (0.0, 1.0)|
|Trauma joint||0.0 (0.0, 0.0)||0.0 (0.0, 0.0)||0.0 (0.0, 0.0)|
|Note: Patients were enrolled at their initial visit, at which baseline data was recorded.|
Conclusions: This first interim analysis of the HEM-POWR study provides real-world evidence that damoctocog alfa pegol is well-tolerated in routine clinical use in patients with mild, moderate, or severe disease.
To cite this abstract in AMA style:Reding M, Teresa Alvarez Román M, Sanabria M, Castaman G, Janbain M, Matsushita T, Meijer K, Schmidt K, Oldenburg J. First Interim Analysis from the Observational HEM-POWR Study Evaluating Effectiveness and Safety of Real-world Treatment with Damoctocog Alfa Pegol in Previously Treated Patients with Hemophilia A [abstract]. Res Pract Thromb Haemost. 2021; 5 (Suppl 2). https://abstracts.isth.org/abstract/first-interim-analysis-from-the-observational-hem-powr-study-evaluating-effectiveness-and-safety-of-real-world-treatment-with-damoctocog-alfa-pegol-in-previously-treated-patients-with-hemophilia-a/. Accessed December 5, 2021.
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