https://orcid.org/0000-0001-5781-7669
Key Points
Longer-term (≥1 year) efficacy and safety results of concizumab were consistent with the 32‑week cut‑off results in the explorer7 study.
Low bleeding rates were maintained on concizumab with no new safety concerns in people with hemophilia A or B with inhibitors.
Concizumab is an anti‐tissue factor pathway inhibitor (TFPI) monoclonal antibody intended for once‐daily subcutaneous prophylactic treatment for people with hemophilia A or B with and without inhibitors. Results from the phase 3 explorer7 study confirmed superiority of concizumab prophylaxis over no prophylaxis in reducing the annualized bleeding rate (ABR) in people with hemophilia A or B with inhibitors (HAwI/HBwI). Male patients aged ≥12 years were randomized 1:2 to no prophylaxis (group 1) or concizumab prophylaxis (group 2), or allocated to concizumab prophylaxis (groups 3 and 4). After ≥24 weeks of treatment, patients in group 1 could switch to concizumab prophylaxis. At the 56-week cut‑off (defined as when all patients in groups 2-4 had completed the visit at 56 weeks or permanently discontinued treatment), bleed-related efficacy, pharmacokinetics and pharmacodynamics, and safety were assessed. Of the 133 patients enrolled (HAwI, n=80; HBwI, n=53), 114 received concizumab prophylaxis (groups 2-4) and 19 were randomized to no prophylaxis (group 1). After ≥24 weeks, 13 patients from group 1 switched to concizumab. Median ABR for treated spontaneous and traumatic bleeding episodes in patients receiving concizumab was 0.8 (interquartile range [IQR] 0.0-3.2) at the 56‑week cut-off, consistent with the low bleeding rates (median ABR 0.0, IQR 0.0-3.3) at the 32‑week cut‑off. Concizumab and free TFPI concentration remained stable over time. No new safety concerns were reported. Longer‑term (≥1 year) efficacy and safety results of concizumab prophylaxis for HAwI/HBwI were consistent with the 32-week cut-off results in explorer7. ClinicalTrials.gov; NCT04083781.
