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Adverse event reporting can be found at the bottom of the page
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Click here for HYMPAVZI®▼ (marstacimab) Prescribing Information.
The efficacy and safety of HYMPAVZI was evaluated in the BASIS study1,2
A one-way cross-over, open-label, multi-centre Phase 3 clinical trial1,2
*For full inclusion and exclusion criteria please see NCT03938792 (BASIS) and NCT05145127 (Open label extension) at clinicaltrials.gov.3,4
†Treated bleeds were defined as bleeds treated with FVIII or FIX; total bleeds were defined as bleeds treated and not treated with FVIII or FIX.1
‡Although the BASIS study inclusion criteria included moderately severe to severe haemophilia B patients, only 1 haemophilia B patient with moderately severe disease was included in the study. Therefore, no conclusions on efficacy in this patient population can be made, and only data pertaining to severe haemophilia B patients are presented.5
Use the buttons below to explore the BASIS trial in more detail:
Study design1,2
Efficacy
*For patients weighing ≥50 kg experiencing ≥2 breakthrough bleeds, dose escalation to 300 mg of HYMPAVZI once weekly was allowed after 6 months. 14/116 (12.1%) patients who received HYMPAVZI for ≥6 months received dose escalation of their maintenance dose.1
†Interim analysis includes efficacy data up to an additional 16 months.1,2
OD, on demand; RP, routine prophylaxis
Primary endpoint: HYMPAVZI showed non-inferiority and statistical superiority over routine factor based prophylaxis (ABR of treated bleeds)1
35.3% reduction in treated bleeds vs prior factor-based prophylaxis (P=0.0376)*In the BASIS study, 14/116 patients (12.1%) who previously received on-demand or factor-based prophylactic treatment and then received HYMPAVZI for at least 6 months underwent dose escalation of their maintenance dose from 150 mg to 300 mg once weekly.1
*The primary endpoint was tested for non-inferiority, then superiority. Criteria for non-inferiority met; P value relates to superiority testing.1
Secondary endpoint: HYMPAVZI proved non-inferior to factor-based prophylaxis across key secondary bleeding endpoints1
ABR with HYMPAVZI prophylaxis vs with previous routine factor-based prophylaxis
Non-inferiority was met for all endpoints.1 The protocol specified non-inferiority criterion (upper bound of the 95% CI for the difference) was 2.5 for treated bleeds, spontaneous bleeds, joint bleeds; 1.2 for target joint bleeds; 2.9 for total bleeds.1
The estimated mean and CIs for the ABR come from a negative binomial regression model.1
HYMPAVZI prophylaxis over time
ABR for treated bleeds achieved at 6 and 12 months were maintained up to an additional 16 months of treatment1*
Mean and median ABR with HYMPAVZI prophylaxis over time
In the BASIS study, 14/116 patients (12.1%) who previously received on-demand or factor-based prophylactic treatment and then received HYMPAVZI for at least 6 months underwent dose escalation of their maintenance dose from 150 mg to 300 mg once weekly.1
The open-label extension data includes both groups (OD & RP).5
Descriptive analyses were conducted to assess prophylaxis over time with HYMPAVZI. The estimated mean ABR comes from a negative binomial regression model; the median and the interquartile range (IQR), 25th percentile to 75th percentile, for the ABR comes from the descriptive summary.1
*In the OLE of the pivotal Phase 3 study, 87 patients received HYMPAVZI at the doses established during participation in the B7841005 study (150 mg or 300 mg subcutaneously once weekly) for up to an additional 16 months (mean: 7 months) where HYMPAVZI was shown to maintain long-term (>12 months) efficacy with no new safety signals identified at time of data cutoff.1
ABR, annualised bleed rate; ARR, absolute risk reduction; CI, confidence interval; FIX, factor IX; FVIII, factor VIII; RP, routine prophylaxis; IQR, interquartile range; OLE, open-label extension; OD, on demand; TFPI, tissue factor pathway inhibitor.
tab 3
Understand the HYMPAVZI dosing schedule and see how HYMPAVZI can be administered.
HYMPAVZI is a human monclonal antibody.1 Learn more about anti-TFPI and how HYMPAVZI works within the clotting cascade.
Adverse events should be reported. Reporting forms and information can be found at https://yellowcard.mhra.gov.uk or search
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