S303: A PHASE 3 STUDY (ATLAS-PPX) TO EVALUATE EFFICACY AND SAFETY OF FITUSIRAN IN PEOPLE WITH HAEMOPHILIA A OR B WHO HAVE SWITCHED FROM PRIOR CLOTTING FACTOR CONCENTRATE OR BYPASSING AGENT PROPHYLAXIS
Bibliographic record
Abstract
Background: Fitusiran, a subcutaneous (SC) investigational siRNA therapeutic, targets antithrombin to rebalance haemostasis in people with haemophilia A or B (PwHA/B), irrespective of inhibitor status. In previous Phase 3 trials, once-monthly fitusiran prophylaxis significantly reduced annualised bleeding rate (ABR) in PwHA/B, with or without inhibitors versus episodic/on-demand treatment. Aims: To evaluate the efficacy and safety of fitusiran versus prior clotting factor concentrate (CFC)/bypassing agent (BPA) prophylaxis in PwHA/B, with or without inhibitors. Methods: This Phase 3, multinational, open-label study (NCT03549871) included males aged ≥12 years with hemophilia A or B, with or without inhibitors, who had prior CFC/BPA prophylaxis. Participants continued CFC/BPA prophylaxis (6 months) before switching to once-monthly 80 mg SC fitusiran prophylaxis (7 months). Primary endpoint was ABR in the CFC/BPA prophylaxis period (Day 168 to Day 1) and fitusiran efficacy period (Day 29 to Day 190). Secondary endpoints included spontaneous ABR (AsBR), joint ABR (AjBR), and health-related quality of life (HRQoL). Safety and tolerability were assessed. Results: Of 80 enrolled participants, 65 (inhibitor/non-inhibitor, n=19/46; haemophilia A/haemophilia B, n=50/15) were eligible for ABR analyses. Median observed (IQR) ABRs were 4.4 (2.2; 10.9) with CFC/BPA and 0.0 (0.0; 2.3) with fitusiran prophylaxis; 41 participants (63.1%) experienced zero treated bleeds with fitusiran. Fitusiran achieved statistically significant reductions in estimated ABR, AsBR and AjBR versus CFC/BPA prophylaxis (Table 1). Fitusiran significantly improved HRQoL versus CFC/BPA as measured by Haem-A-QOL total score (LS mean difference -4.6 [95% CI: -7.6; -1.5; p<0.01]). Serious adverse events (SAEs) occurred in 5/65 participants (7.7%) with CFC/BPA and 9/67 (13.4%) with fitusiran prophylaxis. A total of 17 (25.4%) participants experienced alanine aminotransferase or aspartate transaminase elevations >3x the upper limit of normal in the fitusiran prophylaxis period. Two participants (3.0%) experienced suspected or confirmed thromboembolic events with fitusiran. Summary/Conclusion: Once-monthly fitusiran prophylaxis significantly reduced bleeding versus CFC/BPA prophylaxis with a median ABR of zero in PwHA/B with and without inhibitors, resulting in a meaningful improvement in HRQoL. Reported AEs were generally consistent with previously identified risks of fitusiran.Keywords: Hemophilia
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".