Treatment Of Serious Bleeds With a B-Domain Deleted Recombinant Porcine Sequence Factor VIII (OBI-1) In Patients With Acquired Hemophilia A: A Prospective Clinical Trial
Bibliographic record
Abstract
Abstract Introduction Acquired hemophilia A (AHA) is a rare bleeding disorder, resulting from auto-antibodies to human factor VIII (hFVIII). The challenges created by the management of AHA and the co-morbidities present in this typically elderly population, can be managed by a recombinant, highly pure, B-domain deleted, porcine sequence FVIII (OBI-1) that is not generally susceptible to the inhibitory activity of anti-human FVIII antibodies. Treatment with OBI-1 allows for monitoring of FVIII levels which provides a reproducible and objective surrogate predictor of hemostasis. Eradication of hFVIII inhibitors with immunosuppressive therapy is critical for disease management. During immunosuppression, the patient transitions from a bleeding state at initial presentation to a relative hypercoagulable state which can be an issue in patients who are susceptible to thromboembolic events due to their comorbidities. This transition period is of most concern especially when using traditionally utilized bypassing agents that cannot be monitored. OBI-1 enables measurement of FVIII levels, guiding dosing and enhancing treatment safety during this critical period. Methods This global, prospective, multi-center phase 2/3 open label clinical trial investigates the efficacy and safety of OBI-1 in the treatment of serious bleeds in adults with AHA conducted under ICH guidelines and local IRB/Ethics Committee oversight. Primary efficacy endpoint was assessed at 24 hours (eg. effective, partially effective). All subjects (N= 18) presented with a serious bleed and were treated with an initial dose of OBI-1 (200 U/kg), followed by additional doses based on the subject's target factor VIII levels, anti-OBI-1 titer, and clinical factors. Results In all 18 subjects, a positive response (14 effective/4 partially effective) to treatment was observed at 24 hours. This positive response to OBI-1 treatment was seen by 8 hours in 14/18 of the subjects and at 16 hours in 16/18 of the subjects. Median total exposure to OBI-1 per subject was 1782.5 U/kg. The median total first dose was 14,000 U. For subjects who received additional doses of OBI-1, the median dose was reduced from the initial dose, but did not differ considerably over subsequent doses (9180 to 13561 U; median 11000 U). The majority of subjects (17/18) received concomitant immunosuppressive therapies. No related serious adverse reactions occurred. Non-serious adverse events related to treatment were noted in 5/18 (27.8%) subjects. One subject had mild tachycardia, hypotension and constipation. One subject had 2 instances of mild PICC line occlusion. One subject had a mild hypofibrogenemia. All of these adverse effects completely resolved. Three subjects developed anti-porcine inhibitors after infusion of study drug (range 8-108 BU) and two were discontinued from treatment. Anti-porcine inhibitors were detected prior to infusion in 6/18 patients (range 0.8-29 BU). All of these subjects had a favorable clinical response at 24 hours post-OB-1 infusions. Conclusions Data from this prospective study demonstrate OBI-1 as a safe and effective treatment of bleeding episodes in patients with AHA, with the added advantage over other bypass therapies of allowing FVIII monitoring throughout treatment and healing phase. Disclosures: Kruse-Jarres: Baxter Healthcare: Consultancy; Bayer HealthCare: Consultancy; Biogen IDEC: Consultancy; Grifols: Consultancy; Kedrion: Consultancy; Novo Nordisk: Consultancy. St. Louis:CSL Behring: Research Funding; Octapharma: Consultancy, Research Funding; Baxter: Consultancy; Novo Nordisk: Honoraria. Shapiro:Kedrion Biopharma: Consultancy; Chugai Pharma USA: Consultancy; Biogen IDEC: Consultancy, Membership on an entity’s Board of Directors or advisory committees; Bayer HealthCare: Membership on an entity’s Board of Directors or advisory committees; Novo Nordisk: Consultancy, Membership on an entity’s Board of Directors or advisory committees; Baxter Healthcare: Consultancy, Membership on an entity’s Board of Directors or advisory committees. Chowdary:Baxter Healthcare: Honoraria, Membership on an entity’s Board of Directors or advisory committees, Travel grant Other; Novo Nordisk: Honoraria, Research Funding, Travel grant, Travel grant Other; Bayer HealthCare: Honoraria, Travel grant, Travel grant Other; Pfizer: Honoraria, Membership on an entity’s Board of Directors or advisory committees, Research Funding, Travel grant, Travel grant Other; CSL Behring: Honoraria, Membership on an entity’s Board of Directors or advisory committees, Research Funding, Travel grant Other; Biogen IDEC: Honoraria, Travel, Travel Other. Drebes:Octapharma: Travel grant Other; CSL Behring: Travel grant, Travel grant Other; Leo-pharma: Travel grant, Travel grant Other; Bayer Healthcare: Consultancy, Honoraria. Gomperts:Baxter Healthcare: Consultancy; Asklepios Biopharmaceutoicals Inc: Consultancy; Cangene Inc: Consultancy. Chapman:Baxter Healthcare: Employment. Mo:Baxter Healthcare: Employment. Novack:Baxter Healthcare: Employment. Farin:Baxter Healthcare: Employment.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.002 | 0.001 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.002 | 0.003 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.002 | 0.003 |
| Insufficient payload (model declined to judge) | 0.004 | 0.001 |
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 source (direct Gemma or distilled Codex), 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".