Live from ClinicalTrials.gov + Open Targets, fetched 2026-11-12 04:02 UTC. Every row links to its source record.
Postmortem · what the sponsor and named sources said, kept apart from what merely happened at the same time
Long-term Safety and Efficacy Study and Dose-Escalation Substudy of PF 06838435 in Individuals With Hemophilia B
NCT03307980 · Pfizer · PHASE2 · terminated · last registry update 2026-10-05 · Decision brief
No research has been run for this trial yet, so only the registry's own reason and the timeline are shown.
What was said, and by whom
Stated is the sponsor's own words; Reported is a named third party. The category is our label from a fixed list; the quote is the evidence.
| Kind | Quote | Our category | Source |
|---|---|---|---|
| Stated | “The study was terminated early due to Sponsor and participants may transition into a long-term follow-up study. The decision to terminate the trial was not based on any safety and/or efficacy concerns.” | – | Registry record, Pfizer |
Also happening at the time. Not shown to be a cause.
Registry events on other trials of drugs against F9 within 12 months either side of this trial's last update, live from ClinicalTrials.gov. Nothing here was stated as a reason.
- 2026-11-10Results posted on the registry: University of Maryland, Baltimore, Kcentra + Frozen Plasma Product, Human (NCT03341156)
- 2026-11-10Also stopped (terminated): University of Maryland, Baltimore, Kcentra + Frozen Plasma Product, Human (NCT03341156)
- 2026-11-09Phase 3 first posted: Pfizer, marstacimab (NCT07923981)
- 2026-11-09Results posted on the registry: Octapharma, a drug against F9 (NCT03320603)
- 2026-11-06Also stopped (withdrawn): Emory University, Emicizumab + FEIBA (NCT04563520)
- 2026-10-21Also stopped (terminated): University Health Network, Toronto, Fibrinogen + PCC + Frozen Plasma (NCT04534751)
- 2026-08-14Results posted on the registry: Pfizer, PF-06741086 (NCT03938792)
- 2026-07-31Results posted on the registry: Spur Therapeutics, verbrinacogene setparvovec (NCT05164471)
- 2026-07-31Also stopped (terminated): Spur Therapeutics, verbrinacogene setparvovec (NCT05164471)
- 2026-07-24Also stopped (terminated): AstraZeneca, Ceralasertib + Drug X (NCT06929260)
- 2026-06-25Also stopped (terminated): Octapharma, Octaplex (NCT04867837)
- 2026-06-24Results posted on the registry: SHI Jia, Prothrombin Complex Concentrate, Human + Fresh Frozen Plasma (NCT04244981)
- 2026-06-24Also stopped (terminated): SHI Jia, Prothrombin Complex Concentrate, Human + Fresh Frozen Plasma (NCT04244981)
- 2026-04-07Also stopped (withdrawn): University of Texas Southwestern Medical Center, Eloctate + Adynovate (NCT04690322)
- 2026-02-27Phase 3 first posted: Chulalongkorn University, Switching to low dose emicizumab (NCT07439055)
- 2026-02-18Phase 3 first posted: Hoffmann-La Roche, NXT007 + Emicizumab (NCT07416604)
- 2025-12-10Also stopped (terminated): CSL Behring, BE1116 + Placebo (NCT05568888)
- 2025-11-10Results posted on the registry: CSL Behring, BE1116 + Placebo (NCT05568888)
- 2025-11-06Results posted on the registry: Pfizer, Standard of Care FIX Replacement therapy + Standard of Care FVIII Replacement therapy (NCT03587116)
What is not public
- Internal portfolio and board discussions
- Unpublished trial data and interim analyses
- Terms of any partner or licence decision