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ClinicalTrials.gov 9 recruiting now full pipeline

Hemophilia B: full-pipeline trial registry

9 of 21 indexed Hemophilia B trials are currently recruiting.

Corpus placement: #797 of 28,707 conditions by registered trial count.

21 US clinical trials · 9 currently recruiting · #797 of 28,707 conditions by registered trial count

Hemophilia B: 21 US clinical trials tracked, 9 recruiting.

Hemophilia B is the subject of 21 registered US clinical trials on ClinicalTrials.gov, 9 of them currently open to new participants. 7 are in Phase 3-4 (later-stage) and 6 in Phase 1-2 (earlier-stage). The most active sponsor is Pfizer, running 5 of these trials.

Enrollment posture brief

Registry condition hemophilia-b

OPEN 9 | RECR 43% | LATE 7 | EARLY 6 | RANK #797 | SPON 5

Nearest open-share peer: Acute Myelogenous Leukemia (AML) (43% recruiting · 7 trials)

Hemophilia B (this)43%Anal Cancer42.9%Allergic Conjunctivitis14.3%Attention Deficit Disorder W4.8%Adult Acute Myeloid Leukemia0%
Open-enrollment share among volume-matched conditions near Hemophilia B

Hemophilia B lists 9 open slots (43% of 21 indexed trials). Peers are matched on registered volume, not therapeutic-area browse lists. How peer matching works →

Key findings

What ClinicalTrials.gov does not surface for Hemophilia B on its own pages , computed from the registry mirror as of 2026-08-08. Each line carries its own denominator so it can be quoted as it stands.

  1. Hemophilia B is recruiting above its size-band peers.

    9 of 21 indexed trials (42.9%) are open to enrollment, against a 39.7% average across 762 conditions with 20-99 trials. The peer set uses the same ClinicalTrials.gov-derived counts as this page.

  2. One sponsor concentrates Hemophilia B research.

    Pfizer accounts for 5 of 21 trials (23.8%). 13 distinct sponsors appear on at least one study for this condition label.

  3. Most Hemophilia B trials plan to enrol fewer than 100 people.

    Median target enrolment is 35 among the 21 trials that report a genuine target (sentinel values excluded). 13 of those (61.9%) plan for fewer than 100 participants.

  4. Hemophilia B splits between interventional and observational designs.

    14 interventional and 7 observational studies make up this index (66.7% interventional). Study type is sponsor-reported on ClinicalTrials.gov.

Phase 15Phase 21Phase 37

Open and recent trials

21 total, page 1 of 1

RECRUITING 500 participants

An Observational Cohort Study to Characterize the Effectiveness and Safety of HEMGENIX® in Patients With Hemophilia B

CSL Behring

NCT06008938

RECRUITING Phase 3 245 participants

Open-Label Extension Study of Marstacimab in Hemophilia Participants With or Without Inhibitors

Pfizer

NCT05145127

RECRUITING Phase 3 173 participants

Safety and Effectiveness of Giroctocogene Fitelparvovec or Fidanacogene Elaparvovec in Patients With Hemophilia A or B Respectively

Pfizer

NCT05568719

RECRUITING Phase 1 130 participants

A Study to Investigate the Safety and Effectiveness of a Coagulation Factor IX Gene Insertion Therapy (REGV131-LNP1265) in Pediatric, Adolescent and Adult Participants With Hemophilia B

Regeneron Pharmaceuticals

NCT06379789

RECRUITING Phase 3 100 participants

A Clinical Trial of Study Medicine (Marstacimab) in Pediatric Patients With Hemophilia A or Hemophilia B

Pfizer

NCT05611801

RECRUITING Phase 3 35 participants

Efficacy and Safety of CSL222 (Etranacogene Dezaparvovec) Gene Therapy in Adults With Hemophilia B With Pretreatment Adeno-associated Virus Serotype 5 (AAV5) Neutralizing Antibodies (Nabs)

CSL Behring

NCT06003387

RECRUITING Phase 1 31 participants

A Study of Safety, Tolerability, Pharmacokinetics, and Pharmacodynamics of SR604 in Two Participants Groups (Part A: Healthy Participants, and Part B: Participants With Hemophilia A or Hemophilia B or Factor VII Deficiency)

Equilibra Bioscience

NCT06349473

RECRUITING Phase 1 24 participants

BeCoMe-9: A Clinical Study of BE-101 for the Treatment of Adults With Moderately Severe or Severe Hemophilia B

Be Biopharma

NCT06611436

RECRUITING Phase 3 20 participants

Phase 3, Open-label, Single-dose Study of CSL222 in Adolescent Male Subjects (≥ 12 to < 18 Years of Age) With Severe or Moderately Severe Hemophilia B

CSL Behring

NCT07080905

ACTIVE NOT RECRUITING Phase 3 51 participants

A Study to Evaluate the Efficacy and Safety of Factor IX Gene Therapy With PF-06838435 in Adult Males With Moderately Severe to Severe Hemophilia B

Pfizer

NCT03861273

ACTIVE NOT RECRUITING Phase 1 30 participants

Open-Label Single Ascending Dose of Adeno-associated Virus Serotype 8 Factor IX Gene Therapy in Adults With Hemophilia B

Baxalta now part of Shire

NCT01687608

ACTIVE NOT RECRUITING Phase 2 21 participants

Long-term Safety and Efficacy Study and Dose-Escalation Substudy of PF 06838435 in Individuals With Hemophilia B

Pfizer

NCT03307980

ACTIVE NOT RECRUITING Phase 1 14 participants

Dose-Escalation Study Of A Self Complementary Adeno-Associated Viral Vector For Gene Transfer in Hemophilia B

St. Jude Children's Research Hospital

NCT00979238

ACTIVE NOT RECRUITING 13 participants

Long Term Follow-up (LTFU) of Subjects Who Received SB-318, SB-913, or SB-FIX

Sangamo Therapeutics

NCT04628871

ACTIVE NOT RECRUITING 11 participants

A Trial That Evaluates Disease Characteristics in Hemophilia B Adult Male Participants Receiving Prophylaxis With Standard of Care Factor IX Protein (FIX) Replacement Therapy

Regeneron Pharmaceuticals

NCT05568459

COMPLETED 200 participants

Females With Severe or Moderate Hemophilia A or B: an International Multi-center Study

Weill Medical College of Cornell University

NCT00936312

COMPLETED 150 participants

Needs Assessment of Knowledge, Beliefs, and Attitudes of Patients With Hemophilia B About Gene Therapy

St. Jude Children's Research Hospital

NCT05044845

COMPLETED Phase 3 120 participants

A Study of Fitusiran (ALN-AT3SC) in Severe Hemophilia A and B Patients Without Inhibitors

Genzyme, a Sanofi Company

NCT03417245

COMPLETED 37 participants

AAV Gene Therapy Screening/Observational Protocol (ECLIPSE)

Spur Therapeutics

NCT04272554

COMPLETED NA 20 participants

Correlation Between Vitamin D Status and Bone Mineral Density in Patients With Hemophilia

Virginia Commonwealth University

NCT01090206

COMPLETED 6 participants

Long-Term Safety, Tolerability, and Efficacy of DTX101 (AAVrh10FIX) in Adults With Moderate/Severe to Severe Hemophilia B

Ultragenyx Pharmaceutical

NCT02971969

Phase Distribution

PhaseTrial count
Phase 1 5
Phase 2 1
Phase 3 7

Named interventions

Most-linked intervention names on Hemophilia B records (sponsor-reported on ClinicalTrials.gov). Counts are trial links, not unique products.

Vitamin D and calcium Dietary supplement
1 trials
factor concentrates Drug
1 trials
fitusiran Drug
1 trials
AskBio009 Biological
1 trials
PF-06838435 (formerly SPK-9001) Biological
1 trials
scAAV2/8-LP1-hFIXco Drug
1 trials
Gene Transfer Genetic
1 trials
PF-06838435/ fidanacogene elaparvovec Biological
1 trials

US sites by state

Facility locations filed on Hemophilia B trials. A trial with sites in several states counts in each.

California 11 trials
Michigan 9 trials
New York 8 trials
Florida 7 trials
Pennsylvania 6 trials
Illinois 6 trials
Washington 5 trials
Ohio 5 trials

Source: ClinicalTrials.gov, National Library of Medicine. Data is informational only.

What to do with this Hemophilia B page

21 registered trials, 9 currently recruiting, is a starting point for a conversation, not a diagnosis or a recommendation.

  • 9 Hemophilia B trials are currently recruiting, check eligibility criteria before contacting a site. Browse recruiting trials
  • Pfizer sponsors the most Hemophilia B trials on record, review their full trial history before evaluating a specific study. See Pfizer's trials
  • Bring the specific trial ID (NCT number) to your own doctor before enrolling, this page is a directory, not medical guidance. Read the trial-finding guide

Trial and recruiting counts reflect ClinicalTrials.gov registry status as of the data vintage above; individual trial eligibility and enrollment status can change.

Every figure on PlainTrial is rendered directly from the ClinicalTrials.gov registry, no number is typed in by an editor. This Hemophilia B condition card totals 21 registered trials; most-linked intervention Vitamin D and calcium; top US site state California. See our editorial standards & corrections policy, the methodology behind these numbers, the data changelog, or report a data error.