Severe Hemophilia B — Clinical Trials

MONDO:00157156 active·5 recruitingLast updated: Mar 20, 2026, 9:30 AM

Trial Landscape

Severe Hemophilia B has a growing clinical research program, driven by drug treatment and gene therapy.

Recruiting

Active Trials

By Approach

Drug Treatment3

Gene Therapy2

Biological Therapy1

By Phase

Phase 1

Phase 2

Phase 3

Sponsor Types

Industry6

Top Sponsors

Be Biopharma

CSL Behring

Pfizer

Trial Locations

United States6 trials

Israel4 trials

Australia4 trials

Canada4 trials

South Korea4 trials

Taiwan4 trials

Turkey (Türkiye)4 trials

United Kingdom3 trials

France3 trials

Italy3 trials

Trials often recruit across multiple countries, so totals exceed the trial count.

6 Trials

Phase 3RecruitingGene Therapy

NCT06003387

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)

Sponsor:CSL Behring

United StatesStarted: Jan 2024Est. completion: Apr 2032Updated: Mar 2026

Phase 3Recruiting

NCT07080905

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

Sponsor:CSL Behring

United StatesStarted: Jul 2025Est. completion: Oct 2033Updated: Feb 2026

Phase 3Recruiting

NCT05145127

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

Sponsor:Pfizer

United StatesStarted: Nov 2021Est. completion: Jul 2030Updated: Feb 2026

Phase 3Recruiting

NCT05611801

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

Sponsor:Pfizer

United StatesStarted: Dec 2022Est. completion: Sep 2028Updated: Aug 2025

Phase 1Recruiting

NCT06611436

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

Sponsor:Be Biopharma

United StatesStarted: Dec 2024Est. completion: Jul 2027Updated: Oct 2025

Phase 3Active, Not RecruitingGene Therapy

NCT03861273

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

Sponsor:Pfizer

United StatesStarted: Jul 2019Est. completion: Feb 2031Updated: Mar 2026

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Data sourced from ClinicalTrials.gov via Kisho's automated pipeline. Trials refreshed every 4 hours for monitored diseases.

Last sync: March 20, 2026 at 9:30 AM

Severe Hemophilia B — Clinical Trials

Trial Landscape

By Approach

By Phase

Sponsor Types

Top Sponsors

Trial Locations

6 Trials

Open Trials5

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)

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

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

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

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

Active Trials1

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

Severe Hemophilia B — Clinical Trials

Trial Landscape

By Approach

By Phase

Sponsor Types

Top Sponsors

Trial Locations

6 Trials

Open Trials5

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)

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

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

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

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

Active Trials1

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

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