ORPHA:169793
Severe hemophilia B
Also known as: Severe congenital F9 deficiency · Severe congenital factor IX deficiency
Publications
836
82.4th percentile
Trials
21
Interventional, condition-specific
Researchers
1,153
Distinct authors in sample
Gene link
—
Readiness
2/6
Stages with a signal
Clinical definition (Orphanet)
A severe form of hemophilia B characterized by a large deficiency of factor IX (biological activity <1 IU/dL) leading to frequent spontaneous hemorrhage and abnormal bleeding as a result of minor injuries or following trauma, surgery or tooth extraction. It primarily affects males but may also be observed in female carriers of disease-causing mutations.
How rare: 1-9 / 1 000 000 — roughly one to nine people per million. In a city the size of Kolkata, perhaps a few dozen.
Cross-references
Joined from Mondo / Orphanet. MeSH labels may enter searches; UMLS / OMIM / NCIT are stored for reference.
- MONDO:0015715
- UMLS:C5679576
Additional Mondo synonyms (3)
severe factor IX deficiency · severe haemophilia type B · severe hemophilia type B
Research stages
Trial readiness signals
Where this condition sits on an open-data research pipeline — not how close a treatment is, and not medical advice. Empty stages often mean “not in these databases under this Mondo ID,” not “impossible.”
2/6 stages with a signal
An interventional trial matched this condition name on ClinicalTrials.gov — see trials below.
- Gene identifiedNot found
No GenCC disease–gene assertion in this build
- LiteraturePresent
836 matched papers (460 in last 10 years) Source
- Phenotype characterisedNot found
No HPO disease–phenotype associations via Monarch for these Mondo IDs
- Animal modelNot found
No Alliance genotype “model of” associations via Monarch for these Mondo IDs
- Orphan designationNot found
No FDA or EMA orphan-drug designation matched this disease via UMLS or preferred name Source
- Interventional trialPresent
21 matched on ClinicalTrials.gov (1 recruiting in sample)
Biology
Genes and phenotypes
Gene–disease validity from GenCC, plus phenotypes and animal models joined from Monarch Initiative via Mondo ID — not a clinical diagnosis aid.
Do we know what causes it?
Not yet — the cause hasn't been pinned down in GenCC.
No strong gene–disease assertion joined for this Orphanet entity.
Phenotypes (Monarch / HPO)
None returned for this Mondo ID. That often means “not linked under this ID,” not “no clinical features.”
Animal models (Monarch / Alliance)
None returned for this Mondo ID. Empty here is not proof that no model organism work exists under another name or gene.
Monarch fetch 2026-07-29
Therapies
Designations, candidates, and chemicals
FDA OOPD and EMA orphan designations, Open Targets clinical candidates, and CTD chemical associations via MyDisease.info. These never change the interventional-trial headline.
Orphan designation (FDA · EMA)
No designation matched this disease via UMLS or preferred name on the FDA OOPD mirror or EMA orphan register. Absence here is not proof that none exists under another wording.
Open Targets candidates
No drugs or clinical candidates returned for this Mondo ID on Open Targets.
CTD chemicals (MyDisease.info)
No CTD chemical associations returned for this Mondo ID.
Literature
Is anyone studying this?
836
836 papers have been published on this condition. That is a real research literature — still far smaller than common diseases (breast cancer: over 700,000 papers). Median papers in the last 10 years for a rare disease in this dataset (publications denominator n=3967) is 59.
836 papers since the earliest indexed year in this search — median last-10-year count for a rare disease in this dataset is 59 (publications denominator n=3967).
460 in the last 10 years · high confidence · 82.4th percentile (publications denominator)
Phrase hits: 836 · MeSH hits: 0
Who's working on it?
1,153
Distinct author names in 200 sampled papers — named people below.
Who's working on it?
People publishing on this condition (sampled Europe PMC records). Affiliation is the most recent found in that sample.
- 01Mahlangu J10 papers · 2026
National Coagulation Centre St James's Hospital Dublin Ireland.
Papers in Europe PMC - 02Castaman G9 papers · 2025
Center for Bleeding Disorders and Coagulation, Department of Oncology, Careggi University Hospital, Florence.
Papers in Europe PMC - 03Miesbach W9 papers · 2026
The Haemophilia Center of the Medical Clinic, University Hospital Frankfurt/Main.
Papers in Europe PMC - 04Peyvandi F9 papers · 2026
Angelo Bianchi Bonomi Haemophilia and Thrombosis Center, Fondazione Luigi Villa, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan.
Papers in Europe PMC - 05Pipe SW8 papers · 2026
Department of Pediatrics and Pathology, University of Michigan, Ann Arbor, MI.
Papers in Europe PMC - 06Recht M7 papers · 2025
American Thrombosis and Hemostasis Network, Chicago, Illinois.
Papers in Europe PMC - 07von Drygalski A7 papers · 2026
Division of Hematology/Oncology, Department of Medicine, University of California, San Diego, La Jolla, CA, USA.
Papers in Europe PMC - 08Leebeek FWG6 papers · 2026
Erasmus University Medical Center, Rotterdam, The Netherlands.
Papers in Europe PMC - 09Monahan PE6 papers · 2026
From the Departments of Pediatrics and Pathology, University of Michigan, Ann Arbor (S.W.P.); the Department of Hematology, Erasmus University Medical Center, University Medical Center Rotterdam, Rotterdam (F.W.G.L.), Van Creveldkliniek, University Medical Center Utrecht, University Utrecht, Utrecht (P.V.V.), Vascular Medicine, Amsterdam University Medical Center, University of Amsterdam (M.C.), Amsterdam Cardiovascular Sciences, Pulmonary Hypertension and Thrombosis (M.C.), and uniQure Biopharma (Y.P.L.), Amsterdam, and University Medical Center Groningen, Groningen (K.M.) - all in the Netherlands; Yale University School of Medicine, New Haven, CT (M.R., S.L.); American Thrombosis and Hemostasis Network, Rochester, NY (M.R.); the Department of Medicine and UNC Blood Research Center, University of North Carolina at Chapel Hill, Chapel Hill (N.S.K.); the Center for Bleeding Disorders and Coagulation, Department of Oncology, Careggi University Hospital, Florence, Italy (G.C.); the Department of Hemostaseology and Hemophilia Center, Medical Clinic 2, Institute of Transfusion Medicine and Immunohematology, University Hospital Frankfurt, Frankfurt (W.M.), the Comprehensive Care Hemophilia Treatment Center, Vivantes Klinikum im Friedrichshain, Berlin, and the Institute of Experimental Hematology and Transfusion Medicine, University Hospital Bonn, Medical Faculty, University of Bonn, Bonn (R. Klamroth) - all in Germany; the Department of Vascular Medicine and Hemostasis, Hemophilia Center, University Hospitals Leuven, Leuven (K.P.), the Division of Hematology, Cliniques Universitaires Saint-Luc, Brussels (C.R.J.R.H.), and Université Catholique de Louvain, Louvain-la-Neuve (C.R.J.R.H.) - all in Belgium; the Department of Hematology, Rigshopitalet Copenhagen, Copenhagen (P.K.); National Coagulation Centre, St. James's Hospital, Dublin (N.O.); Barts and the London School of Medicine and Dentistry, Queen Mary University of London (K.J.P., D.P.H.), and the Royal London Hospital Haemophilia Centre, Barts Health NHS Trust (D.P.H.), London, University Hospital Southampton and National Institute for Health and Care Research Clinical Research Facility, Southampton (R. Kazmi), and Cambridge University NHS Foundation Trust, Addenbrooks Hospital, Cambridge (E.S.) - all in the United Kingdom; the Department of Translational Medicine, Lund University, and the Department of Hematology Oncology and Radiation Physics, Skåne University Hospital - both in Malmö, Sweden (J.A.); the Department of Pediatrics, University of Utah, and Primary Children's Hospital, Salt Lake City (R.L.); University of South Florida, Tampa (N.V.); the Department of Medicine, Hemophilia and Thrombosis Treatment Center, San Diego (A.D.), the Cancer and Blood Disorders Institute, Children's Hospital Los Angeles (G.Y.), the Orthopaedic Hemophilia Treatment Center, the Luskin Orthopaedic Institute for Children (D.V.Q.), and the University of Southern California Keck School of Medicine (G.Y.), Los Angeles, and the Center for Inherited Blood Disorders, Orange (E.G.) - all in California; Arkansas Children's Hospital, Pulaski, and University of Arkansas for Medical Sciences, Little Rock (S.E.C.); University of Texas Health Science Center, McGovern Medical School, and Gulf States Hemophilia and Thrombophilia Center - both in Houston (M.E.); Washington Center for Bleeding Disorders and University of Washington, Seattle (R.K.-J.); Hemophilia and Thrombosis Center, University of Colorado Anschutz Medical Campus, Aurora (M.W.); the Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville (A.P.W.); uniQure, Lexington, MA (R.G., R.E.D., D.L.C.); and CSL Behring, King of Prussia, PA (Y.L., B.G., P.E.M.).
Papers in Europe PMC - 10Astermark J5 papers · 2026
Department of Translational Medicine, Lund University, and Department of Hematology, Oncology and Radiation Physics, Skåne University Hospital, Malmö, Sweden.
Papers in Europe PMC
Clinical research
Is a treatment being tested?
21
interventional trials for this specific condition
21 interventional trials matched this specific condition name; 1 currently recruiting in our sample. 99 trials are registered for hemophilia B, the broader category — shown separately because they may or may not enrol this specific subtype.
Data as of 11 September 2026
21 interventional trials — more than 77.2% of diseases in the trials denominator have none at all (5501 of 7126; this disease is at the 95th percentile).
high confidence · 95th percentile (trials denominator)
Recruiting interventional trials
From the matched ClinicalTrials.gov set
21 interventional trials matched after quoted-phrase search and title/condition post-filter.
- NCT07080905·RECRUITING·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
Not reviewed·Conditions: Hemophilia B·Matched via name phrase
Broader category: hemophilia B
99
Interventional trials for the parent category, exclusive of NCT IDs already counted above. Eligibility for this subtype is not guaranteed.
Worth raising with a clinician. How we count trials.
Recruiting under the broader category
- NCT05611801·RECRUITING·A Clinical Trial of Study Medicine (Marstacimab) in Pediatric Patients With Hemophilia A or Hemophilia B
Not reviewed·Conditions: Hemophilia A · Hemophilia B·Matched via name phrase
- NCT05145127·RECRUITING·Open-Label Extension Study of Marstacimab in Hemophilia Participants With or Without Inhibitors
Not reviewed·Conditions: Hemophilia A · Hemophilia B·Matched via name phrase
- NCT06003387·RECRUITING·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)
Not reviewed·Conditions: Hemophilia B·Matched via name phrase
- NCT05630651·RECRUITING·The Efficacy and Safety of ZS801 in Chinese Hemophilia B Patients.
Not reviewed·Conditions: Hemophilia B·Matched via name phrase
- NCT06700096·RECRUITING·An Open-Label, Comparative Study of the Efficacy, Safety and Pharmacodynamics of Single Dose of ANB-002 in Patients With Hemophilia B
Not reviewed·Conditions: Hemophilia B·Matched via name phrase
- NCT06747416·NOT YET RECRUITING·KN057 Multiple Dose Study in Patients with Hemophilia a or Hemophilia B with or Without Inhibitors
Not reviewed·Conditions: Hemophilia a and B·Matched via name phrase
- NCT05709288·RECRUITING·Gene Therapy for Hemophilia B Patients Aged 12-18 Years Old
Not reviewed·Conditions: Hemophilia B·Matched via name phrase
- NCT05641610·RECRUITING·A Study to Evaluate the Safety and Efficacy of ZS801 in Adult Hemophilia B Patients
Not reviewed·Conditions: Hemophilia B·Matched via name phrase
- NCT06565481·RECRUITING·Measurement Properties in People with Hemophilia
Not reviewed·Conditions: Hemophilia a · Hemophilia B · Musculoskeletal Complication · Measurement Error·Matched via name phrase
- NCT04647227·RECRUITING·SEVENFACT® for Bleeding Events in Hemophilia With Inhibitors
Not reviewed·Conditions: Hemophilia A With Inhibitor · Hemophilia B With Inhibitor·Matched via name phrase
- NCT07644832·RECRUITING·An Open-label, Multicenter Phase I/II Clinical Trial to Evaluate the Safety, Tolerability, Efficacy, and Pharmacokinetic/Pharmacodynamic (PK/PD) Characteristics of SR604 Injection in Patients With Hemophilia A/B and Congenital Factor VII Deficiency
Not reviewed·Conditions: Hemophilia A · Hemophilia B · Factor VII Deficiency·Matched via name phrase
- NCT06349473·RECRUITING·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)
Not reviewed·Conditions: Healthy Participants · Hemophilia A · Hemophilia B · Factor VII Deficiency·Matched via name phrase
- NCT05568719·RECRUITING·Safety and Effectiveness of Giroctocogene Fitelparvovec or Fidanacogene Elaparvovec in Patients With Hemophilia A or B Respectively
Not reviewed·Conditions: Hemophilia A · Hemophilia B·Matched via name phrase
- NCT03961243·RECRUITING·Lentiviral FIX Gene Therapy
Not reviewed·Conditions: Hemophilia B·Matched via name phrase
- NCT04817462·RECRUITING·Liver Biopsy In Haemophilia Gene Therapy
Not reviewed·Conditions: Hemophilia B, Severe · Hemophilia A, Severe·Matched via name phrase
Observational and natural-history studies
1 observational study matches this condition. These do not test a treatment and are not counted in the interventional-trial headline, but they are genuine research: natural-history work often defines the endpoints needed for a future rare-disease trial, and families may be able to enroll.
None of the matched observational studies is currently listed as recruiting.
Other registries (secondary)
Broader net from EU CTIS, ISRCTN, and ICTRP when available — deduped against ClinicalTrials.gov IDs already counted above. Dual-model LLM relevance gates what we keep. These rows are not added to the interventional headline.
raw 11 · after dedupe 11 · already on CT.gov 0 · kept 0 · parent 0 · uncertain 11 · dropped 0 · fetched 2026-07-30
Source notes: ictrp: Error: ICTRP public search unavailable (WHO portal is SPA-only; SOAP needs partnership). Tried: https://apps.who.int/tri
No secondary-registry studies passed dual-model relevance for this condition name (after dedupe).
Uncertain / not reviewed (11)
- isrctn·ISRCTN58752772·No longer recruiting·Study to investigate the effectiveness of emicizumab under real-world conditions in paediatric, adolescent, adult and elderly participants with haemophilia A with and without Factor VIII (FVIII) inhibitors
skipped — LLM skipped (--skip-llm)
- isrctn·ISRCTN11104750·No longer recruiting·Pharmacokinetics of the antiviral drug ribavirin in Lassa fever treatment
skipped — LLM skipped (--skip-llm)
- isrctn·ISRCTN91314641·No longer recruiting·A clinical study on evaluation of a novel power toothbrush in eliminating dental plaque
skipped — LLM skipped (--skip-llm)
- ctis·2025-523660-21-00·Authorised·C0371017 - A PHASE 3, NON-INVESTIGATIONAL PRODUCT, MULTI COUNTRY COHORT STUDY TO DESCRIBE THE LONG-TERM SAFETY AND EFFECTIVENESS OF A PRIOR SINGLE-DOSE TREATMENT WITH INVESTIGATIVE GIROCTOCOGENE FITELPARVOVEC OR FIDANACOGENE ELAPARVOVEC IN PARTICIPANTS WITH HEMOPHILIA A OR HEMOPHILIA B, RESPECTIVELY
skipped — LLM skipped (--skip-llm)
- ctis·2023-505805-18-00·Authorised, ongoing·Phase 3, Open-label, Single-dose, Multicenter Study Investigating Efficacy, Safety, and Tolerability of CSL222 (Etranacogene Dezaparvovec) Administered to Adolescent Male Subjects (≥ 12 to < 18 Years of Age) with Severe or Moderately Severe Hemophilia B
skipped — LLM skipped (--skip-llm)
- ctis·2023-509590-23-00·Authorised, recruiting·Phase 3b, Open-label, Multicenter, Single-dose Study Investigating Efficacy and Safety of CSL222 (Etranacogene Dezaparvovec) Gene Therapy Administered to Adult Subjects with Severe or Moderately Severe Hemophilia B with Detectable Pretreatment AAV5 Neutralizing Antibodies.
skipped — LLM skipped (--skip-llm)
- ctis·2024-510738-42-00·Cancelled·Phase III, open-label, single-dose, multi-center multinational trial investigating a serotype 5 adeno-associated viral vector containing the Padua variant of a codon-optimized human factor IX gene (AAV5-hFIXco-Padua, AMT-061) administered to adult subjects with severe or moderately severe hemophilia B
skipped — LLM skipped (--skip-llm)
- ctis·2022-502880-39-00·Cancelled·A Global, Open-label, Adaptive Design Study to Investigate the Efficacy and Safety of SerpinPC in Subjects With Severe Hemophilia A or Moderately Severe to Severe Hemophilia B (PRESent-2)
skipped — LLM skipped (--skip-llm)
- ctis·2022-502844-11-00·Authorised, recruiting·C0371002 - Phase 3, open label, single arm study to evaluate efficacy and safety of FIX gene transfer with
PF-06838435 (rAAV-Spark100-hFIX-R338L) in adult male participants with moderately severe to severe hemophilia B (FIX:C≤2%) (BeneGene-2)
skipped — LLM skipped (--skip-llm)
- ctis·2022-500495-65-00·Authorised, recruiting·B7841008 - AN OPEN-LABEL STUDY IN PEDIATRIC (<18 YEARS OF AGE), SEVERE HEMOPHILIA A PARTICIPANTS (COAGULATION FACTOR ACTIVITY <1%) WITH OR WITHOUT INHIBITORS OR MODERATELY SEVERE TO SEVERE HEMOPHILIA B PARTICIPANTS (COAGULATION FACTOR ACTIVITY ≤2%) WITH OR WITHOUT INHIBITORS COMPARING 12 MONTHS OF HISTORICAL STANDARD TREATMENT TO MARSTACIMAB PROPHYLAXIS
skipped — LLM skipped (--skip-llm)
- ctis·2022-500470-33-00·Authorised, ongoing·B7841007 - An Open-Label Extension Study to Evaluate the Long-Term Safety, Tolerability, and Efficacy of Marstacimab Prophylaxis in Severe (Coagulation Factor Activity <1%) Hemophilia A Participants With or Without Inhibitors or Moderately Severe to Severe Hemophilia B Participants (Coagulation Factor Activity ≤2%) With or Without Inhibitors
skipped — LLM skipped (--skip-llm)
Where to find support
Condition-specific patient organisations, when Orphanet lists them, are on the disease’s Orphanet page. We also link umbrella groups that support undiagnosed and ultra-rare families.
Orphanet entry for Severe hemophilia B — check Associations / patient organisations on that page.
India — NPRD
Last verified 2026-07-26This ORPHAcode is not on our curated NPRD list (direct or Mondo-parent match). That does not decide clinical eligibility; families in India should ask a notified Centre of Excellence about current coverage.
Hand-curated for this project. ORPHAcode mappings are best-effort and may be incomplete or imprecise for umbrella categories. Parent (Mondo) matches mean the policy lists a broader category — confirm eligibility with a Centre of Excellence. Financial entitlements summarised from public policy statements and may change. This is not official government guidance.
How we counted this
Europe PMC query (preferred label + any corrected label + Orphanet and Mondo exact synonyms, stoplisted; unioned with resolved MeSH labels when available). UMLS / OMIM / NCIT cross-references are stored on the overview but are not added to the query string.
"Severe hemophilia B" OR "Severe congenital F9 deficiency" OR "Severe congenital factor IX deficiency" OR "severe factor IX deficiency" OR "severe haemophilia type B" OR "severe hemophilia type B"
ClinicalTrials.gov query (quoted phrases + MeSH via query.cond, plus recall-expansion terms when used):
"Severe hemophilia B" OR "Severe congenital F9 deficiency" OR "Severe congenital factor IX deficiency" OR "severe factor IX deficiency" OR "severe haemophilia type B" OR "severe hemophilia type B"
Interventional trials matched via: phrase (mesh = registered under a MeSH descriptor no name phrase would catch; recall-expansion = gene / selected parent terms used only for trials).
Study-type breakdown: 21 interventional · 1 observational · 0 expanded access. Only interventional studies enter the trial headline.
Parent-category trials query:
"hemophilia B"
Query health: ok — strategies attempted: phrase; with hits: phrase
Run this search on ClinicalTrials.gov
Confidence reasoning
- Preferred label is multi-word and distinctive
- No synonyms dropped by stoplist
- No label/synonym collisions with other diseases in this corpus
Ingested 2026-07-27T08:37:38.482Z
