Hemophilia BPhase 3NCT03587116
A Study to Evaluate Prospective Efficacy and Safety Data of Current FIX Prophylaxis Replacement Therapy in Adult Hemophilia B Subjects (FIX:C≤2%) or Current FVIII Prophylaxis Replacement Therapy in Adult Hemophilia A Subjects (FVIII:C≤1%)
A Phase 3 study of Hemophilia B and Hemophilia A, run by Pfizer at 75 sites in 18 countries.
Trial summary
To establish baseline prospective efficacy data of current FIX prophylaxis replacement therapy in the usual care setting of hemophilia B subjects, who are negative for nAb to AAV-Spark100, prior to the Phase 3 gene therapy study. Read more about this study
- Who is it for?
- Ages 18 to 64 years, men only
- Conditions the study is for
- Hemophilia B, Hemophilia A
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 212 participants
- Where
- 75 sitesin 18 countries
- Study dates
- 26 Jul 2018to 13 Dec 2024
- Phase
- Phase 3
- Are there results?
- Yes, posted in the registrySummary in the doctors' view
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 64 years
- Men only
- No healthy volunteers
- Adult
Who may be able to join
- Hemophilia B Population:
- Evidence of a signed and dated informed consent document indicating that the participant has been informed of all pertinent aspects of the study.
- Willing and able to comply with scheduled visits, FIX prophylaxis treatment plan, laboratory tests and other study procedures.
- Males ≥ 18 and <65 years of age with moderately severe to severe hemophilia B and documented FIX activity (≤2%) prior to baseline visit.
- Previous experience with FIX therapy (≥50 documented exposure days to a FIX protein product such as recombinant, plasma-derived or extended half-life FIX product).
- Participants on FIX prophylaxis replacement therapy (recombinant, plasma-derived or extended half-life FIX product) must have the intention to remain on FIX prophylaxis replacement therapy for the duration of the study.
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- No known hypersensitivity to FIX replacement product.
- No history of FIX inhibitor (clinical or laboratory-based assessment) defined as a titer
- 0.6 BU/mL, regardless of the laboratory normal range, or any measured Bethesda inhibitor titer greater than the upper limit of normal for the laboratory performing the assay. Clinically, no signs or symptoms of decreased response to FIX administration. Participants will not be required to undergo diagnostic evaluation of inhibitor status to participate in the study.
- Hemophilia A Population:
- Evidence of a signed and dated informed consent document indicating that the participant has been informed of all pertinent aspects of the study.
- Willing and able to comply with scheduled visits, FVIII prophylaxis treatment plan, laboratory tests and other study procedures.
- Males ≥18 and <65 years of age with moderately severe to severe hemophilia A and documented FVIII activity (≤1%) prior to baseline visit.
- Previous experience with FVIII therapy (≥150 documented exposure days to a FVIII protein product such as recombinant, plasma-derived or extended half-life FVIII product).
- Participants must be on a stable FVIII prophylaxis replacement therapy (recombinant, plasma-derived or extended half-life FVIII product) at study entry and must have the intention to remain on FVIII prophylaxis replacement therapy for the duration of the study. This does not include nonfactor treatments, which are prohibited.
- No known hypersensitivity to FVIII replacement product.
- No history of FVIII inhibitor (clinical or laboratory-based assessment) defined as a titer ≥0.6 BU/mL, regardless of the laboratory normal range, or any measured Bethesda inhibitor titer greater than the upper limit of normal for the laboratory performing the assay. Clinically, no signs or symptoms of decreased response to FVIII administration. Participants will not be required to undergo diagnostic evaluation of inhibitor status to participate in the study.
Who cannot join
- Anti-AAV-Spark100 neutralizing antibody titer above the established threshold performed by a central laboratory during screening in hemophilia B subjects or Anti-AAV6 neutralizing antibody titer above the established threshold performed by a central laboratory during screening in hemophilia A subjects.
- Lack of participant compliance with documentation of bleeds and/or prophylaxis replacement therapy administration.
- If there is no documentation regarding hepatitis status, as defined below, within the last 12 months prior to screening for hepatitis B and 6 months prior to screening for hepatitis C, then participants will be required to have the following hepatitis testing performed at screening:
- Hepatitis B screening (acute and chronic):
- HBsAg (also referred to as Hepatitis B surface antigen), HBV-DNA viral assay (also referred to as a nucleic acid test for Hepatitis B virus DNA), and Anti-HBc (also referred to as Total Hepatitis B core antibody).
- A participant is not eligible if either HbsAg is positive or HBV-DNA is positive/detectable.
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- Anti-HBc must be obtained in all participants for determination of whether the participant had prior hepatitis B. If the anti-HBc is positive and both HBsAg and HBV DNA are negative this would be consistent with a prior infection and the subject would be eligible for the study. Anti-HBc must be obtained in all subjects to discriminate between those with no prior hepatitis B and those with prior infection in the event of reactivation. FDA has noted reactivation of hepatitis B virus exists.
- One documented negative HBV-DNA viral load is sufficient to assess eligibility. A participant who is currently undergoing anti-viral therapy for hepatitis B is not eligible.
- Hepatitis C (acute or chronic):
- A participant who is currently undergoing anti-viral therapy for chronic hepatitis C is not eligible.
- Participants treated with anti-viral therapy for chronic hepatitis C, must have completed anti-viral therapy at least 6 months prior to screening and have a negative HCV-RNA at least 6 months prior to screening.
- All participants (who are not currently undergoing anti-viral therapy for chronic hepatitis C) must have a single HCV-RNA load assay (also referred to as a nucleic acid test [NAT] for HCV RNA) obtained during the 6 months preceding screening. This includes participants with prior known chronic hepatitis C who have completed treatment with anti-viral therapy.
- A participant is not eligible if his HCV-RNA load assay result is positive/detectable.
- Currently on antiviral therapy for hepatitis B or C.
- Significant liver disease, as defined by pre-existing diagnosis of portal hypertension, splenomegaly, or hepatic encephalopathy.
- All participants who do not have the listed pre existing diagnoses above must have the following assessments performed within the last 12 months prior to screening and if not will need to be tested for liver fibrosis status at screening: a serum albumin level below normal limits and/or significant liver fibrosis by any of the following diagnostic modalities: FibroScan median stiffness score >8 kPa units OR FibroTest/FibroSURE >0.48.
- NOTE: If there is concern regarding the validity of any of the liver fibrosis test results please contact the medical monitor to discuss whether any additional testing needs to be performed (ie, either repeating any test or performing another fibrosis test). Also, note, if a participant has a known history of Gilbert's syndrome, a FibroTest cannot be used for fibrosis testing.
- Documented serological evidence of human immunodeficiency virus HIV-1 or HIV-2 with Cluster of Differentiation 4 positive (CD4+) cell count ≤200 mm3 within the last 12 months prior to screening. Participants who are HIV positive and stable, have an adequate CD4 count (>200/mm3) and undetectable viral load (<50 gc/mL) documented within the preceding 12 months, and are on an antiretroviral drug regimen are eligible to enroll. Participants who have not been tested within the prior 12 months of screening will need to be tested for HIV status at screening.
- History of chronic infection or other chronic disease that the investigator deems an unacceptable risk. In addition, any participant with conditions associated with increased thromboembolic risk such as known inherited or acquired thrombophilia, or a history of thrombotic events including but not limited to stroke, myocardial infarction, and/or venous thromboembolism, is excluded.
- Any concurrent clinically significant major disease or condition that the investigator deems unsuitable for participation or other acute or chronic medical or psychiatric condition including recent (within the past year) or active suicidal ideation or behavior or laboratory abnormality that may increase the risk associated with study participation or may interfere with the interpretation of study results and, in the judgment of the investigator, would make the participant inappropriate for entry into this study. In addition, any participant with a history of a neoplasm (including hepatic malignancy) that required treatment (eg, chemotherapy, radiotherapy, immunotherapy), is excluded, except for adequately treated basal or squamous cell carcinoma of the skin or a surgically removed benign neoplasm not requiring chemotherapy, radiotherapy and/or immunotherapy. Any other neoplasm that has been cured by resection should be discussed between the investigator and sponsor.
- Participation in other studies if involving administration of investigational product(s) within the last 3 months prior to study entry and/or during study participation or in a previous gene therapy clinical study within the last 12 months prior to screening.
- Participants already enrolled in this lead-in study (C0371004) may be allowed to participate in the screening and baseline periods of either C0371002 or C3731003 protocols prior to their completion of the end of study visit in this lead-in study.
- Any participant who previously received fidanacogene elaparvovec (hemophilia B) or giroctocogene fitelparvovec (hemophilia A) or any AAV gene-based therapy.
- Participants using restricted therapies.
- Any participant with a planned surgical procedure requiring FIX (hemophilia B) or FVIII (hemophilia A) surgical prophylactic factor treatment in the next 24 months.
- Investigator site staff members directly involved in the conduct of the study and their family members, site staff members otherwise supervised by the investigator, or participants who are Pfizer employees, including their family members, directly involved in the conduct of the study.
- NOTE: The sponsor's medical team should be contacted if there are any questions regarding any of the inclusion or exclusion criteria (Sections: 4.1 and 4.2).
Trial locations and contacts
75 sites in 18 countries.
75 sites in 18 countries
United States13 sites
Emory University Hospital Midtown
Atlanta, Georgia, 30308
Emory University Hospital
Atlanta, Georgia, 30322
Investigational Drug Service
Atlanta, Georgia, 30322
Hemophilia and Thrombosis Center at the University of Colorado Anschutz Medical Campus
Aurora, Colorado, 80045
Indiana Hemophilia & Thrombosis Center, Inc.
Indianapolis, Indiana, 46260
Alliance for Childhood Diseases
Las Vegas, Nevada, 89135
Mississippi Center for Advanced Medicine
Madison, Mississippi, 39110
Clinical and Translational Research Unit (CTRU)
Palo Alto, California, 94304
Lucile Packard Childrens Hospital
Palo Alto, California, 94304
Penn Blood Disorder Center
Philadelphia, Pennsylvania, 19104
University of California, San Francisco - Outpatient Hematology Clinic
San Francisco, California, 94143
Bloodworks NW
Seattle, Washington, 98104
Stanford Health Care
Stanford, California, 94305
Brazil6 sites
Centro de Hemoterapia e Hematologia do Para - Fundação HEMOPA
Belém, Pará, 66033-000
Centro de Hematologia e Hemoterapia - Hemocentro de Campinas - UNICAMP
Campinas, São Paulo, 13083-878
Hospital Das Clínicas Da Faculdade de Medicina de Ribeirao Preto Da Universidade de Sao Paulo
Ribeirão Preto, São Paulo, 14051-140
lnstituto Estadual de Hematologia Arthur de Siqueira Cavalcanti - HEMORIO
Rio de Janeiro, 20211-030
Hospital das Clinicas da Faculdade de Medicina da Universidade de Sao Paulo
São Paulo, 05403-000
Centro Estadual de Hemoterapia e Hematologia Marcos Daniel Santos - Hemoes
Vitória, Espírito Santo, 29047-105
Japan6 sites
Saitama Medical University Hospital
Iruma-gun, Saitama, 350-0495
Nara Medical University Hospital
Kashihara, Nara, 634-8522
Nagoya University Hospital - Transfusion Medicine
Nagoya, Aichi-ken, 466-8560
Sapporo Tokushukai Hospital
Sapporo, Hokkaido, 004-0041
National Center for Child Health and Development
Setagaya-ku, Tokyo, 157-8535
Ogikubo Hospital
Suginami-ku, Tokyo, 167-0035
Turkey (Türkiye)6 sites
Acibadem Adana Hospital, Department of Pediatric Hematology
Adana, 01130
Akdeniz University Medical Faculty Hospital
Antalya, 07070
Ege Universitesi Tip Fakultesi Cocuk Sagligi Ve Hastaliklari Anabilim Dali Pediatric Hematoloji
Bornova, İ̇zmir, 35040
Ege Universitesi Tip Fakultesi Hematoloji BD
Bornova, İ̇zmir, 35040
Gaziantep University Sahinbey Training and Research Hospital
Gaziantep, 27310
Istanbul University Oncology Institute
Istanbul, 34093
Australia5 sites
Royal Adelaide Hospital
Adelaide, South Australia, 5000
Royal Prince Alfred Hospital
Camperdown, New South Wales, 2050
Royal Brisbane and Women's Hospital
Herston, Queensland, 4029
The Alfred Hospital
Melbourne, Victoria, 3004
Fiona Stanley Hospital
Murdoch, Western Australia, 6150
Spain5 sites
Hospital de la Santa Creu i Sant Pau
Barcelona, 08025
Hospital Universitari Vall d´Hebrón
Barcelona, 08035
Hospital Universitario Virgen de la Arrixaca
El Palmar, Murcia, 30120
H.U. La Paz.
Madrid, 28046
H.U. Rio Hortega
Valladolid, 47012
Taiwan5 sites
Changhua Christian Hospital
Changhua, 500
Kaohsiung Medical University Chung-Ho Memorial Hospital
Kaohsiung City, 807
Chung Shan Medical University Hospital
Taichung, 40201
Taichung Veterans General Hospital
Taichung, 40705
National Taiwan University Hospital
Taipei, 10002
United Kingdom5 sites
Clinical Research Facility
Glasgow, G31 2ER
Department of Haematology
Glasgow, G4 0SF
Guy's and St Thomas' NHS Foundation Trust
London, SE1 7EH
Newcastle upon Tyne Hospitals NHS Foundation Trust
Newcastle upon Tyne, TYNE & WEAR, NE1 4LP
Non Malignant Haematology Research Unit
Newcastle upon Tyne, TYNE & WEAR, NE1 4LP
France4 sites
CHRU de Brest - La Cavale Blanche
Brest, 29200
Hôpital Cardiologique Louis Pradel
Bron, 69677
CHU Hôtel-Dieu
Nantes, 44093
Hopital Necker, Hematologie Adultes
Paris, 75015
Germany4 sites
Vivantes Klinikum Friedrichshain
Berlin, 10249
Universitatsklinikum Bonn. Anstalt des oeffentlichen Rechts
Bonn, 53127
Universitaetsklinikum Giessen
Giessen, 35392
Universität und Universitätsklinikum des Saarlandes
Homburg/Saar, 66421
Italy4 sites
IRCCS - AOU di Bologna, Policlinico di Sant'Orsola
Bologna, BO, 40138
SODc. Malattie Emorragiche e della Coagulazione Centro di Riferimento Regionale per le
Florence, 50134
UOC Medicina Interna - Malattie Emorragiche e Trombotiche
Naples, Naples, 80131
Università degli studi di Roma "La Sapienza"- Policlinico Umberto I
Roma, 00161
South Korea3 sites
Kyungpook National University Hospital
Daegu, 41944
Severance Hospital, Yonsei University Health System
Seoul, 03722
Kyung Hee University Hospital At Gangdong
Seoul, 05278
Canada2 sites
McMaster University Medical Centre - Hamilton Health Sciences
Hamilton, Ontario, L8N 3Z5
St. Michael's Hospital
Toronto, Ontario, M5B 1W8
Greece2 sites
General Hospital of Athens "Hippokration"
Athens, Attica, 11527
General Hospital of Athens "LAIKO", 2nd Regional Blood Transfusion Center
Athens, Attica, 11527
Saudi Arabia2 sites
King Abdulaziz Medical City
Riyadh, 11426
King Faisal Specialist Hospital & Research Center
Riyadh
Belgium1 site
Cliniques universitaires Saint-Luc/Unité d'Hématology et Hémostase
Brussels, 1200
Israel1 site
The Chaim Sheba Medical Center, The National Hemophilia Center
Tel Litwinsky, 5262000
About this study
Official title: AN OPEN-LABEL, NON-INVESTIGATIONAL PRODUCT, LEAD-IN STUDY TO EVALUATE AT LEAST 6 MONTHS OF PROSPECTIVE EFFICACY AND SAFETY DATA OF FACTOR IX OR FACTOR VIII PROPHYLAXIS REPLACEMENT THERAPY IN THE USUAL CARE SETTING OF MODERATELY SEVERE TO SEVERE ADULT HEMOPHILIA B SUBJECTS (FIX:C≤2%) WHO ARE NEGATIVE FOR nAb TO AAV VECTOR-SPARK100 AND MODERATELY SEVERE TO SEVERE HEMOPHILIA A ADULT SUBJECTS (FVIII:C≤1%) WHO ARE NEGATIVE FOR nAb TO AAV VECTOR SB-525 CAPSID (AAV6), PRIOR TO THE RESPECTIVE THERAPEUTIC PH 3 GENE THERAPY STUDIES (See Detailed Description Section for Official Protocol Title)
To establish baseline prospective efficacy data of current FIX prophylaxis replacement therapy in the usual care setting of hemophilia B subjects, who are negative for nAb to AAV-Spark100, prior to the Phase 3 gene therapy study.
To establish baseline prospective efficacy data of current FVIII prophylaxis replacement therapy in the usual care setting of hemophilia A subjects, who are negative for nAb to AAV6, prior to the Phase 3 gene therapy study.
The enrollment for hemophilia A participants is completed. At this time participants are only being enrolled for hemophilia B cohort.
Read the detailed description
AN OPEN-LABEL, NON-INVESTIGATIONAL PRODUCT, MULTI-CENTER, LEAD-IN STUDY TO EVALUATE PROSPECTIVE EFFICACY AND SELECTED SAFETY DATA OF CURRENT FACTOR IX (FIX) OR FACTOR VIII (FVIII) PROPHYLAXIS REPLACEMENT THERAPY IN THE USUAL CARE SETTING OF MODERATELY SEVERE TO SEVERE ADULT HEMOPHILIA B SUBJECTS (FIX:C≤2%) WHO ARE NEGATIVE FOR NEUTRALIZING ANTIBODIES TO ADENO-ASSOCIATED VIRUS VECTOR-SPARK100 (BENEGENE-1) AND MODERATELY SEVERE TO SEVERE HEMOPHILIA A ADULT SUBJECTS (FVIII:C≤1%) WHO ARE NEGATIVE FOR NEUTRALIZING ANTIBODIES TO ADENO-ASSOCIATED VIRUS VECTOR 6 (AAV6), PRIOR TO THE RESPECTIVE THERAPEUTIC PHASE 3 GENE THERAPY STUDIES
- Conditions
- Hemophilia B, Hemophilia A
- Being tested
- Standard of Care FIX Replacement therapy, Standard of Care FVIII Replacement therapy
- Medical subject headings
- Hemophilia B, Hemophilia A
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Standard of Care FIX Replacement therapyDrug
There is no investigational product being administered. Subjects will be administering their own standard of care FIX replacement therapy.
Standard of Care FVIII Replacement therapyDrug
There is no investigational product being administered. Subjects will be administering their own standard of care FVIII replacement therapy.
| Study group | Role | What they receive |
|---|---|---|
| Standard of Care FIX replacement therapy | Other | Not described Receives: Drug: Standard of Care FIX Replacement therapy |
| Standard of Care FVIII replacement therapy | Other | Not described Receives: Drug: Standard of Care FVIII Replacement therapy |
What is being measured
The primary outcome is the main question the study is designed to answer.
Annualized Bleeding Rate (ABR) for Treated Bleeds and All Bleeds During Prospective Data Collection Period in Hemophilia B Participants: Efficacy Analysis Set
ABR per participant was calculated as number of bleeds over number of days from baseline visit (Day 1 of the study) to end of study multiplication(*)365.25 days. All bleeds included treated and untreated bleeds. A treated bleed was defined as an event necessitating administration of coagulation factor within 72 hours of signs or symptoms of bleeding. An untreated bleed was defined as an event not necessitating administration of coagulation factor within 72 hours of signs or symptoms of bleeding. In this outcome measure, ABR for all and treated bleeds during prospective data collection period in hemophilia B participants per efficacy analysis set was reported. Abbreviations used: AAV6 = adeno-associated virus 6; AAV-Spark100 = Bioengineered AAV capsid, derived from a naturally occurring AAV serotype; nAb = neutralizing antibodies.
Measured: During prospective data collection period (from baseline visit of the study [Day 1] up to end of study follow-up [maximum follow-up: 1269 days])
ABR for Treated Bleeds and All Bleeds During Prospective Data Collection Period in Hemophilia B Participants: Per-protocol Analysis Set
ABR per participant was calculated as number of bleeds over number of days from baseline visit (Day 1 of the study) to end of study*365.25 days. All bleeds included treated and untreated bleeds. A treated bleed was defined as an event necessitating administration of coagulation factor within 72 hours of signs or symptoms of bleeding. An untreated bleed was defined as an event not necessitating administration of coagulation factor within 72 hours of signs or symptoms of bleeding. In this outcome measure, ABR for all and treated bleeds during prospective data collection period in hemophilia B participants per protocol analysis set was reported.
Measured: During prospective data collection period (from baseline visit of the study [Day 1] up to end of study follow-up [maximum follow-up: 1269 days])
ABR for Treated Bleeds and All Bleeds During Prospective Data Collection Period in Hemophilia B Participants: Protocol Amendment 5 Analysis Set
ABR per participant was calculated as number of bleeds over number of days from baseline visit (Day 1 of the study) to end of study*365.25 days. All bleeds included treated and untreated bleeds. A treated bleed was defined as an event necessitating administration of coagulation factor within 72 hours of signs or symptoms of bleeding. An untreated bleed was defined as an event not necessitating administration of coagulation factor within 72 hours of signs or symptoms of bleeding. In this outcome measure, ABR for all and treated bleeds during prospective data collection period in hemophilia B participants per protocol amendment 5 analysis set was reported.
Measured: During prospective data collection period (from baseline visit of the study [Day 1] up to end of study follow-up [maximum follow-up: 1269 days])
ABR for Treated Bleeds and All Bleeds During Retrospective Data Collection Period in Hemophilia B Participants: Protocol Amendment 5 Analysis Set
ABR per participant was calculated as number of bleeds over number of days from baseline visit (Day 1 of the study) to end of study*365.25 days. All bleeds included treated and untreated bleeds. A treated bleed was defined as an event necessitating administration of coagulation factor within 72 hours of signs or symptoms of bleeding. An untreated bleed was defined as an event not necessitating administration of coagulation factor within 72 hours of signs or symptoms of bleeding. In this outcome measure, ABR for all and treated bleeds during retrospective data collection period in hemophilia B participants per protocol amendment 5 analysis set was reported.
Measured: During retrospective data collection period (12 months before screening collected in the hemophilia history case report form [CRF])
ABR for Treated Bleeds and All Bleeds From the Combined Retrospective and Prospective Data Collection Period in Hemophilia B Participants: Protocol Amendment 5 Analysis Set
ABR per participant was calculated as number of bleeds over number of days from baseline visit (Day 1 of the study) to end of study*365.25 days. All bleeds included treated and untreated bleeds. A treated bleed was defined as an event necessitating administration of coagulation factor within 72 hours of signs or symptoms of bleeding. An untreated bleed was defined as an event not necessitating administration of coagulation factor within 72 hours of signs or symptoms of bleeding. In this outcome measure, ABR for all and treated bleeds during retrospective and prospective data collection period in hemophilia B participants per protocol amendment 5 analysis set was reported.
Measured: From start of retrospective data collection period (12 months before screening collected in hemophilia history CRF) up to end of prospective data collection follow-up of period (maximum follow-up:1269 days), for a total of approximately 4.5 years
ABR for Treated Bleeds and All Bleeds During Prospective Data Collection Period in Hemophilia A Participants: Efficacy Analysis Set
ABR per participant was calculated as number of bleeds over number of days from baseline visit (Day 1 of the study) to end of study*365.25 days. All bleeds included treated and untreated bleeds. A treated bleed was defined as an event necessitating administration of coagulation factor within 72 hours of signs or symptoms of bleeding. An untreated bleed was defined as an event not necessitating administration of coagulation factor within 72 hours of signs or symptoms of bleeding. In this outcome measure, ABR for all and treated bleeds during prospective data collection period in hemophilia A participants per efficacy analysis set was reported.
Measured: During prospective data collection period (from baseline visit of the study [Day 1] up to end of study follow-up [maximum follow-up: 948 days])
ABR for Treated Bleeds and All Bleeds During Prospective Data Collection Period in Hemophilia A Participants: Per-protocol Analysis Set
ABR per participant was calculated as number of bleeds over number of days from baseline visit (Day 1 of the study) to end of study*365.25 days. All bleeds included treated and untreated bleeds. A treated bleed was defined as an event necessitating administration of coagulation factor within 72 hours of signs or symptoms of bleeding. An untreated bleed was defined as an event not necessitating administration of coagulation factor within 72 hours of signs or symptoms of bleeding. In this outcome measure, ABR for all and treated bleeds during prospective data collection period in hemophilia A participants per protocol analysis set was reported.
Measured: During prospective data collection period (from baseline visit of the study [Day 1] up to end of study follow-up [maximum follow-up: 948 days])
ABR for Treated Bleeds and All Bleeds During Prospective Data Collection Period in Hemophilia A Participants: Protocol Amendment 5 Analysis Set
ABR per participant was calculated as number of bleeds over number of days from baseline visit (Day 1 of the study) to end of study*365.25 days. All bleeds included treated and untreated bleeds. A treated bleed was defined as an event necessitating administration of coagulation factor within 72 hours of signs or symptoms of bleeding. An untreated bleed was defined as an event not necessitating administration of coagulation factor within 72 hours of signs or symptoms of bleeding. In this outcome measure, ABR for all and treated bleeds during prospective data collection period in hemophilia A participants per protocol amendment 5 analysis set was reported.
Measured: During prospective data collection period (from baseline visit of the study [Day 1] up to end of study follow-up [maximum follow-up: 948 days])
ABR for Treated Bleeds and All Bleeds During Retrospective Data Collection Period in Hemophilia A Participants: Protocol Amendment 5 Analysis Set
ABR per participant was calculated as number of bleeds over number of days from baseline visit (Day 1 of the study) to end of study*365.25 days. All bleeds included treated and untreated bleeds. A treated bleed was defined as an event necessitating administration of coagulation factor within 72 hours of signs or symptoms of bleeding. An untreated bleed was defined as an event not necessitating administration of coagulation factor within 72 hours of signs or symptoms of bleeding. In this outcome measure, ABR for all and treated bleeds during retrospective data collection period in hemophilia A participants per protocol amendment 5 analysis set was reported.
Measured: During retrospective data collection period (12 months before screening collected in the hemophilia history CRF)
ABR for Treated Bleeds and All Bleeds From the Combined Retrospective and Prospective Data Collection Period in Hemophilia A Participants: Protocol Amendment 5 Analysis Set
ABR per participant was calculated as number of bleeds over number of days from baseline visit (Day 1 of the study) to end of study*365.25 days. All bleeds included treated and untreated bleeds. A treated bleed was defined as an event necessitating administration of coagulation factor within 72 hours of signs or symptoms of bleeding. An untreated bleed was defined as an event not necessitating administration of coagulation factor within 72 hours of signs or symptoms of bleeding. In this outcome measure, ABR for all and treated bleeds during retrospective and prospective data collection period in hemophilia A participants per protocol amendment 5 analysis set was reported.
Measured: From start of retrospective data collection period (12 months before screening collected in hemophilia history CRF) up to end of prospective data collection follow-up of period (maximum follow-up:948 days), for a total of approximately 3.6 years
Secondary outcomes (24)
Annualized Infusion Rate (AIR) During Prospective Data Collection Period in Hemophilia B Participants: Efficacy Analysis Set
AIR per participant was calculated as the number of infusions received over number of days from baseline visit (Day 1) to end of study * 365.25 days.
Measured: During prospective data collection period (from baseline visit of the study [Day 1] up to end of study follow-up [maximum follow-up: 1269 days])
AIR During Prospective Data Collection Period in Hemophilia B Participants: Per-protocol Analysis Set
AIR per participant was calculated as the number of infusions received over number of days from baseline visit (Day 1) to end of study * 365.25 days.
Measured: During prospective data collection period (from baseline visit of the study [Day 1] up to end of study follow-up [maximum follow-up: 1269 days])
AIR During Prospective Data Collection Period in Hemophilia B Participants: Protocol Amendment 5 Analysis Set
AIR per participant was calculated as the number of infusions received over number of days from baseline visit (Day 1) to end of study * 365.25 days.
Measured: During prospective data collection period (from baseline visit of the study [Day 1] up to end of study follow-up [maximum follow-up: 1269 days])
AIR During Retrospective Data Collection Period in Hemophilia B Participants: Protocol Amendment 5 Analysis Set
AIR per participant was calculated as the number of infusions received over number of days from baseline visit (Day 1) to end of study * 365.25 days.
Measured: During retrospective data collection period (12 months before screening collected in the hemophilia history CRF)
AIR From the Combined Retrospective and Prospective Data Collection Period in Hemophilia B Participants: Protocol Amendment 5 Analysis Set
AIR combining retrospective and prospective data was calculated as (number of infusions from baseline visit (Day 1) to end of study + number of infusions collected in the Hemophilia History form) / (number of days from baseline visit (Day 1) to end of study + 365.25) / 365.25.
Measured: From start of retrospective data collection period (12 months before screening collected in hemophilia history CRF) up to end of prospective data collection follow-up of period (maximum follow-up:1269 days), for a total of approximately 4.5 years
AIR During Prospective Data Collection Period in Hemophilia A Participants: Efficacy Analysis Set
AIR per participant was calculated as the number of infusions received over number of days from baseline visit (Day 1) to end of study * 365.25 days.
Measured: During prospective data collection period (from baseline visit of the study [Day 1] up to end of study follow-up [maximum follow-up: 948 days])
AIR During Prospective Data Collection Period in Hemophilia A Participants: Per-protocol Analysis Set
AIR per participant was calculated as the number of infusions received over number of days from baseline visit (Day 1) to end of study * 365.25 days.
Measured: During prospective data collection period (from baseline visit of the study [Day 1] up to end of study follow-up [maximum follow-up: 948 days])
AIR During Prospective Data Collection Period in Hemophilia A Participants: Protocol Amendment 5 Analysis Set
AIR per participant was calculated as the number of infusions received over number of days from baseline visit (Day 1) to end of study * 365.25 days.
Measured: During prospective data collection period (from baseline visit of the study [Day 1] up to end of study follow-up [maximum follow-up: 948 days])
AIR During Retrospective Data Collection Period in Hemophilia A Participants: Protocol Amendment 5 Analysis Set
AIR per participant was calculated as the number of infusions received over number of days from baseline visit (Day 1) to end of study * 365.25 days.
Measured: During retrospective data collection period (12 months before screening collected in the hemophilia history CRF)
AIR From the Combined Retrospective and Prospective Data Collection Period in Hemophilia A Participants: Protocol Amendment 5 Analysis Set
AIR combining retrospective and prospective data was calculated as (number of infusions from baseline visit (Day 1) to end of study + number of infusions collected in the Hemophilia History form) / (number of days from baseline visit (Day 1) to end of study + 365.25) / 365.25.
Measured: From start of retrospective data collection period (12 months before screening collected in hemophilia history CRF) up to end of prospective data collection follow-up of period (maximum follow-up:948 days), for a total of approximately 3.6 years
Annualized Total Factor IX Replacement Therapy Consumption During Prospective Data Collection Period in Hemophilia B Participants: Efficacy Analysis Set
Annualized factor consumption was calculated as the total factor replacement therapy consumption (in international unit [IU] and dose) *365.25 days/number of days during the observation time period while the participant received factor prophylaxis replacement therapy in the usual care setting from baseline visit (Day 1) to end of study.
Measured: During prospective data collection period (from baseline visit of the study [Day 1] up to end of study follow-up [maximum follow-up: 1269 days])
Annualized Total Factor IX Replacement Therapy Consumption During Prospective Data Collection Period in Hemophilia B Participants: Per-protocol Analysis Set
Annualized factor consumption was calculated as the total factor replacement therapy consumption (in IU and dose) *365.25 days/number of days during the observation time period while the participant received factor prophylaxis replacement therapy in the usual care setting from baseline visit (Day 1) to end of study.
Measured: During prospective data collection period (from baseline visit of the study [Day 1] up to end of study follow-up [maximum follow-up: 1269 days])
Annualized Total Factor IX Replacement Therapy Consumption During Prospective Data Collection Period in Hemophilia B Participants: Protocol Amendment 5 Analysis Set
Annualized factor consumption was calculated as the total factor replacement therapy consumption (in IU and dose) *365.25 days/number of days during the observation time period while the participant received factor prophylaxis replacement therapy in the usual care setting from baseline visit (Day 1) to end of study.
Measured: During prospective data collection period (from baseline visit of the study [Day 1] up to end of study follow-up [maximum follow-up: 1269 days])
Annualized Total Factor IX Replacement Therapy Consumption During Prospective Data Collection Period in Hemophilia A Participants: Efficacy Analysis Set
Annualized factor consumption was calculated as the total factor replacement therapy consumption (in IU and dose) *365.25 days/number of days during the observation time period while the participant received factor prophylaxis replacement therapy in the usual care setting from baseline visit (Day 1) to end of study.
Measured: During prospective data collection period (from baseline visit of the study [Day 1] up to end of study follow-up [maximum follow-up: 948 days])
Annualized Total Factor IX Replacement Therapy Consumption During Prospective Data Collection Period in Hemophilia A Participants: Per-protocol Analysis Set
Annualized factor consumption was calculated as the total factor replacement therapy consumption (in IU and dose) *365.25 days/number of days during the observation time period while the participant received factor prophylaxis replacement therapy in the usual care setting from baseline visit (Day 1) to end of study.
Measured: During prospective data collection period (from baseline visit of the study [Day 1] up to end of study follow-up [maximum follow-up: 948 days])
Annualized Total Factor IX Replacement Therapy Consumption During Prospective Data Collection Period in Hemophilia A Participants: Protocol Amendment 5 Analysis Set
Annualized factor consumption was calculated as the total factor replacement therapy consumption (in IU and dose) *365.25 days/number of days during the observation time period while the participant received factor prophylaxis replacement therapy in the usual care setting from baseline visit (Day 1) to end of study.
Measured: During prospective data collection period (from baseline visit of the study [Day 1] up to end of study follow-up [maximum follow-up: 948 days])
ABR for Spontaneous Treated Bleeds and All Bleeds During Prospective Data Collection Period in Hemophilia B Participants: Efficacy Analysis Set
ABR per participant was calculated as number of bleeds over number of days from baseline visit (Day 1 of the study) to end of study*365.25 days. Spontaneous bleeds were defined as bleeding for no apparent or known reason particularly into the joints, muscles, and soft tissues. All bleeds included treated and untreated bleeds. A treated bleed was defined as an event necessitating administration of coagulation factor within 72 hours of signs or symptoms of bleeding. An untreated bleed was defined as an event not necessitating administration of coagulation factor within 72 hours of signs or symptoms of bleeding. In this outcome measure, ABR for spontaneous all and treated bleeds during prospective data collection period in hemophilia B participants per efficacy analysis set was reported.
Measured: During prospective data collection period (from baseline visit of the study [Day 1] up to end of study follow-up [maximum follow-up: 1269 days])
ABR for Traumatic Treated Bleeds and All Bleeds During Prospective Data Collection Period in Hemophilia B Participants: Efficacy Analysis Set
ABR per participant was calculated as number of bleeds over number of days from baseline visit (Day 1 of the study) to end of study*365.25 days. Traumatic bleeds were defined as bleeding event occurring for an apparent or known reason. All bleeds included treated and untreated bleeds. A treated bleed was defined as an event necessitating administration of coagulation factor within 72 hours of signs or symptoms of bleeding. An untreated bleed was defined as an event not necessitating administration of coagulation factor within 72 hours of signs or symptoms of bleeding. In this outcome measure, ABR for traumatic all and treated bleeds during prospective data collection period in hemophilia B participants per efficacy analysis set was reported.
Measured: During prospective data collection period (from baseline visit of the study [Day 1] up to end of study follow-up [maximum follow-up: 1269 days])
ABR for Spontaneous Treated Bleeds and All Bleeds During Prospective Data Collection Period in Hemophilia B Participants: Per-protocol Analysis Set
ABR per participant was calculated as number of bleeds over number of days from baseline visit (Day 1 of the study) to end of study*365.25 days. Spontaneous bleeds were defined as bleeding for no apparent or known reason particularly into the joints, muscles, and soft tissues. All bleeds included treated and untreated bleeds. A treated bleed was defined as an event necessitating administration of coagulation factor within 72 hours of signs or symptoms of bleeding. An untreated bleed was defined as an event not necessitating administration of coagulation factor within 72 hours of signs or symptoms of bleeding. In this outcome measure, ABR for spontaneous all and treated bleeds during prospective data collection period in hemophilia B participants per protocol analysis set was reported.
Measured: During prospective data collection period (from baseline visit of the study [Day 1] up to end of study follow-up [maximum follow-up: 1269 days])
ABR for Traumatic Treated Bleeds and All Bleeds During Prospective Data Collection Period in Hemophilia B Participants: Per-protocol Analysis Set
ABR per participant was calculated as number of bleeds over number of days from baseline visit (Day 1 of the study) to end of study*365.25 days. Traumatic bleeds were defined as bleeding event occurring for an apparent or known reason. All bleeds included treated and untreated bleeds. A treated bleed was defined as an event necessitating administration of coagulation factor within 72 hours of signs or symptoms of bleeding. An untreated bleed was defined as an event not necessitating administration of coagulation factor within 72 hours of signs or symptoms of bleeding. In this outcome measure, ABR for traumatic all and treated bleeds during prospective data collection period in hemophilia B participants per protocol analysis set was reported.
Measured: During prospective data collection period (from baseline visit of the study [Day 1] up to end of study follow-up [maximum follow-up: 1269 days])
ABR for Spontaneous Treated Bleeds and All Bleeds During Prospective Data Collection Period in Hemophilia A Participants: Efficacy Analysis Set
ABR per participant was calculated as number of bleeds over number of days from baseline visit (Day 1 of the study) to end of study*365.25 days. Spontaneous bleeds were defined as bleeding for no apparent or known reason particularly into the joints, muscles, and soft tissues. All bleeds included treated and untreated bleeds. A treated bleed was defined as an event necessitating administration of coagulation factor within 72 hours of signs or symptoms of bleeding. An untreated bleed was defined as an event not necessitating administration of coagulation factor within 72 hours of signs or symptoms of bleeding. In this outcome measure, ABR for spontaneous all and treated bleeds during prospective data collection period in hemophilia A participants per efficacy analysis set was reported.
Measured: During prospective data collection period (from baseline visit of the study [Day 1] up to end of study follow-up [maximum follow-up: 948 days])
ABR for Traumatic Treated Bleeds and All Bleeds During Prospective Data Collection Period in Hemophilia A Participants: Efficacy Analysis Set
ABR per participant was calculated as number of bleeds over number of days from baseline visit (Day 1 of the study) to end of study*365.25 days. Traumatic bleeds were defined as bleeding event occurring for an apparent or known reason. All bleeds included treated and untreated bleeds. A treated bleed was defined as an event necessitating administration of coagulation factor within 72 hours of signs or symptoms of bleeding. An untreated bleed was defined as an event not necessitating administration of coagulation factor within 72 hours of signs or symptoms of bleeding. In this outcome measure, ABR for traumatic all and treated bleeds during prospective data collection period in hemophilia A participants per efficacy analysis set was reported.
Measured: During prospective data collection period (from baseline visit of the study [Day 1] up to end of study follow-up [maximum follow-up: 948 days])
ABR for Spontaneous Treated Bleeds and All Bleeds During Prospective Data Collection Period in Hemophilia A Participants: Per-protocol Analysis Set
ABR per participant was calculated as number of bleeds over number of days from baseline visit (Day 1 of the study) to end of study*365.25 days. Spontaneous bleeds were defined as bleeding for no apparent or known reason particularly into the joints, muscles, and soft tissues. All bleeds included treated and untreated bleeds. A treated bleed was defined as an event necessitating administration of coagulation factor within 72 hours of signs or symptoms of bleeding. An untreated bleed was defined as an event not necessitating administration of coagulation factor within 72 hours of signs or symptoms of bleeding. In this outcome measure, ABR for spontaneous all and treated bleeds during prospective data collection period in hemophilia A participants per protocol analysis set was reported.
Measured: During prospective data collection period (from baseline visit of the study [Day 1] up to end of study follow-up [maximum follow-up: 948 days])
ABR for Traumatic Treated Bleeds and All Bleeds During Prospective Data Collection Period in Hemophilia A Participants: Per-protocol Analysis Set
ABR per participant was calculated as number of bleeds over number of days from baseline visit (Day 1 of the study) to end of study*365.25 days. Traumatic bleeds were defined as bleeding event occurring for an apparent or known reason. All bleeds included treated and untreated bleeds. A treated bleed was defined as an event necessitating administration of coagulation factor within 72 hours of signs or symptoms of bleeding. An untreated bleed was defined as an event not necessitating administration of coagulation factor within 72 hours of signs or symptoms of bleeding. In this outcome measure, ABR for traumatic all and treated bleeds during prospective data collection period in hemophilia A participants per protocol analysis set was reported.
Measured: During prospective data collection period (from baseline visit of the study [Day 1] up to end of study follow-up [maximum follow-up: 948 days])
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted16 Jul 2018
- Study start26 Jul 2018
- Primary completion13 Dec 2024
- Study completion13 Dec 2024
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
- Other trials for Hemophilia BStudies of the same condition, open and under way.
- More trials run by PfizerThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 3
- Primary purpose
- Other
- Allocation
- Not applicable
- Intervention model
- Single group
- Model description
- The data obtained from this lead-in study will serve as the control group for the subsequent Phase 3 gene therapy study.
- Masking
- None (open label)
- Enrolment
- 212 participants (actual)
Sponsor and investigators
- Lead sponsor
- Pfizer
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
- Investigators
- Pfizer CT.gov Call Center, Study director, Pfizer
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT03587116
- Sponsor's protocol ID
- C0371004
- Other IDs
- 2017-001271-23, 2017
- Status last verified
- Oct 2025
- First submitted
- 29 Jun 2018
- Last updated
- 6 Nov 2025
- Results posted
- Yes, on ClinicalTrials.gov
- Data monitoring committee
- No
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- Yes: Pfizer will provide access to individual de-identified participant data and related study documents (e.g. protocol, Statistical Analysis Plan (SAP), Clinical Study Report (CSR)) upon request from qualified researchers, and subject to certain criteria, conditions, and exceptions. Further details on Pfizer's data sharing criteria and process for requesting access can be found at: https://www.pfizer.com/science/clinical\_trials/trial\_data\_and\_results/data\_requests.
Study at a glance
From the registry record, last updated by the sponsor on 6 Nov 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- AN OPEN-LABEL, NON-INVESTIGATIONAL PRODUCT, LEAD-IN STUDY TO EVALUATE AT LEAST 6 MONTHS OF PROSPECTIVE EFFICACY AND SAFETY DATA OF FACTOR IX OR FACTOR VIII PROPHYLAXIS REPLACEMENT THERAPY IN THE USUAL CARE SETTING OF MODERATELY SEVERE TO SEVERE ADULT HEMOPHILIA B SUBJECTS (FIX:C≤2%) WHO ARE NEGATIVE FOR nAb TO AAV VECTOR-SPARK100 AND MODERATELY SEVERE TO SEVERE HEMOPHILIA A ADULT SUBJECTS (FVIII:C≤1%) WHO ARE NEGATIVE FOR nAb TO AAV VECTOR SB-525 CAPSID (AAV6), PRIOR TO THE RESPECTIVE THERAPEUTIC PH 3 GENE THERAPY STUDIES (See Detailed Description Section for Official Protocol Title)
- ClinicalTrials.gov ID
- NCT03587116
- Acronym / sponsor ID
- C0371004
- Conditions
- Hemophilia B, Hemophilia A
- Phase
- Phase 3
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 212 participants (actual)
- Lead sponsor
- PfizerIndustry (pharma, biotech, devices)
- Study start
- 26 Jul 2018 (actual)
- Primary completion
- 13 Dec 2024 (actual)
- Study completion
- 13 Dec 2024 (actual)
- First posted
- 16 Jul 2018 (actual)
- Results
- Posted 6 Nov 2025
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
To establish baseline prospective efficacy data of current FIX prophylaxis replacement therapy in the usual care setting of hemophilia B subjects, who are negative for nAb to AAV-Spark100, prior to the Phase 3 gene therapy study.
To establish baseline prospective efficacy data of current FVIII prophylaxis replacement therapy in the usual care setting of hemophilia A subjects, who are negative for nAb to AAV6, prior to the Phase 3 gene therapy study.
The enrollment for hemophilia A participants is completed. At this time participants are only being enrolled for hemophilia B cohort.
Detailed description
AN OPEN-LABEL, NON-INVESTIGATIONAL PRODUCT, MULTI-CENTER, LEAD-IN STUDY TO EVALUATE PROSPECTIVE EFFICACY AND SELECTED SAFETY DATA OF CURRENT FACTOR IX (FIX) OR FACTOR VIII (FVIII) PROPHYLAXIS REPLACEMENT THERAPY IN THE USUAL CARE SETTING OF MODERATELY SEVERE TO SEVERE ADULT HEMOPHILIA B SUBJECTS (FIX:C≤2%) WHO ARE NEGATIVE FOR NEUTRALIZING ANTIBODIES TO ADENO-ASSOCIATED VIRUS VECTOR-SPARK100 (BENEGENE-1) AND MODERATELY SEVERE TO SEVERE HEMOPHILIA A ADULT SUBJECTS (FVIII:C≤1%) WHO ARE NEGATIVE FOR NEUTRALIZING ANTIBODIES TO ADENO-ASSOCIATED VIRUS VECTOR 6 (AAV6), PRIOR TO THE RESPECTIVE THERAPEUTIC PHASE 3 GENE THERAPY STUDIES
Study design
- Primary purpose
- Other
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 2
- Model description
- The data obtained from this lead-in study will serve as the control group for the subsequent Phase 3 gene therapy study.
| Arm | Type | Receives |
|---|---|---|
| Standard of Care FIX replacement therapy | Other | Drug: Standard of Care FIX Replacement therapy |
| Standard of Care FVIII replacement therapy | Other | Drug: Standard of Care FVIII Replacement therapy |
Who may qualify
- Ages
- 18 to 64 years
- Sex
- Male only
- Healthy volunteers
- Not accepted
- Age groups
- Adult
Key inclusion criteria (17 listed)
- Evidence of a signed and dated informed consent document indicating that the participant has been informed of all pertinent aspects of the study.
- Willing and able to comply with scheduled visits, FIX prophylaxis treatment plan, laboratory tests and other study procedures.
- Males ≥ 18 and <65 years of age with moderately severe to severe hemophilia B and documented FIX activity (≤2%) prior to baseline visit.
- Previous experience with FIX therapy (≥50 documented exposure days to a FIX protein product such as recombinant, plasma-derived or extended half-life FIX product).
- Participants on FIX prophylaxis replacement therapy (recombinant, plasma-derived or extended half-life FIX product) must have the intention to remain on FIX prophylaxis replacement therapy for the duration of the study.
Key exclusion criteria (27 listed)
- Anti-AAV-Spark100 neutralizing antibody titer above the established threshold performed by a central laboratory during screening in hemophilia B subjects or Anti-AAV6 neutralizing antibody titer above the established threshold performed by a central laboratory during screening in hemophilia A subjects.
- Lack of participant compliance with documentation of bleeds and/or prophylaxis replacement therapy administration.
- If there is no documentation regarding hepatitis status, as defined below, within the last 12 months prior to screening for hepatitis B and 6 months prior to screening for hepatitis C, then participants will be required to have the following hepatitis testing performed at screening:
- HBsAg (also referred to as Hepatitis B surface antigen), HBV-DNA viral assay (also referred to as a nucleic acid test for Hepatitis B virus DNA), and Anti-HBc (also referred to as Total Hepatitis B core antibody).
- Currently on antiviral therapy for hepatitis B or C.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Standard of Care FIX Replacement therapyThere is no investigational product being administered. Subjects will be administering their own standard of care FIX replacement therapy. | Drug | Standard of Care FIX replacement therapy |
| Standard of Care FVIII Replacement therapyThere is no investigational product being administered. Subjects will be administering their own standard of care FVIII replacement therapy. | Drug | Standard of Care FVIII replacement therapy |
Primary outcome
Annualized Bleeding Rate (ABR) for Treated Bleeds and All Bleeds During Prospective Data Collection Period in Hemophilia B Participants: Efficacy Analysis Set
Time frame: During prospective data collection period (from baseline visit of the study [Day 1] up to end of study follow-up [maximum follow-up: 1269 days])
ABR per participant was calculated as number of bleeds over number of days from baseline visit (Day 1 of the study) to end of study multiplication(*)365.25 days. All bleeds included treated and untreated bleeds. A treated bleed was defined as an event necessitating administration of coagulation factor within 72 hours of signs or symptoms of bleeding. An untreated bleed was defined as an event not necessitating administration of coagulation factor within 72 hours of signs or symptoms of bleeding. In this outcome measure, ABR for all and treated bleeds during prospective data collection period in hemophilia B participants per efficacy analysis set was reported. Abbreviations used: AAV6 = adeno-associated virus 6; AAV-Spark100 = Bioengineered AAV capsid, derived from a naturally occurring AAV serotype; nAb = neutralizing antibodies.
ABR for Treated Bleeds and All Bleeds During Prospective Data Collection Period in Hemophilia B Participants: Per-protocol Analysis Set
Time frame: During prospective data collection period (from baseline visit of the study [Day 1] up to end of study follow-up [maximum follow-up: 1269 days])
ABR per participant was calculated as number of bleeds over number of days from baseline visit (Day 1 of the study) to end of study*365.25 days. All bleeds included treated and untreated bleeds. A treated bleed was defined as an event necessitating administration of coagulation factor within 72 hours of signs or symptoms of bleeding. An untreated bleed was defined as an event not necessitating administration of coagulation factor within 72 hours of signs or symptoms of bleeding. In this outcome measure, ABR for all and treated bleeds during prospective data collection period in hemophilia B participants per protocol analysis set was reported.
ABR for Treated Bleeds and All Bleeds During Prospective Data Collection Period in Hemophilia B Participants: Protocol Amendment 5 Analysis Set
Time frame: During prospective data collection period (from baseline visit of the study [Day 1] up to end of study follow-up [maximum follow-up: 1269 days])
ABR per participant was calculated as number of bleeds over number of days from baseline visit (Day 1 of the study) to end of study*365.25 days. All bleeds included treated and untreated bleeds. A treated bleed was defined as an event necessitating administration of coagulation factor within 72 hours of signs or symptoms of bleeding. An untreated bleed was defined as an event not necessitating administration of coagulation factor within 72 hours of signs or symptoms of bleeding. In this outcome measure, ABR for all and treated bleeds during prospective data collection period in hemophilia B participants per protocol amendment 5 analysis set was reported.
ABR for Treated Bleeds and All Bleeds During Retrospective Data Collection Period in Hemophilia B Participants: Protocol Amendment 5 Analysis Set
Time frame: During retrospective data collection period (12 months before screening collected in the hemophilia history case report form [CRF])
ABR per participant was calculated as number of bleeds over number of days from baseline visit (Day 1 of the study) to end of study*365.25 days. All bleeds included treated and untreated bleeds. A treated bleed was defined as an event necessitating administration of coagulation factor within 72 hours of signs or symptoms of bleeding. An untreated bleed was defined as an event not necessitating administration of coagulation factor within 72 hours of signs or symptoms of bleeding. In this outcome measure, ABR for all and treated bleeds during retrospective data collection period in hemophilia B participants per protocol amendment 5 analysis set was reported.
ABR for Treated Bleeds and All Bleeds From the Combined Retrospective and Prospective Data Collection Period in Hemophilia B Participants: Protocol Amendment 5 Analysis Set
Time frame: From start of retrospective data collection period (12 months before screening collected in hemophilia history CRF) up to end of prospective data collection follow-up of period (maximum follow-up:1269 days), for a total of approximately 4.5 years
ABR per participant was calculated as number of bleeds over number of days from baseline visit (Day 1 of the study) to end of study*365.25 days. All bleeds included treated and untreated bleeds. A treated bleed was defined as an event necessitating administration of coagulation factor within 72 hours of signs or symptoms of bleeding. An untreated bleed was defined as an event not necessitating administration of coagulation factor within 72 hours of signs or symptoms of bleeding. In this outcome measure, ABR for all and treated bleeds during retrospective and prospective data collection period in hemophilia B participants per protocol amendment 5 analysis set was reported.
ABR for Treated Bleeds and All Bleeds During Prospective Data Collection Period in Hemophilia A Participants: Efficacy Analysis Set
Time frame: During prospective data collection period (from baseline visit of the study [Day 1] up to end of study follow-up [maximum follow-up: 948 days])
ABR per participant was calculated as number of bleeds over number of days from baseline visit (Day 1 of the study) to end of study*365.25 days. All bleeds included treated and untreated bleeds. A treated bleed was defined as an event necessitating administration of coagulation factor within 72 hours of signs or symptoms of bleeding. An untreated bleed was defined as an event not necessitating administration of coagulation factor within 72 hours of signs or symptoms of bleeding. In this outcome measure, ABR for all and treated bleeds during prospective data collection period in hemophilia A participants per efficacy analysis set was reported.
ABR for Treated Bleeds and All Bleeds During Prospective Data Collection Period in Hemophilia A Participants: Per-protocol Analysis Set
Time frame: During prospective data collection period (from baseline visit of the study [Day 1] up to end of study follow-up [maximum follow-up: 948 days])
ABR per participant was calculated as number of bleeds over number of days from baseline visit (Day 1 of the study) to end of study*365.25 days. All bleeds included treated and untreated bleeds. A treated bleed was defined as an event necessitating administration of coagulation factor within 72 hours of signs or symptoms of bleeding. An untreated bleed was defined as an event not necessitating administration of coagulation factor within 72 hours of signs or symptoms of bleeding. In this outcome measure, ABR for all and treated bleeds during prospective data collection period in hemophilia A participants per protocol analysis set was reported.
ABR for Treated Bleeds and All Bleeds During Prospective Data Collection Period in Hemophilia A Participants: Protocol Amendment 5 Analysis Set
Time frame: During prospective data collection period (from baseline visit of the study [Day 1] up to end of study follow-up [maximum follow-up: 948 days])
ABR per participant was calculated as number of bleeds over number of days from baseline visit (Day 1 of the study) to end of study*365.25 days. All bleeds included treated and untreated bleeds. A treated bleed was defined as an event necessitating administration of coagulation factor within 72 hours of signs or symptoms of bleeding. An untreated bleed was defined as an event not necessitating administration of coagulation factor within 72 hours of signs or symptoms of bleeding. In this outcome measure, ABR for all and treated bleeds during prospective data collection period in hemophilia A participants per protocol amendment 5 analysis set was reported.
ABR for Treated Bleeds and All Bleeds During Retrospective Data Collection Period in Hemophilia A Participants: Protocol Amendment 5 Analysis Set
Time frame: During retrospective data collection period (12 months before screening collected in the hemophilia history CRF)
ABR per participant was calculated as number of bleeds over number of days from baseline visit (Day 1 of the study) to end of study*365.25 days. All bleeds included treated and untreated bleeds. A treated bleed was defined as an event necessitating administration of coagulation factor within 72 hours of signs or symptoms of bleeding. An untreated bleed was defined as an event not necessitating administration of coagulation factor within 72 hours of signs or symptoms of bleeding. In this outcome measure, ABR for all and treated bleeds during retrospective data collection period in hemophilia A participants per protocol amendment 5 analysis set was reported.
ABR for Treated Bleeds and All Bleeds From the Combined Retrospective and Prospective Data Collection Period in Hemophilia A Participants: Protocol Amendment 5 Analysis Set
Time frame: From start of retrospective data collection period (12 months before screening collected in hemophilia history CRF) up to end of prospective data collection follow-up of period (maximum follow-up:948 days), for a total of approximately 3.6 years
ABR per participant was calculated as number of bleeds over number of days from baseline visit (Day 1 of the study) to end of study*365.25 days. All bleeds included treated and untreated bleeds. A treated bleed was defined as an event necessitating administration of coagulation factor within 72 hours of signs or symptoms of bleeding. An untreated bleed was defined as an event not necessitating administration of coagulation factor within 72 hours of signs or symptoms of bleeding. In this outcome measure, ABR for all and treated bleeds during retrospective and prospective data collection period in hemophilia A participants per protocol amendment 5 analysis set was reported.
24 secondary outcomes
Annualized Infusion Rate (AIR) During Prospective Data Collection Period in Hemophilia B Participants: Efficacy Analysis Set
Time frame: During prospective data collection period (from baseline visit of the study [Day 1] up to end of study follow-up [maximum follow-up: 1269 days])
AIR During Prospective Data Collection Period in Hemophilia B Participants: Per-protocol Analysis Set
Time frame: During prospective data collection period (from baseline visit of the study [Day 1] up to end of study follow-up [maximum follow-up: 1269 days])
AIR During Prospective Data Collection Period in Hemophilia B Participants: Protocol Amendment 5 Analysis Set
Time frame: During prospective data collection period (from baseline visit of the study [Day 1] up to end of study follow-up [maximum follow-up: 1269 days])
AIR During Retrospective Data Collection Period in Hemophilia B Participants: Protocol Amendment 5 Analysis Set
Time frame: During retrospective data collection period (12 months before screening collected in the hemophilia history CRF)
AIR From the Combined Retrospective and Prospective Data Collection Period in Hemophilia B Participants: Protocol Amendment 5 Analysis Set
Time frame: From start of retrospective data collection period (12 months before screening collected in hemophilia history CRF) up to end of prospective data collection follow-up of period (maximum follow-up:1269 days), for a total of approximately 4.5 years
AIR During Prospective Data Collection Period in Hemophilia A Participants: Efficacy Analysis Set
Time frame: During prospective data collection period (from baseline visit of the study [Day 1] up to end of study follow-up [maximum follow-up: 948 days])
AIR During Prospective Data Collection Period in Hemophilia A Participants: Per-protocol Analysis Set
Time frame: During prospective data collection period (from baseline visit of the study [Day 1] up to end of study follow-up [maximum follow-up: 948 days])
AIR During Prospective Data Collection Period in Hemophilia A Participants: Protocol Amendment 5 Analysis Set
Time frame: During prospective data collection period (from baseline visit of the study [Day 1] up to end of study follow-up [maximum follow-up: 948 days])
AIR During Retrospective Data Collection Period in Hemophilia A Participants: Protocol Amendment 5 Analysis Set
Time frame: During retrospective data collection period (12 months before screening collected in the hemophilia history CRF)
AIR From the Combined Retrospective and Prospective Data Collection Period in Hemophilia A Participants: Protocol Amendment 5 Analysis Set
Time frame: From start of retrospective data collection period (12 months before screening collected in hemophilia history CRF) up to end of prospective data collection follow-up of period (maximum follow-up:948 days), for a total of approximately 3.6 years
Annualized Total Factor IX Replacement Therapy Consumption During Prospective Data Collection Period in Hemophilia B Participants: Efficacy Analysis Set
Time frame: During prospective data collection period (from baseline visit of the study [Day 1] up to end of study follow-up [maximum follow-up: 1269 days])
Annualized Total Factor IX Replacement Therapy Consumption During Prospective Data Collection Period in Hemophilia B Participants: Per-protocol Analysis Set
Time frame: During prospective data collection period (from baseline visit of the study [Day 1] up to end of study follow-up [maximum follow-up: 1269 days])
Annualized Total Factor IX Replacement Therapy Consumption During Prospective Data Collection Period in Hemophilia B Participants: Protocol Amendment 5 Analysis Set
Time frame: During prospective data collection period (from baseline visit of the study [Day 1] up to end of study follow-up [maximum follow-up: 1269 days])
Annualized Total Factor IX Replacement Therapy Consumption During Prospective Data Collection Period in Hemophilia A Participants: Efficacy Analysis Set
Time frame: During prospective data collection period (from baseline visit of the study [Day 1] up to end of study follow-up [maximum follow-up: 948 days])
Annualized Total Factor IX Replacement Therapy Consumption During Prospective Data Collection Period in Hemophilia A Participants: Per-protocol Analysis Set
Time frame: During prospective data collection period (from baseline visit of the study [Day 1] up to end of study follow-up [maximum follow-up: 948 days])
Annualized Total Factor IX Replacement Therapy Consumption During Prospective Data Collection Period in Hemophilia A Participants: Protocol Amendment 5 Analysis Set
Time frame: During prospective data collection period (from baseline visit of the study [Day 1] up to end of study follow-up [maximum follow-up: 948 days])
ABR for Spontaneous Treated Bleeds and All Bleeds During Prospective Data Collection Period in Hemophilia B Participants: Efficacy Analysis Set
Time frame: During prospective data collection period (from baseline visit of the study [Day 1] up to end of study follow-up [maximum follow-up: 1269 days])
ABR for Traumatic Treated Bleeds and All Bleeds During Prospective Data Collection Period in Hemophilia B Participants: Efficacy Analysis Set
Time frame: During prospective data collection period (from baseline visit of the study [Day 1] up to end of study follow-up [maximum follow-up: 1269 days])
ABR for Spontaneous Treated Bleeds and All Bleeds During Prospective Data Collection Period in Hemophilia B Participants: Per-protocol Analysis Set
Time frame: During prospective data collection period (from baseline visit of the study [Day 1] up to end of study follow-up [maximum follow-up: 1269 days])
ABR for Traumatic Treated Bleeds and All Bleeds During Prospective Data Collection Period in Hemophilia B Participants: Per-protocol Analysis Set
Time frame: During prospective data collection period (from baseline visit of the study [Day 1] up to end of study follow-up [maximum follow-up: 1269 days])
ABR for Spontaneous Treated Bleeds and All Bleeds During Prospective Data Collection Period in Hemophilia A Participants: Efficacy Analysis Set
Time frame: During prospective data collection period (from baseline visit of the study [Day 1] up to end of study follow-up [maximum follow-up: 948 days])
ABR for Traumatic Treated Bleeds and All Bleeds During Prospective Data Collection Period in Hemophilia A Participants: Efficacy Analysis Set
Time frame: During prospective data collection period (from baseline visit of the study [Day 1] up to end of study follow-up [maximum follow-up: 948 days])
ABR for Spontaneous Treated Bleeds and All Bleeds During Prospective Data Collection Period in Hemophilia A Participants: Per-protocol Analysis Set
Time frame: During prospective data collection period (from baseline visit of the study [Day 1] up to end of study follow-up [maximum follow-up: 948 days])
ABR for Traumatic Treated Bleeds and All Bleeds During Prospective Data Collection Period in Hemophilia A Participants: Per-protocol Analysis Set
Time frame: During prospective data collection period (from baseline visit of the study [Day 1] up to end of study follow-up [maximum follow-up: 948 days])
Results and safety
Loading the posted results from ClinicalTrials.gov…
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 6 Nov 2025.
- Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
- To obtain contact information for a study center near you, click here.Link provided by the sponsor.
- Individual participant dataSharing planned: Yes. Pfizer will provide access to individual de-identified participant data and related study documents (e.g. protocol, Statistical Analysis Plan (SAP), Clinical Study Report (CSR)) upon request from qualified researchers, and subject to certain criteria, conditions, and exceptions. Further details on Pfizer's data sharing criteria and process for requesting access can be found at: https://www.pfizer.com/science/clinical_trials/trial_data_and_results/data_requests.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Pfizer CT.gov Call Center study director
Pfizer
75 sites in 18 countries: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 3 study of Hemophilia B and Hemophilia A, run by Pfizer at 75 sites in 18 countries.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 17 inclusion and 27 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 6 Nov 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 75 sites in United States, Brazil, Japan, Turkey (Türkiye), Australia and 13 more countries. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 3 studies compare the treatment with the current standard treatment or a placebo in a large group, to confirm how well it works and watch for side effects.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
Yes. Results are posted in the registry (first posted 6 Nov 2025). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Annualized Bleeding Rate (ABR) for Treated Bleeds and All Bleeds During Prospective Data Collection Period in Hemophilia B Participants: Efficacy Analysis Set (time frame: During prospective data collection period (from baseline visit of the study [Day 1] up to end of study follow-up [maximum follow-up: 1269 days])). The study lists 10 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 6 Nov 2025.