HemophiliaPhase 3ATLAS-NEONCT05662319
A Study to Test a Medicine (Fitusiran) Injected Under the Skin for Preventing Bleeding Episodes in Male Adolescent or Adult Participants With Severe Hemophilia
A Phase 3 study testing Fitusiran, Clotting factor concentrates (CFC) or bypassing agents (BPA) and Antithrombin concentrate (ATIIIC) in people with Hemophilia, run by Sanofi at 50 sites in 17 countries.
Trial summary
This is a multicenter, multinational, open-label, one-way cross-over, Phase 3, single-arm study for treatment of hemophilia. The purpose of this study is to measure the frequency of treated bleeding episodes with fitusiran in male adult and adolescent (≥12 years old) participants with hemophilia A or B, with or… Read more about this study
- Who is it for?
- Ages 12 years and older, men only
- Conditions the study is for
- Hemophilia
- What is being tested?
- Fitusiran, Clotting factor concentrates (CFC) or bypassing agents (BPA) and Antithrombin concentrate (ATIIIC)
- Type of treatment
- Injection or infusion
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 91 participants
- Where
- 50 sitesin 17 countries
- Study dates
- 1 Feb 2023to 25 Jan 2029
- Phase
- Phase 3
- Are there results?
- Not yet: the study is under way
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 12 years and older
- Men only
- No healthy volunteers
- Child, Adult, Older adult
Who may be able to join
- Diagnosis of severe congenital hemophilia A or B (FVIII <1% or FIX level ≤2%) as evidenced by a central laboratory measurement at screening or documented medical record evidence.
- For participants currently not on prophylaxis (CFC or BPA on-demand): A minimum of 4 bleeding episodes requiring BPA (inhibitor participants) or CFC (non-inhibitor participants) treatment within the last 6 months prior to screening.
- Willing and able to comply with the study requirements and to provide written informed consent and assent in the case of participants under the age of legal consent, per local and national requirements
Who cannot join
- Known co-existing bleeding disorders other than congenital hemophilia A or B
- History of arterial or venous thromboembolism, not associated with an indwelling venous access
- History of intolerance to SC injection(s).
- Current participation in immune tolerance induction therapy (ITI)
- Prior gene therapy
- Current or prior participation in a fitusiran trial
Show all 15Show fewer
- Current or prior participation in a gene therapy trial
- Received an investigational drug or device within 30 days prior to the screening visit or within 5 half-lives of the investigational drug (or device) prior to the screening visit, whichever is longer
- Presence of clinically significant liver disease AT activity <60% at Screening
- Co-existing thrombophilic disorder
- Hepatitis C virus antibody positive, except participants who have negative Hepatitis C viral load and no evidence of cirrhosis
- Presence of acute hepatitis, ie, hepatitis A, hepatitis E.
- Presence of acute or chronic hepatitis B infection
- Known to be HIV positive with CD4 count <200 cells/μL.
- Reduced renal function The above information is not intended to contain all considerations relevant to a patient's potential participation in a clinical trial.
Trial locations and contacts
50 sites in 17 countries.
50 sites in 17 countries
United States8 sites
University Hospitals of Cleveland Site Number : 8400001
Cleveland, Ohio, 44106
Children's Medical Center Dallas- Site Number : 8400018
Dallas, Texas, 75235
Hackensack University Site Number : 8400009
Hackensack, New Jersey, 07601
Gulf States Hemophilia and Thrombophilia Center- Site Number : 8400002
Houston, Texas, 77030
M Health Fairview University of Minnesota Medical Center - West Bank- Site Number : 8400016
Minneapolis, Minnesota, 55454
Northwell Health Hemostasis and Thrombosis Center Site Number : 8400015
New Hyde Park, New York, 11040
Center for Inherited Blood Disorders (CIBD) Site Number : 8400012
Orange, California, 92868-4306
UPMC Children's Hospital of Pittsburgh-4401 Penn Ave Site Number : 8400017
Pittsburgh, Pennsylvania, 15224-1334
India5 sites
Investigational Site Number : 3560004
Bangalore, 560 034
Investigational Site Number : 3560007
Bhubaneswar, 751019
Investigational Site Number : 3560001
Pune-411011, 411 011
Investigational Site Number : 3560006
Punjab, 141008
Investigational Site Number : 3560003
Vellore, 632004
Turkey (Türkiye)4 sites
Investigational Site Number : 7920002
Adana, 01130
Investigational Site Number : 7920004
Akdeniz, 07059
Investigational Site Number : 7920001
Çapa, 34390
Investigational Site Number : 7920003
Izmir, TR-35100
Canada3 sites
Investigational Site Number : 1240001
Hamilton, Ontario, L8N 3Z5
Investigational Site Number : 1240002
Hamilton, Ontario, L8N 3Z5
Investigational Site Number : 1240004
Toronto, Ontario, M5G 1X8
China3 sites
Investigational Site Number : 1560003
Beijing, 100045
Investigational Site Number : 1560001
Guangzhou, 510515
Investigational Site Number : 1560002
Jinan, 250013
France3 sites
Investigational Site Number : 2500003
Le Kremlin-Bicêtre, 94275
Investigational Site Number : 2500002
Lille, 59037
Investigational Site Number : 2500001
Paris, 75015
Japan3 sites
Investigational Site Number : 3920001
Kashihara-shi, Nara, 634-8522
Investigational Site Number : 3920003
Nagoya, Aichi-ken, 4668560
Investigational Site Number : 3920002
Saitama-shi, Saitama, 330-8777
Mexico3 sites
Investigational Site Number : 4840004
Chihuahua City, 31000
Investigational Site Number : 4840002
Monterrey, Nuevo León, 64460
Investigational Site Number : 4840001
Veracruz, 91900
Poland3 sites
Investigational Site Number : 6160002
Krakow, Lesser Poland Voivodeship, 30-688
Investigational Site Number : 6160004
Lodz, Lódzkie, 93-510
Investigational Site Number : 6160001
Warsaw, Masovian Voivodeship, 02-776
Germany2 sites
Investigational Site Number : 2760001
Berlin, 10249
Investigational Site Number : 2760002
Hamburg, 20246
Greece2 sites
Investigational Site Number : 3000001
Athens, 115 27
Investigational Site Number : 3000002
Athens, 11527
Italy2 sites
Investigational Site Number : 3800001
Milan, 20122
Investigational Site Number : 3800003
Rozzano, Milano, 20089
South Africa2 sites
Investigational Site Number : 7100003
Johannesburg, 1501
Investigational Site Number : 7100001
Parktown, 2193
South Korea2 sites
Investigational Site Number : 4100001
Seoul, Seoul-teukbyeolsi, 03722
Investigational Site Number : 4100002
Seoul, Seoul-teukbyeolsi, 05278
Spain2 sites
Investigational Site Number : 7240002
A Coruña, A Coruña [La Coruña], 15006
Investigational Site Number : 7240003
Zaragoza, 50009
Taiwan2 sites
Investigational Site Number : 1580001
Taipei, 100
Investigational Site Number : 1580003
Taipei, 11031
About this study
Official title: A Phase 3, Single-arm, Multicenter, Multinational, Open-label, One-way Crossover Study to Investigate the Efficacy and Safety of Fitusiran Prophylaxis in Male Participants Aged ≥ 12 Years With Severe Hemophilia A or B With or Without Inhibitory Antibodies to Factor VIII or IX
This is a multicenter, multinational, open-label, one-way cross-over, Phase 3, single-arm study for treatment of hemophilia.
The purpose of this study is to measure the frequency of treated bleeding episodes with fitusiran in male adult and adolescent (≥12 years old) participants with hemophilia A or B, with or without inhibitory antibodies to factor VIII or IX who have switched from their prior standard of care treatment.
Read more
The total study duration will be up to approximately 50 months (200 weeks, 1 study month is equivalent to 4 weeks) and will include:
- A screening period up to approximately 60 days,
- A standard of care (SOC) period of approximately 6 study months (24 weeks),
- A fitusiran treatment period of approximately 36 study months (144 weeks),
- An antithrombin (AT) follow-up period of approximately 6 study months (24 weeks) but may be shorter or longer depending on individual participants AT recovery.
The frequency for telephone visits will be approximately every 2 weeks. For site visits the frequency will be approximately every 8 weeks during the SOC period and approximately every 4 weeks during the fitusiran treatment period. If applicable and if allowed by local regulation, home and/or remote visits may be conducted during the study
- Conditions
- Hemophilia
- Being tested
- Fitusiran, Clotting factor concentrates (CFC) or bypassing agents (BPA), Antithrombin concentrate (ATIIIC)
- Medical subject headings
- Hemophilia A
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
FitusiranDrug
Pharmaceutical form: Solution for injection Route of administration: Subcutaneous (SC)
Clotting factor concentrates (CFC) or bypassing agents (BPA)Drug
- Coagulation factor VIII (ATC code: B02BD02)
- Coagulation factor IX (ATC code: B02BD04)
- Coagulation factor VIIa (ATC code: B02BD08)
- Factor VIII inhibitor bypassing activity (ATC code: B02BD03)
Pharmaceutical form: Solution for infusion Route of administration: Intravenous (IV)
Antithrombin concentrate (ATIIIC)Drug
Antithrombin III (ATC code: B01AB02) Pharmaceutical form: Solution for infusion Route of administration: Intravenous (IV)
| Study group | Role | What they receive |
|---|---|---|
| All participants | Experimental | In standard of care (SOC) period, participants will receive on-demand or prophylactic treatment with clotting factor concentrates (CFCs) or bypassing agents (BPAs) for 6 months (from Day -168 to Day -1). In fitusiran treatment period, participants will receive subcutaneous fitusiran prophylaxis once every other month (Q2M) or once monthly (QM) for 36 months (from Day 1 to Day 1009). In case of bleeding events participants will receive IV CFCs or BPAs. Participants may receive Antithrombin concentrate (ATIIIC) as rescue medicine.
. Receives: Drug: Fitusiran; Drug: Clotting factor concentrates (CFC) or bypassing agents (BPA); Drug: Antithrombin concentrate (ATIIIC) |
What is being measured
The primary outcome is the main question the study is designed to answer.
Annualized bleeding rate (ABR) in the fitusiran primary efficacy period
A bleeding episode is defined as any occurrence of hemorrhage that requires administration of CFCs or BPAs, e.g., hemarthrosis, muscle, or mucosal bleeding.
Measured: Day 169 to Day 505 (since the first dose of fitusiran)
Secondary outcomes (9)
Annualized bleeding rate (ABR) while on fitusiran prophylaxis in the fitusiran primary efficacy period and ABR while on prophylaxis standard of care (SOC) in the SOC period
A bleeding episode is defined as any occurrence of hemorrhage that requires administration of CFCs or BPAs, e.g., hemarthrosis, muscle, or mucosal bleeding.
Measured: Day 169 to Day 505 (primary efficacy period) and Day -168 to Day -1 (SOC period)
Annualized bleeding rate (ABR) while on fitusiran prophylaxis in the fitusiran primary efficacy period and ABR while on on-demand standard of care (SOC) in the SOC period
A bleeding episode is defined as any occurrence of hemorrhage that requires administration of CFCs or BPAs, e.g., hemarthrosis, muscle, or mucosal bleeding.
Measured: Day 169 to Day 505 (primary efficacy period) and Day -168 to Day -1 (SOC period)
Annualized spontaneous bleeding rate in the fitusiran primary efficacy period and in the SOC period
A bleeding episode is defined as any occurrence of hemorrhage that requires administration of CFCs or BPAs, e.g., hemarthrosis, muscle, or mucosal bleeding.
A spontaneous bleeding episode is a bleeding event that occurs for no apparent or known reason, particularly into the joints, muscles, and soft tissues.
Measured: Day 169 to Day 505 (primary efficacy period) and Day -168 to Day -1 (SOC period)
Annualized joint bleeding rate in the fitusiran primary efficacy period and in the SOC period
A bleeding episode is defined as any occurrence of hemorrhage that requires administration of CFCs or BPAs, e.g., hemarthrosis, muscle, or mucosal bleeding.
A joint bleeding episode is characterized by an unusual sensation in the joint ("aura") in combination with 1) increasing swelling or warmth over the skin over the joint, 2) increasing pain, or 3) progressive loss of range of motion or difficulty in using the limb as compared with baseline.
Measured: Day 169 to Day 505 (primary efficacy period) and Day -168 to Day -1 (SOC period)
Change in Haem-A-QOL physical health score and total score during SOC and during fitusiran prophylaxis
The Haem-A-QoL will be provided to participants ≥17 years of age and includes 46 items contributing to 10 QoL domains (physical health, feelings, view of yourself, sports and leisure, work and school, dealing with hemophilia, treatment, future, family planning, partnership, and sexuality). Scoring for each item is based on a 5-point Likert scale (never, rarely, sometimes, often, and all the time), and higher scores represent greater impairment.
Measured: Day 1 (D1) to Day 505, and from D1 to Day 1009, and during SOC from Day-168 to D-1
Annualized bleeding rate (ABR) in the fitusiran 18-month efficacy period
A bleeding episode is defined as any occurrence of hemorrhage that requires administration of CFCs or BPAs, e.g., hemarthrosis, muscle, or mucosal bleeding.
Measured: Day 1 to Day 505
Annualized bleeding rate (ABR) in the fitusiran 36-month treatment period
A bleeding episode is defined as any occurrence of hemorrhage that requires administration of CFCs or BPAs, e.g., hemarthrosis, muscle, or mucosal bleeding.
Measured: Day 1 to Day 1009
Annualized weight-adjusted consumption of CFC/BPA
All CFC or BPA doses (including doses per kg body weight) administered during the study treatment will be recorded
Measured: Day -168 until Day 1009
Number of participants with adverse events
All AEs (serious or nonserious) will be collected from the signing of the informed consent form (ICF) until last AT follow up visit.
Measured: Date of signed ICF (Day -228 to Day -169) until last visit (approximately 50 months after date of signed ICF)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted22 Dec 2022
- Study start1 Feb 2023
- Primary completion25 Mar 2027 (estimated)
- Study completion25 Jan 2029 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for HemophiliaStudies of the same condition, open and under way.
- More trials run by SanofiThe 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
- Treatment
- Allocation
- Not applicable
- Intervention model
- Crossover
- Model description
- One way cross-over
- Masking
- None (open label)
- Enrolment
- 91 participants (actual)
Sponsor and investigators
- Lead sponsor
- Sanofi
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
- Investigators
- Clinical Sciences & Operations, Study director, Sanofi
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05662319
- Sponsor's protocol ID
- EFC17574
- Other IDs
- U1111-1275-9584, 2022-500221-33
- Acronym
- ATLAS-NEO
- Status last verified
- Feb 2026
- First submitted
- 14 Dec 2022
- Last updated
- 4 Feb 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- Yes: Qualified researchers may request access to patient level data and related study documents including the clinical study report, study protocol with any amendments, blank case report form, statistical analysis plan, and dataset specifications. Patient level data will be anonymized and study documents will be redacted to protect the privacy of trial participants. Further details on Sanofi's data sharing criteria, eligible studies, and process for requesting access can be found at: https://vivli.org
Study at a glance
From the registry record, last updated by the sponsor on 4 Feb 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Phase 3, Single-arm, Multicenter, Multinational, Open-label, One-way Crossover Study to Investigate the Efficacy and Safety of Fitusiran Prophylaxis in Male Participants Aged ≥ 12 Years With Severe Hemophilia A or B With or Without Inhibitory Antibodies to Factor VIII or IX
- ClinicalTrials.gov ID
- NCT05662319
- Acronym / sponsor ID
- ATLAS-NEO / EFC17574
- Conditions
- Hemophilia
- Phase
- Phase 3
- Study type
- Interventional
- Recruitment status
- Active, not recruiting
- Enrolment
- 91 participants (actual)
- Lead sponsor
- SanofiIndustry (pharma, biotech, devices)
- Study start
- 1 Feb 2023 (actual)
- Primary completion
- 25 Mar 2027 (estimated)
- Study completion
- 25 Jan 2029 (estimated)
- First posted
- 22 Dec 2022 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This is a multicenter, multinational, open-label, one-way cross-over, Phase 3, single-arm study for treatment of hemophilia.
The purpose of this study is to measure the frequency of treated bleeding episodes with fitusiran in male adult and adolescent (≥12 years old) participants with hemophilia A or B, with or without inhibitory antibodies to factor VIII or IX who have switched from their prior standard of care treatment.
The total study duration will be up to approximately 50 months (200 weeks, 1 study month is equivalent to 4 weeks) and will include:
- A screening period up to approximately 60 days,
- A standard of care (SOC) period of approximately 6 study months (24 weeks),
- A fitusiran treatment period of approximately 36 study months (144 weeks),
- An antithrombin (AT) follow-up period of approximately 6 study months (24 weeks) but may be shorter or longer depending on individual participants AT recovery.
The frequency for telephone visits will be approximately every 2 weeks. For site visits the frequency will be approximately every 8 weeks during the SOC period and approximately every 4 weeks during the fitusiran treatment period. If applicable and if allowed by local regulation, home and/or remote visits may be conducted during the study
Study design
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Crossover
- Masking
- None (open label)
- Number of arms
- 1
- Model description
- One way cross-over
| Arm | Type | Receives |
|---|---|---|
| All participants | Experimental | Drug: Fitusiran, Drug: Clotting factor concentrates (CFC) or bypassing agents (BPA), Drug: Antithrombin concentrate (ATIIIC)In standard of care (SOC) period, participants will receive on-demand or prophylactic treatment with clotting factor concentrates (CFCs) or bypassing agents (BPAs) for 6 months (from Day -168 to Day -1). In fitusiran treatment period, participants will receive subcutaneous fitusiran prophylaxis once every other month (Q2M) or once monthly (QM) for 36 months (from Day 1 to Day 1009). In case of bleeding events participants will receive IV CFCs or BPAs. Participants may receive Antithrombin concentrate (ATIIIC) as rescue medicine. . |
Who may qualify
- Ages
- 12 years and older
- Sex
- Male only
- Healthy volunteers
- Not accepted
- Age groups
- Child, Adult, Older adult
Key inclusion criteria (3 listed)
- Diagnosis of severe congenital hemophilia A or B (FVIII <1% or FIX level ≤2%) as evidenced by a central laboratory measurement at screening or documented medical record evidence.
- For participants currently not on prophylaxis (CFC or BPA on-demand): A minimum of 4 bleeding episodes requiring BPA (inhibitor participants) or CFC (non-inhibitor participants) treatment within the last 6 months prior to screening.
- Willing and able to comply with the study requirements and to provide written informed consent and assent in the case of participants under the age of legal consent, per local and national requirements
Key exclusion criteria (15 listed)
- Known co-existing bleeding disorders other than congenital hemophilia A or B
- History of arterial or venous thromboembolism, not associated with an indwelling venous access
- History of intolerance to SC injection(s).
- Current participation in immune tolerance induction therapy (ITI)
- Prior gene therapy
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 |
|---|---|---|
| FitusiranPharmaceutical form: Solution for injection Route of administration: Subcutaneous (SC) | Drug | All participants |
| Clotting factor concentrates (CFC) or bypassing agents (BPA)* Coagulation factor VIII (ATC code: B02BD02) * Coagulation factor IX (ATC code: B02BD04) * Coagulation factor VIIa (ATC code: B02BD08) * Factor VIII inhibitor bypassing activity (ATC code: B02BD03) Pharmaceutical form: Solution for infusion Route of administration: Intravenous (IV) | Drug | All participants |
| Antithrombin concentrate (ATIIIC)Antithrombin III (ATC code: B01AB02) Pharmaceutical form: Solution for infusion Route of administration: Intravenous (IV) | Drug | All participants |
Primary outcome
Annualized bleeding rate (ABR) in the fitusiran primary efficacy period
Time frame: Day 169 to Day 505 (since the first dose of fitusiran)
A bleeding episode is defined as any occurrence of hemorrhage that requires administration of CFCs or BPAs, e.g., hemarthrosis, muscle, or mucosal bleeding.
9 secondary outcomes
Annualized bleeding rate (ABR) while on fitusiran prophylaxis in the fitusiran primary efficacy period and ABR while on prophylaxis standard of care (SOC) in the SOC period
Time frame: Day 169 to Day 505 (primary efficacy period) and Day -168 to Day -1 (SOC period)
Annualized bleeding rate (ABR) while on fitusiran prophylaxis in the fitusiran primary efficacy period and ABR while on on-demand standard of care (SOC) in the SOC period
Time frame: Day 169 to Day 505 (primary efficacy period) and Day -168 to Day -1 (SOC period)
Annualized spontaneous bleeding rate in the fitusiran primary efficacy period and in the SOC period
Time frame: Day 169 to Day 505 (primary efficacy period) and Day -168 to Day -1 (SOC period)
Annualized joint bleeding rate in the fitusiran primary efficacy period and in the SOC period
Time frame: Day 169 to Day 505 (primary efficacy period) and Day -168 to Day -1 (SOC period)
Change in Haem-A-QOL physical health score and total score during SOC and during fitusiran prophylaxis
Time frame: Day 1 (D1) to Day 505, and from D1 to Day 1009, and during SOC from Day-168 to D-1
Annualized bleeding rate (ABR) in the fitusiran 18-month efficacy period
Time frame: Day 1 to Day 505
Annualized bleeding rate (ABR) in the fitusiran 36-month treatment period
Time frame: Day 1 to Day 1009
Annualized weight-adjusted consumption of CFC/BPA
Time frame: Day -168 until Day 1009
Number of participants with adverse events
Time frame: Date of signed ICF (Day -228 to Day -169) until last visit (approximately 50 months after date of signed ICF)
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 4 Feb 2026.
- EFC17574 Plain Language Results SummariesLink provided by the sponsor.
- Individual participant dataSharing planned: Yes. Qualified researchers may request access to patient level data and related study documents including the clinical study report, study protocol with any amendments, blank case report form, statistical analysis plan, and dataset specifications. Patient level data will be anonymized and study documents will be redacted to protect the privacy of trial participants. Further details on Sanofi's data sharing criteria, eligible studies, and process for requesting access can be found at: https://vivli.org
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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.
Clinical Sciences & Operations study director
Sanofi
50 sites in 17 countries: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 3 study testing Fitusiran, Clotting factor concentrates (CFC) or bypassing agents (BPA) and Antithrombin concentrate (ATIIIC) in people with Hemophilia, run by Sanofi at 50 sites in 17 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 3 inclusion and 15 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: under way, not looking for participants, as of the sponsor's last update on 4 Feb 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 50 sites in United States, India, Turkey (Türkiye), Canada, China and 12 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?
This study is still under way. Results are not available in the source record yet.
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) in the fitusiran primary efficacy period (time frame: Day 169 to Day 505 (since the first dose of fitusiran)). 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 4 Feb 2026.