Updated May 2026 · ClinicalTrials.gov

RECRUITINGPhase 4INTERVENTIONAL

Long-term Study Evaluating Joint Health in People With Haemophilia A Receiving Real-world Prophylactic Treatment With Efanesoctocog Alfa

A Low-interventional Study to Evaluate Long-term Effectiveness of Real-world Prophylactic Treatment With Efanesoctocog Alfa on Joint Health in People With Haemophilia A (ALTITUDE)

Long-term Study Evaluating Joint Health in People With Haemophilia A Receiving Real-world Prophylactic Treatment With Efanesoctocog Alfa (NCT06940830) is a Phase 4 interventional studying Hemophilia A, sponsored by Swedish Orphan Biovitrum. RECRUITING as of the most recent ClinicalTrials.gov update. Talk to your doctor before contacting the trial site.

About This Trial

The rationale for this study is to further understand and describe the long-term prophylactic effectiveness of efanesoctocog alfa in preventing joint bleeds in a real-life setting.

What Stage of Research Is This?

Phase 4 studies happen after a treatment has been approved by the FDA. They monitor long-term safety, real-world effectiveness, and any rare side effects that only emerge in larger populations over longer periods. Phase 4 results sometimes lead to label changes, additional warnings, or — rarely — withdrawal of approval.

This trial is currently recruiting participants. The sponsor has registered the study with ClinicalTrials.gov as actively enrolling, which means new applicants who meet the eligibility criteria can be considered for screening. Trial status can change between updates — confirm current recruiting status with the study contact before traveling for a screening visit.

Target enrollment of 250 participants puts this in the typical range for a Phase 2-style efficacy study or a moderate Phase 3 trial in a focused Hemophilia A subpopulation. At this scale, the study has enough statistical power to detect a clear treatment effect but is not the largest cohort in the field.

Who May Be Eligible (Plain English)

Who May Qualify: 1. Male or female patient with a diagnosis of haemophilia A. 2. Capable of giving signed willing to sign a consent form, which includes compliance with the requirements and restrictions listed in the willing to sign a consent form form (ICF) and in this protocol. 3. Prescribed with efanesoctocog alfa prophylactic treatment within 6 months prior to study enrolment or at the latest at the enrolment visit, in accordance with local regulations. 4. Must have received prophylactic treatment(s) with any haemophilia product(s) for at least 12 months prior to being prescribed with efanesoctocog alfa treatment. 5. Have documented pre-study treatment data on haemophilia prophylaxis prescriptions and on treated bleeding episodes from the 12-months prior to being prescribed efanesoctocog alfa treatment and until enrolment into this study. 6. Willing to adhere to the visit schedule and to undergo mandatory study assessment (HJHS, PROs). 7. Willingness and the ability of the patient or their legally designated representative to document all bleeding episodes, including any treatments for those episodes. 8. For HEAD-US subgroup: Accept to undergo annual ultrasound assessment on the index joints (ankles, elbows, knees). Who Should NOT Join This Trial: 1. Acquired haemophilia A and other blood clotting disorders than hereditary haemophilia A. 2. Any positive FVIII inhibitor result (defined as inhibitor titre ≥0.6 Bethesda unit \[BU\]/mL) from the medical records in connection to the switch to efanesoctocog alfa until the enrolment visit. 3. Enrolment in a concurrent clinical interventional study, or intake of an investigational medicinal product (IMP), including for haemophilia prophylaxis, within 3 months prior to enrolment in this study. 4. Patient not suitable for participation, whatever the reason, as judged by the Investigator, e.g., patient is not able or willing to perform the study assessments. Always talk to your doctor about whether this trial is right for you.

These are translations of the protocol\'s inclusion and exclusion criteria, simplified for patients and caregivers. The original clinical text appears below. Eligibility is ultimately confirmed by the trial site\'s screening process — this summary is a starting point for a conversation with your doctor, not a final determination.

Original Eligibility Criteria

View original clinical language

Inclusion Criteria: 1. Male or female patient with a diagnosis of haemophilia A. 2. Capable of giving signed informed consent, which includes compliance with the requirements and restrictions listed in the informed consent form (ICF) and in this protocol. 3. Prescribed with efanesoctocog alfa prophylactic treatment within 6 months prior to study enrolment or at the latest at the enrolment visit, in accordance with local regulations. 4. Must have received prophylactic treatment(s) with any haemophilia product(s) for at least 12 months prior to being prescribed with efanesoctocog alfa treatment. 5. Have documented pre-study treatment data on haemophilia prophylaxis prescriptions and on treated bleeding episodes from the 12-months prior to being prescribed efanesoctocog alfa treatment and until enrolment into this study. 6. Willing to adhere to the visit schedule and to undergo mandatory study assessment (HJHS, PROs). 7. Willingness and the ability of the patient or their legally designated representative to document all bleeding episodes, including any treatments for those episodes. 8. For HEAD-US subgroup: Accept to undergo annual ultrasound assessment on the index joints (ankles, elbows, knees). Exclusion Criteria: 1. Acquired haemophilia A and other blood clotting disorders than hereditary haemophilia A. 2. Any positive FVIII inhibitor result (defined as inhibitor titre ≥0.6 Bethesda unit \[BU\]/mL) from the medical records in connection to the switch to efanesoctocog alfa until the enrolment visit. 3. Enrolment in a concurrent clinical interventional study, or intake of an investigational medicinal product (IMP), including for haemophilia prophylaxis, within 3 months prior to enrolment in this study. 4. Patient not suitable for participation, whatever the reason, as judged by the Investigator, e.g., patient is not able or willing to perform the study assessments.

Treatments Being Tested

DRUG

Efanesoctocog alfa

Participant in this study must be prescribed efanesoctocog alfa prophylactic treatment per their standard of care from their physician. No drug will be provided by the Sponsor.

Locations (20)

Trial sites listed on ClinicalTrials.gov for this study. Site activation status can vary — confirm with the specific site before traveling for a screening visit.

Sobi Investigational Site

Zagreb, Croatia

Sobi Investigational Site

Brno, Czechia

Sobi Investigational Site

Ostrava, Czechia

Sobi Investigational Site

Prague, Czechia

Sobi Investigational Site

Bordeaux, France

Sobi Investigational Site

Marseille, France

Sobi Investigational Site

Montpellier, France

Sobi Investigational Site

Nantes, France

Sobi Investigational Site

Paris, France

Sobi Investigational Site

Rennes, France

Sobi Investigational Site

Rouen, France

Sobi Investigational Site

Berlin, Germany

Sobi Investigational Site

Bonn, Germany

Sobi Investigational Site

Frankfurt am Main, Germany

Sobi Investigational Site

Hamburg, Germany

Sobi Investigational Site

Munich, Germany

Sobi Investigational Site

Dublin, Ireland

Sobi Investigational Site

Turin, Italy

Sobi Investigational Site

A Coruña, Spain

Sobi Investigational Site

Barcelona, Spain

How to Talk to Your Doctor About This Trial

Bring the printable summary of this trial — including the NCT ID (NCT06940830), the sponsor (Swedish Orphan Biovitrum), and the key eligibility criteria — to your next appointment. Your doctor can review the inclusion and exclusion criteria against your medical history, lab values, and current treatments to assess whether you are likely to qualify. They can also help you weigh whether trial participation makes sense alongside your existing care plan.

Useful questions to walk through together: What does the trial protocol require beyond standard care? How long is the active treatment phase, and how long is follow-up? Are there study visits at sites I can reach? Who pays for the trial-specific procedures, and who pays for standard-of-care portions? See our 25 questions to ask about clinical trials guide for a more complete checklist.

Authoritative Sources

The official record for this trial lives on ClinicalTrials.gov — the federal registry maintained by the National Library of Medicine at NIH. For background on how this trial fits into the FDA approval pathway, see the FDA drug approval process. For oncology-specific guidance for patients considering trials, the National Cancer Institute publishes patient-oriented overviews. International trial registries are aggregated by the WHO ICTRP.

Frequently Asked Questions

What is the NCT06940830 clinical trial studying?

The rationale for this study is to further understand and describe the long-term prophylactic effectiveness of efanesoctocog alfa in preventing joint bleeds in a real-life setting. The full protocol is registered on ClinicalTrials.gov and includes the primary outcome measures, eligibility criteria, and study endpoints.

Who can participate in NCT06940830?

Eligibility for this trial depends on the specific inclusion and exclusion criteria set by the sponsor. The plain-English summary above translates the most important criteria into accessible language; the official clinical text is preserved in the collapsible section underneath. Whether you fit any specific trial is a medical decision your doctor needs to confirm — bring the trial information to your treating physician for a full review against your medical history.

How do I contact the trial site for NCT06940830?

Contact information registered with ClinicalTrials.gov is shown in the sidebar of this page. Before reaching out, confirm with your treating physician that this trial is appropriate for your situation. The trial site will then walk you through the screening process to determine final eligibility.

Is participating in a clinical trial safe?

Clinical trials in the United States are regulated by the FDA and overseen by Institutional Review Boards (IRBs) that review the protocol for safety. Risk varies by trial — Phase 1 studies test new treatments in humans for the first time, while Phase 3 trials use treatments that have already passed earlier safety screening. The informed consent document for any specific trial details the known risks and what to expect. Discuss those risks with your physician before deciding whether to participate.

Where can I verify the data on this page?

Every detail on this page comes directly from the ClinicalTrials.gov API. Click "View on ClinicalTrials.gov" in the sidebar to see the official, unmodified record. The federal record is always authoritative; this page is a structured presentation with a plain-English eligibility translation. For background on how clinical trials are regulated, see the FDA drug approval process documentation.

How This Page Is Built

Every field on this page is pulled directly from the ClinicalTrials.gov API v2 — no estimates, no proxies. The plain-English eligibility translation is generated from the original protocol text and reviewed for fidelity to the underlying clinical criteria. The original clinical text remains visible in the collapsible section above so users and clinicians can verify the translation. Read the full methodology for the data pipeline and known limitations.

Source: ClinicalTrials.gov API v2 record for NCT06940830. Maintained by the National Library of Medicine at NIH. Public domain. Cite as: "TrialFinderData. NCT06940830. Data: ClinicalTrials.gov."

Medical disclaimer: This page is informational, not medical advice. Talk to your doctor about whether a clinical trial is right for you.

Last updated 2026-05-08 · Data from ClinicalTrials.gov.