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Long-term joint health monitoring in people with haemophilia A on efanesoctocog alfa prophylaxis

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)

Phase 4 Interventional Swedish Orphan Biovitrum · NCT06940830

This will test if long-term preventive treatment with efanesoctocog alfa helps protect joints in people with haemophilia A who are prescribed the medicine.

Quick facts

PhasePhase 4
Study typeInterventional
Enrollment250 (estimated)
SexAll
SponsorSwedish Orphan Biovitrum Industry-sponsored
Locations27 sites (Zagreb and 26 other locations)
Trial IDNCT06940830 on ClinicalTrials.gov

What this trial studies

This is a low-interventional, retrospective-prospective study following people with haemophilia A who have been prescribed efanesoctocog alfa as routine prophylaxis. The study collects 12 months of retrospective treatment and bleed data before starting efanesoctocog alfa and then follows participants with mandatory on-site joint assessments and patient-reported outcomes yearly for 24 to 36 months. Enrollment is limited to patients prescribed efanesoctocog alfa within six months before or at the enrollment visit, and a broad range of ages and disease severities are eligible. Data will be gathered from designated Sobi investigational sites and managed in collaboration with a contract research organization.

Who should consider this trial

Good fit: People of any age or haemophilia A severity who have been on prophylactic treatment for at least 12 months and who were prescribed efanesoctocog alfa within six months prior to or at enrollment are ideal candidates.

Not a fit: Patients who are not prescribed efanesoctocog alfa, who lack the required 12-month pre-treatment records, or who cannot attend mandatory on-site joint assessments are unlikely to benefit from participation.

Why it matters

Potential benefit: If successful, the findings could show reduced joint bleeds and improved long-term joint health for people using efanesoctocog alfa, helping doctors and patients choose prophylaxis strategies.

How similar studies have performed: Prior clinical trials of efanesoctocog alfa have shown reduced bleed rates, but long-term, real-world joint outcome data remain limited, so this real-world design addresses a gap in evidence.

Eligibility criteria

Show full inclusion / exclusion criteria 
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.

Where this trial is running

Zagreb and 26 other locations

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
View on ClinicalTrials.gov → Find more trials like this →
Conditions Hemophilia AJoint HealthProphylaxisFactor VIII DeficiencyBlood coagulation disorderEfanesoctogoc alfaCoagulation protein disorderALTUVOCT
Last reviewed 2026-06-10 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.