Sobi.BIVV001-003 is an open-label, 2-period, fixed sequence study for intra-participant comparison of the PK profiles of efanesoctocog alfa and the extended half-life rFVIII products damactocog alfa pegol or turoctocog alfa pegol after a single i.v. injection in previously treated males, 18-65 years of age, with severe haemophilia A.

Participants who are receiving treatment with damoctocog alfa pegol (n~12) or turoctocog alfa pegol (n~12) will be enrolled in the study. The study will start with a screening period (up to 28 days), including a wash-out period prior to start of the actual study period.

During the the first visit, a single dose of damactocog alfa pegol or turoctocog alfa pegol (corresponding to the participant's pre-study treatment) will be administered. A PK sampling period will follow over 7 visits. Following completion of the PK sampling of the original treatment regimen, the patients will be given a single dose of efanesoctocog alfa at visit 8, after which a new PK sampling period will follow (visit 8-15).

The primary objective for the study is to compare the half-life of efanesoctocog alfa with that of the two comparator drugs after a single iv. injections.

Secondary objectives include comparison of area under the curve for efanesoctocog alfa vs. the two comparator drugs, characterization of PK parameters for all three drugs as well as well as to evaluate safety and tolerability of a single iv. injection of efanesoctocog alfa.

Inclusion Criteria:

• Participant must be male, 18 to 65 years of age, inclusive, at the time of signing the informed consent form (ICF).
• Severe haemophilia A, defined as <1 IU/dL (<1%) endogenous FVIII activity, as documented in historical medical records from a clinical laboratory demonstrating <1% FVIII coagulant activity or a documented genotype known to produce severe haemophilia A.
• Previous treatment for haemophilia A with any marketed recombinant and/or plasma derived FVIII for at least 150 exposure days.
• Currently receiving treatment with damoctocog alfa pegol or turoctocog alfa pegol at Screening.

Exclusion Criteria:

• Any history of a positive inhibitor test, defined as >0.6 Bethesda units (BU)/mL in at least two consecutive Bethesda inhibitor assays, or any value greater than or equal to the lower sensitivity cut-off for laboratories with cut-offs for inhibitor detection between 0.7 and 1.0 BU/mL. Family history of inhibitors will not exclude the participant.
• Positive FVIII inhibitor result (assessed by central laboratory), defined as ≥0.6 BU/mL at Screening.

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 Sobi's data sharing criteria and process for requesting access can be found at: https://www.sobi.com/en/policies

Within 1 year following completion of the trial, or at the time of CSR finalization.

A decision on sharing will be based on the following:

The scientific merit of the proposal - i.e. the proposal should be scientifically sound, ethical, and have the potential to contribute to the advancement of public health.

The feasibility of the research proposal - i.e. the requesting research team must be scientifically qualified and have the resources to conduct the proposed project.

Maintenance of personal integrity - i.e. Sobi will not consider sharing individual data if there is a risk of re-identification of individuals despite a proper anonymisation. Moreover, the patients' informed consent will always be respected. Sobi reserves the right to reject the proposal if the anonymisation process will render unusable data.

Publication of results - the applicants should commit to submit their findings to a peer-reviewed scientific journal, alternatively to present the results at a congress (poster or similar), regardless of the research outcome