ANTITHROMBIN III HUMAN for Congenital antithrombin deficiency

Inclusion criteria

• {"criterion_text":"- Adult male or female patients aged ≥18 to ≤80 years for all treatment arms; Adolescent male or female patients aged ≥12 to <17 years from non-European Union countries for the PK phase (who may continue in the Treatment Phase, if applicable)"}
• {"criterion_text":"- Documented congenital antithrombin deficiency, defined by plasma activity level of antithrombin ≤60% from medical history"}
• {"criterion_text":"- Personal or family history of TEs or TEEs (except for PK patients)"}
• {"criterion_text":"- For the Treatment Phase: either a) non-pregnant surgical patients scheduled for elective surgical procedure(s) known to be associated with a high risk for occurrence of TEs or TEEs, or b) pregnant patients of at least 27 weeks gestational age who are scheduled for caesarean section or delivery"}
• {"criterion_text":"- For female patients of childbearing potential entering the PK Phase who are not known to be pregnant, and for female surgical patients of childbearing potential entering the Treatment Phase for any procedure other than caesarean section or delivery, a negative urine pregnancy test at screening and at baseline"}
• {"criterion_text":"- Patient has provided informed consent"}

Exclusion criteria

• {"criterion_text":"- Requires emergency surgery or emergency caesarean section"}
• {"criterion_text":"- Known hypersensitivity or allergic reaction to antithrombin or any of the excipients in Atenativ"}
• {"criterion_text":"- History of anaphylactic reaction(s) to blood or blood components"}
• {"criterion_text":"- Refusal to receive transfusion of blood-derived products"}
• {"criterion_text":"- Administration of any antithrombin concentrate or antithrombin-containing blood product within 14 days of either of the two phases of the study"}
• {"criterion_text":"- Persons dependent on the sponsor, the investigator or the centre of investigation"}
• {"criterion_text":"- Persons placed in an institution by administrative or judicial order"}
• {"criterion_text":"- Prior diagnosis of heparin-induced thrombocytopenia"}
• {"criterion_text":"- TE or TEE within the last 6 months"}
• {"criterion_text":"- Female patients who are nursing at the time of screening1 1not applicable for female patients who plan to breastfeed after giving birth"}
• {"criterion_text":"- Have participated in another investigational study within the last 30 days"}
• {"criterion_text":"- Has undergone surgery within the last 6 weeks"}
• {"criterion_text":"- History or suspicion of another hereditary thrombophilic disorder other than antithrombin deficiency (e.g., activated protein C [APC] resistance/Factor V Leiden, Protein S or C deficiency, prothrombin gene mutation [G20210A], or acquired [lupus anticoagulant] thrombophilic disorder)"}
• {"criterion_text":"- Malignancies, renal failure (patients on renal replacement therapy), or severe liver disease (aspartate aminotransferase [ASAT] >5 times the upper limit of normal)"}
• {"criterion_text":"- Body mass index >40 kg/m2 (for non-pregnant patients, only)"}

Primary endpoints

• {"endpoint_text":"- Incidence of the composite of TEs and TEEs in patients with congenital antithrombin deficiency under cover of Atenativ for surgical procedures or parturition to 30 days post treatment initiation.","definition_or_measurement_approach":"Incidence of the composite of Thrombotic Events (TEs) and Thromboembolic Event (TEEs) measured up to 30 days after treatment initiation in patients receiving Atenativ for surgical procedures or delivery."}

Secondary endpoints

• {"endpoint_text":"- • PK parameters: o Area under the curve (AUCnorm(0–∞)) o Maximum plasma concentration (Cmax) o Half-life (t1/2) o Mean residence time (MRT) o Clearance (CL) o Incremental in vivo recovery (IVR; peak concentration of antithrombin observed within the first hour after infusion) o Volume of distribution at steady state (Vss) o Time to reach Maximum Plasma Concentration (Tmax)","definition_or_measurement_approach":"Pharmacokinetic parameters as listed (AUC, Cmax, t1/2, MRT, CL, IVR, Vss, Tmax) measured following single-dose Atenativ administration in the PK phase."}
• {"endpoint_text":"- • Efficacy Parameters: o Antithrombin activity; o Coagulation parameters (activated partial thromboplastin time [aPTT], prothrombin time [PT], international normalised ratio [INR] and fibrinogen)","definition_or_measurement_approach":"Laboratory measures including antithrombin activity and coagulation parameters (aPTT, PT, INR, fibrinogen) to assess efficacy."}
• {"endpoint_text":"- • Safety Parameters: o Adverse events (AEs) and serious AEs (SAEs); o Length of hospital stay; o Vital signs (including systolic and diastolic blood pressure, pulse rate, body temperature, respiration rate, results of physical examination); o Standard haematological and clinical chemistry safety variables, as well as thrombogenicity markers including D-dimer, prothrombin fragment 1 + 2 (F1+2)*, and thrombin-antithrombin complex (TAT)* * if available from local laboratories","definition_or_measurement_approach":"Safety assessed by collection and evaluation of AEs/SAEs, hospital stay duration, vital signs, standard hematology/clinical chemistry, and thrombogenicity markers (D-dimer, F1+2, TAT) where available."}

Methods

• K1_Recruitment arrangements documents (country-specific K1 recruitment arrangements submitted for multiple Member States) — target audience: patients with congenital antithrombin deficiency undergoing surgery or delivery
• Participant/Patient cards (documents labelled K2 / L2, Participation Card, Patient Card) — informational material for enrolled participants
• GP Letter (document labelled GP Letter) — use of general practitioner notification/engagement to support recruitment

Romania

Latest Decision Or Authorization Date

17-04-2026

Number Of Sites

1

Number Of Participants

6

France

Latest Decision Or Authorization Date

16-04-2026

Number Of Sites

3

Number Of Participants

3

Czechia

Latest Decision Or Authorization Date

14-04-2026

Number Of Sites

1

Number Of Participants

2

Italy

Latest Decision Or Authorization Date

13-04-2026

Number Of Sites

4

Number Of Participants

5

Spain

Latest Decision Or Authorization Date

15-04-2026

Number Of Sites

4

Number Of Participants

4

Germany

Latest Decision Or Authorization Date

15-04-2026

Number Of Sites

4

Number Of Participants

3

Hungary

Latest Decision Or Authorization Date

14-04-2026

Number Of Sites

1

Number Of Participants

3

Austria

Latest Decision Or Authorization Date

13-04-2026

Number Of Sites

1

Number Of Participants

2

Primary sponsor

Full Name

Octapharma AG

Organisation Type

Pharmaceutical company

Country Of Registered Address

Switzerland

Contract research organisations

Name

Syneos Health UK Limited

Responsibilities

Startup & Site Contract Management; other sponsor duties (codes: 1,12,2,5,6,7,8)

Name

ERGOMED Center for Data Management and Statistics GmbH

Responsibilities

Data management and statistics (sponsor duties codes: 10,6)

Name

LKF Laboratorium fuer Klinische Forschung GmbH

Responsibilities

Laboratory services (sponsor duties code: 4)

Third parties

• {"country":"Germany","full_name":"LKF Laboratorium fuer Klinische Forschung GmbH","duties_or_roles":"sponsorDuties codes: [\"4\"]","organisation_type":"Laboratory/Research/Testing facility"}
• {"country":"United Kingdom","full_name":"Syneos Health UK Limited","duties_or_roles":"sponsorDuties codes: [\"1\",\"12\",\"15\",\"2\",\"5\",\"6\",\"7\",\"8\"] (includes 'Startup & Site Contract Management')","organisation_type":"Pharmaceutical company"}
• {"country":"Germany","full_name":"ERGOMED Center for Data Management and Statistics GmbH","duties_or_roles":"sponsorDuties codes: [\"10\",\"6\"]","organisation_type":"Pharmaceutical company"}