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NCT Number: NCT05802836

Dynamics of the Anti-factor VIII Antibody Signature During Treatment With Emicizumab

The goal of this observational study is to learn about the changes of antibodies and inhibitors against the coagulation factor VIII in patients with severe hemophilia A receiving emicizumab therapy. No additional visits or procedures are planned. Patients in this study will continue to receive their routine care and analysis will be done from left over samples from routine visits.

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Key information

Conditions

Severe Hemophilia A Blood Coagulation Disorders Blood Coagulation Disorders, Inherited Coagulation Protein Disorders Congenital, Hereditary, and Neonatal Diseases and Abnormalities Genetic Diseases, Inborn Hematologic Diseases Hemic and Lymphatic Diseases Hemophilia A Hemorrhagic Disorders Severe Hemophilia A With Inhibitor Severe Hemophilia A Without Inhibitor

Sex eligibility

All sexes

Study type

Observational

Primary location

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Severe congenital hemophilia A (CHA)
  • Treatment with emicizumab irrespective of any other treatment
  • Informed consent

Exclusion criteria

  • No therapy with emicizumab
  • Immunosuppressive therapy
  • HIV-infection with CD4 (cluster of differentiation 4) cells <200/µl

Treatment and study plan

No interventions

Other

no intervention, only 3 different patients groups

Primary outcomes

  1. FVIII inhibitor development in inhibitor negative subjects

    Time frame: 3 years

    Rate of FVIII inhibitor development during three years of emicizumab prophylaxis in inhibitor negative subjects. Assessed with Bethesda Assay (BU/ml). Number of patients who develop an FVIII inhibitor within the study period, but were FVIII inhibitor negative at start of the study.

  2. FVIII antibody development in inhibitor negative subjects

    Time frame: 3 years

    Rate of FVIII antibody development during three years of emicizumab prophylaxis in inhibitor negative subjects. FVIII anti drug antibody (ADA) is assessed by FVIII specific ELISA (OD=Optical Density). Number of patients who develop an FVIII antibody (ADA) within the study period, but were FVIII inhibitor negative at start of the study.

  3. FVIII inhibitor disappearance in inhibitor positive subjects

    Time frame: 3 years

    Rate of FVIII inhibitor disappearance during three years of emicizumab prophylaxis in inhibitor positive subjects. Assessed with Bethesda Assay (BU/ml). Number of patients who loose an FVIII inhibitor within the study period, but were FVIII inhibitor positive at start of the study.

  4. FVIII antibody disappearance in inhibitor positive subjects

    Time frame: 3 years

    Rate of FVIII antibody disappearance during three years of emicizumab prophylaxis in inhibitor positive subjects. FVIII anti drug antibody (ADA) is assessed by FVIII specific ELISA (OD=Optical Density). Number of patients who develop an FVIII antibody within the study period, but were FVIII inhibitor positive at start of the study.

Secondary outcomes

  1. Anti-FVIII inhibitor development

    Time frame: 3 years

    Anti-FVIII inhibitor development (median BU/ml) over time. Assessed with Bethesda Assay (BU/ml). Description of inhibitor development in the different patient groups within the study period. Cut off is 0,6 BU/ml.

  2. Anti-FVIII antibody development

    Time frame: 3 years

    Anti-FVIII antibody development (median arbitrary units, OD) over time. Description of antibody development in the different patient groups within the study period.

  3. Time to negative inhibitor titers

    Time frame: 3 years

    Time to negative inhibitor titers. Assessed with Bethesda Assay (BU/ml). Description of the Time (days) observed for FVIII inhibitor disappearance within the study period in the patient groups. Cut off for inhibitor titer is 0,6 BU/ml.

  4. Treatment of bleeds

    Time frame: 3 years

    Description of the use of FVIII and/or Bypassing agents treatment in addition to Emicizumab treatment in case of bleeds.

  5. Response to treatment

    Time frame: 3 years

    Classification of bleeds as Effective, Partially Effective, Ineffective. Defined as: Effective: Bleeding episode responded to the usual number of injections or dose of FVIII as expected by the treating physician; Partially Effective: The bleeding episode responded with a higher number of injections and/or dose as expected by the treating physician; Ineffective: Routine failure to control hemostasis or hemostatic control required additional agents

  6. Quality of the antibody response (FVIII epitopes)

    Time frame: 3 years

    Description of the location of FVIII epitopes over time, assessed by epitope mapping technique (ELISA)

  7. Quality of the antibody response (IgG subclasses)

    Time frame: 3 years

    Description of a potential immune response over time, assessed by IgG subclass determination (ELISA).

Study contacts

Contact information is provided by the study sponsor or research team.

Christoph Koenigs, PD Dr. Dr

CONTACT

[email protected]

+4969630183030

Stephan Schultze-Strasser, Dr.

CONTACT

[email protected]

+496963016998

Sponsors and collaborators

Lead sponsor

Christoph Königs

Other

Collaborators

  • Chugai Pharma Germany GmbH
  • Roche Pharma AG

Registry information

Acronym: NAVIGATE

Important dates

Study start
2023
Primary completion
2028
Study completion
2029
First posted
Apr 7, 2023
Registry last updated
Jul 10, 2023

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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