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Completed

NCT Number: NCT05876221

Platelet Response to Caplacizumab in the Treatment of Acquired Thrombotic Thrombocytopenic Purpura

The interpretation of platelet counts has to be revaluated in the light of caplacizumab. By effectively blocking platelet binding sites on VWF-multimers, the nanobody leads to a rapid normalization of the platelet count within 3 to 4 days. Most importantly, caplacizumab uncouples platelet counts from ADAMTS13 activity and thereby launches unprecedented thrombocyte dynamics, with potential pitfalls for over- and undertreatment.

A relevant number of patients responds to caplacizumab with a brisk increase in platelet count, followed by a marked dip of platelets (patient on the left). This may mislead treating physicians into re-intensifying therapy, with a respective risk for adverse side-effects and complications. Taken together, these observations call for reliable descriptions and the identification of predictive parameters to predict the platelet response upon administration of caplacizumab in a large patient cohort. Here, PREDICT-2020 is designed as a retrospective study to specifically address the following aspects:

* Identifying and describing clusters of platelet responses to caplacizumab * Identifying potential pitfalls for treating physicians * Predicting the individual thrombocyte response * Correlating platelet responses with individual patient outcome

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Key information

Conditions

Acquired Thrombotic Thrombocytopenic Purpura Blood Coagulation Disorders Blood Platelet Disorders Cytopenia Hematologic Diseases Hemic and Lymphatic Diseases Hemorrhage Pathologic Processes Pathological Conditions, Signs and Symptoms Purpura Purpura, Thrombocytopenic Purpura, Thrombotic Thrombocytopenic Signs and Symptoms Skin Manifestations Thrombocytopenia Thrombophilia Thrombotic Microangiopathies

Age range

18 year and older

Sex eligibility

All sexes

Study type

Observational

Primary location

University Hospital of Cologne

Cologne, Germany

Who can participate

Healthy volunteers accepted: No

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

Inclusion criteria

  • Confirmed diagnosis of autoimmune thrombotic thrombocytopenic purpura
  • Treatment with at least a single dose of caplacizumab, either i.v. or s.c.
  • Male or female patients older than 18 years of age

Exclusion criteria

  • Hereditary thrombotic thrombocytopenic purpura

Treatment and study plan

Cablivi

Drug

Patients with immune Thrombotic Thrombocytopenic Purpura, who have been treated with caplacizumab (Cablivi®)

Primary outcomes

  1. Reliable description and prediction of platelet responses to caplacizumab

    Time frame: Enrollment

    Reliable description and prediction of platelet responses to caplacizumab employing mathematic modelling algorithms

Secondary outcomes

  1. Determination of different clusters of platelet responses to caplacizumab

    Time frame: Enrollment

    It will be hypothesized the existence of different clusters of caplacizumab responders during the first weeks of therapy, when ADAMTS13 activity typically is still <10%. A detailed cluster analysis and description of thrombocyte responses to caplacizumab in a large cohort will reliably identify these different responders

  2. Correlation of platelet responses to caplacizumab with patient outcome

    Time frame: Enrollment

    It will be hypothesized the existence of different clusters of caplacizumab responders during the first weeks of therapy, when ADAMTS13 activity typically is still <10%. A detailed cluster analysis and description of thrombocyte responses to caplacizumab in a large cohort will reliably identify these different responders

  3. Risk stratification of iTTP patients based on their platelet response to caplacizumab

    Time frame: Enrollment

    Description: Predicting the individual thrombocyte response to caplacizumab improves risk stratification of iTTP patients after initiation of caplacizumab therapy. An early risk stratification allows an optimal timing of monitoring intervals during the first weeks after diagnosis, which are often critical

Sponsors and collaborators

Lead sponsor

University of Cologne

Other

Registry information

Acronym: PREDICT2020

Important dates

Study start
2023
Primary completion
2025
Study completion
2025
First posted
May 25, 2023
Registry last updated
Sep 12, 2025

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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