Pathogen-Reduced Platelet Concentrates: Experience in Routine Practice in Germany

The safety of blood products has significantly improved over the past 30 years due to enhanced donor selection and more sensitive testing for infectious agents. Nevertheless, a residual risk remains, particularly the risk of bacterial contamination in platelet concentrates. To mitigate this, pathogen reduction methods and/or bacterial detection tests can be employed. In Germany, there is currently limited large-scale experience under real-world conditions regarding how pathogen reduction of platelet concentrates (PC) affects the various stages of the process chain from production, distribution through to the clinical application and its impact on safety and efficacy.To better understand the effects, the non-interventional post-authorization safety study INITIATE evaluates various aspects of pathogen-reduced, platelet concentrates across the entire process chain and compares results to historical data of standard, non-pathogen reduced PC. This project is a multi-center, open-label, prospective, non-interventional post-authorisation safety-study and is divided into two parts:

Part 1 focuses on product- and process-related objectives. It includes all pathogen-reduced PC units produced at participating manufacturing sites to analyse the product and supply-related endpoints including manufacturing data, quality control data, logistics and supply, safety and costs. Part 1 shall include data on 20.000 PC.

Part 2 includes a defined number of patients requiring PC transfusions at participating clinical study centers. It aims to collect data on safety (primary and co-primary endpoint: transfusion reactions (frequency, type, severity, imputability and outcome, according to CTCAE) and efficacy (bleeding, platelet increment (subgroup of patients), alloimmunization or platelet refractoriness). Part 2 shall include 850 patients (with an expected total number of 4.500 to 5.000 PC transfusions).

Inclusion criteria

• Patients ≥ 18 years
• Patients who, based on clinical indications*, receive at least one platelet transfusion with a pathogen-reduced platelet concentrate for treatment of bleeding risk caused by severe thrombocytopenia resulting from impaired platelet production.

(* Taking into account the Cross-sectional Guidelines on the transfusion of blood components and plasma derivatives issued by the German Medical Association (Bundesärztekammer) in its current version.)

Exclusion criteria

Patients will not be included if they fulfil at least one of the following exclusion criteria:

• Known hypersensitivity to amotosalen HCl or psoralens. In this case, platelet concentrates treated with this pathogen inactivation method should not be used.
• Known allergies of the recipient to human plasma proteins.
• Known immune thrombocytopenia.
• Thrombotic microangiopathy (thrombotic thrombocytopenic purpura; haemolytic uremic syn-drome).
• Post-transfusion purpura.
• Heparin-induced thrombocytopenia.
• Congenital platelet function disorders, such as Glanzmann's thrombasthenia or Bernard- Souli-er syndrome