• The platelet corrected count increment measured 1 hour post transfusion.
  

• The platelet corrected count increment measured 24 hours post-transfusion.
  
• The number of days between platelet transfusions during the period of the study.
  
• The number of platelet transfusions per subject.
  
• The number of platelets infused per subject.
  
• The number of platelets used.
  
• The frequency of refractoriness to platelet transfusion.
  
• In case of refractoriness, the evidence for neoantigen immunization against test product.
  
• The number of red blood cell transfusions during the study period.
  
• The incidence of serious adverse events in relation to platelet transfusions.
  
• The incidence of any adverse events in relation to platelet transfusions.
  
• The occurrence of bleeding episodes.
  

The objective of the study is to determine if the MIRASOL Pathogen Reduction Technology (PRT) System for Platelets device performs safely and maintains adequate platelet performance in a clinical setting. This will be achieved by comparing the platelet corrected count increment measured 1 hour post transfusion and the incidence of serious adverse events in response to the infusion of platelet concentrates treated with the device (test product) versus untreated (reference product) in thrombocytopenic subjects requiring platelet transfusions. The performance, safety, and tolerability profile of the device will be further assessed by monitoring and comparing the incidence of discontinuations due to adverse events in relation to platelet transfusion up to 4 weeks after transfusion, including the incidence of transfusion associated infections, and the number and time between transfusions.