The primary objective of the study is to measure platelet corrected count increments and the incidence of serious adverse events (SAE). The primary endpoint is the platelet corrected count increment measured 1-hour post transfusion in response to the infusion of platelet concentrates treated with the Mirasol PRT System device (test product) versus untreated (reference product).

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.

Inclusion Criteria:

• Male or female of age of 16 years or older
• Women of Child Bearing Potential not pregnant
• Subject must have signed and dated the Informed Consent form
• Hospitalized, thrombocytopenic subjects and expected to receive at least two platelets transfusion

Exclusion Criteria:

• History of any hypersensitivity reaction to riboflavin or metabolites
• History of refractoriness to platelet transfusions
• Positive lymphocytotoxic antibody test
• Active bleeding
• Splenomegaly
• Acute or chronic Disseminated Intravascular Coagulation
• History or diagnosis of Immune/Idiopathic Thrombocytopenic Purpura, Thrombotic Thrombocytopenia Purpura, or Haemolytic Uremic Syndrome
• History or diagnosis of an autoimmune disease affecting haemostasis
• History of solid organ transplants
• Evidence of occlusive venous disease
• Clinical signs of infection at the time of inclusion
• Pregnant or lactating females
• Chronic alcohol misuse
• Use of prohibited medications