Part 1 completed, part 2 not done due to slow enrollment

The PRESS trial is a single-center, two-part, randomized cross-over pilot study in Copenhagen that will evaluate 1) the safety and performance of Mirasol-treated and untreated platelet products stored for 2-4 days and for 7-days in Platelet Additive Solution (PAS) and 2) the correlation between the TEG® parameters and platelet count increments after platelet transfusions in thrombocytopenic subjects.

1. To evaluate in thrombocytopenic subjects the efficacy and safety of platelets treated with Mirasol Pathogen Reduction Technology (PRT) in Platelet Additive Solution. The following safety and efficacy measures will be compared between Mirasol treated and untreated platelets stored for 2-4 days and stored for 7 days:

   • Thrombelastography (TEG®) parameters: reaction time R, alpha angle α and maximal amplitude (MA)
   • Platelet Count Increment and Corrected Count Increment
   • Time to next platelet transfusion
   • Incidence of transfusion related (serious) adverse events
   • Incidence and severity of bleedings

2. To evaluate the use of the TEG® parameters as a measure for platelet transfusion efficacy and to evaluate the correlation between the TEG® parameters and the platelet Corrected Count Increments after platelet transfusions in thrombocytopenic subjects.

Inclusion Criteria:

• Male or female of age of 18 years or older.
• Have thrombocytopenia or expected to develop thrombocytopenia requiring at least 3 platelet transfusions.
• Woman of child bearing potential must have a negative serum or urine pregnancy test within 72 hours before randomization.
• Subjects must have signed and dated the Informed Consent Form before performing any protocol related procedure.

Exclusion Criteria:

• History of any hypersensitivity reaction to riboflavin or metabolites.
• History of refractoriness to platelet transfusions (defined as 2 successive CCI1hr<5000) or presence of human leukocyte antigen (HLA) antibodies or positive lymphocytotoxicity or previously documented alloimmunization.
• Previous exposure to PRT-treated platelet concentrates.
• Active bleeding requiring one or more red cells concentrate transfusions (i.e. grade 3 or 4 bleeding according to the WHO bleeding assessment scale in Appendix 1).
• Exposure to an investigational product, within 30 days before randomization.
• Splenomegaly (presence of a palpable spleen whose border could be felt more than 4 cm below the costal margin) or splenectomy.
• History or diagnosis of Immune/Idiopathic Thrombocytopenic Purpura (ITP), Thrombotic Thrombocytopenia Purpura (TTP), or Haemolytic Uremic Syndrome (HUS).
• Use of prohibited medication (see section 5.5).
• Pregnant or lactating females.
• Any medical condition or treatment that would be expected to compromise the effectiveness of a platelet transfusion or that would interfere with an expected platelet count increment.
• Any other medical condition that would compromise the participation of the subject in the study.

24 hours from start of transfusion

Only transfusion related events

Small numbers of subjects