Efficacy of Mirasol-treated Apheresis Platelets in Patients With Hypoproliferative Thrombocytopenia

Patients will be randomized 1:1 to Mirasol-treated platelets (test platelets) or to
conventional, untreated platelets (control platelets). The blood centers will collect the
apheresis donor platelets and supply the test platelets to the hospital sites for transfusion
into patients. Hospital sites will order control platelets as per their normal process, from
their standard vendor.

The target population for the MIPLATE study are patients with hematologic malignancies with
hypoproliferative thrombocytopenia who are expected to have platelet (PLT) count(s) of ≤
10,000/μL requiring ≥ 2 PLT transfusions.

The primary objective of MIPLATE is to determine if the hemostatic efficacy of
Mirasol-treated plasma stored Trima Accel® Aph PLTs are non-inferior to Conventional plasma
stored Aph PLTs in subjects with hypoproliferative thrombocytopenia requiring PLT
transfusions. The secondary objectives include comparing other efficacy and safety endpoints
between the treatment groups.

Subjects with hematologic malignancies with hypoproliferative thrombocytopenia are
anticipated to experience a "transfusion episode" where they will require PLT transfusion
support until bone marrow recovery. During this period all PLT transfusions required for a
study subject will be given according to the subject's treatment allocation for 28 days after
the initial PLT transfusion OR until transfusion independence (10 days without PLT
transfusion) prior to Day 28.

Additionally, serum samples for HLA antibody testing will be collected weekly for 28 days and
on Days 42 and 56.

At a minimum, the initial post-randomization prophylactic PLT transfusion will be initiated
for a PLT count ≤ 10,000/µL. Thereafter, indications for PLT transfusions may be PLT
count-related prophylaxis, intervention-related prophylaxis, or therapeutic (treatment of
active bleeding) as determined by the treating physician(s). The indication(s) for the
transfusion(s) will be captured.

Inclusion Criteria:

1. Weight > 10 kg (22 lbs)

2. Subject has a hematologic malignancy with hypoproliferative thrombocytopenia and is
expected to have PLT count(s) ≤ 10,000/µL requiring ≥ 2 PLT transfusions

3. Laboratory results within 5 days prior to anticipated initiation of the first post
randomization PLT transfusion:

1. Prothrombin time (PT) and/or international normalized ratio (INR) ≤ 1.3 × the
upper limit of normal (ULN)

2. Activated partial thromboplastin time (aPTT) ≤ 1.3 × ULN

3. Fibrinogen ≥ 100 mg/dL

4. Women of childbearing potential must have a negative pregnancy test and agree to
practice a medically acceptable contraception regimen for the study duration. Women
who are postmenopausal for at least 1 year (> 12 months since last menses) or are
surgically sterilized do not require this test

5. IC from the subject or assent from the subject and consent from a parent or guardian,
if the subject is < 18 years of age

Exclusion Criteria:

1. Previous treatment with pathogen-reduced blood products

2. Subject has previously been enrolled in this study and received at least 1 per
protocol PLT transfusion

3. Subject is receiving anticoagulant, pro-coagulant or antithrombotic, antiplatelet
agents, and/or PLT specific growth factors within 10 days prior to randomization

4. Subject has ≥ grade 2 bleeding at the time of randomization

5. Planned administration of bedside LR PLT transfusion(s)

6. Subject is anticipated to need washed or volume reduced PLT during the course of this
study

7. Presently with or a history of acute promyelocytic leukemia (APML), idiopathic
thrombocytopenic purpura (ITP), thrombotic thrombocytopenic purpura (TTP), or
hemolytic uremic syndrome (HUS)

8. Subject is receiving anticoagulant, pro-coagulant or antithrombotic, antiplatelet
agents, and/or PLT specific growth factors within 10 days prior to randomization

9. Splenomegaly (presence of a palpable spleen whose border could be felt more than 4 cm
below the costal margin)

10. History or diagnosis of a disease affecting hemostasis

11. Currently taking, or participating in a clinical study involving PLT substitutes, PLT
growth factors, or pharmacologic agents intended to enhance (ie, antifibrinolytic
agents) or decrease PLT hemostatic function

12. Acute or chronic medical disorder that, in the opinion of the investigator, would
impair the ability of the subject to receive protocol treatment

13. Subject is pregnant or lactating

14. Inability of the subject to comply with study procedures and/or follow-up