The SOLID Platelet Study

Phase 2

Terminated

Conditions: Thrombocytopenia
Platelet Transfusion Refractoriness (PTR)

Interventions: Other: Platelet Transfusion - LONG Platelet Transfusion
Other: Platelet Transfusion - SHORT Platelet Transfusion

Registration Number: NCT03712618

Lead Sponsor: National Institutes of Health Clinical Center (CC)

Brief Summary: Background:

Platelets are cell fragments in the blood that help it clot. Some people get very low platelet counts during a disease or treatment. Low platelet counts can cause severe bleeding. Some people are not helped by platelet transfusions at the standard transfusion rate. This is called platelet transfusion refractoriness (PTR). Researchers want to learn more about transfusing platelets so they can make transfusions more effective.

Objectives:

To study the effects of transfusing platelets more slowly than the standard rate. To obtain data to improve the effectiveness of platelet transfusions in people with PTR and decrease the risk of bleeding in some people.

Eligibility:

Adults ages 18-100 who have very low platelet counts requiring platelet transfusion, and have evidence of PTR

Design:

Participants will be screened with a review their recent NIH medical records. They will have blood drawn.

Participants will have up to three 12-hour treatment blocks. They can have only one block per day. During each block, they will have 2 platelet transfusions in those 12 hours.

One transfusion will take place over 1 hour (SHORT infusion). The other will take place over 4 hours (LONG infusion).

Participants will be randomly put in 1 of 2 treatment groups. This will dictate whether they get the SHORT or LONG infusion first.

Participants will have blood drawn:

* When they enroll

* Right before each transfusion

* 2, 4, and 6 hours after each transfusion

Each blood draw will consist of a complete blood count. Smaller tubes that require only small amounts of blood will be used to minimize the amount of blood drawn.

Detailed Description: Platelet transfusion can be a life-saving procedure in preventing or treating serious bleeding in patients who have low and/or dysfunctional platelets. Treatment of blood cancer and other blood diseases, as well as bone marrow transplantation, is not possible without platelet transfusion support. Unfortunately, 15- 25% of chronically transfused patients platelet counts will stop responding to these transfusions, putting them at risk for serious bleeding complications. The development of human leukocyte antigen (HLA) antibodies is responsible for 4- 8% of this platelet transfusion refractoriness. The presence of HLA antibodies is a clinical complication that is generally managed by the selection of products that are negative for the antigens for which the patient has antibodies. Often, for patients with chronic and ongoing need, this selection is facilitated by targeted recruitment of donors with known HLA types (i.e., types that lack antigens cognate to the patients known antibodies and are thus predicted to be compatible). However, for very broadly HLA- alloimmunized patients, compatible products may be exceedingly scarce or completely unavailable, precluding the ability to consistently provide products the patient will likely increment from. This research protocol is designed to evaluate the efficacy of a 4-hour continuous infusion of single donor, apheresis platelets in overcoming both alloimmune-mediated and non-alloimmune-mediated platelet refractoriness. We hypothesize that when we transfuse patients over a long duration, who have platelet refractoriness, the platelet counts will increase to higher numbers for an extended period of time in the peri-transfusion period when compared to shorter transfusion intervals.

Recruitment & Eligibility

Status: TERMINATED

Sex: All

Target Recruitment: 2

Inclusion Criteria

Not provided

Exclusion Criteria

Not provided

Study & Design

Study Type: INTERVENTIONAL

Study Design: CROSSOVER

Arm && Interventions

Group	Intervention	Description
Group A	Platelet Transfusion - LONG Platelet Transfusion	Group A: Long Transfusion followed by Short Transfusion in the first block
Group A	Platelet Transfusion - SHORT Platelet Transfusion	Group A: Long Transfusion followed by Short Transfusion in the first block
Group B	Platelet Transfusion - LONG Platelet Transfusion	Group B: Short Transfusion followed by Long Transfusion in the first block
Group B	Platelet Transfusion - SHORT Platelet Transfusion	Group B: Short Transfusion followed by Long Transfusion in the first block
Group A: LONG then SHORT transfusion	Platelet Transfusion - LONG Platelet Transfusion	Subjects with thrombocytopenia (due to congenital causes, bone marrow failure, hematologic malignancies, and treatment-related) randomized to receive LONG platelet transfusion (Transfused over 4-HOURS via infusion pump or gravity) with follow up until 6 hours and then SHORT platelet transfusion (Transfused over 60-minutes via infusion pump or gravity) with follow up until 6 hours for a combined total of 12 hours. Subjects may receive up to two further subsequent blocks (one per day) to be administered to a subject in alternating order of SHORT and LONG platelet transfusions, for a maximum number of three blocks per subject.
Group A: LONG then SHORT transfusion	Platelet Transfusion - SHORT Platelet Transfusion	Subjects with thrombocytopenia (due to congenital causes, bone marrow failure, hematologic malignancies, and treatment-related) randomized to receive LONG platelet transfusion (Transfused over 4-HOURS via infusion pump or gravity) with follow up until 6 hours and then SHORT platelet transfusion (Transfused over 60-minutes via infusion pump or gravity) with follow up until 6 hours for a combined total of 12 hours. Subjects may receive up to two further subsequent blocks (one per day) to be administered to a subject in alternating order of SHORT and LONG platelet transfusions, for a maximum number of three blocks per subject.
Group B: SHORT then LONG transfusion	Platelet Transfusion - LONG Platelet Transfusion	Subjects with thrombocytopenia (due to congenital causes, bone marrow failure, hematologic malignancies, and treatment-related) randomized to receive SHORT platelet transfusion (Transfused over 60-minutes via infusion pump or gravity) with follow up until 6 hours and then LONG platelet transfusion (Transfused over 4-HOURS via infusion pump or gravity) with follow up until 6 hours for a combined total of 12 hours. Subjects may receive up to two further subsequent blocks (one per day) to be administered to a subject in alternating order of LONG and SHORT platelet transfusions, for a maximum number of three blocks per subject.
Group B: SHORT then LONG transfusion	Platelet Transfusion - SHORT Platelet Transfusion	Subjects with thrombocytopenia (due to congenital causes, bone marrow failure, hematologic malignancies, and treatment-related) randomized to receive SHORT platelet transfusion (Transfused over 60-minutes via infusion pump or gravity) with follow up until 6 hours and then LONG platelet transfusion (Transfused over 4-HOURS via infusion pump or gravity) with follow up until 6 hours for a combined total of 12 hours. Subjects may receive up to two further subsequent blocks (one per day) to be administered to a subject in alternating order of LONG and SHORT platelet transfusions, for a maximum number of three blocks per subject.

Primary Outcome Measures

Name	Time	Method
Adjusted Platelet Increment Area Under the Curve (AUC)	0-6 hours post transfusion	The adjusted platelet increment area under the curve (AUC), obtained between 0-hours and 6-hours after start of the platelet transfusion. The AUC (i.e., AUC above the pretransfusion complete blood count (CBC) platelet count, minus the AUC below the pre-transfusion CBC's platelet count) determined by the 0-hour, 2-hour, 4-hour, and 6-hour CBC platelet concentrations, calculated using the trapezoid rule. Adjustment to the measured AUC done for the number of platelets transfused during the two transfusion periods (LONG and SHORT Transfusion durations) in one block.

Secondary Outcome Measures

Name	Time	Method
Participants With Bleeding During the Peri-transfusion Period	One day before the first Transfusion Block until one day after the last Transfusion Block; up to 5 days total	The efficacy of continuous platelet infusion on bleeding outcomes was assessed by number of participants with bleeding grade 1 or higher, measured during the peri-transfusion period by daily hemostatic assessments using the World Health Organization (WHO) bleeding scale. The WHO Bleeding Scale is a standardized tool used to assess and grade the severity of bleeding from 0-4: Grade 0: No bleeding. Grade 1: Petechiae (small, pinpoint hemorrhages). Grade 2: Mild blood loss. Grade 3: Gross blood loss (visible blood loss). Grade 4: Debilitating blood loss (severe blood loss that causes weakness)