The SOLID Platelet Study

NCT03712618 | Terminated Phase 2 Results FDA Drug

• 2 other identifiers: 19000519-CC-0005
• Study Type: interventional
• Target: 2
• Locations: 1 country
• Sites: 1

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.

Conditions

Platelet Transfusion Refractoriness (PTR); Thrombocytopenia

Keywords

Platelet Transfusion Refractoriness; Continuous Platelet Transfusion

Outcome Measures

Primary Outcomes (1)

• Adjusted Platelet Increment Area Under the Curve (AUC)

  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.

  0-6 hours post transfusion

Secondary Outcomes (1)

• 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

Study Arms (2)

Group A: LONG then SHORT transfusion

ACTIVE COMPARATOR

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.

Biological: Platelet Transfusion - LONG Platelet Transfusion; Biological: Platelet Transfusion - SHORT Platelet Transfusion

Group B: SHORT then LONG transfusion

ACTIVE COMPARATOR

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.

Biological: Platelet Transfusion - LONG Platelet Transfusion; Biological: Platelet Transfusion - SHORT Platelet Transfusion

Interventions

Platelet Transfusion - LONG Platelet Transfusion BIOLOGICAL

Platelets transfused over 4-HOURS

Group A: LONG then SHORT transfusion; Group B: SHORT then LONG transfusion

Platelet Transfusion - SHORT Platelet Transfusion BIOLOGICAL

Platelets transfused over 60-minutes

Group A: LONG then SHORT transfusion; Group B: SHORT then LONG transfusion

Eligibility Criteria

• Age: 18 Years - 100 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Ability to comprehend the investigational nature of the study and provide informed consent
• Thrombocytopenia
• Causes of thrombocytopenia may be due to:
• Congenital causes
• Bone marrow
• Hematologic malignancies
• Treatment related
• Thrombocytopenia is generally defined as one of the following:
• Platelet count \<10K/uL without bleeding
• Platelet count \<20K/uL for "complicated prophylaxis" in patients determined to be at increased risk of bleeding or other complications
• Platelet count \<50K/uL with evidence of active bleeding, such as intracranial hemorrhage, GI bleeding, pulmonary hemorrhage, uncontrolled epistaxis, hematuria.
• The treating provider may change the platelet transfusion threshold based on the clinical circumstance, patient population, and/or concurrent primary protocol considerations - similar to the PLADO study.
• Diagnosed with PTR, characterized by the following:
• Lack of adequate post-transfusion platelet count increment, defined by, Corrected Count Increment (CCI) \<5000/ul at 10-60 min after each of at least 2 consecutive platelet transfusions
• Presence of anti-HLA class 1 type A and/or type B antibody, in the setting of PTR, as defined above, constitutes the HLA alloimmune-mediated subtype of PTR. Presence of one or more HPA antibodies in the setting of PTR, as defined above, constitutes the HPA alloimmune-mediated subtype of PTR. Failure to detect HLA or HPA antibodies will be categorized as non-alloimmune-mediated PTR. .

You may not qualify if:

• Less than 18-years-old
• Lack of ability to obtain informed consent
• Pregnant female
• Presence of ITP/autoimmune thrombocytopenia
• Immune platelet refractoriness responsive to treatment with IVIg or eculizumab, or other immunosuppressive therapy within the 3 preceding months. This is based on the wide variation in the duration therapeutic antibodies, with the upper limit frequently cited as 3 months.

Sponsors & Collaborators

• National Institutes of Health Clinical Center (CC): lead

Study Sites (1)

National Institutes of Health Clinical Center

Bethesda, Maryland, 20892, United States

Location

Related Links

• NIH Clinical Center Detailed Web Page

MeSH Terms

Conditions

Thrombocytopenia

Condition Hierarchy (Ancestors)

Blood Platelet Disorders; Hematologic Diseases; Hemic and Lymphatic Diseases; Cytopenia

Limitations and Caveats

Study was terminated due to recruitment issue

Results Point of Contact

• Title: Dr. Willy Flegel
• Organization: National Institutes of Health, Clinical Center (NIH CC)

bill.flegel@nih.gov

+1 301 594 7401

Study Officials

• Willy A Flegel, M.D.

  National Institutes of Health Clinical Center (CC)

  PRINCIPAL INVESTIGATOR

Publication Agreements

• PI is Sponsor Employee: Yes

Study Design

• Study Type: interventional
• Phase: phase 2
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: CROSSOVER
• Sponsor Type: NIH
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: October 18, 2018
• First Posted: October 19, 2018
• Study Start: June 10, 2019
• Primary Completion: July 31, 2021
• Study Completion: July 31, 2021
• Last Updated: May 9, 2025
• Results First Posted: May 9, 2025

Record last verified: 2025-02

Data Sharing

• IPD Sharing: Will share
• Time Frame: After study completion
• Access Criteria: Other researchers may access the data through Biomedical Translational Research Information System (BTRIS) database

Locations

US (1)