Strategies for Transfusion of Platelets (SToP)

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT00420914
Recruitment Status : Terminated (Stopped at the request of the Data Safety Monitoring Board for safety reasons.)
First Posted : January 11, 2007
Last Update Posted : May 28, 2008
Dartmouth-Hitchcock Medical Center
Haukeland University Hospital
Ottawa Hospital Research Institute
Cedars-Sinai Medical Center
University Health Network, Toronto
Information provided by:
McMaster University

Brief Summary:
To evaluate the hemostatic efficacy of a low dose platelet transfusion strategy compared to a standard dose platelet transfusion strategy.

Condition or disease Intervention/treatment Phase
Thrombocytopenia Procedure: low dose of 2.25 x 10^11 platelets/transfusion (range 1.5 to 2.9) Phase 3

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Detailed Description:

BACKGROUND:Platelet transfusions play a major role in the management of thrombocytopenic patients. Platelet transfusions may be given either in the absence of hemorrhage (prophylactic transfusions), or to control bleeding (therapeutic transfusions). Prophylactic platelet transfusion therapy is most commonly used in patients with decreased marrow platelet production (hypoproliferative thrombocytopenia) and accounts for the majority of platelets transfused to these patients. As platelet use continues to increase at a rate disproportionately higher than that of red cells, it is important to identify the most cost-effective strategies for providing platelet support. The two most important factors - within the control of the ordering physician - that will significantly influence the total amount of platelets transfused are:

  1. the prophylactic platelet transfusion "trigger" selected for transfusion;
  2. the number of platelets given per transfusion. The optimal quantity of platelets to be used per transfusion remains a highly controversial subject. No prospective platelet transfusion trials have been performed in which patients are randomized to an assigned platelet dose throughout their period of thrombocytopenia to evaluate the effects of different doses on transfusion outcomes.

INTRODUCTION: A randomized prospective platelet dose trial is proposed to determine a safe, efficient, and cost-effective dosing strategy for transfusing platelets. The trial is designed to answer two fundamental questions: 1) Are low dose platelet transfusions not inferior to standard dose platelet transfusion for patients with chemotherapy induced thrombocytopenia as measured by the frequency of WHO bleeding Grade 2 or greater; and 2) How does the dose of platelets transfused affect the interval between platelet transfusion events, and, thereby, the total number of platelets transfused?

GENERAL OBJECTIVE: To evaluate the hemostatic efficacy of low dose platelet transfusions.

PRIMARY OBJECTIVE: This will be a non-inferiority study designed to determine if low dose prophylactic platelet transfusions can be transfused to patients with chemotherapy induced thrombocytopenia without an increase in the frequency of WHO bleeding (Grade 2 or greater ) when compared to the current transfusion strategy of using standard dose platelet products.

The low dose platelet transfusions will be targeted at 2.25 x 10^11 platelets/transfusion (range 1.5-2.9 x 10^11/product).

The standard dose platelet transfusions will be targeted at 4.5 x 10^11 platelets/transfusion (range 3.0-6.0 x 10^11/ product)

STUDY DESIGN: This will be a multicenter prospective randomized controlled trial in which eligible patients will be randomized to receive low dose or standard dose prophylactic platelet transfusions. Patients will be transfused prophylactically using a transfusion trigger of a platelet count equal to or below a level of 10 x 10^9/L (10,000/uL)or at a higher trigger (dependant on transfusion guidelines set by individual institutions).

Clinical evidence of bleeding will be assessed daily according to the WHO classification of bleeding. Study personnel involved in the daily hemostatic assessments of patients will be blinded as to the patient's randomization assignment. The grade of bleeding will be assigned using an Adjudication Committee blinded to the treatment that each patient is receiving. Each patient will be followed throughout their period of thrombocytopenia.

A Data and Safety Monitoring Board (DSMB) has been established and is comprised of two hematologists not associated with the study, one critical care physician, and a biostatistician. Three of these individuals have experience serving on Data Safety Monitoring Boards and all have expertise in clinical research methodology. The DSMB will receive and review any adverse events and regular reports. The information on the report will be blinded by designating treatment groups as A or B.

STRATIFICATION: There will be two levels of stratification in this study. The first level of stratification will be by center as there will be center differences in the chemotherapy and bone marrow or stem cell transplant protocols used. The second level of stratification will be by diagnostic grouping: bone marrow/stem cell transplant; and non transplant patients.

TREATMENT ALLOCATION: Eligible patients who have given written consent, will be randomized to a treatment arm when they require their first prophylactic platelet transfusion.

INTERVENTION: Patients will be randomized to one of two prophylactic platelet transfusion strategies either low dose or standard dose.

At the time of each platelet transfusion, a platelet count will be performed on the product and the weight of the platelet bag will be recorded so that the absolute number of platelets given with each platelet transfusion can be calculated. Either apheresis platelets or whole blood derived platelet concentrates will be used to achieve the required platelet dose based on product availability or the preferences of the patient's physician.

PERIOD OF FOLLOW-UP: Study patients will be followed throughout their period of thrombocytopenia until bone marrow recovery has occurred (with a platelet count of ≥ 50 x10^9/L (50,000/uL) or the patient has been on the study for 30 days, withdraws consent, dies or is discharged from hospital or to a setting that does not allow for daily assessment of bleeding.

SERIOUS ADVERSE EVENTS: WHO Grade 3 or 4 bleeding will be considered a serious adverse event and will be monitored throughout the study. These serious adverse events will be reported to the data coordinating center and to the relevant IRB within 24 hours.

ANALYSIS OF PRIMARY OBJECTIVE: There will be two analyses performed: the first will compare the proportion of patients in each treatment group that have Grade 2 or greater bleeding: the second will be a recurrent event analysis which uses a strategy that includes the proportion of patients who bleed, the numbers of bleeds that occur and the timing of the bleed (i.e. whether it occurs early or late during the period of thrombocytopenia).

Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 130 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double
Primary Purpose: Health Services Research
Official Title: Strategies for Transfusion of Platelets (SToP) [Formerly Titled "Evaluation of the Hemostatic Efficacy and Platelet Utilization Rates of Low Versus Standard Dose Platelet Therapy"]
Study Start Date : October 2003

Resource links provided by the National Library of Medicine

Primary Outcome Measures :
  1. Daily hemostatic assessments will be conducted to determine presence of WHO Grade 2 bleeding or greater.

Secondary Outcome Measures :
  1. Number of platelets transfused during a defined period of thrombocytopenia
  2. Number of platelet transfusion events(frequency)
  3. Number of platelets transfused and frequency per thrombocytopenic day
  4. Mean duration of thrombocytopenia
  5. Percentage of days at risk of bleeding
  6. Differences in the severity of bleeding between treatment groups
  7. Correlation between the actual platelet dose given per transfusion for each patient and bleeding on the day following transfusion
  8. Correlation between the actual number between the actual number of platelets transfused/kg body weight for each patient and bleeding on the day following transfusion
  9. Pre- and post-transfusion bleeding grade in response to the dose of therapeutic platelets transfused
  10. Surrogate outcomes for hemostatic efficacy including death due to bleeding as the primary and contributory cause of mortality
  11. Platelet transfusion given above trigger
  12. Platelet transfusion more often than once a day
  13. Platelet transfusion given above their assigned dose in each case because of >/= WHO Grade 2 bleeding
  14. Number of platelets transfused
  15. Frequency of transfusions and duration of transfusions given because of bleeding
  16. Total number of RBC transfusions
  17. The mean per thrombocytopenic day for each patient
  18. Platelet response (pre-transfusion platelet counts, post-transfusion platelet counts, platelet increments, and corrected platelet count increments (at 1 and/or 24 hours)
  19. Cost analysis.

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Ages Eligible for Study:   17 Years and older   (Child, Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • Patients with hypoproliferative thrombocytopenia who are expected to have a platelet count of ≤ 10,000/µL (10x10^9/L) for ≥ 10 days (Note: the prophylactic platelet trigger may be higher than10,000/µL (10x10^9/L) in some participating institutions; however, the patient will still be eligible for participation as long as they are expected to be thrombocytopenic for 10 days)
  • Must be an inpatient.
  • Weight between 40 and 100 kg.

Exclusion Criteria:

  • Diagnosis of promyelocytic leukemia.
  • A history or current diagnosis of immune thrombocytopenia (ITP), thrombotic thrombocytopenia (TTP), or hemolytic uremia syndrome (HUS).
  • Evidence of ≥ WHO Grade 2 bleeding while being assessed for the study entry.
  • Patients who will receive bedside Leukoreduced platelet transfusions.
  • Patients who are pregnant.

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT00420914

United States, California
Cedars-Sinai Medical Center
Los Angeles, California, United States, 90048
United States, New Hampshire
Dartmouth-Hitchcock Medical Center
Lebanon, New Hampshire, United States, 03756
Canada, Ontario
McMaster University
Hamilton, Ontario, Canada, L8N3Z5
Ottawa Health Research Institute
Ottawa, Ontario, Canada, K1H 8L6
University Health Network
Toronto, Ontario, Canada, M5G2M9
Haukeland University Hospital
Bergen, Norway
Sponsors and Collaborators
Hamilton Health Sciences Corporation
Dartmouth-Hitchcock Medical Center
Haukeland University Hospital
Ottawa Hospital Research Institute
Cedars-Sinai Medical Center
University Health Network, Toronto
Principal Investigator: Nancy M Heddle, MSc., FCSMLS(D) McMaster University

Publications automatically indexed to this study by Identifier (NCT Number): Identifier: NCT00420914     History of Changes
Other Study ID Numbers: SToP Study
First Posted: January 11, 2007    Key Record Dates
Last Update Posted: May 28, 2008
Last Verified: May 2008

Keywords provided by McMaster University:

Additional relevant MeSH terms:
Blood Platelet Disorders
Hematologic Diseases