Platelet Function in Idiopathic Thrombocytopenic Purpura (ITP) Patients With Eltrombopag

Ingrid Pabinger, MD30 enrolled

Overview

This is a single-center, prospective, controlled study with one eltrombopag treatment group and 2 control groups, one on standard steroid treatment, and another one untreated. The aim of the study is to determine the effect of Thrombopoietin Receptor (MPL) agonists on shear-induced platelet activation.

STUDY DESIGN: Single-center (Medical University Vienna), prospective, controlled study. Patients will be recruited at the Division of Haematology and Haemostaseology at the Medical University in Vienna, one eltrombopag treatment group and 2 control groups, one on standard steroid treatment, another one untreated. AIM OF THE STUDY: To determine the effect of MPL agonists on shear-induced platelet activation. Data obtained from patients treated with eltrombopag shall be compared to those from untreated patients and patients on steroids. These investigations will extend previous studies that investigated platelet function without in vitro activation in patients receiving eltrombopag. PATIENTS: Trial Population: Total number of patients n=34: 12 on eltrombopag, 12 on corticosteroids and 10 without treatment will be included in this trial. Treatment with eltrombopag or corticosteroids. Eltrombopag starting dose: 25 mg/day, increased as needed (to 50 mg or maximum 75 mg once daily) every 2 weeks to reach a platelet count between 50,000-100000/µL and tapering the dosis if platelet count \>= 100,000/µL. Afterwards, if platelet count stable (tolerance +/- 20%), platelet control every 4 weeks, otherwise weekly. Prednisolone starting dose: 1 mg/kg/day to reach a platelet count between 50,000-100,000 /µL tapering of the dosage if platelet count \>= 100,000/µL. Laboratory Investigations: In the eltrombopag group and in the newly treated prednisolone group platelet counts and platelet function tests will be performed at planned visits. In patients who are on continuous corticosteroids (part of control group I) and untreated patients (control group II), which have a platelet count between 50,000 and 100,000/µL platelet counts, reticulated platelets, platelet function tests and platelet antibodies will be studied at entry and after 4 weeks (+ 5 days).

Study Type

INTERVENTIONAL

Allocation

NON_RANDOMIZED

Purpose

DIAGNOSTIC

Masking

NONE

Enrollment

Conditions

Idiopathic Thrombocytopenic Purpura

Interventions

eltrombopagDRUG

eltrombopag tablets daily, in increasing dosage, for three months

corticosteroids (Aprednislon)DRUG

corticosteroids in decreasing dosage

Eligibility

Sex: ALLMin age: 18 YearsMax age: 90 Years

Medical Language ↔ Plain English

Inclusion Criteria (for all groups): * Male and female patients with an established chronic autoimmune thrombocytopenia (cAITP) * Age ≥ 18 and ≤ 90 years * Females, if not pregnant, not nursing and consenting to perform safe anti-contraception * Written consent before any study related procedure Inclusion Criteria (for patients treated with eltrombopag): * Platelet count \< 50,000 /µL at screening * At least one prior alternative cITP therapy Inclusion Criteria (for patients treated with corticosteroids - Control group 1): * Platelet count \< 50,000 /µL in history * At least 50% of the patients should have \< 50,000 /µL at inclusion and should be followed for 3 months Inclusion Criteria (for patients untreated - Control group 2): * Platelet count \< 50,000 /µL in history * At screening platelet count between 50,000 and 100,000 /µL Exclusion Criteria (for all patients): * History of venous or arterial thromboembolism or stroke * Known coronary heart disease or cardiac arrythmias * Known HIV or Hepatitis C infection * Impaired liver function defined as elevated ALT \> 1.5 UNL, bilirubin more than ULN, albumin less than normal value * Prothrombin time less than normal value * Elevated creatinine level (\> 1.3 ULN) * Unable/unwilling to follow protocol * Previous or active malignancy * Patients who have been included in any other study with eltrombopag any time before * Patients treated with another investigational product within the last 3 months

Outcomes

Primary Outcomes

The shear-induced platelet activation (SC) is considered as the primary outcome measure.

Time frame: After an average of 2-4 weeks, when patient has a platelet count between 50,000 and 100,000/µL.

Secondary Outcomes

Rise of reticulated platelets and variation of platelet antibodies.

Time frame: After an average of 2-4 weeks, when patient has a platelet count between 50,000 and 100,000/µL.

Data from ClinicalTrials.gov

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