long-term study of romiplostim in thrombocytopenic pediatric patients with immune thrombocytopenia (itp)

Conditions: Immune Thrombocytopenia

Summary: this is a phase 3b single arm, open label, multicenter study describing the percentage of time pediatric participants with itp have a platelet response while receiving romiplostim, defined as a platelet count ≥ 50 x 10\^9/l in the absence of itp rescue medications for the past 4 weeks.


Eligibility criteria:
inclusion criteria: * diagnosis of primary itp according to the american society of hematology (ash) guidelines at least 6 months before screening, regardless of splenectomy status * age ≥ 1 year and \< 18 years of age * refractory to prior itp therapy, relapsed after at prior itp therapy, or be ineligible for other therapies. examples of prior therapy include: corticosteroids, intravenous immunoglobulin (ivig), anti-d immunoglobulin, platelet transfusions. * platelet count ≤ 30 x10\^9/l or is experiencing uncontrolled bleeding * has provided informed consent before any study-specific procedure; * adequate hematologic, renal, and liver function during screening: * hemoglobin \> 10.0 g/dl * serum creatinine ≤ 1.5 x the upper limit of normal (uln) * total serum bilirubin ≤ 1.5 x the uln * aspartate aminotransferase (ast) and alanine aminotransferase (alt) ≤ 3.0 x the uln * for the eu, switzerland and turkey protocol supplement, subject must agree to a scheduled bone marrow biopsy and aspirate at year 1 or year 2 following romiplostim treatment and any unscheduled biopsies if clinically indicated * for the eu, switzerland and turkey protocol supplement, a reticulin grade of 0, 1, 2, or 3 according to the modified bauermeister grading scale, as assessed by central laboratory from a bone marrow biopsy performed within 1 year prior to planned first dose of romiplostim or consent to a pre-treatment bone marrow biopsy and aspirate prior to planned first dose of romiplostim exclusion criteria: * history of a bone marrow stem cell disorder (any abnormal bone marrow findings other than those typical of itp must be approved by amgen before a subject may be enrolled) * prior bone marrow transplant or peripheral blood progenitor cell transplant * active or prior malignancy except non-melanoma skin cancers within the last 5 years * history of myelodysplastic syndrome * history of bleeding diathesis * history of congenital thrombocytopenia * history of hepatitis b, hepatitis c or human immunodeficiency virus (hiv) * history of systemic lupus erythematosus, evans syndrome, or autoimmune neutropenia * history of antiphospholipid antibody syndrome or known positive for lupus anticoagulant * history of disseminated intravascular coagulation, hemolytic uremic syndrome, or thrombotic thrombocytopenic purpura * history of venous thromboembolism or thrombotic events * previous use of romiplostim or previous use of eltrombopag within 4 weeks of enrollment * previous use of pegylated recombinant human megakaryocyte growth and development factor (peg-rhumgdf), recombinant human thrombopoietin (rhutpo) or any other platelet producing agent * rituximab (for any indication) or 6-mercaptopurine within 8 weeks of enrollment, or anticipated use at any time during the study * splenectomy within 4 weeks of the screening visit * alkylating agents within 8 weeks before the screening visit or anticipated use during the time of the proposed study * vaccinations known to decrease platelet counts within 8 weeks before the screening visit * currently enrolled in another investigational device or drug study, or less than 30 days since ending investigational study * will have investigational procedures while enrolled on study * female subject of child bearing potential (defined as having first menses) not willing to use, in combination with her partner highly effective methods of birth control during treatment and for 1 month after the end of treatment * subject is pregnant or breast feeding, or might become pregnant within 1 month after the end of treatment * subject has known hypersensitivity to any recombinant escherichia coli derived product (eg, infergen®, neupogen®, somatropin, and actimmune®) * has previously enrolled into this study * will not be available for protocol-required study visits or procedures, to the best of the subject's and investigator's knowledge * any kind of disorder that, may compromise the subject to give written informed consent and/or to comply with all required study procedures

Keywords: pediatric immune thrombocytopenia amgen