Intervention: HYDROCHLORIC ACID
Trial phase: Phase 3
ATC code: A09AB03 | B05XA13
SMILES: Cl
Sex: All
Age groups: Child | Adult
Healthy volunteers: No
Participants at risk: 203
Group description: Participants received romiplostim administered weekly by subcutaneous injection for up to 3 years. The starting dose was 1 µg/kg titrated in 1 µg/kg increments up to a maximum of 10 µg/kg to reach a target platelet count ≥ 50 x 10⁹/L.
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