A Study of Romiplostim to Prevent Low Platelet Counts in Children and Young Adults Receiving Chemotherapy for Solid Tumors

Inclusion Criteria:

* Documented diagnosis of a primary solid tumor. Patients must have histological verification of malignancy at MSKCC.
* Male and female patients aged 1-21 years with a primary solid tumor undergoing treatment with the pre-defined chemotherapy regimens of EFT, MAP, D9803. Prior to enrollment patient could have been undergoing induction therapy with a similarly myelosuppressive regimen as long as they will be continuing with EFT, MAP, D9803 at the time of study enrollment.
* Patients undergoing treatment with MAP chemotherapy w ho have had ≥ 1 platelet transfusion during induction stage of treatment.
* Total Bilirubin (sum of conjugated + unconjugated) ≤ 3 times institutional upper limit of normal (ULN) for age and ALT/AST ≤ 3 times institutional ULN for age.
* Normal cardiac function:

  * Shortening fraction greater than or equal to 28% by echocardiogram OR Left ventricular ejection fraction (LVEF) greater than or equal to 50% on technetium- 99m pertechnetate radionuclide cineangiography (MUGA) or echocardiogram.
  * Screening ECG with corrected QT (QTc) interval of \< 470 msec.
  * Timing of cardiac assessment: We will utilize the most recent EKG/ECHO when assessing cardiac function. See section 9.0 for additional details.
* Adequate renal function, defined as an estimated Creatinine Clearance or GFR \>40ml/min or an normal creatine for age (see below)

Serum Creatinine by age:

Age (years) \<6: Maximum Serum Creatinine (mg/dL), Male 0.8, Female 0.8 Age (years) 6 to \<10: Maximum Serum Creatinine (mg/dL), Male 1, Female 1 Age (years) 10 to \<13: Maximum Serum Creatinine (mg/dL), Male 1.2, Female 1.2 Age (years) 13 to \<16: Maximum Serum Creatinine (mg/dL), Male 1.5, Female 1.4 Age (years) \>16: Maximum Serum Creatinine (mg/dL), Male 1.7, Female 1.4

These threshold creatine values were derived from the Scwartz formula estimating GFR, utilizing child length and statured published by the CDC.

Exclusion Criteria:

* Patients with history of hematologic malignancies or allogenic/autogenic stem cell transplant.
* Patients with a currently known predisposition to a myeloid stem cell disorder, myeloid leukemia, and/or bone marrow failure syndrome including, but not limited to:

  * Aplastic anemia
  * Ataxia telangiectasia
  * Bloom syndrome
  * Congenital amegakaryocytic thrombocytopenia
  * Cyclic neutropenia
  * Diamond Blackfan anemia
  * Dyskeratosis congenita
  * Familial AML/MDS syndromes (including ANKRD26, CEBPA, DDX41, ETV6, GATA2, RUNX1, SRP72)
  * Fanconi anemia
  * Kostmann disease
  * Li-Fraumeni syndrome
  * Neurofibromatosis
  * Nijmegen breakage syndrome
  * Noonan syndrome
  * Paroxysmal nocturnal hemoglobinuria
  * Pearson syndrome
  * Poland syndrome
  * Rothmund-Thomson syndrome
  * Severe congenital neutropenia
  * Thrombocytopenia absent radii syndrome
  * Trisomy 8
  * Trisomy 21
  * WHIM syndrome
  * Wiskott Aldrich syndrome
  * Xeroderma pigmentosa
* Secondary malignancy in the past 5 years.
* Patients who have previously undergone up-front chemotherapy and have relapsed or progressed through therapy.
* Patients who have received 4 or more cycles of induction chemotherapy for their current malignancy prior to time of enrollment.
* Previous use of romiplostim, eltrombopag, recombinant human TPO, or any other TPO receptor agonist, or any investigational platelet producing agent.
* Patients receiving other investigational agents are not eligible for study entry.

History of uncontrolled arrhythmias, clinically significant electrocardiogram (ECG) abnormalities, active heart failure or pericardial disease.

* Patients with current or prior venous thrombotic event or arterial thrombotic event at time of enrollment will be ineligible for this study.
* Pregnant women/lactating mothers.
* Patients unwilling to use effective contraception method, which includes abstinence.
* Patients with an inability to return for follow-up visits or obtain follow-up studies required to assess toxicity to therapy.