Study Of Palbociclib Combined With Chemotherapy In Pediatric Patients With Recurrent/Refractory Solid Tumors

Why are we doing this research?

This study will evaluate palbociclib in combination with chemotherapy (temozolomide and irinotecan) in children, adolescents and young adults with recurrent or refractory solid tumors. The main purpose of this study is to evaluate the safety of palbociclib in combination with chemotherapy in order to estimate the maximum tolerated dose. Pharmacokinetics and efficacy of palbociclib in combination with chemotherapy will be evaluated.


Who can participate?

Inclusion Criteria:

  • For dose escalation part: Histologically confirmed solid tumor (including CNS tumors but not lymphomas).
  • For dose expansion cohort: Histologically confirmed solid tumor including but not limited to Ewing sarcoma, rhabdoid tumor, rhabdomyosarcoma, neuroblastoma, and medulloblastoma.
  • For tumor-specific cohorts: Histologically confirmed solid tumor including but not limited to rhabdoid tumor, rhabdomyosarcoma, neuroblastoma, and medulloblastoma. Ewing sarcoma is not eligible for tumor-specific cohorts.
  • Age ≥2 and <21 years at the time of study entry.
  • Lansky performance status ≥50% for patients ≤12 years of age, or Eastern Cooperative Oncology Group (ECOG) 0, 1 or 2 for patients >12 years of age.
  • Adequate bone marrow function: Absolute neutrophil count ≥1000/mm3; Platelet count ≥100,000/mm3 (transfusion independent); Hemoglobin ≥8.5 g/dL (transfusion allowed);
  • Adequate renal function (serum creatinine level based on age/gender must be less than or equal to the maximum upper limits specified in protocol)
  • Adequate liver function, including:Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) ≤2.5 × upper limit of normal (ULN) or ≤5 × ULN for age, if attributable to disease involvement of the liver; Total bilirubin ≤1.5 × ULN for age.
  • Measurable disease as defined by RECIST version 1.1 or modified RANO criteria for CNS disease.
  • Recovered to CTCAE Grade ≤1, or to baseline, from any non-hematological acute toxicities of prior surgery, chemotherapy, immunotherapy, radiotherapy, differentiation therapy or biologic therapy, with the exception of alopecia.
  • Serum/urine pregnancy test (for all girls ≥8 years of age) negative at screening and at the baseline visit.
  • Willing and able to comply with scheduled visits, treatment plan, laboratory tests, and other procedures.

Exclusion Criteria:

  • Prior treatment with a CDK4/6 inhibitor or progression while on treatment with an IRN-containing regimen that includes TMZ. Patients who have received the combination of IRN and TMZ and did not progress while on these medications are eligible.
  • Prior intolerability to IRN and/or TMZ.
  • Use of strong cytochrome P450 (CYP) 3A inhibitors or inducers or strong uridine diphosphate-glucuronosyl transferase 1A1 (UGT1A1) inhibitors within 12 days of Cycle 1 Day 1 (C1D1).
  • Prior growth factors within 7 days before study entry or peg-filgrastim within 14 days before study entry.
  • Radiation therapy within 14 days before study entry.
  • Systemic anti cancer therapy within 2 weeks prior to study entry and 6 weeks for nitrosoureas.
  • Previous high dose chemotherapy requiring stem cell rescue within 90 days or persistent AE >Grade 1.
  • Prior irradiation to >50% of the bone marrow.
  • Participation in other studies involving investigational drug(s) within 2 weeks or 5 half lives, whichever is longer, prior to study entry.
  • Major surgery within 4 weeks prior to study entry. Surgical biopsies or central line placement are not considered major surgeries.
  • Known or suspected hypersensitivity to palbociclib, IRN and/or TMZ.
  • Patients with known symptomatic brain tumors or brain metastases and require steroids, unless they have been on a stable or on a decreasing steroid dose for >14 days.
  • Patients with previously diagnosed brain metastases are eligible if they have completed their prior treatment and have recovered from the acute effects of radiation therapy or surgery prior to study entry for these metastases for at least 14 days post radiation and 4 weeks post-surgery and are neurologically stable.
  • Hereditary bone marrow failure disorder.
  • QTc >470 msec.
  • History of clinically significant or uncontrolled cardiac disease, including: history of or active congestive heart failure; if patient had congestive heart failure resolve and >1 year from resolution, patient will be considered eligible; clinically significant ventricular arrhythmia (such as ventricular tachycardia, ventricular fibrillation or Torsades de Pointes); diagnosed or suspected congenital or acquired prolonged QT syndrome; need for medications known to prolong the QT interval; uncorrected hypomagnesemia or hypokalemia because of potential effects on the QT interval; left ventricular ejection fraction <50% or shortening fraction <28%.
  • Recent or ongoing clinically significant gastrointestinal disorder that may interfere with absorption of orally administered drugs (eg, gastrectomy).
  • Evidence of serious active or uncontrolled bacterial, fungal or viral infection or known history of hepatitis B virus, hepatitis C virus, or human immunodeficiency virus infection or acquired immunodeficiency syndrome-related illness.
  • Other severe acute or chronic medical or laboratory test abnormality that may increase the risk associated with study participation or investigational product administration or may interfere with the interpretation of study results, and in the judgment of the Investigator, would make the patient inappropriate for entry into this study.
  • Investigator site staff members directly involved in the conduct of the study and their family members, site staff members otherwise supervised by the investigator, or patients who are Pfizer employees, including their family members, directly involved in the conduct of the study.
  • Fertile male patients and female patients of childbearing potential who are unwilling or unable to use a highly effective method of contraception as outlined in this protocol for the duration of the study and for at least 90 after the last dose of investigational product.


  • 2 Years to 20 Years


  • Brain Spinal Tumors Medulloblastoma Relapse
  • Adult - Brain Spinal Tumors Medulloblastoma Relapse
  • Brain Spinal Neurofibromatosis Sarcoma MPNST Relapse
  • Adult - Brain Spinal Neurofibromatosis Sarcoma MPNST Relapse
  • Sarcoma Osteosarcoma Relapse
  • Adult - Sarcoma Osteosarcoma Relapse
  • Sarcoma Ewing Relapse
  • Adult - Sarcoma Ewing Relapse
  • Sarcoma Rhabdomyosarcoma Relapse
  • Adult - Sarcoma Rhabdomyosarcoma Relapse
  • Neuroblastoma Relapse - Refractory
  • Adult - Neuroblastoma Relapse - Refractory
  • Liver Relapse - Refractory
  • Adult - Liver Relapse - Refractory
  • Adult - Kidney Relapse - Refractory
  • Kidney Relapse - Refractory
  • Solid Tumor Retinoblastoma Relapse - Refractory
  • Adult - Solid Tumor Retinoblastoma Relapse - Refractory
  • Solid Tumor Neurofibromatosis Sarcoma MPNST Relapse - Refractory
  • Adult - Solid Tumor Neurofibromatosis Sarcoma MPNST Relapse - Refractory


Cincinnati Children’s Hospital Medical Center
Division of Hematology/Oncology
3333 Burnet Ave., Cincinnati, OH 45229-3039
Phone: 513-636-2799