Phase Ib Trial Evaluating the Combination of CDK4 Inhibitor with Immunotherapy in Patients with Undifferentiated Pleomorphic Sarcoma (UPS)

Inclusion Criteria:

A potential subject must meet all the following inclusion criteria to be eligible to participate in the study.

• Male or female patients aged greater than or equal to 12 years old
• ECOG Performance Status of less than or equal to 2
• Any patient with the diagnosis of locally advanced, unresectable or undifferentiated pleomorphic sarcoma (UPS) who have progressed on at least 1 prior line of therapy and for whom pembrolizumab is an appropriate next standard treatment.
• Patients with any number of prior lines of therapy including newly diagnosed locally advanced unresectable or metastatic disease.
• Patients with no known CNS disease, except for treated brain metastasis. Treated brain metastases are defined as having no evidence of progression or hemorrhage after treatment and no ongoing treatment for dexamethasone (as ascertained by clinical examination and brain imaging) during the screening period. Stable dose of anticonvulsants is allowed. Treatment for brain metastases may include whole brain radiotherapy, radiosurgery, or a combination as deemed appropriate by the treating physician. Patients with CNS metastases treated by neurosurgical resection or brain biopsy performed within 3 months prior to Day 1 will be excluded.
• Ability to understand and the willingness to sign a written informed consent or assent in case of patients less than 18 years old.

Exclusion Criteria:

A potential subject who meets any of the following exclusion criteria is ineligible to participate in the study.

• Lab values in the below ranges:

  • Neutrophil count < 1000/mm3
  • Platelet count < 100,000/mm3
  • Hemoglobin < 9 g/dL Transfusion to meet eligibility allowed
  • AST/SGOT and ALT/SGPT > 3.0x upper limit of normal (ULN) without disease involvement or > 5.0x ULN if the transaminase elevation is due to disease involvement
  • Alkaline phosphatase > 5.0x ULN without known bony metastases
  • Serum bilirubin > 1.5x ULN
  • Serum creatinine > 1.5x ULN or 24-hour creatinine clearance < 30 mL/min per Cockroft- Gault equation
  • Total serum calcium < lower limit of normal (LLN) or if calcium is below LLN the corrected calcium for serum albumin is greater than or equal to LLN
  • Serum potassium < 3.0
  • Serum sodium < 130
  • Serum albumin < 2.5 g/dL
• History of myocardial infarction. unstable angina, stroke or transient ischemic attack within 6 months prior to Day 1
• Prior checkpoint inhibitor or CDK4 inhibitor for advanced UPS. If immunotherapy or CDK4 inhibitor was used as part of neoadjuvant therapy, then 6 months should have elapsed from prior immunotherapy or CDK4i use
• History or drug induced pneumonitis (both pembrolizumab and Palbociclib can cause pneumonitis)
• Subjects requiring hemodialysis
• Patients with severe hepatic impairment (Childs-Pugh Class C).
• Other concurrent severe and/or uncontrolled medical conditions in the opinion of the investigator which will preclude participation
• Pregnancy (positive pregnancy test) or lactation
• If you are a woman who can become pregnant, or a man who is sexually active with a partner who can become pregnant you must use two forms of birth control while on the study and for up to 3 months after the last dose of study drug. Patients who have received chemotherapy or any investigational drug < 4 weeks prior to starting study or who have not recovered from side effects of prior therapy (2 weeks of washout)
• Concomitant use of any other anti-cancer therapy or radiation therapy of the target lesion. Palliative radiation therapy is permitted to non-target lesions.
• Patients with any significant history of non-compliance to medical regimens or with inability to grant a reliable informed consent