Using palbociclib and pembrolizumab for treating undifferentiated pleomorphic sarcoma

Phase Ib Trial Evaluating the Combination of CDK4 Inhibitor With Immunotherapy in Patients With Sarcoma

Phase 1 Interventional University of Iowa · NCT06113809

This study is testing if a combination of two drugs, palbociclib and pembrolizumab, can help improve treatment for people with undifferentiated pleomorphic sarcoma by looking at changes in their tumors after a few weeks.

Quick facts

PhasePhase 1
Study typeInterventional
Enrollment8 (estimated)
Ages12 Years and up
SexAll
SponsorUniversity of Iowa Academic / other
Drugs / interventionspembrolizumab, immunotherapy, radiation
Locations1 site (Iowa City, Iowa)
Trial IDNCT06113809 on ClinicalTrials.gov

What this trial studies

This clinical study evaluates the effects of palbociclib, a CDK4/6 inhibitor, on the tumor microenvironment in patients with undifferentiated pleomorphic sarcoma (UPS). Participants will receive palbociclib for two weeks following a biopsy to establish a baseline, after which a second biopsy will assess changes in the tumor environment. Pembrolizumab, an immune checkpoint inhibitor, will be administered concurrently with the second biopsy, and disease response will be evaluated after eight weeks of treatment. This single-arm, open-label design aims to gather insights into the combined therapeutic effects of these agents.

Who should consider this trial

Good fit: Ideal candidates include patients aged 12 and older with locally advanced, unresectable, or metastatic UPS who have progressed on at least one prior line of therapy.

Not a fit: Patients with known CNS disease, except for treated brain metastases, may not benefit from this study.

Why it matters

Potential benefit: If successful, this approach could enhance treatment outcomes for patients with undifferentiated pleomorphic sarcoma by improving the tumor's response to immunotherapy.

How similar studies have performed: While the combination of palbociclib and pembrolizumab is a novel approach, similar studies have shown promise in other cancer types, suggesting potential for success.

Eligibility criteria

Show full inclusion / exclusion criteria
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 \> or = 12 years old
* ECOG Performance Status of \< or = 2
* Any patient with the diagnosis of locally advanced, unresectable or metastatic sarcoma for which PD-1 inhibitors are approved (undifferentiated pleomorphic sarcoma, myxofibrosarcoma, angiosarcoma, pleomorphic rhabdomyosarcoma, pleomorphic liposarcoma, alveolar soft part sarcoma) who have progressed on at least 1 prior line of therapy. Prior immunotherapy treatment is allowed, including prior treatment with a PD-1 inhibitor.
* 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 \< 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/mm3L
* 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 \> 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
* 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
* 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

Where this trial is running

Iowa City, Iowa

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Sarcoma
Last reviewed 2026-06-15 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.