Palbociclib and Pembrolizumab in Sarcoma

May 20, 2026 updated by: John Rieth

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

This is a single-arm open-label window of opportunity clinical study assessing the impact of pre-treatment with palbociclib in patients with soft tissue sarcomas for which PD-1 inhibitors are approved (includes undifferentiated pleomorphic sarcoma, myxofibrosarcoma, angiosarcoma, pleomorphic rhabdomyosarcoma, pleomorphic liposarcoma, or alveolar soft part sarcoma).

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

Patients will be given palbociclib for 2 weeks following a pre-treatment ultrasound guided biopsy used to establish immunological baseline of the tumor microenvironment. After 2 weeks of palbociclib therapy, a second biopsy will be performed to assess the impact of palbociclib on the tumor microenvironment. Pembrolizumab will be started the same day as the second biopsy. After 2 doses of pembrolizumab, a third (optional) biopsy may be performed if the subject consents. At 8 weeks of therapy disease response will be assessed as per standard of care.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
8

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Phase 1

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Locations

  • United States
    • Iowa
      • Iowa City, Iowa, United States, 52242
        • Recruiting
        • University of Iowa Hospitals & Clinics
        • Contact:

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Child
  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

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

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Combination of Palbociclib with Pembrolizumab
Palbociclib given for 2 weeks following a pre-treatment ultrasound guided biopsy used to establish an immunological baseline of the tumor microenvironment. After the conclusion of palbociclib therapy, a post-treatment biopsy will be performed to assess the impact of palbociclib on the tumor microenvironment; pembrolizumab will be started the same day as the second biopsy. After 2 doses of pembrolizumab, a third (optional) biopsy could be performed.
Drug: Palbociclib

Palbociclib is a CDK4/6 inhibitor.

Palbociclib, 125 mg, (pediatric dose 75mg/m2 up to 125mg) daily for 21 days out of every 28 days, PO (orally) starting 14 days prior to Pembrolizumab

Drug: Pembrolizumab

Pembrolizumab is a PD-1 blocking antibody.

Given 14 days following Palbociclib: Pembrolizumab, 200 mg, once every three weeks, intravenously (IV)

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Dose limiting toxicities (DLTs) and adverse events (AEs) per CTCAE v5
Time Frame: The dose limiting toxicity period is 4 weeks after starting the first dose of pembrolizumab
Confirm the safety of the combination of Palbociclib and pembrolizumab in sarcomas for which PD-1 inhibitors are approved as defined by the incidence of DLTs
The dose limiting toxicity period is 4 weeks after starting the first dose of pembrolizumab

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Response rate per RECIST 1.1 criteria
Time Frame: 8 weeks following treatment intiation
To assess the response (per RECIST 1.1 criteria) of patients with advanced UPS with the combination of CDK4/6 inhibitor and anti-PD-1 immunotherapy
8 weeks following treatment intiation

Other Outcome Measures

Other Outcome Measures

For clinical trials, a planned measurement described in the protocol that is used to determine the effect of an intervention/treatment on participants. For observational studies, a measurement or observation that is used to describe patterns of diseases or traits, or associations with exposures, risk factors, or treatment. Types of outcome measures include primary outcome measure and secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Progression free survival
Time Frame: Up to two years following completion of treatment
To assess progression free survival as calculated by the time from start of treatment until the time of progression of disease or death due to any cause
Up to two years following completion of treatment

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
John Rieth

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: John Rieth, MD, University of Iowa Hospitals & Clinics

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
February 1, 2024

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
July 1, 2028

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
July 1, 2028

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
October 16, 2023

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
November 1, 2023

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
November 2, 2023

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
May 22, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
May 20, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
May 1, 2026

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • 202305133

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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