Palbociclib and Pembrolizumab in Sarcoma

Phase 1

Recruiting

• Conditions: Sarcoma
• Interventions: Drug: Palbociclib; Drug: Pembrolizumab

• Registration Number: NCT06113809
• Lead Sponsor: John Rieth

Brief Summary

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).

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 Timeline

• Study First Submitted: 2023-10-16
• Study First Submitted QC: 2023-11-01
• Study First Posted: 2023-11-02
• Study Start: 2024-02-01
• Status Verified: 2025-05
• Last Update Submitted: 2025-05-28
• Last Update Posted: 2025-06-03
• Primary Completion: 2028-07
• Study Completion: 2028-07

Recruitment & Eligibility

• Status: RECRUITING
• Sex: All
• Target Recruitment: 8

Inclusion Criteria

Not provided

Exclusion Criteria

Not provided

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: SINGLE_GROUP

Arm && Interventions

Group	Intervention	Description
Combination of Palbociclib with Pembrolizumab	Palbociclib	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.
Combination of Palbociclib with Pembrolizumab	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.

Primary Outcome Measures

Name	Time	Method
Dose limiting toxicities (DLTs) and adverse events (AEs) per CTCAE v5	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

Secondary Outcome Measures

Name	Time	Method
Response rate per RECIST 1.1 criteria	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

Trial Locations

Locations (1)

University of Iowa Hospitals & Clinics; 🇺🇸 Iowa City, Iowa, United States