Testing the Addition of an Anti-cancer Drug, Abemaciclib, to the Usual Chemotherapy Treatment (Gemcitabine) for Soft Tissue Sarcoma

Phase I/II Study to Evaluate the Feasibility and Efficacy of Sequential Abemaciclib and Gemcitabine Treatment in Patients With Retinoblastoma (Rb)+ Sarcomas

This phase I/II trial tests the side effects and best dose of abemaciclib when added to gemcitabine and compares the effectiveness of that treatment to the usual treatment of gemcitabine with docetaxel for the treatment of patients with soft tissue sarcoma that may have spread from where it first started to nearby tissue, lymph nodes, or distant parts of the body (advanced) or that has spread from where it first started (primary site) to other places in the body (metastatic) (phase 1) or patients with leiomyosarcoma or dedifferentiated liposarcoma (phase 2). Abemaciclib is in a class of medications called kinase inhibitors. It works by blocking the action of an abnormal protein that signals tumor cells to multiply. This helps slow or stop the spread of tumor cells. Gemcitabine is a chemotherapy drug that blocks the cells from making deoxyribonucleic acid and may kill tumor cells. Docetaxel is in a class of medications called taxanes. It stops cancer cells from growing and dividing and may kill them. Giving abemaciclib with gemcitabine may be safe and effective when compared to treatment with gemcitabine and docetaxel for patients with advanced or metastatic soft tissue sarcoma or leiomyosarcoma or dedifferentiated liposarcoma.

Study Overview

• Status: Recruiting
• Conditions: Metastatic Leiomyosarcoma; Stage III Soft Tissue Sarcoma of the Trunk and Extremities AJCC v8; Advanced Soft Tissue Sarcoma; Metastatic Soft Tissue Sarcoma; Advanced Leiomyosarcoma; Stage IV Soft Tissue Sarcoma of the Trunk and Extremities AJCC v8; Advanced Dedifferentiated Liposarcoma; Metastatic Dedifferentiated Liposarcoma
• Intervention / Treatment: Drug: Gemcitabine; Drug: Docetaxel; Procedure: Computed Tomography; Procedure: Biospecimen Collection; Drug: Abemaciclib; Procedure: Biopsy Procedure

Detailed Description

PRIMARY OBJECTIVES:

I. The primary objective of the phase 1 part of this trial is to define the schedule of sequential abemaciclib and gemcitabine and recommended phase 2 dose (RP2D) of retinoblastoma positive (Rb[+ve]) sarcomas.

II. The primary objective of the phase 2 part of the trial is to define the progression-free survival (PFS) of sequential abemaciclib followed by gemcitabine at RP2D compared to the standard of care gemcitabine and docetaxel in advanced Rb(+ve) leiomyosarcomas and dedifferentiated liposarcomas.

SECONDARY OBJECTIVES:

I. To observe and record anti-tumor activity in phase 1. II. To determine cell cycle arrest and recovery with abemaciclib 200mg twice per day (BID) 5 to 7 days by blood thymidine kinase activity (Tka).

III. To assess the toxicity profile of the sequential abemaciclib followed by gemcitabine treatment using Common Terminology Criteria for Adverse Events (CTCAE) version 5 in phase 1 & phase 2.

IV. To determine the preliminary objective response rate (ORR) by Response Criteria in Solid Tumors (RECIST)1.1 in phase 1.

V. To compare overall survival (OS) of sequential abemaciclib followed by gemcitabine at RP2D to the standard of care gemcitabine and docetaxel in phase 2.

VI. To compare the objective response rate (ORR) at time of best response by RECIST1.1 of sequential abemaciclib followed by gemcitabine at RP2D to the standard of care gemcitabine and docetaxel in phase 2.

VII. To compare PFS and ORR after cross-over in each treatment arm. VIII. To identify mechanisms of resistance to sequential treatment through correlative studies of the cell cycle genes.

OUTLINE: Patients in phase 1 part A are assigned to cohort 1 or 2. Patients in phase 2 are randomized to arm A or arm B and may cross over to the alternate arm after disease progression.

PHASE 1 PART A:

COHORT I: Patients receive abemaciclib orally (PO) twice per day (BID) on days 1-5 and 15-19 of each cycle and gemcitabine intravenously (IV) over 90 minutes on days 8 and 22 of each cycle. Cycles repeat every 28 days for up to 2 years of total treatment in the absence of disease progression or unacceptable toxicity. Patients may change to Phase 1 Part B treatment once the recommended schedule is determined. Patients also undergo computed tomography (CT) during screening and on study. Additionally, patients undergo blood sample collection during screening and on study.

COHORT II: Patients receive abemaciclib PO BID on days 1-7 and gemcitabine IV over 90 minutes on day 10 of each cycle. Cycles repeat every 21 days for up to 2 years of total treatment in the absence of disease progression or unacceptable toxicity. Patients may change to Phase 1 Part B treatment once the recommended schedule is determined. Patients also undergo CT during screening and on study. Additionally, patients undergo blood sample collection during screening and on study.

PHASE 1 PART B: Patients receive the selected treatment schedule, Cohort 1 or Cohort 2, as above. Cycles repeat every 21 or 28 days for up to 2 years of total treatment in the absence of disease progression or unacceptable toxicity.

PHASE 2:

ARM A: Patients receive abemaciclib PO BID and gemcitabine IV on the schedule determined in phase 1 of the trial. Cycles repeat every 21 or 28 days for up to 2 years of total treatment in the absence of disease progression or unacceptable toxicity. At the time of disease progression, patients may cross over to arm B. Patients undergo blood sample collection throughout the study. Patients also undergo tumor biopsy during screening and optionally on study.

ARM B: Patients receive gemcitabine IV over 90 minutes on days 1 and 8 of each cycle and docetaxel IV over 60 minutes on day 8 of each cycle. Cycles repeat every 21 days for up to 2 years of total treatment in the absence of disease progression or unacceptable toxicity. At the time of disease progression, patients may cross over to arm A. Patients undergo blood sample collection throughout the study. Patients also undergo tumor biopsy during screening and optionally on study.

After completion of study treatment, patients are followed up every 3 months for up to 2 years.

• Study Type: Interventional
• Enrollment (Estimated): 74
• Phase: Phase 2; Phase 1

Contacts and Locations

Study Locations

• United States
  • Texas
    • Houston, Texas, United States, 77030
      • Recruiting
      • M D Anderson Cancer Center
      • Contact: Site Public Contact; Phone Number: 877-632-6789; Email: askmdanderson@mdanderson.org
      • Principal Investigator: Elise F. Nassif

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Phase 1: Patients must have advanced/metastatic histologically confirmed soft tissue sarcoma and have received at least one prior standard systemic therapy (prior gemcitabine is allowed)
• Phase 2: Patients must have advanced/metastatic pathologically confirmed leiomyosarcoma or dedifferentiated liposarcoma for which gemcitabine and docetaxel is considered standard-of-care, patients may be systemic-treatment naïve. Prior gemcitabine is not allowed
• Patients must have presence of measurable/assessable tumor
• Patients must have intact Rb gene expression in the baseline tumor biopsy or archived tumor sample, as assessed by immunohistochemistry (at MD Anderson: clone G3- 245, BD Pharmagen, RRID:AB_385259, Clinical Laboratory Improvement Act [CLIA] certified antibody)
• Age ≥ 18 years. Because no dosing or adverse event data are currently available on the use of abemaciclib in combination with gemcitabine in patients < 18 years of age, children are excluded from this study
• Eastern Cooperative oncology Group (ECOG) performance status ≤ 2 (Karnofsky ≥ 60%)
• Absolute neutrophil count ˃ 1.2K/µL
• Hemoglobin ˃ 9.0 g/dL
• Platelets ˃ 100K/mm^3
• Glomerular filtration rate (GFR) ≥ 60 mL/min unless data exists supporting safe use at lower kidney function values, no lower than 30 mL/min
• Total bilirubin ≤ 1.5 × institutional upper limit of normal (ULN), patient with Gilbert's syndrome ≤ 2.0 times ULN, or direct bilirubin within normal limits
• Aspartate aminotransferase (AST)(serum glutamic oxaloacetic transaminase [SGOT]) ≤ 1.5 × institutional ULN
• Alanine aminotransferase (ALT)(serum glutamic pyruvic transaminase [SGPT]) ≤ 1.5 × institutional ULN
• Human immunodeficiency virus (HIV)-infected patients on effective anti-retroviral therapy with undetectable viral load within 6 months are eligible for this trial
• For patients with evidence of chronic hepatitis B virus (HBV) infection, the HBV viral load must be undetectable on suppressive therapy, if indicated
• Patients with a history of hepatitis C virus (HCV) infection must have been treated and cured. For patients with HCV infection who are currently on treatment, they are eligible if they have an undetectable HCV viral load
• Patients with treated brain metastases are eligible if follow-up brain imaging after central nervous system (CNS)-directed therapy shows no evidence of progression
• Patients with a prior or concurrent malignancy whose natural history or treatment does not have the potential to interfere with the safety or efficacy assessment of the investigational regimen are eligible for this trial
• Patients with known history or current symptoms of cardiac disease, or history of treatment with cardiotoxic agents, should have a clinical risk assessment of cardiac function using the New York Heart Association (NYHA) Functional Classification. To be eligible for this trial, patients should be class congestive heart failure (CHF) II or better
• Patients must have a life expectancy of greater than 6 months
• Females of childbearing potential must have a negative serum pregnancy test within one week of trial enrollment and be willing to use an adequate method of contraception to avoid pregnancy throughout the trial and for up to 6 months after the last dose of drug therapy. The effects of abemaciclib on the developing human fetus are unknown. For this reason and because CDK 4/6 inhibiting agents as well as gemcitabine are known to be teratogenic, women of child-bearing potential and men must agree to use adequate contraception (hormonal or barrier method of birth control; abstinence) prior to study entry and for the duration of study participation. Should a woman become pregnant or suspect she is pregnant while she or her partner is participating in this study, she should inform her treating physician immediately. Men treated or enrolled on this protocol must also agree to use adequate contraception prior to the study, for the duration of study participation, and 4 months after completion of abemaciclib administration. Abstinence is considered an effective method only if defined as refraining from heterosexual intercourse during the entire period of risk associated with the study ranging from three weeks prior to initiation of treatment and up to 6 months after the last dose of treatment
• Ability to understand and the willingness to sign a written informed consent document. Legally authorized representatives may sign and give informed consent on behalf of study participants
• Patient is capable of swallowing oral medications

Exclusion Criteria:

• Patients who have not recovered from adverse events due to prior anti-cancer therapy (i.e., have residual toxicities > grade 1) with the exception of alopecia
• Patients who are receiving any other investigational agents. There must be no investigational drug use within 30 days or 5 half-lives of receiving the first dose of treatment on this treatment
• History of allergic reactions attributed to compounds of similar chemical or biologic composition to abemaciclib or gemcitabine
• Patients with uncontrolled intercurrent illness or any other significant condition(s) that would make participation in this protocol unreasonably hazardous
• Pregnant women are excluded from this study because abemaciclib is a CDK4/6 inhibiting agent with the potential for teratogenic or abortifacient effects. Because there is an unknown but potential risk for adverse events in nursing infants secondary to treatment of the mother with abemaciclib or gemcitabine, breastfeeding should be discontinued if the mother is treated with abemaciclib or gemcitabine
• Use of strong CYP34A inhibitors which cannot be discontinued by the patient prior to trial initiation. The washout period of these drugs should be 5 half-lives
• Progression on prior CDK4 inhibitor therapy
• Phase 2 only: Prior gemcitabine-based chemotherapy
• Presence of significant cardiac disease. Significant cardiac disease includes personal history of any of the following conditions: syncope of cardiovascular etiology, ventricular arrhythmia of pathological origin (including, but not limited to, ventricular tachycardia and ventricular fibrillation), or sudden cardiac arrest
• Patients with interstitial lung disease (ILD)
• Patients with gastrointestinal conditions that may affect the absorption of oral medications
• Patients must not have received or be scheduled to receive radiation therapy within 7 days or less from gemcitabine administration
• Patients must not have had major surgery within 14 days prior to randomization

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Sequential Assignment
• Masking: None (Open Label)

Number of Arms

5

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Phase I Part B (abemaciclib, gemcitabine); Patients receive the selected treatment schedule, Cohort 1 or Cohort 2, as above. Cycles repeat every 21 or 28 days for up to 2 years of total treatment in the absence of disease progression or unacceptable toxicity.	Drug: Gemcitabine; Given IV; Other Names: dFdCyd; dFdC; Difluorodeoxycytidine; Procedure: Computed Tomography; Undergo CT; Other Names: CT; CAT; CAT Scan; Computed Axial Tomography; Computerized Axial Tomography; Computerized Tomography; CT Scan; tomography; Computerized axial tomography (procedure); Computerized Tomography (CT) scan; Diagnostic CAT Scan; Diagnostic CAT Scan Service Type; Procedure: Biospecimen Collection; Undergo blood sample collection; Other Names: Biological Sample Collection; Biospecimen Collected; Specimen Collection; Sample Collection; Drug: Abemaciclib; Given PO; Other Names: LY-2835219; LY2835219; Verzenio; LY 2835219
Experimental: Phase 2 Arm A (abemaciclib, gemcitabine); Patients receive abemaciclib PO BID and gemcitabine IV on the schedule determined in phase 1 of the trial. Cycles repeat every 21 or 28 days for up to 2 years of total treatment in the absence of disease progression or unacceptable toxicity. At the time of disease progression, patients may cross over to arm B. Patients undergo blood sample collection throughout the study. Patients also undergo tumor biopsy on study.	Drug: Gemcitabine; Given IV; Other Names: dFdCyd; dFdC; Difluorodeoxycytidine; Procedure: Biospecimen Collection; Undergo blood sample collection; Other Names: Biological Sample Collection; Biospecimen Collected; Specimen Collection; Sample Collection; Drug: Abemaciclib; Given PO; Other Names: LY-2835219; LY2835219; Verzenio; LY 2835219; Procedure: Biopsy Procedure; Undergo tumor biopsy; Other Names: Bx; BIOPSY_TYPE; Biopsy
Active Comparator: Phase 2 Arm B (gemcitabine, docetaxel); Patients receive gemcitabine IV over 90 minutes on days 1 and 8 of each cycle and docetaxel IV over 60 minutes on day 8 of each cycle. Cycles repeat every 21 days for up to 2 years of total treatment in the absence of disease progression or unacceptable toxicity. At the time of disease progression, patients may cross over to arm A. Patients undergo blood sample collection throughout the study. Patients also undergo tumor biopsy during screening and optionally on study.	Drug: Gemcitabine; Given IV; Other Names: dFdCyd; dFdC; Difluorodeoxycytidine; Drug: Docetaxel; Given IV; Other Names: Taxotere; Docecad; RP56976; Taxotere Injection Concentrate; RP 56976; RP-56976; Procedure: Biospecimen Collection; Undergo blood sample collection; Other Names: Biological Sample Collection; Biospecimen Collected; Specimen Collection; Sample Collection; Procedure: Biopsy Procedure; Undergo tumor biopsy; Other Names: Bx; BIOPSY_TYPE; Biopsy
Experimental: Phase I Part A Cohort I (abemaciclib, gemcitabine); Patients receive abemaciclib PO BID on days 1-5 and 15-19 of each cycle and gemcitabine IV over 90 minutes on days 8 and 22 of each cycle. Cycles repeat every 28 days for up to 2 years of total treatment in the absence of disease progression or unacceptable toxicity. Patients may change to Phase 1 Part B treatment once the recommended schedule is determined. Patients also undergo CT during screening and on study. Additionally, patients undergo blood sample collection during screening and on study.	Drug: Gemcitabine; Given IV; Other Names: dFdCyd; dFdC; Difluorodeoxycytidine; Procedure: Computed Tomography; Undergo CT; Other Names: CT; CAT; CAT Scan; Computed Axial Tomography; Computerized Axial Tomography; Computerized Tomography; CT Scan; tomography; Computerized axial tomography (procedure); Computerized Tomography (CT) scan; Diagnostic CAT Scan; Diagnostic CAT Scan Service Type; Procedure: Biospecimen Collection; Undergo blood sample collection; Other Names: Biological Sample Collection; Biospecimen Collected; Specimen Collection; Sample Collection; Drug: Abemaciclib; Given PO; Other Names: LY-2835219; LY2835219; Verzenio; LY 2835219
Experimental: Phase I Part A Cohort II (abemaciclib, gemcitabine); Patients receive abemaciclib PO BID on days 1-7 and gemcitabine IV over 90 minutes on day 10 of each cycle. Cycles repeat every 21 days for up to 2 years of total treatment in the absence of disease progression or unacceptable toxicity. Patients may change to Phase 1 Part B treatment once the recommended schedule is determined. Patients also undergo CT during screening and on study. Additionally, patients undergo blood sample collection during screening and on study.	Drug: Gemcitabine; Given IV; Other Names: dFdCyd; dFdC; Difluorodeoxycytidine; Procedure: Computed Tomography; Undergo CT; Other Names: CT; CAT; CAT Scan; Computed Axial Tomography; Computerized Axial Tomography; Computerized Tomography; CT Scan; tomography; Computerized axial tomography (procedure); Computerized Tomography (CT) scan; Diagnostic CAT Scan; Diagnostic CAT Scan Service Type; Procedure: Biospecimen Collection; Undergo blood sample collection; Other Names: Biological Sample Collection; Biospecimen Collected; Specimen Collection; Sample Collection; Drug: Abemaciclib; Given PO; Other Names: LY-2835219; LY2835219; Verzenio; LY 2835219

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Progression free survival (PFS) (phase II)	Will be estimated using the Kaplan-Meier method.	From randomization to either disease progression as defined by Response Evaluation Criteria in Solid Tumors (RECIST) or death from any cause, up to 2 years
Time course of blood thymidine kinase activity (TKa) (Phase 1 Part A)	Will be graphically evaluated: the change of blood TKa over time to facilitate a selection of regimen that has maximum decrease in blood TKa after end of abemaciclib (cell cycle arrest) and has maximum increase in blood TKa at time of gemcitabine injection. Descriptive statistics (mean, standard deviation) and graphical methods will be applied to examine the distribution of the data, error checking, and outlier identification. Since blood TKa and fluorothymidine F-18 (18F-FLT) positron emission tomography (PET) will be measured at baseline and multiple post treatment time points, if appropriate, linear mixed effect models for repeated measures analysis will be employed to assess its change over time. Appropriate transformation of the marker values will be used to satisfy the normality assumption of linear mixed effect model.	Baseline up to 2 years
Maximum tolerated dose (Phase I Part B)		Up to 28 days

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Anti-tumor activity (phase I)		Up to 2 years
Cell cycle recovery (phase I)	Measured by blood TKa.	At 5 to 7 days
Incidence of adverse events (phase I)	Using Common Terminology Criteria for Adverse Events (CTCAE) version 5.	Up to 2 years
Objective response rate (ORR) (phase I)	By Response Criteria in Solid Tumors 1.1 with a 95% exact CI will be provided.	Up to 2 years
Overall survival (phase II)	Respective point estimates will be provided along with 95% confidence interval (CI) by treatment arms and then by histologic groups within treatment arm. The hazard ratio along with 95% CI using Cox proportional hazard models will be estimated. Will be estimated using the Kaplan-Meier method.	From randomization to death, up to 2 years
ORR at time of best response (phase II)	A 95% exact CI will be provided.	Up to 2 years
Incidence of adverse events (phase II)	Assessed by CTCAE v5.	Up to 2 years
Cell cycle arrest (phase II)	Measured by blood TKa.	At day 5-7
Cell cycle recovery (phase II)	Measured by blood TKa.	At day 5-7
Mechanisms of resistance to sequential treatment (phase II)		Up to 2 years
PFS after crossover	Will be estimated using the Kaplan-Meier method.	From randomization to either disease progression as defined by RECIST or death from any cause, up to 2 years
ORR after crossover	A 95% exact CI will be provided.	Up to 2 years
Cell cycle arrest (phase I)	Measured by blood TKa.	At 5 to 7 days

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Cell cycle recovery	By 18F-FLT PET and its associations with blood TKa.	From baseline to gemcitabine
Cell cycle arrest	By 18F-FLT PET and its associations with blood TKa.	From baseline to gemcitabine

Collaborators and Investigators

• Sponsor: National Cancer Institute (NCI)
• Investigators: Principal Investigator: Elise F Nassif, University of Texas MD Anderson Cancer Center LAO

Study record dates

Study Major Dates

• Study Start (Actual): March 18, 2026
• Primary Completion (Estimated): January 31, 2027
• Study Completion (Estimated): January 31, 2027

Study Registration Dates

• First Submitted: July 10, 2024
• First Submitted That Met QC Criteria: July 10, 2024
• First Posted (Actual): July 12, 2024

Study Record Updates

• Last Update Posted (Actual): May 13, 2026
• Last Update Submitted That Met QC Criteria: May 12, 2026
• Last Verified: March 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Neoplasms; Neoplasms by Histologic Type; Neoplasms, Connective and Soft Tissue; Neoplasms, Muscle Tissue; Neoplasms, Adipose Tissue; Sarcoma; Leiomyosarcoma; Liposarcoma; Organic Chemicals; Heterocyclic Compounds, 1-Ring; Heterocyclic Compounds; Investigative Techniques; Clinical Laboratory Techniques; Diagnostic Techniques and Procedures; Diagnosis; Surgical Procedures, Operative; Cytological Techniques; Cytodiagnosis; Hydrocarbons; Cycloparaffins; Hydrocarbons, Alicyclic; Hydrocarbons, Cyclic; Terpenes; Taxoids; Cyclodecanes; Diterpenes; Deoxycytidine; Cytidine; Pyrimidine Nucleosides; Pyrimidines; Diagnostic Techniques, Surgical; Docetaxel; Gemcitabine; Biopsy; Specimen Handling; abemaciclib
• Other Study ID Numbers: NCI-2024-05665 (Registry Identifier: CTRP (Clinical Trial Reporting Program)); UM1CA186688 (U.S. NIH Grant/Contract); 10657 (Other Identifier: CTEP)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: NCI is committed to sharing data in accordance with NIH policy. For more details on how clinical trial data is shared, access the link to the NIH data sharing policy page.

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