A Phase 2 interventional study of Palbociclib and Cemiplimab in Advanced Dedifferentiated Liposarcoma, Locally Advanced Dedifferentiated Liposarcoma and Metastatic Dedifferentiated Liposarcoma, sponsored by Alliance for Clinical Trials in Oncology. Active, not recruiting at 194 sites in United States. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-10-20.
Sponsored by Alliance for Clinical Trials in Oncology · Phase 2, Interventional, and Treatment
This phase II trial compares the effect of treatment with palbociclib alone to treatment with palbociclib plus cemiplimab for treating patients with dedifferentiated liposarcoma that may have spread from where it first started to nearby tissue, lymph nodes, or distant parts of the body (advanced). Palbociclib may stop the growth of cancer cells by blocking some of the enzymes needed for cell growth. Cemiplimab is a monoclonal antibody that may interfere with the ability of cancer cells to grow and spread. The combination of these two drugs may be more effective in shrinking or stabilizing advanced dedifferentiated liposarcoma compared to palbociclib alone.
PRIMARY OBJECTIVES:
I. To perform a safety lead-in among 6 patients to confirm that the combination of palbociclib and cemiplimab is safe and tolerable.
II. To evaluate whether palbociclib in combination with cemiplimab (Arm 2) demonstrates a superior progression-free survival (PFS) compared to palbociclib monotherapy (Arm 1) for patients with advanced dedifferentiated liposarcoma (DDLPS).
SECONDARY OBJECTIVES:
I. To evaluate the toxicity profile in and across each treatment arm as determined by both Common Terminology Criteria for Adverse Events (CTCAE) and Patient Reported Outcomes (PRO)-CTCAE criteria.
II. To evaluate and compare the objective response rate (ORR) and duration of response (DOR) in and across each treatment arm.
III. To evaluate and compare the overall survival (OS) in and across each treatment arm.
IV. To evaluate and compare progression-free rate at 12 weeks (PFR12) in and across each treatment arm.
EXPLORATORY OBJECTIVES:
I. To collect genomic sequencing data previously collected as standard of care, including data on CDK4 copy number (as determined by fluorescence in situ hybridization [FISH] or other molecular testing).
II. To conduct multiplex immunohistochemistry using archival tumor tissue (where available) to define densities of infiltrating immune cell subsets and tumor and immune cell major histocompatibility complex (MHC) and PD-L1 expression.
III. To perform an exploratory analysis to evaluate for any relationship between CDK4 copy number and (a) the tumor immune microenvironment as defined by multiplex immunohistochemistry and (b) clinical outcomes from study treatment.
IV. To explore efficacy and toxicity endpoints, including PFS and ORR, for patients who progress on palbociclib monotherapy and crossover to the palbociclib plus cemiplimab combination.
OUTLINE: Patients are randomized to 1 of 2 arms.
ARM I: Patients receive palbociclib orally (PO) on study. Patients will be allowed to cross over to Arm II following documentation of disease progression. Patients undergo magnetic resonance imaging (MRI) or computed tomography (CT) scans throughout the trial. Patients may also undergo blood sample collection on study.
ARM II: Patients receive palbociclib PO and cemiplimab intravenously (IV) on study. Patients undergo MRI or CT scans throughout the trial. Patients may also undergo blood sample collection on study.
160 studies on the registry are indexed under Liposarcoma; 36 are open to participants now.
This study's enrollment of 77 is above the median of 52 across 136 interventional studies indexed under Liposarcoma.
Browse Liposarcoma studies →Alliance for Clinical Trials in Oncology is the lead sponsor of 509 studies on the registry; 28 are open to participants now.
Of its 6 completed or terminated interventional studies of FDA-regulated products, 6 (100%) have results posted.
Counted across the registry records on this site, refreshed daily.
Inclusion Criteria:
ELIGIBILITY CRITERIA (STEP 1): Patients must have documented dedifferentiated liposarcoma (DDLPS). Patients with mixed well-differentiated/dedifferentiated liposarcoma (WD/DD LPS) tumors are eligible provided there is a histologically confirmed DDLPS component at some point during the treatment course
RE-REGISTRATION ELIGIBILITY CRITERIA (FOR STEP 2 CROSSOVER FROM ARM 1 TO ARM 2): Patients may not have experienced a grade 3 or higher non-hematologic adverse event deemed in the opinion of the treating investigator, or have discontinued palbociclib due to toxicity, while participating on Arm 1
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
The diagnosis was confirmed by looking at a sample under a microscope: tissue from a biopsy or surgery (histology), or cells from a fluid or needle sample (cytology).
Your pathology report is the document that shows this.
Cancer that has spread from where it began to other parts of the body. “Metastatic” cancer is cancer that has spread this way.
The standard rules for measuring tumours on CT or MRI scans, to tell whether a cancer is shrinking, stable or growing during treatment.
“Measurable disease per RECIST 1.1” usually means at least one tumour 10 mm or more at its longest on a CT scan, or a lymph node 15 mm or more across its short axis.
PD-1, PD-L1 and CTLA-4 are proteins that act as brakes on the immune system. Checkpoint inhibitors, such as pembrolizumab or nivolumab, block them so the immune system can attack a cancer.
PD-L1 can also be measured in a tumour sample. Some scores count stained tumour cells only (TPS); others also count certain immune cells (CPS). The study names the score and the minimum it uses.
The US National Cancer Institute’s scale of how severe an adverse event is — any unwanted medical event during a study, such as a symptom, an illness or an abnormal test result, whether or not a treatment caused it. Whether it did is judged separately.
“Side effects of earlier treatment resolved to grade 1 or less” means they have settled to mild or gone.
A scale of how much an illness limits everyday activity. For people being assessed to join a study, scores run from 0 (fully active) to 4; lower is more active.
Studies most often ask for 0–1 or 0–2. Your doctor gives the score; the WHO scale uses the same steps. The full scale also has 5, which records death.
The number of neutrophils, white blood cells that help fight infection, in a given amount of blood. Too few raises the risk of infection.
It is a count, not a percentage of the white cells. Limits are written in units that mean the same: ≥ 1.5 × 10⁹/L is ≥ 1,500 per mm³ (µL). Each lab has its own reference range.
Blood cells that help blood clot. Too few raises the risk of bleeding and bruising. A usual adult range is about 150–400 × 10⁹/L (150,000–400,000 per µL); each lab has its own reference range.
The protein in red blood cells that carries oxygen. A low level is anaemia, which can cause tiredness and breathlessness. Measured in g/dL or g/L (9 g/dL is 90 g/L).
How quickly the kidneys clear creatinine, a waste product, from the blood. A study may estimate it from a blood test with age, weight and sex (often by the Cockcroft–Gault formula), or measure it using blood and urine collected over a set time. Given in mL/min; higher is better.
A yellow substance made when red blood cells are broken down, which the liver clears. A high level can mean a problem with the liver or the bile ducts.
Criteria often allow more for people with Gilbert’s syndrome, a harmless inherited condition that raises bilirubin.
The top of the normal range for a blood test, as set by the laboratory that runs it. Each lab prints its own range next to your result.
“≤ 2.5 × ULN” means the result can be up to two and a half times that top value.
Two enzymes measured in a routine blood test of the liver. Higher levels can mean the liver is under strain or damaged. SGPT and SGOT are older names for ALT and AST.
Criteria usually give a limit as a multiple of the upper limit of normal (ULN), often higher when cancer has spread to the liver.
The New York Heart Association’s four classes of how much heart failure limits physical activity.
Studies set their own limit — many outside heart failure leave out class III–IV, while heart failure studies may ask for a particular class. Check the class this study names.
Hepatitis B is a virus that infects the liver. These are separate tests: HBsAg positive usually means a current infection (a recent vaccination can briefly cause it too); total anti-HBc (HBcAb) positive means an infection now or in the past; HBV DNA measures how much virus is in the blood.
Some studies accept a past infection if HBV DNA is undetectable, sometimes with antiviral medicine during the study. Check what this study allows.
Hepatitis C is a virus that infects the liver. An HCV antibody test can stay positive after an infection has cleared (and is occasionally positive without one); an HCV RNA test shows whether the virus is there now.
After treatment, hepatitis C counts as cured when HCV RNA is still undetectable 12 weeks or more after the treatment ended. Studies often accept people cured this way.
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
Cancer deposits in the brain from a cancer that started elsewhere in the body (CNS metastases include the spinal cord).
Studies differ: some leave out any brain metastases, some accept ones treated and stable for some weeks. Check what this study allows.
Cancer that has spread to the leptomeninges, the thin layers covering the brain and spinal cord, and the fluid between them. It is not the same as brain metastases.
Criteria often treat it separately, and many studies leave it out even where treated brain metastases are allowed.
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
CYP3A is a group of enzymes, mainly CYP3A4, in the liver and gut that break down many medicines. Some medicines, supplements and foods (grapefruit, St John’s wort) slow them down or speed them up, which changes how much of a study drug stays in the body.
Studies list them so they can be avoided or switched; bring a list of everything you take, including supplements.
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).
Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.
Histologically or cytologically confirmed
The diagnosis was confirmed by looking at a sample under a microscope: tissue from a biopsy or surgery (histology), or cells from a fluid or needle sample (cytology).
Your pathology report is the document that shows this.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Metastases
Cancer that has spread from where it began to other parts of the body. “Metastatic” cancer is cancer that has spread this way.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
RECIST
The standard rules for measuring tumours on CT or MRI scans, to tell whether a cancer is shrinking, stable or growing during treatment.
“Measurable disease per RECIST 1.1” usually means at least one tumour 10 mm or more at its longest on a CT scan, or a lymph node 15 mm or more across its short axis.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
PD-1, PD-L1 and checkpoint inhibitors
PD-1, PD-L1 and CTLA-4 are proteins that act as brakes on the immune system. Checkpoint inhibitors, such as pembrolizumab or nivolumab, block them so the immune system can attack a cancer.
PD-L1 can also be measured in a tumour sample. Some scores count stained tumour cells only (TPS); others also count certain immune cells (CPS). The study names the score and the minimum it uses.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
CTCAE grade
The US National Cancer Institute’s scale of how severe an adverse event is — any unwanted medical event during a study, such as a symptom, an illness or an abnormal test result, whether or not a treatment caused it. Whether it did is judged separately.
“Side effects of earlier treatment resolved to grade 1 or less” means they have settled to mild or gone.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ECOG performance status
A scale of how much an illness limits everyday activity. For people being assessed to join a study, scores run from 0 (fully active) to 4; lower is more active.
Studies most often ask for 0–1 or 0–2. Your doctor gives the score; the WHO scale uses the same steps. The full scale also has 5, which records death.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Absolute neutrophil count (ANC)
The number of neutrophils, white blood cells that help fight infection, in a given amount of blood. Too few raises the risk of infection.
It is a count, not a percentage of the white cells. Limits are written in units that mean the same: ≥ 1.5 × 10⁹/L is ≥ 1,500 per mm³ (µL). Each lab has its own reference range.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Platelets
Blood cells that help blood clot. Too few raises the risk of bleeding and bruising. A usual adult range is about 150–400 × 10⁹/L (150,000–400,000 per µL); each lab has its own reference range.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hemoglobin (Hb)
The protein in red blood cells that carries oxygen. A low level is anaemia, which can cause tiredness and breathlessness. Measured in g/dL or g/L (9 g/dL is 90 g/L).
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Creatinine clearance (CrCl)
How quickly the kidneys clear creatinine, a waste product, from the blood. A study may estimate it from a blood test with age, weight and sex (often by the Cockcroft–Gault formula), or measure it using blood and urine collected over a set time. Given in mL/min; higher is better.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Bilirubin
A yellow substance made when red blood cells are broken down, which the liver clears. A high level can mean a problem with the liver or the bile ducts.
Criteria often allow more for people with Gilbert’s syndrome, a harmless inherited condition that raises bilirubin.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ULN (upper limit of normal)
The top of the normal range for a blood test, as set by the laboratory that runs it. Each lab prints its own range next to your result.
“≤ 2.5 × ULN” means the result can be up to two and a half times that top value.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ALT and AST (liver enzymes)
Two enzymes measured in a routine blood test of the liver. Higher levels can mean the liver is under strain or damaged. SGPT and SGOT are older names for ALT and AST.
Criteria usually give a limit as a multiple of the upper limit of normal (ULN), often higher when cancer has spread to the liver.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
NYHA class (heart failure)
The New York Heart Association’s four classes of how much heart failure limits physical activity.
Studies set their own limit — many outside heart failure leave out class III–IV, while heart failure studies may ask for a particular class. Check the class this study names.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hepatitis B tests
Hepatitis B is a virus that infects the liver. These are separate tests: HBsAg positive usually means a current infection (a recent vaccination can briefly cause it too); total anti-HBc (HBcAb) positive means an infection now or in the past; HBV DNA measures how much virus is in the blood.
Some studies accept a past infection if HBV DNA is undetectable, sometimes with antiviral medicine during the study. Check what this study allows.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hepatitis C tests
Hepatitis C is a virus that infects the liver. An HCV antibody test can stay positive after an infection has cleared (and is occasionally positive without one); an HCV RNA test shows whether the virus is there now.
After treatment, hepatitis C counts as cured when HCV RNA is still undetectable 12 weeks or more after the treatment ended. Studies often accept people cured this way.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
HIV
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Cancer (malignancy)
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Investigational drug or device
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Brain metastases
Cancer deposits in the brain from a cancer that started elsewhere in the body (CNS metastases include the spinal cord).
Studies differ: some leave out any brain metastases, some accept ones treated and stable for some weeks. Check what this study allows.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Leptomeningeal disease
Cancer that has spread to the leptomeninges, the thin layers covering the brain and spinal cord, and the fluid between them. It is not the same as brain metastases.
Criteria often treat it separately, and many studies leave it out even where treated brain metastases are allowed.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Corticosteroids (steroids)
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
CYP3A (CYP3A4) inhibitors and inducers
CYP3A is a group of enzymes, mainly CYP3A4, in the liver and gut that break down many medicines. Some medicines, supplements and foods (grapefruit, St John’s wort) slow them down or speed them up, which changes how much of a study drug stays in the body.
Studies list them so they can be avoided or switched; bring a list of everything you take, including supplements.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Clinically significant
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Childbearing potential
Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).
Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Patients receive palbociclib PO daily (QD) on days 1-21 of each cycle. Cycles repeat every 28 days for up to 24 cycles in the absence of disease progression or unacceptable toxicity. Patients will be allowed to cross over to Arm II following documentation of disease progression. Patients undergo MRI or CT scans throughout the trial. Patients may also undergo blood sample collection on study.
Drug: Palbociclib · Procedure: Magnetic Resonance Imaging · Procedure: Computed Tomography · Procedure: Biospecimen collection · Other: Questionnaire Administration
Patients receive palbociclib PO QD on days 1-21 of each cycle and cemiplimab intravenously (IV) over 30 minutes every 14 days beginning at cycle 1 day 15 (C1D15). Cycles repeat every 28 days for up to 24 cycles in the absence of disease progression or unacceptable toxicity. Patients undergo MRI or a CT scan throughout the trial. Patients may also undergo blood sample collection on study.
Drug: Palbociclib · Biological: Cemiplimab · Procedure: Magnetic Resonance Imaging · Procedure: Computed Tomography · Procedure: Biospecimen collection · Other: Questionnaire Administration
Given PO
Also known as: PD-0332991
Given IV
Also known as: Cemiplimab RWLC, Immunoglobulin G4
undergo MRI
Also known as: MRI
Undergo a CT Scan
Also known as: CAT Scan, CT Scan
Undergo blood sample collection
Ancillary Studies
Progression-free survival (PFS)
Efficacy analyses will be based on intention to treat principles. PFS will be compared between the two treatment arms using Kaplan-Meier methods. The hazard ratio, median PFS, and estimated PFS rates at 12, 24, 36, and 48 months will be estimated along with corresponding 95% confidence intervals. A log-rank test will be used to compare the PFS distributions between the two treatment arms in this cohort. Cox proportional hazards models will also be used to assess the impact of treatment arm on PFS when stratifying on the stratification factors.
Time frame: The time from randomization to the first documentation of disease progression or death, assessed up to 48 months.
Incidence of adverse events
Patients will be evaluated for adverse events using the National Cancer Institute Common Toxicity Criteria for Adverse Events version 5.0. Summary statistics (e.g., mean, median, standard deviation) and frequency tables will be used to describe the distributions of adverse events. Rates of adverse events occurring in the treatment arm will be compared to the control arm with chi-squared tests (or suitable alternative) used for comparisons where applicable. Tolerability will also be evaluated, summarizing rates of dose delays or modifications, reasons patients end treatment, and time to end of active treatment.
Time frame: Up to 2 years
Duration of response (DoR)
Defined for all evaluable patients who have achieved an objective response as the date at which the patient's earliest best objective status is first noted to be either a complete response or partial response to the earliest date progression is documented, or death if no prior evidence of disease progression. The distribution of DoR will be estimated using the method of Kaplan-Meier.
Time frame: up to 2 years
Overall survival (OS)
Defined as the time from randomization to death due to any cause. Patients who are alive will be censored at last follow-up for OS. The distribution of survival time will be estimated using the method of Kaplan-Meier. OS will be compared between treatment arms using the log-rank test. OS medians, survival rates and hazard ratio will be estimated along with 95% confidence intervals.
Time frame: up to 2 years
Progression free rate at 12 weeks (PFR12)
Defined as the proportion of evaluable patients who are alive and without evidence of disease progression 12 weeks after initiation of study therapy. The final PFR12 point estimate and corresponding 95% confidence interval calculated using Clopper-Pearson method.
Time frame: At 12 weeks
CDK4 copy number
Explore data on CDK4 copy number (by fluorescence in situ hybridization \[FISH\] or other molecular testing) through plots and summary statistics.
Time frame: Up to 2 years
Infiltrating immune cell subsets and tumor and immune cell major histocompatibility complex (MHC) and PD-L1 expression
Conduct multiplex immunohistochemistry using archival tumor tissue (where available) to summarize densities of infiltrating immune cell subsets and tumor and immune cell MHC and PD-L1 expression.
Time frame: Up to 2 years
Relationship between CDK4 copy number and the tumor immune microenvironment and clinical outcomes
Explore the relationship between CDK4 copy number and (a) the tumor immune microenvironment as defined by multiplex immunohistochemistry and (b) clinical outcomes from study treatment Clinical endpoints include PFS, objective response rate, OS, PFR8, and DoR. Cox regression will be used on time-to-event outcomes and T-test on binary outcomes
Time frame: up to 2 years
Efficacy and toxicity endpoints
Explore the efficacy and toxicity endpoints for patients who progress on palbociclib monotherapy and crossover to the palbociclib plus cemiplimab combination A sensitivity analysis will be conducted to see how crossover effects overall survival. Rate and severity of adverse events will be used to assess differences between crossover and non-crossover patients.
Time frame: Up to 2 years
Showing the first 100 of 194 sites. Choose a country and city above to see the rest.
Started Jun 2023 (actual). Primary completion is estimated for Apr 2028, 58 months after the start.
Of 35 phase 2 interventional studies under Liposarcoma, half reached primary completion within 73 months of starting (the median), counting those still running; a quarter within 38 and three quarters within 94. This study's planned 58 months is below that.
Since we started tracking on Sep 25, 2026, the dates moved once, on Oct 20, 2026: primary completion May 2027 → Apr 2028 and completion May 2027 → Apr 2028.
Earlier changes are on the record history on ClinicalTrials.gov ↗
How these figures are worked out, and which studies are left out of them.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
This study is active, not recruiting, as verified in Oct 2026. You cannot join it, but the record below documents what was studied.
Get an email when the registry record changes — status, dates, results — or when someone posts here.
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Studies of the drug tested here: Cemiplimab
Alliance for Clinical Trials in Oncology →