A Phase 3 interventional study of Carboplatin and Computed Tomography in Endometrial Clear Cell Adenocarcinoma, Endometrial Dedifferentiated Carcinoma and Endometrial Endometrioid Adenocarcinoma, sponsored by National Cancer Institute (NCI). Active, not recruiting at 397 sites in 5 countries. Open to female participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-10-21.
Sponsored by National Cancer Institute (NCI) · Phase 3, Interventional, and Treatment
This phase III trial studies how well the combination of pembrolizumab, paclitaxel and carboplatin works compared with paclitaxel and carboplatin alone in treating patients with endometrial cancer that is stage III or IV, or has come back after a period of improvement (recurrent). Immunotherapy with monoclonal antibodies, such as pembrolizumab, may help the body's immune system attack the cancer, and may interfere with the ability of tumor cells to grow and spread. Paclitaxel and carboplatin are chemotherapy drugs used as part of the usual treatment approach for this type of cancer. This study aims to assess if adding immunotherapy to these drugs is better or worse than the usual approach for treatment of this cancer.
PRIMARY OBJECTIVE:
I. To evaluate the efficacy of pembrolizumab (MK-3475) in combination with paclitaxel and carboplatin in patients with advanced stage (measurable stage III or IVA), stage IVB and recurrent endometrial cancer.
SECONDARY OBJECTIVES:
I. To determine the nature, frequency and degree of toxicity as assessed by Common Terminology Criteria for Adverse Events (CTCAE) for each treatment arm.
II. To evaluate blinded independent central review (BICR) assessed or investigator assessed objective response rate (ORR) as assessed by Response Evaluation Criteria in Solid Tumors (RECIST) 1.1 by treatment arm and by mismatch repair (MMR) immunohistochemistry (IHC) status in patients who enter the study with measurable disease.
III. To evaluate BICR assessed or investigator assessed duration of response (DOR) by treatment arm and by MMR IHC status in patients who enter the study with measurable disease.
IV. To evaluate the effect of pembrolizumab (MK-3475) on overall survival (OS) in patients with mismatch repair protein proficient (pMMR) or mismatch repair deficiency (dMMR).
V. To determine whether the addition of pembrolizumab (MK-3475) to standard combination chemotherapy is associated with improved patient reported physical function as measured with the Patient-Reported Outcomes Measurement Information System (PROMIS)-physical function scale (short form), quality of life as measured with the Functional Assessment of Cancer Therapy (FACT) - Endometrial Trial Outcome Index (En TOI) and worsened fatigue as measured with the PROMIS-Fatigue scale (short form) in the pMMR patients.
VI. To determine concordance between institutional MMR IHC testing and centralized MMR IHC.
EXPLORATORY OBJECTIVES:
I. To explore the correlation between patient-reported physical function as measured with the PROMIS-physical function scale (short form) and quality of life as measure with the FACT-En TOI.
II. To explore whether the addition of pembrolizumab (MK-3475) to standard combination chemotherapy is associated with self-reported neurotoxicity as measured with the FACT/Gynecologic Oncology Group Neurotoxicity (GOG-Ntx) subscale (short) and the extent to which patients differ on their self-reported bother from side effects of cancer therapy in the pMMR patients.
III. To evaluate the efficacy of pembrolizumab (MK-3475) in combination with paclitaxel and carboplatin in patients with advanced stage (measurable stage III or IVA), stage IVB and recurrent endometrial cancer by Programmed Death Ligand 1 (PD-L1) IHC (positive versus [vs] negative).
IV. To assess the association between PD-L1 IHC (positive vs negative) and mismatch repair status (pMMR and dMMR).
OUTLINE: Patients are randomized to 1 of 2 arms.
ARM I:
COMBINATION PHASE: Patients receive placebo intravenously (IV) over 30 minutes on day 1 of each cycle, paclitaxel IV over 3 hours on day 1 of each cycle, and carboplatin IV over 30-60 minutes on day 1 of each cycle. Treatment repeats every 3 weeks for 6 cycles in the absence of disease progression or unacceptable toxicity. Patients with stable disease (SD) or partial response (PR) who still have measurable disease may continue treatment for up to a total 10 cycles (if deemed necessary by the treating physician) in the absence of disease progression or unacceptable toxicity.
MAINTENANCE PHASE: Patients receive placebo IV over 30 minutes on day 1 of each cycle. Treatment repeats every 6 weeks for up to 14 cycles in the absence of disease progression or unacceptable toxicity.
On February 6, 2023, all patient treatment assignments were unblinded. Patients randomized to Arm I will not receive additional placebo infusions.
ARM II:
COMBINATION PHASE: Patients receive pembrolizumab IV over 30 minutes on day 1 of each cycle, paclitaxel IV over 3 hours on day 1 of each cycle, and carboplatin IV over 30-60 minutes on day 1 of each cycle. Treatment repeats every 3 weeks for 6 cycles in the absence of disease progression or unacceptable toxicity. Patients with SD or PR who still have measurable disease may continue treatment for up to a total of 10 cycles (if deemed necessary by the treating physician) in the absence of disease progression or unacceptable toxicity.
MAINTENANCE PHASE: Patients receive pembrolizumab IV over 30 minutes on day 1 of each cycle. Treatment repeats every 6 weeks for up to 14 cycles in the absence of disease progression or unacceptable toxicity.
Patients undergo computed tomography (CT) scan throughout the study.
After completion of study treatment, patients are followed up every 3 months for 2 years and then every 6 months for 3 years.
1,425 studies on the registry are indexed under Endometrial Neoplasms; 473 are open to participants now.
This study's enrollment of 813 is above the median of 71 across 1,026 interventional studies indexed under Endometrial Neoplasms.
Browse Endometrial Neoplasms studies →National Cancer Institute (NCI) is the lead sponsor of 3,556 studies on the registry; 336 are open to participants now.
Of its 411 completed or terminated interventional studies of FDA-regulated products, 373 (91%) have results posted.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Patients may have received
Administration of study drugs (pembrolizumab [MK-3475], paclitaxel, carboplatin) may have an adverse effect on pregnancy and poses a risk to the human fetus, including embryo-lethality. Women of (WOCBP) must agree to use adequate (hormonal or barrier method of birth control; abstinence) from at least 14 days prior to Step 2 registration (for oral contraceptives), during treatment, and for 120 days after the last dose of study medication. Should a woman become pregnant or suspect she is pregnant while she is participating in this study, she should inform her treating physician immediately. Patients will be considered of nonreproductive potential if they are either:
Exclusion Criteria:
Patients who have a diagnosis of immunodeficiency or are receiving systemic therapy or any other form of therapy within 7 days prior to Step 2 registration.
Known liver disease, including active viral, alcoholic, or other hepatitis; and cirrhosis.
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 amount of disease can be tracked with a defined measurement, so the study can see whether it shrinks or grows. It might be a tumour measured on a scan or, in some blood cancers such as myeloma, a marker measured in blood or urine.
The criteria or the study team say which measurement counts — having no tumour visible on a scan does not by itself rule you out.
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.
Neoadjuvant treatment is given before the main treatment (usually surgery), often to shrink a tumour. Adjuvant treatment is given after it, to lower the chance of the cancer coming back.
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 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.
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.
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.
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 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.
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.
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Periods have stopped for good: usually no period for 12 months in a row without another medical reason, sometimes confirmed by a blood test (FSH).
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.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
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.
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
The other ingredients in a medicine besides the active drug, such as fillers, colours or preservatives.
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.
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
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.
A condition in which the immune system attacks the body’s own tissues, such as rheumatoid arthritis, lupus, psoriasis, type 1 diabetes or inflammatory bowel disease.
Immunotherapy studies often leave out active autoimmune disease, and some name exceptions, such as thyroid disease on replacement hormone. Check the exceptions this study lists.
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.
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.
Measurable disease
The amount of disease can be tracked with a defined measurement, so the study can see whether it shrinks or grows. It might be a tumour measured on a scan or, in some blood cancers such as myeloma, a marker measured in blood or urine.
The criteria or the study team say which measurement counts — having no tumour visible on a scan does not by itself rule you out.
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.
Adjuvant and neoadjuvant
Neoadjuvant treatment is given before the main treatment (usually surgery), often to shrink a tumour. Adjuvant treatment is given after it, to lower the chance of the cancer coming back.
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.
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.
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.
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.
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.
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.
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.
Contraception
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Postmenopausal
Periods have stopped for good: usually no period for 12 months in a row without another medical reason, sometimes confirmed by a blood test (FSH).
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.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
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.
Hypersensitivity
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Excipients
The other ingredients in a medicine besides the active drug, such as fillers, colours or preservatives.
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.
Immunosuppression
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
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.
Autoimmune disease
A condition in which the immune system attacks the body’s own tissues, such as rheumatoid arthritis, lupus, psoriasis, type 1 diabetes or inflammatory bowel disease.
Immunotherapy studies often leave out active autoimmune disease, and some name exceptions, such as thyroid disease on replacement hormone. Check the exceptions this study lists.
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.
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.
COMBINATION PHASE: Patients receive placebo IV over 30 minutes on day 1 of each cycle, paclitaxel IV over 3 hours on day 1 of each cycle, and carboplatin IV over 30-60 minutes on day 1 of each cycle. Treatment repeats every 3 weeks for 6 cycles in the absence of disease progression or unacceptable toxicity. Patients with SD or PR who still have measurable disease may continue treatment for up to a total of 10 cycles (if deemed necessary by the treating physician) in the absence of disease progression or unacceptable toxicity. MAINTENANCE PHASE: Patients receive placebo IV over 30 minutes on day 1 of each cycle. Treatment repeats every 6 weeks for up to 14 cycles in the absence of disease progression or unacceptable toxicity. Patients undergo CT scan throughout the study. On February 6, 2023, all patient treatment assignments were unblinded. Patients randomized to Arm 1 will not receive additional placebo infusions.
Drug: Carboplatin · Procedure: Computed Tomography · Drug: Paclitaxel · Other: Placebo Administration · Other: Quality-of-Life Assessment · Other: Questionnaire Administration
COMBINATION PHASE: Patients receive pembrolizumab IV over 30 minutes on day 1 of each cycle, paclitaxel IV over 3 hours on day 1 of each cycle, and carboplatin IV over 30 minutes on day 1 of each cycle. Treatment repeats every 3 weeks for 6 cycles in the absence of disease progression or unacceptable toxicity. Patients with SD or PR who still have measurable disease may continue treatment for up to a total of 10 cycles (if deemed necessary by the treating physician) in the absence of disease progression or unacceptable toxicity. MAINTENANCE PHASE: Patients receive pembrolizumab IV over 30-60 minutes on day 1 of each cycle. Treatment repeats every 6 weeks for up to 14 cycles in the absence of disease progression or unacceptable toxicity. Patients undergo CT scan throughout the study.
Drug: Carboplatin · Procedure: Computed Tomography · Drug: Paclitaxel · Biological: Pembrolizumab · Other: Quality-of-Life Assessment · Other: Questionnaire Administration
Given IV
Also known as: Blastocarb, Carboplat, Carboplatin Hexal, Carboplatino, Carboplatinum, Carbosin, Carbosol, Carbotec, CBDCA, Displata, Ercar, JM-8, JM8, Nealorin, Novoplatinum, Paraplatin, Paraplatin AQ, Paraplatine, Platinwas, Ribocarbo
Undergo CT scan
Also known as: CAT, CAT Scan, Computed Axial Tomography, Computerized Axial Tomography, Computerized axial tomography (procedure), Computerized Tomography, Computerized Tomography (CT) scan, CT, CT Scan, Diagnostic CAT Scan, Diagnostic CAT Scan Service Type, tomography
Given IV
Also known as: Anzatax, Asotax, Bristaxol, Praxel, Taxol, Taxol Konzentrat
Given IV
Also known as: BCD-201, GME 751, GME751, Keytruda, Lambrolizumab, MK 3475, MK-3475, MK3475, Pembrolizumab Biosimilar BCD-201, Pembrolizumab Biosimilar GME751, Pembrolizumab Biosimilar QL2107, Pembrolizumab Biosimilar RPH-075, Pembrolizumab Biosimilar SB27, QL2107, RPH 075, RPH-075, RPH075, SB 27, SB-27, SB27, SCH 900475, SCH-900475, SCH900475
Given IV
Ancillary studies
Also known as: Quality of Life Assessment
Ancillary studies
Progression-free Survival (PFS)
Progression free survival (PFS) Note: For arm 2 (dMMR Cohort), the point estimate and the upper limit of the confidence interval are not able to be estimated due to insufficient events.
Time frame: Duration of time from study entry to time of progression per RECIST criteria or death due to any cause, whichever occurs first. The interquartile range for follow-up was (6.37 months, 30.62 months). The maximum for follow-up was 37.85 months.
Adverse Events With Grade 3 (or Higher)
Assessed by Common Terminology Criteria for Adverse Events (CTCAE V5.0). The endpoint is the count of participants with an adverse event of grade 3 (or higher) by treatment group.
Time frame: For the adverse event time frame, the interquartile range was (0.79 months, 3.42 months); the maximum was 28.39 months.
Objective Tumor Response
Assessed by Response Evaluation Criteria for Solid Tumors (RECIST) 1.1.
Time frame: For the time frame for tumor response, the interquartile range was (2.27 months, 8.66 months) and the maximum was 36.37 months.
Duration of Objective Response
The time difference between the dates of first response and first progression; patients who do not progress are considered censored. Note: for Arm 2 (dMMR Cohort), the upper limit of the confidence interval is not able to be estimated due to an insufficient number of events.
Time frame: For the duration of objective response, the interquartile range is (4.24 months, 7.92 months); the maximum is 28.68 months.
Overall Survival (OS)
Overall Survival (OS). This endpoint will be assessed by Kaplan-Meier.
Time frame: Time from study entry to time of death or the date of last contact, assessed up to 5 years
Quality of Life (QoL) in pMMR Patients Only
QoL are collected in pMMR patients only and measured with the Function Assessment of Cancer Therapy -Endometrial Trial Outcome Index (FACT En-TOI). The FACT-En TOI scores range 0 - 120 with a larger score suggesting better or favorable state of QOL.
Time frame: 0-54 weeks from start of treatment
Concordance Between Institutional Mismatch Repair (MMR) Immunohistochemistry (IHC) Testing and Centralized MMR IHC
Concordance between institutional MMR IHC testing and centralized MMR IHC. The concordance of institutional MMR IHC testing and centralized MMR IHC will be characterized by agreement statistics including the kappa statistic (e.g. Cohen's kappa coefficient).
Time frame: IHC testing values (for both central and institutional) were collected at baseline.
Incidence of Pembrolizumab Treatment and Self-reported Neurotoxicity
Patient-reported neurotoxicity will be measured with FACT/GOG-Ntx subscale (short form).
Time frame: 0-54 weeks from start of treatment
Effect of Pembrolizumab on PFS and OS by Program Death Ligand 1 (PD-L1) IHC
Will assess the effect of pembrolizumab on PFS and OS by PD-L1 (combined positive score \[CPS\]) within proficient MMR (pMMR) and deficient MMR (dMMR) populations. The effectiveness of pembrolizumab will be compared by PD-L1 status (CPS). A formal test will be conducted by examining the interaction term between pembrolizumab treatment (yes or no) with PD-L1 status. The association between PD-L1 CPS status and MMR IHC status will be assessed with odds ratios. A test may be conducted with a Fisher's Exact Test, and confidence intervals will be provided.
Time frame: 5 years
Association Between PD-L1 IHC and MMR Status
Measures of association between PD-L1 IHC (CPS) and MMR IHC status. The concordance of institutional MMR IHC testing and centralized MMR IHC will be characterized by agreement statistics such as kappa statistics (e.g. Cohen's kappa coefficient).
Time frame: 5 years
| Milestone | (dMMR Cohort): Arm 1: Active Comparator (Placebo, Paclitaxel, Carboplatin) | (dMMR Cohort): Arm 2: Experimental (Pembrolizumab, Paclitaxel, Carboplatin) | (pMMR Cohort): Arm 1: Active Comparator (Placebo, Paclitaxel, Carboplatin) | (pMMR Cohort): Arm 2: Experimental (Pembrolizumab, Paclitaxel, Carboplatin) |
|---|---|---|---|---|
| Started | 113 | 112 | 295 | 293 |
| Completed | 113 | 112 | 295 | 293 |
| Not completed | 0 | 0 | 0 | 0 |
Progression free survival (PFS) Note: For arm 2 (dMMR Cohort), the point estimate and the upper limit of the confidence interval are not able to be estimated due to insufficient events.
| Months | (dMMR Cohort): Arm 1: Active Comparator (Placebo, Paclitaxel, Carboplatin) | (dMMR Cohort): Arm 2: Experimental (Pembrolizumab, Paclitaxel, Carboplatin) | (pMMR Cohort): Arm 1: Active Comparator (Placebo, Paclitaxel, Carboplatin) | (pMMR Cohort): Arm 2: Experimental (Pembrolizumab, Paclitaxel, Carboplatin) |
|---|---|---|---|---|
| Progression-free Survival (PFS) | 7.6 (6.4 to 9.9) | NA (30.6 to NA) | 8.7 (8.4 to 10.7) | 11.7 (11.0 to 15.0) |
Assessed by Common Terminology Criteria for Adverse Events (CTCAE V5.0). The endpoint is the count of participants with an adverse event of grade 3 (or higher) by treatment group.
| Participants | (dMMR Cohort): Arm 1: Active Comparator (Placebo, Paclitaxel, Carboplatin) | (dMMR Cohort): Arm 2: Experimental (Pembrolizumab, Paclitaxel, Carboplatin) | (pMMR Cohort): Arm 1: Active Comparator (Placebo, Paclitaxel, Carboplatin) | (pMMR Cohort): Arm 2: Experimental (Pembrolizumab, Paclitaxel, Carboplatin) |
|---|---|---|---|---|
| Adverse Events With Grade 3 (or Higher) | 50 | 68 | 124 | 151 |
Assessed by Response Evaluation Criteria for Solid Tumors (RECIST) 1.1.
| Participants | (dMMR Cohort): Arm 1: Active Comparator (Placebo, Paclitaxel, Carboplatin) | (dMMR Cohort): Arm 2: Experimental (Pembrolizumab, Paclitaxel, Carboplatin) | (pMMR Cohort): Arm 1: Active Comparator (Placebo, Paclitaxel, Carboplatin) | (pMMR Cohort): Arm 2: Experimental (Pembrolizumab, Paclitaxel, Carboplatin) |
|---|---|---|---|---|
| Objective Tumor Response | 65 | 75 | 136 | 150 |
The time difference between the dates of first response and first progression; patients who do not progress are considered censored. Note: for Arm 2 (dMMR Cohort), the upper limit of the confidence interval is not able to be estimated due to an insufficient number of events.
| Months | (dMMR Cohort): Arm 1: Active Comparator (Placebo, Paclitaxel, Carboplatin) | (dMMR Cohort): Arm 2: Experimental (Pembrolizumab, Paclitaxel, Carboplatin) | (pMMR Cohort): Arm 1: Active Comparator (Placebo, Paclitaxel, Carboplatin) | (pMMR Cohort): Arm 2: Experimental (Pembrolizumab, Paclitaxel, Carboplatin) |
|---|---|---|---|---|
| Duration of Objective Response | 6.2 (4.3 to 9.2) | 28.7 (20.2 to NA) | 6.2 (4.8 to 6.5) | 9.2 (7.1 to 14.7) |
Overall Survival (OS). This endpoint will be assessed by Kaplan-Meier.
Results for this outcome have not been posted.
QoL are collected in pMMR patients only and measured with the Function Assessment of Cancer Therapy -Endometrial Trial Outcome Index (FACT En-TOI). The FACT-En TOI scores range 0 - 120 with a larger score suggesting better or favorable state of QOL.
| score | (pMMR Cohort): Arm 1: Active Comparator (Placebo, Paclitaxel, Carboplatin) | (pMMR Cohort): Arm 2: Experimental (Pembrolizumab, Paclitaxel, Carboplatin) |
|---|---|---|
| Baseline | 94.5 ± 18.0 | 95.3 ± 16.7 |
| 6 weeks | 94.1 ± 15.1 | 92.0 ± 15.5 |
| 18 weeks | 93.4 ± 15.5 | 90.3 ± 16.2 |
| 30 weeks | 95.7 ± 16.6 | 94.6 ± 15.7 |
| 54 weeks | 93.5 ± 18.2 | 96.8 ± 15.0 |
Concordance between institutional MMR IHC testing and centralized MMR IHC. The concordance of institutional MMR IHC testing and centralized MMR IHC will be characterized by agreement statistics including the kappa statistic (e.g. Cohen's kappa coefficient).
| agreement score | Arm I: Active Comparator (Placebo, Paclitaxel, Carboplatin) | Arm II: Experimental (Pembrolizumab, Paclitaxel, Carboplatin) |
|---|---|---|
| Concordance Between Institutional Mismatch Repair (MMR) Immunohistochemistry (IHC) Testing and Centralized MMR IHC | 0.9197 (0.875 to 0.9644) | 0.8944 (0.8438 to 0.945) |
Patient-reported neurotoxicity will be measured with FACT/GOG-Ntx subscale (short form).
Results for this outcome have not been posted.
Will assess the effect of pembrolizumab on PFS and OS by PD-L1 (combined positive score \[CPS\]) within proficient MMR (pMMR) and deficient MMR (dMMR) populations. The effectiveness of pembrolizumab will be compared by PD-L1 status (CPS). A formal test will be conducted by examining the interaction term between pembrolizumab treatment (yes or no) with PD-L1 status. The association between PD-L1 CPS status and MMR IHC status will be assessed with odds ratios. A test may be conducted with a Fisher's Exact Test, and confidence intervals will be provided.
Results for this outcome have not been posted.
Measures of association between PD-L1 IHC (CPS) and MMR IHC status. The concordance of institutional MMR IHC testing and centralized MMR IHC will be characterized by agreement statistics such as kappa statistics (e.g. Cohen's kappa coefficient).
Results for this outcome have not been posted.
Collected over Adverse Events monitored/assessed up to 28.39 months; the interquartile range was (0.79 months, 3.42 months). All-Cause Mortality monitored/assessed up to 37.85 months; the interquartile range was (6.37 months, 30.62 months).. Non-serious events are listed at a 0% frequency threshold.
| Group | Deaths | Serious | Other |
|---|---|---|---|
| (dMMR Cohort): Arm 1: Active Comparator (Placebo, Paclitaxel, Carboplatin) | 16/113 (14.2%) | 50/106 (47.2%) | 105/106 (99.1%) |
| (dMMR Cohort): Arm 2: Experimental (Pembrolizumab, Paclitaxel, Carboplatin) | 7/112 (6.3%) | 66/109 (60.6%) | 107/109 (98.2%) |
| (pMMR Cohort): Arm 1: Active Comparator (Placebo, Paclitaxel, Carboplatin) | 47/295 (15.9%) | 125/274 (45.6%) | 256/274 (93.4%) |
| (pMMR Cohort): Arm 2: Experimental (Pembrolizumab, Paclitaxel, Carboplatin) | 42/293 (14.3%) | 152/276 (55.1%) | 258/276 (93.5%) |
| Event | (dMMR Cohort): Arm 1: Active Comparator (Placebo, Paclitaxel, Carboplatin) | (dMMR Cohort): Arm 2: Experimental (Pembrolizumab, Paclitaxel, Carboplatin) | (pMMR Cohort): Arm 1: Active Comparator (Placebo, Paclitaxel, Carboplatin) | (pMMR Cohort): Arm 2: Experimental (Pembrolizumab, Paclitaxel, Carboplatin) |
|---|---|---|---|---|
| AnemiaBlood and lymphatic system disorders | 10/106 | 20/109 | 25/274 | 38/276 |
| Neutrophil count decreasedInvestigations | 18/106 | 13/109 | 32/274 | 50/276 |
| White blood cell decreasedInvestigations | 12/106 | 8/109 | 17/274 | 25/276 |
| HypertensionVascular disorders | 6/106 | 9/109 | 13/274 | 13/276 |
| Lymphocyte count decreasedInvestigations | 8/106 | 6/109 | 8/274 | 16/276 |
| HypokalemiaMetabolism and nutrition disorders | 5/106 | 8/109 | 9/274 | 10/276 |
| Thromboembolic eventVascular disorders | 2/106 | 7/109 | 12/274 | 11/276 |
| SyncopeNervous system disorders | 6/106 | 6/109 | 8/274 | 7/276 |
| Febrile neutropeniaBlood and lymphatic system disorders | 0/106 | 5/109 | 4/274 | 9/276 |
| DiarrheaGastrointestinal disorders | 1/106 | 5/109 | 3/274 | 4/276 |
| Event | (dMMR Cohort): Arm 1: Active Comparator (Placebo, Paclitaxel, Carboplatin) | (dMMR Cohort): Arm 2: Experimental (Pembrolizumab, Paclitaxel, Carboplatin) | (pMMR Cohort): Arm 1: Active Comparator (Placebo, Paclitaxel, Carboplatin) | (pMMR Cohort): Arm 2: Experimental (Pembrolizumab, Paclitaxel, Carboplatin) |
|---|---|---|---|---|
| FatigueGeneral disorders | 59/106 | 78/109 | 165/274 | 175/276 |
| Peripheral sensory neuropathyNervous system disorders | 66/106 | 71/109 | 157/274 | 153/276 |
| AlopeciaSkin and subcutaneous tissue disorders | 63/106 | 62/109 | 143/274 | 136/276 |
| AnemiaBlood and lymphatic system disorders | 58/106 | 63/109 | 144/274 | 152/276 |
| NauseaGastrointestinal disorders | 44/106 | 55/109 | 114/274 | 121/276 |
| ConstipationGastrointestinal disorders | 40/106 | 47/109 | 106/274 | 120/276 |
| DiarrheaGastrointestinal disorders | 36/106 | 46/109 | 88/274 | 99/276 |
| White blood cell decreasedInvestigations | 38/106 | 35/109 | 79/274 | 78/276 |
| Platelet count decreasedInvestigations | 31/106 | 38/109 | 58/274 | 83/276 |
| Neutrophil count decreasedInvestigations | 34/106 | 28/109 | 72/274 | 87/276 |
Randomized population (with definitive MMR status)
| Age, Continuous(years) | (dMMR Cohort): Arm 1: Active Comparator (Placebo, Paclitaxel, Carboplatin) | (dMMR Cohort): Arm 2: Experimental (Pembrolizumab, Paclitaxel, Carboplatin) | (pMMR Cohort): Arm 1: Active Comparator (Placebo, Paclitaxel, Carboplatin) | (pMMR Cohort): Arm 2: Experimental (Pembrolizumab, Paclitaxel, Carboplatin) | Total |
|---|---|---|---|---|---|
| Median | 66 (37 to 85) | 67 (38 to 81) | 65 (29 to 90) | 66 (31 to 93) | 66 (29 to 93) |
| Sex: Female, Male(Participants) | (dMMR Cohort): Arm 1: Active Comparator (Placebo, Paclitaxel, Carboplatin) | (dMMR Cohort): Arm 2: Experimental (Pembrolizumab, Paclitaxel, Carboplatin) | (pMMR Cohort): Arm 1: Active Comparator (Placebo, Paclitaxel, Carboplatin) | (pMMR Cohort): Arm 2: Experimental (Pembrolizumab, Paclitaxel, Carboplatin) | Total |
|---|---|---|---|---|---|
| Female | 113 | 112 | 295 | 293 | 813 |
| Male | 0 | 0 | 0 | 0 | 0 |
| Ethnicity (NIH/OMB)(Participants) | (dMMR Cohort): Arm 1: Active Comparator (Placebo, Paclitaxel, Carboplatin) | (dMMR Cohort): Arm 2: Experimental (Pembrolizumab, Paclitaxel, Carboplatin) | (pMMR Cohort): Arm 1: Active Comparator (Placebo, Paclitaxel, Carboplatin) | (pMMR Cohort): Arm 2: Experimental (Pembrolizumab, Paclitaxel, Carboplatin) | Total |
|---|---|---|---|---|---|
| Hispanic or Latino | 6 | 5 | 16 | 21 | 48 |
| Not Hispanic or Latino | 99 | 106 | 273 | 263 | 741 |
| Unknown or Not Reported | 8 | 1 | 6 | 9 | 24 |
| Race (NIH/OMB)(Participants) | (dMMR Cohort): Arm 1: Active Comparator (Placebo, Paclitaxel, Carboplatin) | (dMMR Cohort): Arm 2: Experimental (Pembrolizumab, Paclitaxel, Carboplatin) | (pMMR Cohort): Arm 1: Active Comparator (Placebo, Paclitaxel, Carboplatin) | (pMMR Cohort): Arm 2: Experimental (Pembrolizumab, Paclitaxel, Carboplatin) | Total |
|---|---|---|---|---|---|
| American Indian or Alaska Native | 2 | 0 | 2 | 2 | 6 |
| Asian | 4 | 3 | 14 | 17 | 38 |
| Native Hawaiian or Other Pacific Islander | 0 | 0 | 3 | 1 | 4 |
| Black or African American | 9 | 11 | 51 | 45 | 116 |
| White | 86 | 92 | 212 | 212 | 602 |
| More than one race | 0 | 0 | 1 | 1 | 2 |
| Unknown or Not Reported | 12 | 6 | 12 | 15 | 45 |
Showing the first 100 of 397 sites across 5 countries. Choose a country and city above to see the rest.
PDFs hosted by the registry, ClinicalTrials.gov.
Plan to share: Yes — 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
Data sharing details ↗ · grants.nih.gov
Ran from Aug 2019 to primary completion in Dec 2022, 39 months.
Results were first posted in Mar 2025, 2 years 3 months after primary completion.
Of 44 phase 3 interventional studies under Endometrial Neoplasms, half reached primary completion within 53 months of starting (the median), counting those still running; a quarter within 45 and three quarters within 126. This study's 39 months is below that.
Completion moved once since we started tracking on Sep 25, 2026: Sep 2026 → Sep 2027, on Oct 20, 2026.
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 Sep 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.
Sign in to followQuestions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.
Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.
Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.
Studies of the drug tested here: Pembrolizumab
National Cancer Institute (NCI) →