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Study of Pembrolizumab (MK-3475) vs Placebo for Participants With Non-small Cell Lung Cancer After Resection With or Without Standard Adjuvant Therapy (MK-3475-091/KEYNOTE-091)

A Randomized, Phase 3 Trial With Anti-PD-1 Monoclonal Antibody Pembrolizumab (MK-3475) Versus Placebo for Patients With Early Stage NSCLC After Resection and Completion of Standard Adjuvant Therapy (PEARLS)

Status
Completed
Phases
Phase 3
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT02504372
Acronym
PEARLS
Enrollment
1177
Registered
2015-07-21
Start date
2015-11-06
Completion date
2026-01-21
Last updated
2026-03-17

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Non-small Cell Lung Cancer

Keywords

Non-small cell lung cancer (NSCLC), Programmed Cell Death Receptor 1 (PD-1), Programmed Cell Death Receptor Ligand 1 (PD-L1), Programmed Cell Death Receptor Ligand (PDL)

Brief summary

In this study, participants with Stage IB/II-IIIA non-small cell lung cancer (NSCLC) who have undergone surgical resection (lobectomy or pneumonectomy) with or without adjuvant chemotherapy will be treated with pembrolizumab or placebo. The primary study hypothesis is that pembrolizumab will provide improved disease-free survival (DFS) versus placebo.

Interventions

BIOLOGICALPembrolizumab

IV infusion

OTHERPlacebo

IV infusion

Sponsors

Merck Sharp & Dohme LLC
Lead SponsorINDUSTRY
ETOP
CollaboratorUNKNOWN
European Organisation for Research and Treatment of Cancer - EORTC
CollaboratorNETWORK

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
TRIPLE (Subject, Investigator, Outcomes Assessor)

Eligibility

Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No

Inclusion criteria

* Pathological diagnosis of NSCLC confirmed at surgery, any histology. Participants with two synchronous primary non-small cell lung cancers are excluded from the study * Union for International Cancer Control (UICC) v7 Stage IB with T ≥ 4 cm, II-IIIA NSCLC after complete surgical resection with resection margins proved microscopically free of disease (R0). Carcinoma in situ can be present at the bronchial margin * Available tumor sample obtained at surgical resection for programmed cell death ligand-1 (PD-L1) Immunohistochemistry (IHC) expression assessment * Eastern Cooperative Oncology Group (ECOG) Performance Status 0-1 * Adequate organ function performed within 10 days of treatment initiation * Female participants of childbearing potential must have a negative urine or serum pregnancy test at screening (within 72 hours of first infusion of study medication). If the urine test cannot be confirmed as negative, a serum pregnancy test will be required. The serum pregnancy test must be negative for the participant to be eligible * Female participants of childbearing potential must be willing to use 2 methods of birth control or be surgically sterile, or abstain from heterosexual activity starting with the first infusion of study treatment through 120 days after the last infusion of study treatment * Female participants who are breast feeding must discontinue nursing prior to the first infusion of study medication and until 120 days after the last infusion study treatment * Male participants must agree to use an adequate method of contraception starting with the first infusion of study treatment through 120 days after the last infusion of study treatment * Absence of severe comorbidities that in the opinion of the Investigator might hamper the participation to the study and/or the treatment administration * No prior or planned neo-adjuvant or adjuvant radiotherapy and/or neo-adjuvant chemotherapy for the current malignancy is allowed

Exclusion criteria

* Evidence of disease at clinical examination and/or baseline radiological assessment as documented by contrast enhanced chest/upper abdomen CT scan, brain CT/MRI and clinical examination * More than 4 cycles of adjuvant therapy * Prior treatment with anti-programmed cell death (anti-PD)-1, anti-PD ligand-1/2, anti-CD137, or cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) modulators or any other immune-modulating agents * Live vaccine within 30 days prior to the first infusion of study treatment * Current participation or treatment with an investigational agent or use of an investigational device within 4 weeks of the first infusion of study treatment * History of Human Immunodeficiency Virus (HIV) (known HIV 1/2 antibodies positive). No known active Hepatitis B or C * Chronic use of immunosuppressive agents and/or systemic corticosteroids or any use in the last 3 days prior to the first infusion of study treatment * History of interstitial lung disease or (non-infectious) pneumonitis that required oral or IV steroids (other than COPD exacerbation) or current pneumonitis * Active autoimmune disease that has required systemic treatment in past 2 years * History of a hematologic or primary solid tumor malignancy, unless in remission for at least 5 years with the exception of pT1-2 prostatic cancer Gleason score \< 6, superficial bladder cancer, non melanomatous skin cancer or carcinoma in situ of the cervix * Previous allogeneic tissue/solid organ transplant * Active infection requiring therapy * Surgery- or chemotherapy-related toxicity (non-hematological) not resolved to Grade 1 with the exception of alopecia, fatigue, neuropathy and lack of appetite /nausea * Pregnant or breastfeeding, or expecting to conceive or father children within the projected duration of the trial, starting with the screening visit through 120 days after the last infusion of study treatment * Participant will not be eligible if the participant is or has an immediate family member (e.g., spouse, parent/legal guardian, sibling or child) who is investigational site or Sponsor staff directly involved with this trial, unless prospective site Review Board approval is given allowing exception to this criterion for a specific participant

Design outcomes

Primary

MeasureTime frameDescription
Disease-Free Survival (DFS)Up to approximately 84 monthsDFS was defined as the time from randomization to either the date of disease recurrence or death (whatever the cause) as assessed by the investigator. Recurrence of disease was defined as local regional recurrence, a distant (metastatic) recurrence, or a second primary cancer. Occurrence of a second extra-pulmonary malignancy was considered to be an event.
DFS in Programmed Death Ligand-1 (PDL-1) Strong Positive Participants With Tumor Proportion Score (TPS) ≥50%Up to approximately 84 monthsDFS in PDL-1 strong positive participants with TPS ≥50% was defined as the time from randomization to either the date of disease recurrence or death (whatever the cause) as assessed by the investigator. Recurrence of disease was defined as local regional recurrence, a distant (metastatic) recurrence, or a second primary cancer. Occurrence of a second extra-pulmonary malignancy was considered to be an event.

Secondary

MeasureTime frameDescription
Overall Survival (OS)Up to approximately 132 monthsOS was defined as the time from randomization to the date of death.
OS in PDL-1 Strong Positive Participants With TPS ≥50%Up to approximately 132 monthsOS in PDL-1 Strong Positive Participants with TPS ≥50% was defined as the time from randomization to the date of death.
OS in PDL-1 Strong Positive Participants With TPS ≥1%Up to approximately 132 monthsOS in PDL-1 Strong Positive Participants with TPS ≥1% was defined as the time from randomization to the date of death.
Number of Participants Who Experienced an Adverse Event (AE)Up to approximately 22 monthsAn AE was defined as any untoward medical occurrence in a participant or clinical investigation participant administered a pharmaceutical product and which does not necessarily have to have a causal relationship with this treatment. An AE can therefore be any unfavourable and unintended sign (including an abnormal laboratory finding, for example), symptom, or disease temporally associated with the use of a medicinal product or protocol specified procedure, whether or not considered related to the medicinal product or protocol specified procedure. The number of participants who experienced an AE were reported.
Lung Cancer Specific Survival (LCSS)Up to approximately 132 monthsLCSS was defined as the time from randomization to the date of death (due to lung cancer specifically).
Number of Participants Who Discontinued Study Treatment Due to an AEUp to approximately 19 monthsAn AE was defined as any untoward medical occurrence in a participant or clinical investigation participant administered a pharmaceutical product and which does not necessarily have to have a causal relationship with this treatment. An AE can therefore be any unfavourable and unintended sign (including an abnormal laboratory finding, for example), symptom, or disease temporally associated with the use of a medicinal product or protocol specified procedure, whether or not considered related to the medicinal product or protocol specified procedure. The number of participants who discontinued study treatment due to an AE were reported.
DFS in PDL-1 Strong Positive Participants With TPS ≥1%Up to approximately 84 monthsDFS in PDL-1 strong positive participants with TPS ≥1% was defined as the time from randomization to either the date of disease recurrence or death (whatever the cause) as assessed by the investigator. Recurrence of disease was defined as local regional recurrence, a distant (metastatic) recurrence, or a second primary cancer. Occurrence of a second extra-pulmonary malignancy was considered to be an event.

Contacts

STUDY_DIRECTORMedical Director

Merck Sharp & Dohme LLC

Participant flow

Pre-assignment details

One participant randomized to the study in error did not provide informed consent and was not included. No data was collected on this participant.

Participants by arm

ArmCount
Pembrolizumab
Participants received pembrolizumab 200 mg, intravenously (IV), every 3 weeks, for one year.
590
Placebo
Participants received placebo, IV, every 3 weeks, for one year.
587
Total1,177

Baseline characteristics

CharacteristicTotalPembrolizumabPlacebo
Adjuvant Chemotherapy at Baseline
No
167 Participants84 Participants83 Participants
Adjuvant Chemotherapy at Baseline
Yes
1010 Participants506 Participants504 Participants
Age, Continuous64.3 Years
STANDARD_DEVIATION 8.4
64.1 Years
STANDARD_DEVIATION 8.5
64.5 Years
STANDARD_DEVIATION 8.4
Disease Stage at Baseline
Stage IB
172 Participants85 Participants87 Participants
Disease Stage at Baseline
Stage II
668 Participants330 Participants338 Participants
Disease Stage at Baseline
Stage IIIA
335 Participants175 Participants160 Participants
Disease Stage at Baseline
Stage IV
2 Participants0 Participants2 Participants
Geographic region
Asia
211 Participants106 Participants105 Participants
Geographic region
Eastern Europe
229 Participants116 Participants113 Participants
Geographic region
Rest of the World
133 Participants65 Participants68 Participants
Geographic region
Western Europe
604 Participants303 Participants301 Participants
Programmed Cell Death-Ligand 1 (PD-L1) Tumor Expression Status at Baseline
TPS <1%
465 Participants233 Participants232 Participants
Programmed Cell Death-Ligand 1 (PD-L1) Tumor Expression Status at Baseline
TPS 1-49%
379 Participants189 Participants190 Participants
Programmed Cell Death-Ligand 1 (PD-L1) Tumor Expression Status at Baseline
TPS ≥50%
333 Participants168 Participants165 Participants
Race and Ethnicity Not Collected0 Participants
Race (NIH/OMB)
American Indian or Alaska Native
1 Participants1 Participants0 Participants
Race (NIH/OMB)
Asian
214 Participants107 Participants107 Participants
Race (NIH/OMB)
Black or African American
3 Participants0 Participants3 Participants
Race (NIH/OMB)
More than one race
13 Participants10 Participants3 Participants
Race (NIH/OMB)
Native Hawaiian or Other Pacific Islander
0 Participants0 Participants0 Participants
Race (NIH/OMB)
Unknown or Not Reported
41 Participants22 Participants19 Participants
Race (NIH/OMB)
White
905 Participants450 Participants455 Participants
Sex: Female, Male
Female
373 Participants189 Participants184 Participants
Sex: Female, Male
Male
804 Participants401 Participants403 Participants
Smoking status
Current smoker
165 Participants75 Participants90 Participants
Smoking status
Former smoker
859 Participants428 Participants431 Participants
Smoking status
Never smoker
153 Participants87 Participants66 Participants
Tumor Histology
Non-squamous
761 Participants398 Participants363 Participants
Tumor Histology
Squamous
416 Participants192 Participants224 Participants

Adverse events

Event typeEG000
affected / at risk
EG001
affected / at risk
deaths
Total, all-cause mortality
136 / 590154 / 587
other
Total, other adverse events
510 / 580458 / 581
serious
Total, serious adverse events
142 / 58090 / 581

Outcome results

Primary

DFS in Programmed Death Ligand-1 (PDL-1) Strong Positive Participants With Tumor Proportion Score (TPS) ≥50%

DFS in PDL-1 strong positive participants with TPS ≥50% was defined as the time from randomization to either the date of disease recurrence or death (whatever the cause) as assessed by the investigator. Recurrence of disease was defined as local regional recurrence, a distant (metastatic) recurrence, or a second primary cancer. Occurrence of a second extra-pulmonary malignancy was considered to be an event.

Time frame: Up to approximately 84 months

Population: All randomized PDL-1 strong positive participants with TPS ≥50%. One participant randomized to the study in error did not provide informed consent and was not included. No data was collected on this participant.

ArmMeasureValue (MEDIAN)
PembrolizumabDFS in Programmed Death Ligand-1 (PDL-1) Strong Positive Participants With Tumor Proportion Score (TPS) ≥50%67.0 Months
PlaceboDFS in Programmed Death Ligand-1 (PDL-1) Strong Positive Participants With Tumor Proportion Score (TPS) ≥50%47.6 Months
p-value: 0.1349995% CI: [0.59, 1.16]Regression, Cox
Primary

Disease-Free Survival (DFS)

DFS was defined as the time from randomization to either the date of disease recurrence or death (whatever the cause) as assessed by the investigator. Recurrence of disease was defined as local regional recurrence, a distant (metastatic) recurrence, or a second primary cancer. Occurrence of a second extra-pulmonary malignancy was considered to be an event.

Time frame: Up to approximately 84 months

Population: All randomized participants. One participant randomized to the study in error did not provide informed consent and was not included. No data was collected on this participant.

ArmMeasureValue (MEDIAN)
PembrolizumabDisease-Free Survival (DFS)53.8 Months
PlaceboDisease-Free Survival (DFS)43.0 Months
95% CI: [0.68, 0.96]
Secondary

DFS in PDL-1 Strong Positive Participants With TPS ≥1%

DFS in PDL-1 strong positive participants with TPS ≥1% was defined as the time from randomization to either the date of disease recurrence or death (whatever the cause) as assessed by the investigator. Recurrence of disease was defined as local regional recurrence, a distant (metastatic) recurrence, or a second primary cancer. Occurrence of a second extra-pulmonary malignancy was considered to be an event.

Time frame: Up to approximately 84 months

Population: All randomized PDL-1 strong positive participants with TPS ≥1%. One participant randomized to the study in error did not provide informed consent and was not included. No data was collected on this participant.

ArmMeasureValue (MEDIAN)
PembrolizumabDFS in PDL-1 Strong Positive Participants With TPS ≥1%58.7 Months
PlaceboDFS in PDL-1 Strong Positive Participants With TPS ≥1%42.8 Months
p-value: 0.0132795% CI: [0.62, 0.97]Regression, Cox
Secondary

Lung Cancer Specific Survival (LCSS)

LCSS was defined as the time from randomization to the date of death (due to lung cancer specifically).

Time frame: Up to approximately 132 months

Secondary

Number of Participants Who Discontinued Study Treatment Due to an AE

An AE was defined as any untoward medical occurrence in a participant or clinical investigation participant administered a pharmaceutical product and which does not necessarily have to have a causal relationship with this treatment. An AE can therefore be any unfavourable and unintended sign (including an abnormal laboratory finding, for example), symptom, or disease temporally associated with the use of a medicinal product or protocol specified procedure, whether or not considered related to the medicinal product or protocol specified procedure. The number of participants who discontinued study treatment due to an AE were reported.

Time frame: Up to approximately 19 months

ArmMeasureValue (COUNT_OF_PARTICIPANTS)
PembrolizumabNumber of Participants Who Discontinued Study Treatment Due to an AE116 Participants
PlaceboNumber of Participants Who Discontinued Study Treatment Due to an AE34 Participants
Secondary

Number of Participants Who Experienced an Adverse Event (AE)

An AE was defined as any untoward medical occurrence in a participant or clinical investigation participant administered a pharmaceutical product and which does not necessarily have to have a causal relationship with this treatment. An AE can therefore be any unfavourable and unintended sign (including an abnormal laboratory finding, for example), symptom, or disease temporally associated with the use of a medicinal product or protocol specified procedure, whether or not considered related to the medicinal product or protocol specified procedure. The number of participants who experienced an AE were reported.

Time frame: Up to approximately 22 months

Population: All randomized participants who received at least one dose of study treatment.

ArmMeasureValue (COUNT_OF_PARTICIPANTS)
PembrolizumabNumber of Participants Who Experienced an Adverse Event (AE)556 Participants
PlaceboNumber of Participants Who Experienced an Adverse Event (AE)529 Participants
Secondary

OS in PDL-1 Strong Positive Participants With TPS ≥1%

OS in PDL-1 Strong Positive Participants with TPS ≥1% was defined as the time from randomization to the date of death.

Time frame: Up to approximately 132 months

Secondary

OS in PDL-1 Strong Positive Participants With TPS ≥50%

OS in PDL-1 Strong Positive Participants with TPS ≥50% was defined as the time from randomization to the date of death.

Time frame: Up to approximately 132 months

Secondary

Overall Survival (OS)

OS was defined as the time from randomization to the date of death.

Time frame: Up to approximately 132 months

Other Pre-specified

DFS at 68 Months

DFS was defined as the time from randomization to either the date of disease recurrence or death (whatever the cause) as assessed by the investigator. Recurrence of disease was defined as local regional recurrence, a distant (metastatic) recurrence, or a second primary cancer. Occurrence of a second extra-pulmonary malignancy was considered to be an event.

Time frame: Up to approximately 68 months

Population: All randomized participants. One participant randomized to the study in error did not provide informed consent and was not included. No data was collected on this participant.

ArmMeasureValue (MEDIAN)
PembrolizumabDFS at 68 Months53.6 Months
PlaceboDFS at 68 Months42.0 Months
p-value: 0.0014395% CI: [0.63, 0.91]Regression, Cox

Source: ClinicalTrials.gov · Data processed: Mar 18, 2026