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Efficacy and Safety Study of Pembrolizumab (MK-3475) Versus Paclitaxel in Asian Participants With Advanced Gastric or Gastroesophageal Junction Adenocarcinoma Who Progressed After First-line Therapy With Platinum and Fluoropyrimidine (MK-3475-063/KEYNOTE-063)

A Phase III, Randomized, Open-label Clinical Trial of Pembrolizumab (MK-3475) Versus Paclitaxel in Asian Subjects With Advanced Gastric or Gastroesophageal Junction Adenocarcinoma Who Progressed After First-Line Therapy With Platinum and Fluoropyrimidine

Status
Terminated
Phases
Phase 3
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT03019588
Enrollment
94
Registered
2017-01-12
Start date
2017-02-16
Completion date
2021-06-29
Last updated
2023-03-30

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

Conditions

Gastric Neoplasms, Gastroesophageal Junction Adenocarcinoma

Keywords

Programmed Cell Death-1 (PD1, PD-1), Programmed Cell Death 1 Ligand 1 (PDL1, PD-L1), Programmed Cell Death 1 Ligand 2 (PDL2, PD-L2)

Brief summary

The study will compare the efficacy and safety of treatment with pembrolizumab (MK-3475) versus paclitaxel in Asian, programmed death-ligand 1 (PD-L1) positive participants with advanced gastric or gastroesophageal junction (GEJ) adenocarcinoma who have progressed after failure of any combination chemotherapy containing a platinum and a fluoropyrimidine agent. The primary study hypotheses are that pembrolizumab prolongs Overall Survival (OS) compared to paclitaxel and that pembrolizumab prolongs Progression-free Survival (PFS) per Response Evaluation Criteria in Solid Tumors version 1.1 (RECIST 1.1) assessed by blinded central radiologists' review compared to paclitaxel.

Detailed description

Once the participant has achieved the study objective or the study has ended, the participant will be discontinued from the study and may be enrolled in an extension study to continue protocol-defined assessments and treatment. Enrollment in the extension study will be conditional on participant consent. Treatment with pembrolizumab or paclitaxel will continue until documented disease progression, unacceptable adverse event(s), intercurrent illness that prevents further administration of treatment, investigator's decision to discontinue the participant, participant withdraws consent, pregnancy of the participant, participant receives 35 administrations (approximately 2 years) of pembrolizumab, or administrative reasons requiring cessation of treatment.

Interventions

BIOLOGICALPembrolizumab

IV infusion

DRUGPaclitaxel

IV infusion

Sponsors

Merck Sharp & Dohme LLC
Lead SponsorINDUSTRY

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
NONE

Eligibility

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

Inclusion criteria

* Has histologically or cytologically-confirmed diagnosis of gastric or GEJ adenocarcinoma. * Has metastatic disease or locally advanced, unresectable disease. * Has measurable disease as defined by RECIST 1.1 as determined by investigator. * Has a performance status of 0 or 1 on the Eastern Cooperative Oncology Group (ECOG) Performance Scale within 3 days prior to the first dose of study treatment. * Has experienced documented objective radiographic or clinical disease progression during or after first-line therapy containing any platinum/fluoropyrimidine doublet. * Is willing to provide tissue for PD-L1 biomarker analysis. * Has PD-L1 positive tumor (based on analysis of sample provided to core lab). * Female participants of childbearing potential must be willing to use 2 methods of birth control or be surgically sterile, or abstain from heterosexual activity for the course of the study through 120 days after the last dose of study treatment for the pembrolizumab arm and through 180 days after the last dose of study treatment for the paclitaxel arm. * Male participants should agree to use an adequate method of contraception starting with the first dose of study therapy through 120 days after the last dose of study treatment for the pembrolizumab arm and through 180 days after the last dose of study treatment for the paclitaxel arm. * Demonstrates adequate organ function.

Exclusion criteria

* Is currently participating and receiving study therapy or has participated in a study of an investigational agent and received study therapy or used an investigation device within 4 weeks of the first dose of trial treatment. * Has squamous cell or undifferentiated gastric cancer. * Has active autoimmune disease that has required systemic treatment in past 2 years. * Has had a prior anti-cancer monoclonal antibody (mAb) within 4 weeks prior to the first dose of trial treatment or who has not recovered (i.e., ≤ Grade 1 or at Baseline) from AEs due to agents administered more than 4 weeks earlier. * Has had prior chemotherapy, targeted small molecule therapy, radiation therapy, or any other agents used as systemic treatment for cancer, within 2 weeks prior to the first dose of trial treatment or who has not recovered (i.e., ≤ Grade 1 or at Baseline) from AEs due to a previously administered agent. * Has a known additional malignancy that is progressing or has required active treatment within the past 5 years. Exceptions include basal cell carcinoma of the skin, squamous cell carcinoma of the skin, or in situ cervical cancer that has undergone potentially curative therapy. * Has known active central nervous system (CNS) metastases and/or carcinomatous meningitis. * Has a history of (non-infectious) pneumonitis that required steroids or current pneumonitis. * Has an active infection requiring systemic therapy. * Is pregnant or breastfeeding, or expecting to conceive or father children within the projected duration of the study, starting with the screening visit through 120 days after the last dose of study treatment for the pembrolizumab arm and through 180 days after the last dose of study treatment for the paclitaxel arm. * Has received prior therapy with an anti-programmed cell death protein 1 (anti-PD-1), anti-PD-L1, or anti-PD-L2 agent or with an agent directed to another stimulatory or co-inhibitory T-cell receptor (e.g. cytotoxic T-lymphocyte-associated protein 4 \[CTLA-4\], OX-40, CD137). * Has a known history of Human Immunodeficiency Virus (HIV) infection. * Has known active Hepatitis B or C virus infection. * Has received a live vaccine within 30 days of planned start of study treatment. * Has known allergy or hypersensitivity to paclitaxel or any components used in the paclitaxel preparation or other contraindication for taxane therapy.

Design outcomes

Primary

MeasureTime frameDescription
Overall Survival (OS)Up to approximately 50 monthsOS is defined as the time from randomization to death due to any cause. Participants without documented death at the time of the final analysis were censored at the date of the last follow-up.
Progression-free Survival (PFS) Per Response Evaluation Criteria in Solid Tumors Version 1.1 (RECIST 1.1)Up to approximately 50 monthsPFS is defined as the time from randomization to the first documented disease progression or death due to any cause, whichever occurs first. Per RECIST 1.1, progressive disease was defined as at least a 20% increase in the sum of diameters of target lesions, taking as reference the smallest sum on study. In addition to the relative increase of 20%, the sum must also demonstrate an absolute increase of at least 5 mm. Note: The appearance of one or more new lesions was also considered progression. PFS as assessed by blinded independent central review will be presented.

Secondary

MeasureTime frameDescription
Objective Response Rate (ORR) Per RECIST 1.1Up to approximately 50 monthsORR was defined as the percentage of participants in the analysis population who had a Complete Response (CR: Disappearance of all target lesions) or a Partial Response (PR: At least a 30% decrease in the sum of diameters of target lesions, taking as reference the baseline sum diameters) per RECIST 1.1.
Number of Participants Who Experience an Adverse Event (AE)Up to approximately 50 monthsAn adverse event is defined as any untoward medical occurrence in a participant administered a pharmaceutical product and which does not necessarily have to have a causal relationship with this treatment.
Number of Participants Who Discontinue Study Treatment Due to an AEUp to approximately 25 monthsAn adverse event is defined as any untoward medical occurrence in a participant administered a pharmaceutical product and which does not necessarily have to have a causal relationship with this treatment.

Countries

China, Malaysia, South Korea, Taiwan

Participant flow

Participants by arm

ArmCount
Pembrolizumab 200 mg
Participants receive pembrolizumab 200 mg intravenous (IV) infusion on Day 1 of each 3-week cycle for up to 35 cycles (up to approximately 2 years).
47
Paclitaxel 80 mg/m^2
Participants receive paclitaxel 80 mg/m\^2 IV infusion on Days 1, 8 and 15 of each 4-week cycle for up to approximately 2 years.
47
Total94

Withdrawals & dropouts

PeriodReasonFG000FG001
Overall StudyDeath4446
Overall StudyStudy terminated by Sponsor31

Baseline characteristics

CharacteristicPaclitaxel 80 mg/m^2TotalPembrolizumab 200 mg
Age, Continuous59.0 years
STANDARD_DEVIATION 11.2
58.5 years
STANDARD_DEVIATION 10.8
58.0 years
STANDARD_DEVIATION 10.4
Eastern Cooperative Oncology Group Performance Status (ECOG PS)
ECOG = 0
12 Participants26 Participants14 Participants
Eastern Cooperative Oncology Group Performance Status (ECOG PS)
ECOG = 1
35 Participants68 Participants33 Participants
Ethnicity (NIH/OMB)
Hispanic or Latino
0 Participants0 Participants0 Participants
Ethnicity (NIH/OMB)
Not Hispanic or Latino
47 Participants94 Participants47 Participants
Ethnicity (NIH/OMB)
Unknown or Not Reported
0 Participants0 Participants0 Participants
Race (NIH/OMB)
American Indian or Alaska Native
0 Participants0 Participants0 Participants
Race (NIH/OMB)
Asian
47 Participants94 Participants47 Participants
Race (NIH/OMB)
Black or African American
0 Participants0 Participants0 Participants
Race (NIH/OMB)
More than one race
0 Participants0 Participants0 Participants
Race (NIH/OMB)
Native Hawaiian or Other Pacific Islander
0 Participants0 Participants0 Participants
Race (NIH/OMB)
Unknown or Not Reported
0 Participants0 Participants0 Participants
Race (NIH/OMB)
White
0 Participants0 Participants0 Participants
Sex: Female, Male
Female
10 Participants25 Participants15 Participants
Sex: Female, Male
Male
37 Participants69 Participants32 Participants
Time to progression on first-line therapy
< 6 months
30 Participants60 Participants30 Participants
Time to progression on first-line therapy
>= 6 months
17 Participants34 Participants17 Participants

Adverse events

Event typeEG000
affected / at risk
EG001
affected / at risk
deaths
Total, all-cause mortality
44 / 4746 / 47
other
Total, other adverse events
46 / 4743 / 44
serious
Total, serious adverse events
13 / 4714 / 44

Outcome results

Primary

Overall Survival (OS)

OS is defined as the time from randomization to death due to any cause. Participants without documented death at the time of the final analysis were censored at the date of the last follow-up.

Time frame: Up to approximately 50 months

Population: Analysis population includes all randomized participants.

ArmMeasureValue (MEDIAN)
Pembrolizumab 200 mgOverall Survival (OS)8.4 Months
Paclitaxel 80 mg/m^2Overall Survival (OS)7.7 Months
p-value: 0.2995% CI: [0.58, 1.36]Log Rank
Primary

Progression-free Survival (PFS) Per Response Evaluation Criteria in Solid Tumors Version 1.1 (RECIST 1.1)

PFS is defined as the time from randomization to the first documented disease progression or death due to any cause, whichever occurs first. Per RECIST 1.1, progressive disease was defined as at least a 20% increase in the sum of diameters of target lesions, taking as reference the smallest sum on study. In addition to the relative increase of 20%, the sum must also demonstrate an absolute increase of at least 5 mm. Note: The appearance of one or more new lesions was also considered progression. PFS as assessed by blinded independent central review will be presented.

Time frame: Up to approximately 50 months

Population: Analysis population includes all randomized participants.

ArmMeasureValue (MEDIAN)
Pembrolizumab 200 mgProgression-free Survival (PFS) Per Response Evaluation Criteria in Solid Tumors Version 1.1 (RECIST 1.1)1.9 Months
Paclitaxel 80 mg/m^2Progression-free Survival (PFS) Per Response Evaluation Criteria in Solid Tumors Version 1.1 (RECIST 1.1)4.0 Months
p-value: 0.995495% CI: [1.14, 2.74]Log Rank
Secondary

Number of Participants Who Discontinue Study Treatment Due to an AE

An adverse event is defined as any untoward medical occurrence in a participant administered a pharmaceutical product and which does not necessarily have to have a causal relationship with this treatment.

Time frame: Up to approximately 25 months

Population: Analysis population includes all randomized participants who received at least one dose of study treatment.

ArmMeasureValue (COUNT_OF_PARTICIPANTS)
Pembrolizumab 200 mgNumber of Participants Who Discontinue Study Treatment Due to an AE2 Participants
Paclitaxel 80 mg/m^2Number of Participants Who Discontinue Study Treatment Due to an AE7 Participants
Secondary

Number of Participants Who Experience an Adverse Event (AE)

An adverse event is defined as any untoward medical occurrence in a participant administered a pharmaceutical product and which does not necessarily have to have a causal relationship with this treatment.

Time frame: Up to approximately 50 months

Population: Analysis population includes all randomized participants who received at least one dose of study treatment.

ArmMeasureValue (COUNT_OF_PARTICIPANTS)
Pembrolizumab 200 mgNumber of Participants Who Experience an Adverse Event (AE)46 Participants
Paclitaxel 80 mg/m^2Number of Participants Who Experience an Adverse Event (AE)43 Participants
Secondary

Objective Response Rate (ORR) Per RECIST 1.1

ORR was defined as the percentage of participants in the analysis population who had a Complete Response (CR: Disappearance of all target lesions) or a Partial Response (PR: At least a 30% decrease in the sum of diameters of target lesions, taking as reference the baseline sum diameters) per RECIST 1.1.

Time frame: Up to approximately 50 months

Population: Analysis population includes all randomized participants.

ArmMeasureValue (NUMBER)
Pembrolizumab 200 mgObjective Response Rate (ORR) Per RECIST 1.112.8 Percentage of participants
Paclitaxel 80 mg/m^2Objective Response Rate (ORR) Per RECIST 1.119.1 Percentage of participants
p-value: 0.788495% CI: [-21.6, 9.3]Z-test

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