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Pembrolizumab (MK-3475) Plus Chemotherapy Versus Placebo Plus Chemotherapy in Participants Gastric or Gastroesophageal Junction (GEJ) Adenocarcinoma (MK-3475-859/KEYNOTE-859)

Registration Number
NCT03675737
Lead Sponsor
Merck Sharp & Dohme LLC
Brief Summary

The purpose of this study is to evaluate the efficacy of pembrolizumab (MK-3745) in combination with chemotherapy (Cisplatin combined with 5-Fluorouracil \[FP regimen\] or oxaliplatin combined with capecitabine \[CAPOX regimen\]) versus placebo in combination with chemotherapy (FP or CAPOX regimens) in the treatment of human epidermal growth factor receptor 2 (HER2) negative advanced gastric or GEJ adenocarcinoma in adult participants.

The primary hypotheses of this study are that pembrolizumab plus chemotherapy is superior to placebo plus chemotherapy in terms of overall survival (OS).

Detailed Description

Not available

Recruitment & Eligibility

Status
COMPLETED
Sex
All
Target Recruitment
1579
Inclusion Criteria

Not provided

Exclusion Criteria

Not provided

Study & Design

Study Type
INTERVENTIONAL
Study Design
PARALLEL
Arm && Interventions
GroupInterventionDescription
Pembrolizumab + Chemotherapy (FP or CAPOX regimen)PembrolizumabParticipants receive pembrolizumab 200 mg intravenously (IV) on Day 1 of each 21-day cycle (Q3W) for up to 35 cycles (approximately 2 years) + physicians' choice of either cisplatin 80 mg/m\^2 IV on Day 1 Q3W and 5-fluorouracil (5FU) 800 mg/m\^2/day via continuous IV infusion on Days 1 to 5 Q3W (FP regimen) OR oxaliplatin 130 mg/m\^2 IV on Day 1 Q3W + capecitabine 1000 mg/m\^2 orally twice a day (BID) on Days 1 to 14 Q3W (CAPOX regimen). Participants who complete up to 35 administrations of pembrolizumab (approximately 2 years) or achieve a complete response (CR) but experience progression of disease (PD), can initiate a second course of pembrolizumab for up to 17 cycles (approximately 1 additional year).
Placebo + Chemotherapy (FP or CAPOX regimen)Placebo for PembrolizumabParticipants receive placebo on Day 1 Q3W for up to 35 cycles (approximately 2 years) + physicians' choice of either cisplatin 80 mg/m\^2 IV on Day 1 Q3W and 5FU 800 mg/m\^2/day via continuous IV infusion on Days 1 to 5 Q3W (FP regimen) OR oxaliplatin 130 mg/m\^2 IV on Day 1 Q3W + capecitabine 1000 mg/m\^2 orally BID on Days 1 to 14 Q3W (CAPOX regimen).
Pembrolizumab + Chemotherapy (FP or CAPOX regimen)CisplatinParticipants receive pembrolizumab 200 mg intravenously (IV) on Day 1 of each 21-day cycle (Q3W) for up to 35 cycles (approximately 2 years) + physicians' choice of either cisplatin 80 mg/m\^2 IV on Day 1 Q3W and 5-fluorouracil (5FU) 800 mg/m\^2/day via continuous IV infusion on Days 1 to 5 Q3W (FP regimen) OR oxaliplatin 130 mg/m\^2 IV on Day 1 Q3W + capecitabine 1000 mg/m\^2 orally twice a day (BID) on Days 1 to 14 Q3W (CAPOX regimen). Participants who complete up to 35 administrations of pembrolizumab (approximately 2 years) or achieve a complete response (CR) but experience progression of disease (PD), can initiate a second course of pembrolizumab for up to 17 cycles (approximately 1 additional year).
Pembrolizumab + Chemotherapy (FP or CAPOX regimen)5-fluorouracilParticipants receive pembrolizumab 200 mg intravenously (IV) on Day 1 of each 21-day cycle (Q3W) for up to 35 cycles (approximately 2 years) + physicians' choice of either cisplatin 80 mg/m\^2 IV on Day 1 Q3W and 5-fluorouracil (5FU) 800 mg/m\^2/day via continuous IV infusion on Days 1 to 5 Q3W (FP regimen) OR oxaliplatin 130 mg/m\^2 IV on Day 1 Q3W + capecitabine 1000 mg/m\^2 orally twice a day (BID) on Days 1 to 14 Q3W (CAPOX regimen). Participants who complete up to 35 administrations of pembrolizumab (approximately 2 years) or achieve a complete response (CR) but experience progression of disease (PD), can initiate a second course of pembrolizumab for up to 17 cycles (approximately 1 additional year).
Pembrolizumab + Chemotherapy (FP or CAPOX regimen)oxaliplatinParticipants receive pembrolizumab 200 mg intravenously (IV) on Day 1 of each 21-day cycle (Q3W) for up to 35 cycles (approximately 2 years) + physicians' choice of either cisplatin 80 mg/m\^2 IV on Day 1 Q3W and 5-fluorouracil (5FU) 800 mg/m\^2/day via continuous IV infusion on Days 1 to 5 Q3W (FP regimen) OR oxaliplatin 130 mg/m\^2 IV on Day 1 Q3W + capecitabine 1000 mg/m\^2 orally twice a day (BID) on Days 1 to 14 Q3W (CAPOX regimen). Participants who complete up to 35 administrations of pembrolizumab (approximately 2 years) or achieve a complete response (CR) but experience progression of disease (PD), can initiate a second course of pembrolizumab for up to 17 cycles (approximately 1 additional year).
Pembrolizumab + Chemotherapy (FP or CAPOX regimen)capecitabineParticipants receive pembrolizumab 200 mg intravenously (IV) on Day 1 of each 21-day cycle (Q3W) for up to 35 cycles (approximately 2 years) + physicians' choice of either cisplatin 80 mg/m\^2 IV on Day 1 Q3W and 5-fluorouracil (5FU) 800 mg/m\^2/day via continuous IV infusion on Days 1 to 5 Q3W (FP regimen) OR oxaliplatin 130 mg/m\^2 IV on Day 1 Q3W + capecitabine 1000 mg/m\^2 orally twice a day (BID) on Days 1 to 14 Q3W (CAPOX regimen). Participants who complete up to 35 administrations of pembrolizumab (approximately 2 years) or achieve a complete response (CR) but experience progression of disease (PD), can initiate a second course of pembrolizumab for up to 17 cycles (approximately 1 additional year).
Placebo + Chemotherapy (FP or CAPOX regimen)5-fluorouracilParticipants receive placebo on Day 1 Q3W for up to 35 cycles (approximately 2 years) + physicians' choice of either cisplatin 80 mg/m\^2 IV on Day 1 Q3W and 5FU 800 mg/m\^2/day via continuous IV infusion on Days 1 to 5 Q3W (FP regimen) OR oxaliplatin 130 mg/m\^2 IV on Day 1 Q3W + capecitabine 1000 mg/m\^2 orally BID on Days 1 to 14 Q3W (CAPOX regimen).
Placebo + Chemotherapy (FP or CAPOX regimen)CisplatinParticipants receive placebo on Day 1 Q3W for up to 35 cycles (approximately 2 years) + physicians' choice of either cisplatin 80 mg/m\^2 IV on Day 1 Q3W and 5FU 800 mg/m\^2/day via continuous IV infusion on Days 1 to 5 Q3W (FP regimen) OR oxaliplatin 130 mg/m\^2 IV on Day 1 Q3W + capecitabine 1000 mg/m\^2 orally BID on Days 1 to 14 Q3W (CAPOX regimen).
Placebo + Chemotherapy (FP or CAPOX regimen)oxaliplatinParticipants receive placebo on Day 1 Q3W for up to 35 cycles (approximately 2 years) + physicians' choice of either cisplatin 80 mg/m\^2 IV on Day 1 Q3W and 5FU 800 mg/m\^2/day via continuous IV infusion on Days 1 to 5 Q3W (FP regimen) OR oxaliplatin 130 mg/m\^2 IV on Day 1 Q3W + capecitabine 1000 mg/m\^2 orally BID on Days 1 to 14 Q3W (CAPOX regimen).
Placebo + Chemotherapy (FP or CAPOX regimen)capecitabineParticipants receive placebo on Day 1 Q3W for up to 35 cycles (approximately 2 years) + physicians' choice of either cisplatin 80 mg/m\^2 IV on Day 1 Q3W and 5FU 800 mg/m\^2/day via continuous IV infusion on Days 1 to 5 Q3W (FP regimen) OR oxaliplatin 130 mg/m\^2 IV on Day 1 Q3W + capecitabine 1000 mg/m\^2 orally BID on Days 1 to 14 Q3W (CAPOX regimen).
Primary Outcome Measures
NameTimeMethod
Overall Survival (OS) in All ParticipantsUp to 45.9 months

OS was defined as the time from randomization to death due to any cause. Participants without documented death at the time of the analysis were censored at the date of the last follow-up. OS was estimated using the product-limit (Kaplan-Meier) method for censored data.

Overall Survival (OS) In Participants With Programmed Cell Death Ligand 1 (PD-L1) Combined Positive Score (CPS) ≥1Up to 45.9 months

OS was defined as the time from randomization to death due to any cause. Participants without documented death at the time of the analysis were censored at the date of the last follow-up. OS was estimated using the product-limit (Kaplan-Meier) method for censored data.

Overall Survival (OS) In Participants With Programmed Cell Death Ligand 1 (PD-L1) Combined Positive Score (CPS) ≥10Up to 45.9 months

OS was defined as the time from randomization to death due to any cause. Participants without documented death at the time of the analysis were censored at the date of the last follow-up. OS was estimated using the product-limit (Kaplan-Meier) method for censored data.

Secondary Outcome Measures
NameTimeMethod
Objective Response Rate (ORR) Per Response Evaluation Criteria in Solid Tumors Version 1.1 (RECIST 1.1) Assessed by Blinded Independent Central Review (BICR) in All ParticipantsUp to 49.5 months

ORR was defined as the percentage of the participants who had a confirmed Complete Response (CR: disappearance of all target lesions) or Partial Response (PR: ≥30% decrease in the sum of diameters (SOD) of target lesions, taking as reference the baseline SOD) according to RECIST 1.1 as assessed by BICR.

Objective Response Rate (ORR) Per Response Evaluation Criteria in Solid Tumors Version 1.1 (RECIST 1.1) Assessed by Blinded Independent Central Review (BICR) in Participants With Programmed Cell Death Ligand 1 (PD-L1) Combined Positive Score (CPS) ≥1Up to 49.5 months

ORR was defined as the percentage of the participants who had a confirmed Complete Response (CR: disappearance of all target lesions) or Partial Response (PR: ≥30% decrease in the sum of diameters (SOD) of target lesions, taking as reference the baseline SOD) according to RECIST 1.1 as assessed by BICR.

Objective Response Rate (ORR) Per Response Evaluation Criteria in Solid Tumors Version 1.1 (RECIST 1.1) Assessed by Blinded Independent Central Review (BICR) in Participants With Programmed Cell Death Ligand 1 (PD-L1) Combined Positive Score (CPS) ≥10Up to 49.5 months

ORR was defined as the percentage of the participants who had a confirmed Complete Response (CR: disappearance of all target lesions) or Partial Response (PR: ≥30% decrease in the sum of diameters (SOD) of target lesions, taking as reference the baseline SOD) according to RECIST 1.1 as assessed by BICR.

Progression Free Survival (PFS) Per Response Evaluation Criteria in Solid Tumors Version 1.1 (RECIST 1.1) Assessed by Blinded Independent Central Review (BICR) in All ParticipantsUp to 49.5 months

PFS was defined as the time from randomization to the first documented progressive disease (PD) or death due to any cause, whichever occurred first. Per RECIST 1.1 as assessed by BICR, PD was defined as ≥20% increase in the sum of diameters of target lesions. In addition to the relative increase of 20%, the sum must also have demonstrated an absolute increase of ≥5 mm. The appearance of ≥1 new lesions was also considered PD. PFS was estimated using the product-limit (Kaplan-Meier) method for censored data.

Progression Free Survival (PFS) Per Response Evaluation Criteria in Solid Tumors Version 1.1 (RECIST 1.1) Assessed by Blinded Independent Central Review (BICR) in Participants With Programmed Cell Death Ligand 1 (PD-L1) Combined Positive Score (CPS) ≥1Up to 49.5 months

PFS was defined as the time from randomization to the first documented progressive disease (PD) or death due to any cause, whichever occurred first. Per RECIST 1.1 as assessed by BICR, PD was defined as ≥20% increase in the sum of diameters of target lesions. In addition to the relative increase of 20%, the sum must also have demonstrated an absolute increase of ≥5 mm. The appearance of ≥1 new lesions was also considered PD. PFS was estimated using the product-limit (Kaplan-Meier) method for censored data.

Progression Free Survival (PFS) Per Response Evaluation Criteria in Solid Tumors Version 1.1 (RECIST 1.1) Assessed by Blinded Independent Central Review (BICR) in Participants With Programmed Cell Death Ligand 1 (PD-L1) Combined Positive Score (CPS) ≥10Up to 49.5 months

PFS was defined as the time from randomization to the first documented progressive disease (PD) or death due to any cause, whichever occurred first. Per RECIST 1.1 as assessed by BICR, PD was defined as ≥20% increase in the sum of diameters of target lesions. In addition to the relative increase of 20%, the sum must also have demonstrated an absolute increase of ≥5 mm. The appearance of ≥1 new lesions was also considered PD. PFS was estimated using the product-limit (Kaplan-Meier) method for censored data.

Duration of Response (DOR) Per Response Evaluation Criteria in Solid Tumors Version 1.1 (RECIST 1.1) Assessed by Blinded Independent Central Review (BICR) in All ParticipantsUp to 49.5 months

DOR was defined as the time from first documented evidence of a confirmed Complete Response (CR) or Partial Response (PR) until progressive disease (PD) or death, whichever occurred first. Per RECIST 1.1 as assessed by BICR, CR was the disappearance of all target lesions and PR was ≥30% decrease in the sum of diameters (SOD) of target lesions, taking as reference the baseline SOD. PD was defined as ≥20% increase in the SOD of target lesions according to RECIST 1.1. In addition to the relative increase of 20%, the SOD must also have demonstrated an absolute increase of ≥5 mm. The appearance of ≥1 new lesions was also considered PD. DOR for participants who had not progressed or died at the time of analysis was censored at the date of the last tumor assessment. DOR was estimated using the product-limit (Kaplan-Meier) method for censored data.

Duration of Response (DOR) Per Response Evaluation Criteria in Solid Tumors Version 1.1 (RECIST 1.1) Assessed by Blinded Independent Central Review (BICR) in Participants With Programmed Cell Death Ligand 1 (PD-L1) Combined Positive Score (CPS) ≥1Up to 49.5 months

DOR was defined as the time from first documented evidence of a confirmed Complete Response (CR) or Partial Response (PR) until progressive disease (PD) or death, whichever occurred first. Per RECIST 1.1 as assessed by BICR, CR was the disappearance of all target lesions and PR was ≥30% decrease in the sum of diameters (SOD) of target lesions, taking as reference the baseline SOD. PD was defined as ≥20% increase in the SOD of target lesions according to RECIST 1.1. In addition to the relative increase of 20%, the SOD must also have demonstrated an absolute increase of ≥5 mm. The appearance of ≥1 new lesions was also considered PD. DOR for participants who had not progressed or died at the time of analysis was censored at the date of the last tumor assessment. DOR was estimated using the product-limit (Kaplan-Meier) method for censored data.

Duration of Response (DOR) Per Response Evaluation Criteria in Solid Tumors Version 1.1 (RECIST 1.1) Assessed by Blinded Independent Central Review (BICR) in Participants With Programmed Cell Death Ligand 1 (PD-L1) Combined Positive Score (CPS) ≥10Up to 49.5 months

DOR was defined as the time from first documented evidence of a confirmed Complete Response (CR) or Partial Response (PR) until progressive disease (PD) or death, whichever occurred first. Per RECIST 1.1 as assessed by BICR, CR was the disappearance of all target lesions and PR was ≥30% decrease in the sum of diameters (SOD) of target lesions, taking as reference the baseline SOD. PD was defined as ≥20% increase in the SOD of target lesions according to RECIST 1.1. In addition to the relative increase of 20%, the SOD must also have demonstrated an absolute increase of ≥5 mm. The appearance of ≥1 new lesions was also considered PD. DOR for participants who had not progressed or died at the time of analysis was censored at the date of the last tumor assessment. DOR was estimated using the product-limit (Kaplan-Meier) method for censored data.

Number of Participants Who Experienced an Adverse Event (AE)Up to 36.7 months

An AE was defined as any untoward medical occurrence, in a clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. An AE could therefore have been any unfavorable and unintended sign (including an abnormal laboratory finding), symptom, or disease (new or exacerbated) temporally associated with the use of a study intervention. The number of participants with at least one AE is presented.

Number of Participants Who Discontinued Study Treatment Due To an Adverse Event (AE)Up to 33.7 months

An AE was defined as any untoward medical occurrence in a clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. An AE could therefore have been any unfavorable and unintended sign (including an abnormal laboratory finding), symptom, or disease (new or exacerbated) temporally associated with the use of a study intervention. The number of participants who discontinued study treatment due to an AE is presented.

Trial Locations

Locations (215)

UCLA Hematology/Oncology - Westwood (Building 200 Suite 120) ( Site 0124)

🇺🇸

Los Angeles, California, United States

UC Irvine Health/Division of Hematology Oncology, Dept of Medicine ( Site 0128)

🇺🇸

Orange, California, United States

University of Miami, Sylvester Comprehensive Cancer Center ( Site 0113)

🇺🇸

Miami, Florida, United States

Greater Baltimore Medical Center ( Site 0102)

🇺🇸

Baltimore, Maryland, United States

Minnesota Oncology Hematology, PA ( Site 8000)

🇺🇸

Minneapolis, Minnesota, United States

University of Rochester ( Site 0122)

🇺🇸

Rochester, New York, United States

Cancer Treatment Centers of America - Philadelphia ( Site 0112)

🇺🇸

Philadelphia, Pennsylvania, United States

Allegheny General Hospital ( Site 0118)

🇺🇸

Pittsburgh, Pennsylvania, United States

Oncology & Hematology Assoc. SW Virginia, Inc., DBA Blue Ridge Cancer Care ( Site 8001)

🇺🇸

Roanoke, Virginia, United States

Wenatchee Valley Clinic [Wenatchee, WA] ( Site 0116)

🇺🇸

Wenatchee, Washington, United States

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UCLA Hematology/Oncology - Westwood (Building 200 Suite 120) ( Site 0124)
🇺🇸Los Angeles, California, United States

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