Participant flow

Pembrolizumab (MK-3475) Plus Chemotherapy Versus Placebo Plus Chemotherapy in Participants Gastric or Gastroesophageal Junction (GEJ) Adenocarcinoma (MK-3475-859/KEYNOTE-859) · Source last updated 2026-02-27

Results reported by the registry submitting party. Population, time horizon, units and missing values must be read together.

groups

1. description

   Participants received 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 completed up to 35 administrations of pembrolizumab (approximately 2 years) or achieved a complete response (CR) but experienced progression of disease (PD), could have initiated a second course of pembrolizumab for up to 17 cycles (approximately 1 additional year).

   id

   FG000

   title

   Pembrolizumab + Chemotherapy (FP or CAPOX Regimen)

2. description

   Participants received 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).

   id

   FG001

   title

   Placebo + Chemotherapy (FP or CAPOX Regimen)

periods

1. drop Withdraws

   1. reasons

      1. group Id

         FG000

         num Subjects

         685

      2. group Id

         FG001

         num Subjects

         726

      type

      Death

   2. reasons

      1. group Id

         FG000

         num Subjects

         2

      2. group Id

         FG001

         num Subjects

         4

      type

      Lost to Follow-up

   3. reasons

      1. group Id

         FG000

         num Subjects

         15

      2. group Id

         FG001

         num Subjects

         13

      type

      Withdrawal by Subject

   4. reasons

      1. group Id

         FG000

         num Subjects

         88

      2. group Id

         FG001

         num Subjects

         46

      type

      Sponsor Decision

   milestones

   1. achievements

      1. group Id

         FG000

         num Subjects

         790

      2. group Id

         FG001

         num Subjects

         789

      type

      STARTED

   2. achievements

      1. group Id

         FG000

         num Subjects

         785

      2. group Id

         FG001

         num Subjects

         787

      type

      Treated

   3. achievements

      1. group Id

         FG000

         num Subjects

         12

      2. group Id

         FG001

         num Subjects

         0

      type

      Received Pembrolizumab Second Course

   4. achievements

      1. group Id

         FG000

         num Subjects

         0

      2. group Id

         FG001

         num Subjects

         0

      type

      COMPLETED

   5. achievements

      1. group Id

         FG000

         num Subjects

         790

      2. group Id

         FG001

         num Subjects

         789

      type

      NOT COMPLETED

   title

   Overall Study

Download exact source JSON → · Snapshot ctgov-results-191f4516d4760045304b24a0

Preserved source evidence · Not medical advice