NCT02362594 · OUTCOME

Number of Participants Positive for Anti-Drug Antibodies (ADA) After Pembrolizumab Treatment

Study of Pembrolizumab (MK-3475) Versus Placebo After Complete Resection of High-Risk Stage III Melanoma (MK-3475-054/1325-MG/KEYNOTE-054) · Source last updated 2026-03-05

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

Measure: COUNT_OF_PARTICIPANTS
Unit: Participants
Interval / dispersion: Not reported
Time frame: Pre-dose on Day 1 of Cycles 1, 2, 4, 6, and 8, and then Day 1 of cycle for every 4 cycles afterwards (up to approximately 16 months). Each cycle is 3 weeks.

What was measured

Pre- and post-baseline serum samples from participants treated with pembrolizumab were analyzed for ADA by means of a neutralizing antibody assay which assessed the ability of ADA to block (neutralize) binding of pembrolizumab to Programmed Cell Death-1 (PD-1) protein. Overall immunogenicity was defined as the number of treatment emergent positive participants based on the total number of evaluable participants (treatment emergent positive, non-treatment emergent positive and negative immunogenicity status).

Analysis population: All randomized participants in Part 1 who had at least one ADA sample available after treatment with pembrolizumab and who had treatment emergent positive, non-treatment emergent positive, or negative immunogenicity status. Participants receiving Placebo treatment in Part 1 were not analyzed for ADA.

Groups in this outcome

Pembrolizumab

In Part 1, participants received pembrolizumab 200 mg IV as post-surgery therapy Q3W for up to 1 year.

Placebo

In Part 1, participants received placebo IV as post-surgery therapy Q3W.

Group identifiers and denominators belong to this outcome only. They may differ in another outcome or in safety reporting.

Analysis denominator · Participants

Group	Source count
Pembrolizumab	495
Placebo	0

Reported measurements

Negative

Values in Participants · Interval/dispersion: Not reported
Group	Value	Spread	Lower	Upper	Comment
Pembrolizumab	473	Not reported	Not reported	Not reported	Not reported

Non-Treatment emergent positive

Values in Participants · Interval/dispersion: Not reported
Group	Value	Spread	Lower	Upper	Comment
Pembrolizumab	5	Not reported	Not reported	Not reported	Not reported

Treatment emergent positive

Values in Participants · Interval/dispersion: Not reported
Group	Value	Spread	Lower	Upper	Comment
Pembrolizumab	17	Not reported	Not reported	Not reported	Not reported

Complete source fields

classes

categories
measurements
group Id
OG000
value
473
title
Negative
categories
measurements
group Id
OG000
value
5
title
Non-Treatment emergent positive
categories
measurements
group Id
OG000
value
17
title
Treatment emergent positive

denoms

counts
group Id
OG000
value
495
group Id
OG001
value
0
units
Participants

description

groups

description
In Part 1, participants received pembrolizumab 200 mg IV as post-surgery therapy Q3W for up to 1 year.
id
OG000
title
Pembrolizumab
description
In Part 1, participants received placebo IV as post-surgery therapy Q3W.
id
OG001
title
Placebo

param Type

COUNT_OF_PARTICIPANTS

population Description

All randomized participants in Part 1 who had at least one ADA sample available after treatment with pembrolizumab and who had treatment emergent positive, non-treatment emergent positive, or negative immunogenicity status. Participants receiving Placebo treatment in Part 1 were not analyzed for ADA.

reporting Status

POSTED

time Frame

Pre-dose on Day 1 of Cycles 1, 2, 4, 6, and 8, and then Day 1 of cycle for every 4 cycles afterwards (up to approximately 16 months). Each cycle is 3 weeks.

title

Number of Participants Positive for Anti-Drug Antibodies (ADA) After Pembrolizumab Treatment

type

SECONDARY

unit Of Measure

Participants

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

Preserved source evidence · Not medical advice