Long-term Safety and Efficacy Extension Study for Participants With Advanced Tumors Who Are Currently on Treatment or in Follow-up in a Pembrolizumab (MK-3475) Study (MK-3475-587/KEYNOTE-587)

The purpose of this study is to evaluate the long-term safety and efficacy of pembrolizumab
(MK-3475) in participants from previous Merck pembrolizumab-based parent studies who
roll-over into this extension study.

This study will consist of three phases: 1) First Course Phase, 2) Survival Follow-up Phase
or 3) Second Course Phase. Each participant will roll-over to this extension study in one of
the following three phases, depending on the study phase they were in at the completion of
the parent study. Participants who were in the First Course Phase of study treatment in their
parent study will enter the First Course Phase of this study and complete up to 35 doses or
more every 3 weeks (Q3W) or 17 doses or more every 6 weeks (Q6W) of study treatment with
pembrolizumab or a pembrolizumab-based combination according to arm assignment. Participants
who were in the Follow-up Phase in the parent study (post-treatment or Survival Follow-up
Phase) will enter the Survival Follow-up Phase of this study. Participants who were in the
Second Course Phase in their parent study will enter Second Course Phase of this study and
complete up to 17 doses Q3W or 8 doses Q6W of study treatment with pembrolizumab or a
pembrolizumab-based combination according to arm assignment.

Any participant originating from a parent trial where crossover to pembrolizumab was
permitted upon disease progression may be may be eligible for 35 doses as Q3W or 17 doses Q6W
of pembrolizumab (approximately 2 years), if they progress while on the control arm and
pembrolizumab is approved for the indication in the country where the potential eligible
crossover participant is being evaluated.

Treatment Sites in Georgia