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 rollover
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 cycles of
study treatment with pembrolizumab or a pembrolizumab-based combination. 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 cycles of study treatment with pembrolizumab or a pembrolizumab-based combination.