NCT03486873 · Merck Sharp & Dohme LLC
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)
What this study is about
The purpose of this study is to evaluate the long-term safety and effectiveness of pembrolizumab (MK-3475) in participants from previous Merck pembrolizumab-based parent studies who transition 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.
View original scientific description
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 transition 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.
Interventions
DRUG
Pembrolizumab
200 or 400 mg IV infusion
DRUG
Standard of Care (SOC)
IV infusion or oral tablets
DRUG
Lenvatinib
Oral capsules
DRUG
Olaparib
300mg or 250mg or 100mg oral tablers
DRUG
MK-4280
IV Infusion
BIOLOGICAL
MK-4280A
800mg favezelimab + 200mg pembrolizumab IV Infusion
BIOLOGICAL
Pembrolizumab (+) Berahyaluronidase alfa
395 mg or 790 mg SC administration
Primary outcome measures
Overall Survival (OS)
Time frame: Up to approximately 10 years
OS is defined as the time from randomization or start of study treatment for non-randomized participants (on the parent study) to death due to any cause. Participants without documented death at the time of analysis will be censored at the date of the last known to be alive.
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- Treated on the parent pembrolizumab studies established by the Sponsor as MK-3475-587 ready.
- Currently receiving pembrolizumab, pembrolizumab based combinations or lenvatinib from parent studies or in a follow-up phase. Additional eligibility criteria for participants who enter Second Course Phase once they are enrolled on MK-3475-587:
- Has not received any anticancer systemic treatment since the last dose of pembrolizumab or a pembrolizumab-based combination in First Course Phase.
- Has an Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1.
- Demonstrates adequate organ function.
- Have resolution of any toxic effect(s) of First Course Phase trial treatment with pembrolizumab or a pembrolizumab-based combination to Grade 1 or less (except alopecia) before trial treatment in Second Course Phase is started. If participant received major surgery or radiation therapy of \>30 Gray (Gy), they must have recovered from the toxicity and/or compli
Where
- Tucson, Arizona
- Bakersfield, California
- Fresno, California
- Fullerton, California
- Los Angeles, California
- Orange, California
- Palo Alto, California
- San Francisco, California
- Santa Monica, California
- Aurora, Colorado
- New Haven, Connecticut
- Washington D.C., District of Columbia
And 47 more locations — see the full list below.
Related conditions & keywords
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Jul 8, 2026 · Source of record for eligibility and locations