Keytrudapembrolizumab
According to the FDA label: KEYTRUDA is a programmed death receptor-1 (PD-1)-blocking antibody indicated: Melanoma for the treatment of patients with unresectable or metastatic melanoma. ( 1.1 ) for the adjuvant treatment of adult and pediatric (12 years and older) patients with Stage IIB, IIC, or III melanoma following complete resection.
100,428 adverse event reports submitted to the FDA (2012–2026)
Top Reported Adverse Events
The most frequently reported events in association with Keytruda in the FAERS database. These are events reported by patients taking this medication, not necessarily caused by it. A single report may include multiple events.
Show these terms with plain-language definitions
Tap any term below for a plain-language definition.
Malignant Neoplasm Progression 11,562 reports
A report that a cancer grew or spread. This describes the course of the illness, not necessarily an effect of the drug. Malignant neoplasm is the medical term for a cancerous growth.
Full definition in the glossary →Death 5,718 reports
A report that the person died. A death appearing in reports for a drug does not mean the drug caused it. Reports record that a death occurred while the medication was being used, which can happen for many unrelated reasons.
Full definition in the glossary →Diarrhoea 5,487 reports
Loose or watery bowel movements, often frequent. Also spelled diarrhea in American English.
Full definition in the glossary → See all drugs reporting this event →Fatigue 4,928 reports
Extreme tiredness or lack of energy that does not improve with rest.
Full definition in the glossary → See all drugs reporting this event →Off Label Use 4,623 reports
Using a medication for a condition or in a way that the FDA has not officially approved. This is common and often legal, and a report of it does not mean something went wrong. Doctors sometimes prescribe drugs off label based on their judgment.
Full definition in the glossary →Pyrexia 3,745 reports
The medical term for fever, meaning a raised body temperature.
Full definition in the glossary → See all drugs reporting this event →Rash 3,554 reports
An area of irritated, red, or bumpy skin.
Full definition in the glossary → See all drugs reporting this event →Product Use in Unapproved Indication 3,468 reports
Using a medication for a condition it is not officially approved to treat. Like off label use, this is a reporting category and does not by itself mean harm occurred.
Full definition in the glossary →Nausea 3,449 reports
The feeling of sickness in your stomach that often comes before vomiting.
Full definition in the glossary → See all drugs reporting this event →Decreased Appetite 3,216 reports
Hypertension 3,102 reports
- Hypothyroidism 2,799 reports
Asthenia 2,688 reports
Physical weakness or lack of strength.
Full definition in the glossary →Drug Ineffective 2,498 reports
A report that the medication did not work as expected for the person taking it. This is a reporting category, not a sign the drug is defective. It simply means someone felt it was not helping their condition.
Full definition in the glossary →Product Use Issue 2,494 reports
A general report that there was some problem in how the medication was used.
Full definition in the glossary →
Ranked by frequency of reports, not severity. The most-reported event is not necessarily the most dangerous or the most common in patients taking this drug.
Who Is Reporting
Demographics of patients in FAERS reports that included this information. Not all reports include patient demographics.
By Sex
View reporter sex data as a table
| Sex | Reports |
|---|---|
| Female | 47,325 |
| Male | 46,785 |
| Unknown | 6 |
By Age Group
View age group data as a table
| Age group | Reports |
|---|---|
| 0-17 | 5,232 |
| 18-34 | 1,632 |
| 35-49 | 7,208 |
| 50-64 | 23,124 |
| 65-74 | 23,776 |
| 75+ | 14,318 |
This shows who filed reports, reflecting who takes this drug and who tends to report, not who is at greatest risk.
Reported Outcomes
Outcomes recorded in FAERS reports that included Keytruda. A single report may involve multiple reactions, each with a different outcome. These categories are defined by FDA reporting guidelines, not by PillSignal.
View outcome data as a table
| Outcome | Reports |
|---|---|
| Other Serious | 60,361 |
| Hospitalization | 42,162 |
| Death | 18,175 |
| Non-Serious | 12,801 |
| Life-Threatening | 6,369 |
| Disability | 2,211 |
Serious outcomes are far more likely to be reported than mild ones, so this overstates how often outcomes are serious. A recorded death does not mean the drug caused it.
Report Volume Over Time
Number of FAERS reports received per quarter for Keytruda. Changes in volume may reflect shifts in prescribing rates, media attention, or reporting behavior, not changes in the medication's safety profile.
View report trend as a table
| Year | Reports |
|---|---|
| 2012 | 1 |
| 2013 | 1 |
| 2014 | 596 |
| 2015 | 1,281 |
| 2016 | 2,323 |
| 2017 | 4,119 |
| 2018 | 4,867 |
| 2019 | 6,374 |
| 2020 | 6,810 |
| 2021 | 8,400 |
| 2022 | 12,623 |
| 2023 | 15,879 |
| 2024 | 16,080 |
| 2025 | 17,341 |
| 2026 (partial) | 3,733 |
The steep increase around 2004 reflects the FDA's move to electronic submission, not a change in this drug's safety. Trends track reporting volume, not risk.
Medications commonly reported with Keytruda
In FDA adverse event reports that mention Keytruda, these medications appeared most often in the same report.
- Carboplatin (19,732 reports)
- Lenvatinib (13,228 reports)
- Pemetrexed Disodium (11,282 reports)
- Paclitaxel (10,337 reports)
- Paclitaxel Aibumin-bound (9,622 reports)
This reflects co-occurrence in submitted reports, not evidence of drug interaction or combined risk. People often report several medications taken for the same condition or for unrelated reasons. Talk to a doctor or pharmacist about your specific medications.
Related Drugs
Other medications with similar adverse event profiles in FDA FAERS reports.
Data Source
This data is sourced from the FDA's Adverse Event Monitoring System (AEMS), formerly FAERS, via the OpenFDA API. PillSignal is not affiliated with the FDA.
View this data on the FDA website →Data last updated: June 2026