This page presents data from the FDA Adverse Event Reporting System (FAERS) and the FDA-approved drug label. A report submitted to FAERS does not prove a drug caused the reported event. Always consult a healthcare provider about medications.

Keytruda Qlex (pembrolizumab)

endoglycosidase

Last updated: October 12, 2026

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Keytruda Qlex is the brand name for pembrolizumab, a endoglycosidase. According to the FDA-approved label, KEYTRUDA QLEX is a combination of pembrolizumab, a programmed death receptor-1 (PD-1)-blocking antibody, and berahyaluronidase alfa, an endoglycosidase, indicated: Melanoma for the treatment of adult patients with unresectable or metastatic melanoma. FAERS contains 104,596 submissions naming this drug from 2012 through 2026; the top three reactions cited are malignant neoplasm progression, death, and diarrhoea.

Most-Reported Reactions

Counts of the reactions most often cited in FAERS submissions that named Keytruda Qlex. Inclusion here does not establish causation - submitters describe what was observed, not what was confirmed. One submission can list several reactions, so the totals exceed the report count.

Patient Demographics

Patient sex and age across the FAERS submissions that named Keytruda Qlex. Percentages here are computed only from submissions where these fields were filled in - many leave them blank.

By Sex

By Age Group

Severity Outcomes

Severity flags recorded across the 104,596 FAERS submissions that named Keytruda Qlex. Each bar shows the count of those reports carrying that flag. A single case can carry more than one (a hospitalization that became life-threatening, for example), so these bars are independent rates - they don't sum to 100%. Inclusion of a case under any flag does not establish that the drug caused the outcome.

Submissions Per Quarter

Quarterly count of FAERS submissions that named Keytruda Qlex. Ups and downs on this chart can track prescribing volume, news cycles, or shifts in how reports get filed, rather than the drug becoming safer or more dangerous.

From the FDA-Approved Label

Excerpts from the official FDA-approved prescribing information for Keytruda Qlex. This is the authoritative source on indications, warnings, and known adverse reactions.

Indications

1 INDICATIONS AND USAGE KEYTRUDA QLEX is a combination of pembrolizumab, a programmed death receptor-1 (PD-1)-blocking antibody, and berahyaluronidase alfa, an endoglycosidase, indicated: Melanoma for the treatment of adult patients with unresectable or metastatic melanoma. ( 1.1 ) for the adjuvant treatment of adult and pediatric patients 12 years and older with Stage IIB, IIC, or III melanoma following complete resection. ( 1.1 ) Non-Small Cell Lung Cancer (NSCLC) in combination with pemetrexed and platinum chemotherapy, as first-line treatment of adult patients with metastatic nonsquamous NSCLC, with no EGFR or ALK genomic tumor aberrations. ( 1.2 ) in combination with carboplatin and either paclitaxel or paclitaxel protein-bound, as first-line treatment of adult patients with metastatic squamous NSCLC. ( 1.2 ) as a single agent for the first-line treatment of adult patients with NSCLC expressing PD-L1 [Tumor Proportion Score (TPS) ≥1%] as determined by an FDA-authorized test, with no EGFR or ALK genomic tumor aberrations, and is: Stage III where patients are not candidates for surgical resection or definitive chemoradiation, or metastatic. ( 1.2 , 2. (continues in label)

Adverse Reactions (from label)

6 ADVERSE REACTIONS The following clinically significant adverse reactions are described elsewhere in the labeling. Severe and fatal immune-mediated adverse reactions [see Warnings and Precautions (5.1) ] . Hypersensitivity and Administration-Related Reactions [see Warnings and Precautions (5.2) ]. The most common adverse reactions (≥20%) in patients treated with KEYTRUDA QLEX in combination with chemotherapy were nausea, fatigue, and musculoskeletal pain. ( 6.1 ) The safety of KEYTRUDA QLEX for the approved indications is also based on the safety of intravenous pembrolizumab given as a single agent or in combination with other antitumor medicines. The most common adverse reactions (reported in ≥20% of patients) with intravenous pembrolizumab were: As a single agent: fatigue, musculoskeletal pain, rash, diarrhea, pyrexia, cough, decreased appetite, pruritus, dyspnea, constipation, pain, abdominal pain, nausea, and hypothyroidism. ( 6.1 ) In combination with chemotherapy or chemoradiotherapy: fatigue/asthenia, nausea, constipation, diarrhea, decreased appetite, rash, vomiting, cough, dyspnea, pyrexia, alopecia, peripheral neuropathy, mucosal inflammation, stomatitis, headache, weigh...

FDA label effective date: 2026-07-31

Disclaimer

AdverseEvent.ai is not affiliated with the FDA. Adverse-event counts come from the FDA Adverse Event Reporting System (FAERS). Drug labels come from the FDA drug label dataset. A report submitted to FAERS does not prove a drug caused the reported event — always consult a healthcare provider about medications. This site is for informational purposes only and is not medical advice.