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KEYTRUDA QLEX

pembrolizumab and berahyaluronidase alfa-pmph · Injection, Solution

Prescription Biologic BLA Official labelling
Informational index, not medical advice. Content is reproduced from public FDA and NLM data. Always confirm against the manufacturer's current prescribing information. Report adverse events to FDA MedWatch.

Overview

Brand name
KEYTRUDA QLEX
Generic name
pembrolizumab and berahyaluronidase alfa-pmph
Dosage form
Injection, Solution
Route
Subcutaneous
Marketing category
BLA · BLA
Labeler
Merck Sharp & Dohme LLC
Product type
Human Prescription Drug
DEA schedule
Not scheduled
Active ingredients
2
NDC product codes
2
Packages
2
Data completeness
74% of corroborating sources present

Active ingredients

Source: NDC Directory
Active ingredients and strengths as listed in the NDC Directory.
Ingredient Strength RxCUI Monograph
Berahyaluronidase Alfa 2000 U/mL 2723762 —
Pembrolizumab 165 mg/mL 2723762 —

Forms, strengths and routes

Source: NDC Directory
Dosage form
Injection, Solution
Route of administration
Subcutaneous
Presentations
4

Pharmacologic classes are listed in the class section below.

Pharmacologic class

Source: NDC Directory
Established pharmacologic classes (EPC), mechanisms of action (MoA), chemical structures (CS) and physiologic effects (PE).
Class Type Browse
Endoglycosidase [EPC] EPC 6 members — no class page
Glycoside Hydrolases [CS] CS 6 members — no class page
Programmed Death Receptor-1 Blocking Antibody [EPC] EPC 5 members — no class page
Programmed Death Receptor-1-directed Antibody Interactions [MoA] MoA 5 members — no class page

Regulatory status

Source: Drugs@FDANDC Directory
Application number
761467
Application type
BLA · Biologics License Application
Approval date
September 19, 2025
Sponsor
MERCK SHARP DOHME
Products on application
2
Submissions recorded
11
Products approved under application 761467.
Product Trade name Form Strength Ingredient Status TE Flags
761467-001 KEYTRUDA QLEX INJECTABLE PEMBROLIZUMAB; BERAHYALURONIDASE ALFA-PMPH Prescription —
761467-002 KEYTRUDA QLEX INJECTABLE PEMBROLIZUMAB; BERAHYALURONIDASE ALFA-PMPH Prescription —

Approval history

Source: Drugs@FDA
Most recent submissions on application 761467.
Type No. Action Status Date Review
Supplement 15 Labeling Approved July 31, 2026 Standard
Supplement 12 Efficacy Approved July 10, 2026 Priority
Supplement 4 Efficacy Approved June 24, 2026 Standard
Supplement 9 Efficacy Approved June 12, 2026 Priority
Supplement 7 Labeling Approved May 12, 2026 Standard
Supplement 3 Efficacy Approved April 24, 2026 Standard
Supplement 13 Labeling Approved April 6, 2026 Standard
Supplement 2 Efficacy Approved February 10, 2026 Priority
Supplement 1 Efficacy Approved November 21, 2025 Priority
Original application 2 Efficacy Approved September 19, 2025 Priority
Original application 1 Type 1 - New Molecular Entity Approved September 19, 2025 Priority

Review documents

  • 0 · Supplement · August 4, 2026
  • 0 · Supplement · August 4, 2026
  • 0 · Supplement · July 15, 2026
  • 0 · Supplement · July 15, 2026
  • 0 · Supplement · July 13, 2026
  • 0 · Supplement · June 29, 2026
  • 0 · Supplement · June 26, 2026
  • 0 · Supplement · June 18, 2026
  • 0 · Supplement · June 17, 2026
  • 0 · Supplement · June 16, 2026
  • 0 · Supplement · May 18, 2026
  • 0 · Supplement · May 13, 2026
  • 0 · Supplement · April 28, 2026
  • 0 · Supplement · April 27, 2026
  • 0 · Supplement · April 8, 2026
  • 0 · Supplement · April 7, 2026
  • 0 · Supplement · February 12, 2026
  • 0 · Supplement · February 12, 2026
  • 0 · Supplement · November 25, 2025
  • 0 · Supplement · November 25, 2025
  • 0 · Supplement · November 24, 2025
  • 0 · Original application · October 6, 2025
  • 0 · Original application · October 6, 2025
  • 0 · Original application · October 6, 2025
  • 0 · Original application · October 6, 2025
  • 0 · Original application · September 22, 2025
  • 0 · Original application · September 22, 2025
  • 0 · Original application · September 22, 2025

Prescribing information

Source: openFDA Drug Labeling

Reproduced verbatim from the Structured Product Labeling submitted to the FDA (effective 20260731). This is the manufacturer's labelling text, not a summary and not advice.

HUMAN PRESCRIPTION DRUG · 20260731

Recent Major Changes

openFDA Drug Labeling

Indications and Usage ( 1 ) 07/2026 Dosage and Administration ( 2 ) 08/2026 Warnings and Precautions ( 5 ) 05/2026

Indications and Usage

openFDA Drug Labeling

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 , 2.1 ) as a single agent for the treatment of adult patients with metastatic NSCLC whose tumors express PD-L1 (TPS ≥1%) as determined by an FDA-authorized test, with disease progression on or after platinum-containing chemotherapy. Patients with EGFR or ALK genomic tumor aberrations should have disease progression on FDA-approved therapy for these aberrations prior to receiving KEYTRUDA QLEX. ( 1.2 , 2.1 ) for the treatment of adult patients with resectable (tumors ≥4 cm or node positive) NSCLC in combination with platinum-containing chemotherapy as neoadjuvant treatment, and then continued as a single agent as adjuvant treatment after surgery. ( 1.2 ) as a single agent, for adjuvant treatment following resection and platinum-based chemotherapy for adult patients with Stage IB (T2a ≥4 cm), II, or IIIA NSCLC. ( 1.2 ) Malignant Pleural Mesothelioma (MPM) in combination with pemetrexed and platinum chemotherapy, as first-line treatment of adult patients with unresectable advanced or metastatic MPM. ( 1.3 ) Head and Neck Squamous Cell Cancer (HNSCC) for the treatment of adult patients with resectable locally advanced HNSCC whose tumors express PD-L1 [Combined Positive Score (CPS) ≥1] as determined by an FDA-authorized test, as a single agent as neoadjuvant treatment, continued as adjuvant treatment in combination with radiotherapy (RT) with or without cisplatin and then as a single agent. ( 1.4 ) in combination with platinum and FU for the first-line treatment of adult patients with metastatic or with unresectable, recurrent HNSCC. ( 1.4 ) as a single agent for the first-line treatment of adult patients with metastatic or with unresectable, recurrent HNSCC whose tumors express PD-L1 [Combined Positive Score (CPS) ≥1] as determined by an FDA-authorized test. ( 1.4 , 2.1 ) as a single agent for the treatment of adult patients with recurrent or metastatic HNSCC with disease progression on or after platinum-containing chemotherapy. ( 1.4 ) Urothelial Cancer in combination with enfortumab vedotin-ejfv, for the treatment of adult patients with locally advanced or metastatic urothelial cancer. ( 1.5 ) as a single agent for the treatment of adult patients with locally advanced or metastatic urothelial carcinoma who: are not eligible for any platinum-containing chemotherapy, or who have disease progression during or following platinum-containing chemotherapy or within 12 months of neoadjuvant or adjuvant treatment with platinum-containing chemotherapy. ( 1.5 ) in combination with enfortumab vedotin-ejfv, as neoadjuvant treatment and then continued after cystectomy as adjuvant treatment of adult patients with muscle invasive bladder cancer (MIBC). ( 1.5 ) as a single agent for the treatment of adult patients with Bacillus Calmette-Guerin (BCG)-unresponsive, high-risk, non-muscle invasive bladde …

Dosage and Administration

openFDA Drug Labeling

2 DOSAGE AND ADMINISTRATION KEYTRUDA QLEX has different recommended dosage and administration than intravenous pembrolizumab. ( 2.2 ) KEYTRUDA QLEX is for subcutaneous use in the thigh or abdomen only. ( 2.2 ) Do not administer KEYTRUDA QLEX intravenously. ( 2.2 ) KEYTRUDA QLEX must be administered by a healthcare provider. ( 2.2 ) The recommended dose for adults and pediatric patients 12 years and older who weigh greater than 40 kg is: Every 3-week dosing (395 mg/4,800 units): Inject 2.4 mL subcutaneously in the abdomen or thigh over 1 minute. ( 2.3 ) Every 6-week dosing (790 mg/9,600 units): Inject 4.8 mL subcutaneously in the abdomen or thigh over 2 minutes. ( 2.3 ) For RCC, administer KEYTRUDA QLEX as a single agent in the adjuvant setting, or in the advanced setting with either: axitinib 5 mg orally twice daily or lenvatinib 20 mg orally once daily. ( 2.3 ) For ccRCC, administer KEYTRUDA QLEX in combination with belzutifan 120 mg orally once daily in the adjuvant setting. ( 2.3 ) For Endometrial Carcinoma, administer KEYTRUDA QLEX: in combination with carboplatin and paclitaxel regardless of MMR or MSI status, or in combination with lenvatinib 20 mg orally once daily for pMMR or not MSI-H tumors, or as a single agent for MSI-H or dMMR tumors. ( 2.3 ) See Full Prescribing Information for dosage modifications for adverse reactions and preparation and administration instructions. ( 2.4 , 2.5 ) 2.1 Patient Selection See information on FDA-authorized tests for intravenous pembrolizumab. Information on FDA-authorized tests for patient selection is available at: http://www.fda.gov/CompanionDiagnostics . Patient Selection for Single-Agent Treatment Select patients for treatment with KEYTRUDA QLEX as a single agent based on the presence of positive PD-L1 expression in: Stage III NSCLC who are not candidates for surgical resection or definitive chemoradiation [see Clinical Studies (14.4) ] . metastatic NSCLC [see Clinical Studies (14.4) ]. first-line treatment of metastatic or unresectable, recurrent HNSCC [see Clinical Studies (14.6) ] . previously treated recurrent locally advanced or metastatic esophageal cancer [see Clinical Studies (14.11) ] . recurrent or metastatic cervical cancer with disease progression on or after chemotherapy [see Clinical Studies (14.12) ] . For the MSI-H/dMMR indications, select patients for treatment with KEYTRUDA QLEX as a single agent based on MSI-H/dMMR status in tumor specimens [see Clinical Studies (14.8 , 14.9) ]. For the TMB-H indication, select patients for treatment with KEYTRUDA QLEX as a single agent based on TMB-H status in tumor specimens [see Clinical Studies (14.18) ]. Because subclonal dMMR mutations and microsatellite instability may arise in high-grade gliomas during temozolomide therapy, it is recommended to test for TMB-H, MSI-H, and dMMR in the primary tumor specimens obtained prior to initiation of temozolomide chemotherapy in patients with high-grade gliomas. Additional Patient Selection Information for MSI-H or dMMR in Patients with non-CRC Solid Tumors Due to discordance between local tests and FDA-authorized tests, confirmation of MSI-H or dMMR status is recommended by an FDA-authorized test in patients with MSI-H or dMMR solid tumors, if feasible. If unable to perform confirmatory MSI-H/dMMR testing, the presence of TMB ≥10 mut/Mb, as determined by an FDA-authorized test, may be used to select patients for treatment [see Clinical Studies (14.8) ] . Patient Selection for Combination Therapy For use of KEYTRUDA QLEX as a single agent as neoadjuvant treatment, then in combination with radiotherapy (RT) with or without chemotherapy then continued as a single agent as adjuvant treatment, select patients based on presence of positive PD-L1 expression (CPS ≥1) in resectable locally advanced HNSCC [see Clinical Studies (14.6) ] . For use of KEYTRUDA QLEX in combination with chemotherapy, select patients based on the presence of positive PD-L1 expression (CPS ≥1) in locally advanced …

Dosage Forms and Strengths

openFDA Drug Labeling

3 DOSAGE FORMS AND STRENGTHS KEYTRUDA QLEX is a clear to slightly opalescent, colorless to slightly yellow solution provided as: Injection: 395 mg pembrolizumab and 4,800 units berahyaluronidase alfa per 2.4 mL (165 mg/2,000 units per mL) in a single-dose vial Injection: 790 mg pembrolizumab and 9,600 units berahyaluronidase alfa per 4.8 mL (165 mg/2,000 units per mL) in a single-dose vial Injection: ( 3 ) 395 mg pembrolizumab and 4,800 units berahyaluronidase alfa per 2.4 mL (165 mg/2,000 units per mL) in a single-dose vial 790 mg pembrolizumab and 9,600 units berahyaluronidase alfa per 4.8 mL (165 mg/2,000 units per mL) in a single-dose vial

Contraindications

openFDA Drug Labeling

4 CONTRAINDICATIONS KEYTRUDA QLEX is contraindicated in patients with known hypersensitivity to berahyaluronidase alfa, hyaluronidase or to any of its excipients. KEYTRUDA QLEX is contraindicated in patients with known hypersensitivity to berahyaluronidase alfa, hyaluronidase or to any of its excipients. ( 4 )

Warnings and Cautions

openFDA Drug Labeling

5 WARNINGS AND PRECAUTIONS Immune-Mediated Adverse Reactions ( 5.1 ) Immune-mediated adverse reactions, which may be severe or fatal, can occur in any organ system or tissue, including the following: immune-mediated pneumonitis, immune-mediated colitis, immune-mediated hepatitis, immune-mediated endocrinopathies, immune-mediated nephritis with renal dysfunction, immune-mediated dermatologic adverse reactions, and solid organ transplant rejection. Monitor for early identification and management. Evaluate liver enzymes, creatinine, and thyroid function at baseline and periodically during treatment. Withhold or permanently discontinue based on severity and type of reaction. Hypersensitivity and Administration-Related Reactions: Interrupt injection and resume upon symptom resolution, or permanently discontinue KEYTRUDA QLEX based on the severity of reaction. ( 5.2 ) Complications of Allogeneic HSCT: Fatal and other serious complications can occur in patients who receive allogeneic HSCT before or after being treated with a PD-1/PD-L1 blocking antibody. ( 5.3 ) Treatment of patients with multiple myeloma with a PD-1 or PD-L1 blocking antibody in combination with a thalidomide analogue plus dexamethasone is not recommended outside of controlled clinical trials. ( 5.4 ) Embryo-Fetal toxicity: Can cause fetal harm. Advise females of reproductive potential of the potential risk to a fetus and to use effective method of contraception. ( 5.5 , 8.1 , 8.3 ) 5.1 Severe and Fatal Immune-Mediated Adverse Reactions KEYTRUDA QLEX is a monoclonal antibody that belongs to a class of drugs that bind to either the programmed death-receptor 1 (PD-1) or the PD-ligand 1 (PD-L1), blocking the PD-1/PD-L1 pathway, thereby removing inhibition of the immune response, potentially breaking peripheral tolerance and inducing immune-mediated adverse reactions. Important immune-mediated adverse reactions listed under WARNINGS AND PRECAUTIONS may not include all possible severe and fatal immune-mediated adverse reactions. Immune-mediated adverse reactions, which may be severe or fatal, can occur in any organ system or tissue and can affect more than one body system simultaneously. Immune-mediated adverse reactions can occur at any time after starting treatment with a PD-1/PD-L1 blocking antibody. While immune-mediated adverse reactions usually manifest during treatment with PD-1/PD-L1 blocking antibodies, immune-mediated adverse reactions can also manifest after discontinuation of PD-1/PD-L1 blocking antibodies. Early identification and management of immune-mediated adverse reactions are essential to ensure safe use of PD-1/PD-L1 blocking antibodies. Monitor patients closely for symptoms and signs that may be clinical manifestations of underlying immune-mediated adverse reactions. Evaluate liver enzymes, creatinine, and thyroid function at baseline and periodically during treatment. For patients with TNBC treated with KEYTRUDA QLEX in the neoadjuvant setting, monitor blood cortisol at baseline, prior to surgery, and as clinically indicated. In cases of suspected immune-mediated adverse reactions, initiate appropriate workup to exclude alternative etiologies, including infection. Institute medical management promptly, including specialty consultation as appropriate. Withhold or permanently discontinue KEYTRUDA QLEX depending on severity [see Dosage and Administration (2.4) ] . In general, if KEYTRUDA QLEX requires interruption or discontinuation, administer systemic corticosteroid therapy (1 to 2 mg/kg/day prednisone or equivalent) until improvement to Grade 1 or less. Upon improvement to Grade 1 or less, initiate corticosteroid taper and continue to taper over at least 1 month. Consider administration of other systemic immunosuppressants in patients whose immune-mediated adverse reactions are not controlled with corticosteroid therapy. Toxicity management guidelines for adverse reactions that do not necessarily require systemic steroids (e.g., endocrinopathies and …

Adverse Reactions

openFDA Drug Labeling

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, weight loss, abdominal pain, arthralgia, myalgia, insomnia, palmar-plantar erythrodysesthesia, urinary tract infection, hypothyroidism, radiation skin injury, dysphagia, dry mouth and musculoskeletal pain. ( 6.1 ) In combination with chemotherapy and bevacizumab: peripheral neuropathy, alopecia, anemia, fatigue/asthenia, nausea, neutropenia, diarrhea, hypertension, thrombocytopenia, constipation, arthralgia, vomiting, urinary tract infection, rash, leukopenia, hypothyroidism, decreased appetite, pyrexia, epistaxis, decreased white blood cell count, and stomatitis. ( 6.1 ) In combination with axitinib: diarrhea, fatigue/asthenia, hypertension, hepatotoxicity, hypothyroidism, decreased appetite, palmar-plantar erythrodysesthesia, nausea, stomatitis/mucosal inflammation, dysphonia, rash, cough, and constipation. ( 6.1 ) In combination with lenvatinib: hypothyroidism, hypertension, fatigue, diarrhea, musculoskeletal disorders, nausea, decreased appetite, vomiting, stomatitis, weight loss, abdominal pain, urinary tract infection, proteinuria, constipation, headache, hemorrhagic events, palmar-plantar erythrodysesthesia, dysphonia, rash, hepatotoxicity, and acute kidney injury. ( 6.1 ) In combination with belzutifan (reported in ≥25%): decreased hemoglobin, increased alanine aminotransferase, fatigue, increased aspartate aminotransferase, decreased lymphocytes, and increased alkaline phosphatase. ( 6.1 ) In combination with enfortumab vedotin-ejfv: rash, peripheral neuropathy, fatigue, pruritus, diarrhea, alopecia, weight loss, decreased appetite, dry eye, nausea, constipation, dysgeusia, and urinary tract infection. ( 6.1 ) In combination with sacituzumab govitecan-hziy: anemia, neutropenia, diarrhea, nausea, fatigue, alopecia, constipation, rash, vomiting, headache and abdominal pain. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Merck Sharp & Dohme LLC at 1-877-888-4231 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch . 6.1 Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. The data described in the WARNINGS AND PRECAUTIONS reflect exposure to intravenous pembrolizumab as a single agent in 2799 patients in three randomized, open-label, active-controlled trials (KEYNOTE-002, KEYNOTE-006, and KEYNOTE-010), which enrolled 912 patients with melanoma and 682 patients with NSCLC, and one single-arm trial (KEYNOTE-001), which enrolled 655 patients with melanoma and 550 patients with NSCLC. In addition to the 2799 patients, certain subsections in the WARNINGS AND PRECAUTIONS describe adverse reactions observed with exposu …

Use in Specific Populations

openFDA Drug Labeling

8 USE IN SPECIFIC POPULATIONS Lactation: Advise not to breastfeed. ( 8.2 ) 8.1 Pregnancy Risk Summary Based on its mechanism of action [see Clinical Pharmacology (12.1) ] , KEYTRUDA QLEX can cause fetal harm when administered to a pregnant woman. There are no available human data informing the risk of embryo-fetal toxicity. In animal models, the PD-1/PD-L1 signaling pathway is important in the maintenance of pregnancy through induction of maternal immune tolerance to fetal tissue (see Data ) . Human IgG4 (immunoglobulins) are known to cross the placenta; therefore, pembrolizumab has the potential to be transmitted from the mother to the developing fetus. Advise pregnant women of the potential risk to a fetus. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2 to 4% and 15 to 20%, respectively. Data Animal Data KEYTRUDA QLEX for subcutaneous injection contains pembrolizumab and berahyaluronidase alfa [see Description (11) ] . Pembrolizumab: Animal reproduction studies have not been conducted with pembrolizumab to evaluate its effect on reproduction and fetal development. A literature-based assessment of the effects of the PD-1 pathway on reproduction demonstrated that a central function of the PD-1/PD-L1 pathway is to preserve pregnancy by maintaining maternal immune tolerance to the fetus. Blockade of PD-L1 signaling has been shown in murine models of pregnancy to disrupt tolerance to the fetus and to result in an increase in fetal loss; therefore, potential risks of administering pembrolizumab during pregnancy include increased rates of abortion or stillbirth. As reported in the literature, there were no malformations related to the blockade of PD-1 signaling in the offspring of these animals; however, immune-mediated disorders occurred in PD-1 knockout mice. Based on its mechanism of action, fetal exposure to pembrolizumab may increase the risk of developing immune-mediated disorders or of altering the normal immune response. Berahyaluronidase alfa: In an embryo-fetal development study, pregnant rabbits were administered daily subcutaneous injections of 138,600, 403,200, or 1,209,600 U/kg berahyaluronidase alfa during the period of organogenesis (gestation days 6 to 19). Berahyaluronidase alfa caused delayed fetal development at doses ≥403,200 U/kg, which is >2,500 times higher than the human dose (U/kg basis). Increased post-implantation loss and visceral malformations (supernumerary fissure lung lobe) were observed at 1,209,600 U/kg, which is >7,500 times higher than the human dose. In an embryo-fetal development study in rats, there were no adverse embryo-fetal findings in pregnant animals administered daily subcutaneous injections of berahyaluronidase alfa at doses up to 2,520,000 U/kg (>15,000 times higher than the human dose) during the period of organogenesis (gestation days 6 to 17). In a pre- and post-natal development study in rats, pregnant animals were administered daily subcutaneous injections of 280,000, 840,000, or 2,520,000 U/kg berahyaluronidase alfa from implantation through lactation and weaning (gestation day 6 to lactation day 21). There were no adverse effects on sexual maturation, learning and memory, or fertility of the offspring at doses up to 2,520,000 U/kg, which is >15,000 times higher than the human dose. 8.2 Lactation Risk Summary There are no data on the presence of pembrolizumab or berahyaluronidase alfa in either animal or human milk or its effects on the breastfed child or on milk production. Maternal IgG is known to be present in human milk. The effects of local gastrointestinal exposure and limited systemic exposure in the breastfed child to KEYTRUDA QLEX are unknown. Because of the potential for serious adverse reactions in breastfed children, advise women not to breastfeed during treatment with KEYTRUDA QLEX and for 4 months after the last dose. 8.3 Females and Males of Reproductive Potential Base …

Mechanism of Action

openFDA Drug Labeling

12.1 Mechanism of Action Binding of the PD-1 ligands, PD-L1 and PD-L2, to the PD-1 receptor found on T cells, inhibits T cell proliferation and cytokine production. Upregulation of PD-1 ligands occurs in some tumors and signaling through this pathway can contribute to inhibition of active T-cell immune surveillance of tumors. Pembrolizumab is a monoclonal antibody that binds to the PD-1 receptor and blocks its interaction with PD-L1 and PD-L2, releasing PD-1 pathway-mediated inhibition of the immune response, including the anti-tumor immune response. In syngeneic mouse tumor models, blocking PD-1 activity resulted in decreased tumor growth. In syngeneic mouse tumor models, combination treatment of a PD-1 blocking antibody and kinase inhibitor lenvatinib decreased tumor-associated macrophages, increased activated cytotoxic T cells, and reduced tumor growth compared to either treatment alone. Berahyaluronidase alfa, an endoglycosidase, is a variant of human hyaluronidase PH20 that temporarily and locally breaks down hyaluronan. Hyaluronan is a polysaccharide found in the extracellular matrix of the subcutaneous tissue. Unlike the stable structural components of the interstitial matrix, hyaluronan has a half-life of approximately 0.5 days. Hyaluronidase increases permeability of the subcutaneous tissue by depolymerizing hyaluronan. In the doses administered, the effects of berahyaluronidase alfa are reversible and permeability of the subcutaneous tissue is restored within 24 to 48 hours.

Description

openFDA Drug Labeling

11 DESCRIPTION KEYTRUDA QLEX is a fixed-combination drug product containing pembrolizumab and berahyaluronidase alfa. Pembrolizumab is a programmed death receptor-1 (PD 1)-blocking antibody. Pembrolizumab is a humanized monoclonal IgG4 kappa antibody with an approximate molecular weight of 149 kDa. Pembrolizumab is produced in recombinant Chinese hamster ovary (CHO) cells. Berahyaluronidase alfa is an endoglycosidase used to enhance dispersion and permeation, which facilitates delivery of increased volume of pembrolizumab that is co-administered subcutaneously. It is produced by mammalian CHO (Chinese Hamster Ovary) cells containing a DNA plasmid encoding a variant of human hyaluronidase PH20. It is a glycosylated protein with an approximate molecular weight of 49 kDa under nonreducing, deglycosylated conditions. KEYTRUDA QLEX (pembrolizumab and berahyaluronidase alfa-pmph) injection is a sterile, preservative-free, clear to slightly opalescent, colorless to slightly yellow solution supplied in single-dose vials for subcutaneous administration. KEYTRUDA QLEX is supplied as two different configurations: Each KEYTRUDA QLEX 2.4 mL single-dose vial contains 395 mg of pembrolizumab and 4,800 units of berahyaluronidase alfa, and histidine (0.7 mg), histidine hydrochloride monohydrate (4.1 mg), methionine (3.6 mg), polysorbate 80 (0.5 mg), sucrose (168 mg), and Water for Injection, USP. The pH is 5.3-5.9. Each KEYTRUDA QLEX 4.8 mL single-dose vial contains 790 mg of pembrolizumab and 9,600 units of berahyaluronidase alfa, and histidine (1.4 mg), histidine hydrochloride monohydrate (8.2 mg), methionine (7.2 mg), polysorbate 80 (1 mg), sucrose (336 mg), and Water for Injection, USP. The pH is 5.3-5.9.

How Supplied / Storage and Handling

openFDA Drug Labeling

16 HOW SUPPLIED/STORAGE AND HANDLING KEYTRUDA QLEX (pembrolizumab and berahyaluronidase alfa-pmph) injection is a sterile, preservative-free, clear to slightly opalescent, colorless to slightly yellow solution supplied in single-dose vials for subcutaneous administration. Each carton contains one single-dose vial either as: 395 mg pembrolizumab and 4,800 units berahyaluronidase alfa per 2.4 mL (165 mg/ 2,000 units per mL), NDC 0006-3083-01 790 mg pembrolizumab and 9,600 units berahyaluronidase alfa per 4.8 mL (165 mg/ 2,000 units per mL), NDC 0006-5083-01 Store vials refrigerated at 2°C to 8°C (36°F to 46°F) in original carton to protect from light. Do not freeze. Do not shake.

Adverse event reports

Source: openFDA FAERS
104,614
FAERS reports mentioning this drug
as of 2026-09-25T03:42:24+00:00
A report count is not a risk measure. FAERS accepts voluntary and mandatory reports without establishing causation, and reporting is influenced by how widely a drug is used, how long it has been marketed, and media attention. FDA states that reports “do not prove that the drug caused the event”. Compare rates, not totals.

Attributed to this product's most-reported active ingredient: PEMBROLIZUMAB. Combination products with more than six active ingredients are not attributed, because a report count summed across a long ingredient list measures the list, not the medicine.

Packaging and NDCs

Source: NDC Directory
Every National Drug Code package associated with this medication. The NDC is the identifier used for dispensing, billing and pharmacovigilance in the United States.
Package NDC Product NDC Labeler Description Marketing start
0006-3083-01 0006-3083 Merck Sharp & Dohme LLC 1 VIAL in 1 CARTON (0006-3083-01) / 2.4 mL in 1 VIAL (0006-3083-99) September 19, 2025
0006-5083-01 0006-5083 Merck Sharp & Dohme LLC 1 VIAL in 1 CARTON (0006-5083-01) / 4.8 mL in 1 VIAL (0006-5083-99) September 19, 2025
0006-3083 0006-3083 Merck Sharp & Dohme LLC — September 19, 2025
0006-5083 0006-5083 Merck Sharp & Dohme LLC — September 19, 2025

Sources for this page

Every dataset that contributed a fact to this page.
Dataset Agency Used for
NDC Directory FDA Identity, ingredients, strengths, forms, routes, labelers, packages
Drugs@FDA FDA Application, sponsor, submissions, review documents, marketing status
Drug Labeling FDA / NLM Prescribing information reproduced above
FAERS FDA Adverse event report counts
Purple Book FDA Biologic licence classification

Generated September 25, 2026 · 10 sections on this page.