Pembrolizumab and Berahyaluronidase Alfa is a prescription medicine (Programmed Death Receptor-1 Blocking Antibody; Endoglycosidase). The sections below reproduce one FDA label for it, named under "Label". Products in other forms, strengths or from other makers have their own labels, which can differ.
- Type
- Prescription only (Rx)
- Brand names
- Keytruda Qlex
- Drug class
- Programmed Death Receptor-1 Blocking Antibody; Endoglycosidase
- Taken
- Subcutaneous
- Label
- Merck Sharp & Dohme LLC, revised July 31, 2026 · full label on DailyMed
- Biosimilars
- 1 approved · details
What it is used for
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 bladder cancer (NMIBC) with carcinoma in situ (CIS) with or without papillary tumors who are ineligible for or have elected not to undergo cystectomy. ( 1.5 ) Microsatellite Instability-High or Mismatch Repair Deficient Cancer for the treatment of adult and pediatric patients 12 years and older with unresectable or metastatic microsatellite instability-high (MSI-H) or mismatch repair deficient (dMMR) solid tumors, as determined by an FDA-authorized test, that have progressed following prior treatment and who have no satisfactory alternative treatment options. ( 1.6 , 2.1 ) Microsatellite Instability-High or Mismatch Repair Deficient Colorectal Cancer (CRC) for the treatment of adult patients with unresectable or metastatic MSI-H or dMMR colorectal cancer (CRC) as determined by an FDA-authorized test. ( 1.7 , 2.1 ) Gastric Cancer in combination with trastuzumab, fluoropyrimidine- and platinum-containing chemotherapy, for the first-line treatment of adults with locally advanced unresectable or metastatic HER2-positive gastric or gastroesophageal junction (GEJ) adenocarcinoma whose tumors express PD-L1 (CPS ≥1) as determined by an FDA-authorized test. ( 1.8 ) in combination with fluoropyrimidine- and platinum-containing chemotherapy, for the first-line treatment of adults with locally advanced unresectable or metastatic HER2-negative gastric or gastroesophageal junction (GEJ) adenocarcinoma whose tumors express PD-L1 (CPS ≥1) as determined by an FDA-authorized test. ( 1.8 ) Esophageal Cancer for the treatment of adult patients with locally advanced or metastatic esophageal or gastroesophageal junction (GEJ) (tumors with epicenter 1 to 5 centimeters above the GEJ) carcinoma that is not amenable to surgical resection or definitive chemoradiation either: in combination with platinum- and fluoropyrimidine-based chemotherapy for patients whose tumors express PD-L1 (CPS ≥1) as determined by an FDA-authorized test, or as a single agent after one or more prior lines of systemic therapy for patients with tumors of squamous cell histology that express PD-L1 (CPS ≥10) as determined by an FDA-authorized test. ( 1.9 , 2.1 ) Cervical Cancer in combination with chemoradiotherapy, for the treatment of adult patients with locally advanced cervical cancer involving the lower third of the vagina, with or without extension to pelvic sidewall, or hydronephrosis/non-functioning kidney, or spread to adjacent pelvic organs (FIGO 2014 Stage III-IVA). ( 1.10 ) in combination with chemotherapy, with or without bevacizumab, for the treatment of adult patients with persistent, recurrent, or metastatic cervical cancer whose tumors express PD-L1 (CPS ≥1) as determined by an FDA-authorized test. ( 1.10 , 2.1 ) as a single agent for the treatment of adult patients with recurrent or metastatic cervical cancer with disease progression on or after chemotherapy whose tumors express PD-L1 (CPS ≥1) as determined by an FDA-authorized test. ( 1.10 , 2.1 ) Hepatocellular Carcinoma (HCC) for the treatment of adult patients with HCC secondary to hepatitis B who have received prior systemic therapy other than a PD-1/PD-L1-containing regimen. ( 1.11 ) Biliary Tract Cancer (BTC) in combination with gemcitabine and cisplatin, for the treatment of adult patients with locally advanced unresectable or metastatic biliary tract cancer. ( 1.12 ) Merkel Cell Carcinoma (MCC) for the treatment of adult and pediatric patients 12 years and older with recurrent locally advanced or metastatic Merkel cell carcinoma. ( 1.13 ) Renal Cell Carcinoma (RCC) in combination with axitinib, for the first-line treatment of adult patients with advanced RCC. ( 1.14 ) in combination with lenvatinib, for the first-line treatment of adult patients with advanced RCC. ( 1.14 ) for the adjuvant treatment of adult patients with RCC at intermediate-high or high risk of recurrence following nephrectomy, or following nephrectomy and resection of metastatic lesions. […]
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
Who should not take it (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 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 dermatologic reactions) are discussed below. Immune-Mediated Pneumonitis KEYTRUDA QLEX can cause immune-mediated pneumonitis. The incidence of pneumonitis is higher in patients who have received prior thoracic radiation. Immune-mediated pneumonitis occurred in 5% (13/251) of patients receiving KEYTRUDA QLEX in combination with chemotherapy, including fatal (0.4%), Grade 3 (2%), and Grade 2 (1.2%) adverse reactions. Intravenous Pembrolizumab as a Single Agent Immune-mediated pneumonitis occurred in 3.4% (94/2799) of patients receiving intravenous pembrolizumab, including fatal (0.1%), Grade 4 (0.3%), Grade 3 (0.9%), and Grade 2 (1.3%) adverse reactions. Systemic corticosteroids were required in 67% (63/94) of patients with pneumonitis. Pneumonitis led to permanent discontinuation of intravenous pembrolizumab in 1.3% (36) of patients and withholding of intravenous pembrolizumab in 0.9% (26) of patients. All patients who were withheld reinitiated intravenous pembrolizumab after symptom improvement; of these, 23% had recurrence of pneumonitis. Pneumonitis resolved in 59% of the 94 patients. In a clinical study enrolling 580 adult patients with resected NSCLC (KEYNOTE-091) who received intravenous pembrolizumab as a single agent for adjuvant treatment, pneumonitis occurred in 41 (7%) patients, including fatal (0.2%), Grade 4 (0.3%), and Grade 3 (1%) adverse reactions. Patients received high-dose corticosteroids for a median duration of 10 days (range: 1 day to 2.3 months). Pneumonitis led to discontinuation of intravenous pembrolizumab in 26 (4.5%) of patients. Of the patients who developed pneumonitis, 54% interrupted intravenous pembrolizumab, 63% discontinued intravenous pembrolizumab, and 71% had resolution. Immune-Mediated Colitis KEYTRUDA QLEX can cause immune-mediated colitis, which may present with diarrhea. Cytomegalovirus (CMV) infection/reactivation has been reported in patients with corticosteroid-refractory immune-mediated colitis. In cases of corticosteroid-refractory colitis, consider repeating infectious workup to exclude alternative etiologies. Immune-mediated colitis occurred in 1.2% (3/251) of patients receiving KEYTRUDA QLEX in combination with chemotherapy, including Grade 3 (0.8%), and Grade 2 (0.4%) adverse reactions. Intravenous Pembrolizumab as a Single Agent Immune-mediated colitis occurred in 1.7% (48/2799) of patients receiving intravenous pembrolizumab, including Grade 4 (<0.1%), Grade 3 (1.1%), and Grade 2 (0.4%) adverse reactions. Systemic corticosteroids were required in 69% (33/48) of patients with colitis. Additional immunosuppressant therapy was required in 4.2% of patients. Colitis led to permanent discontinuation of intravenous pembrolizumab in 0.5% (15) of patients and withholding of intravenous pembrolizumab in 0.5% (13) of patients. All patients who were withheld reinitiated intravenous pembrolizumab after symptom improvement; of these, 23% had recurrence of colitis. Colitis resolved in 85% of the 48 patients. Hepatotoxicity and Immune-Mediated Hepatitis KEYTRUDA QLEX can cause immune-mediated hepatitis. Immune-mediated hepatitis occurred in 0.4% (1/251) of patients receiving KEYTRUDA QLEX in combination with chemotherapy, including Grade 2 (0.4%) adverse reactions. Intravenous Pembrolizumab as a Single Agent Immune-mediated hepatitis occurred in 0.7% (19/2799) of patients receiving intravenous pembrolizumab, including Grade 4 (<0.1%), Grade 3 (0.4%), and Grade 2 (0.1%) adverse reactions. Systemic corticosteroids were required in 68% (13/19) of patients with hepatitis. Eleven percent of these patients required additional immunosuppressant therapy. Hepatitis led to permanent discontinuation of intravenous pembrolizumab in 0.2% (6) of patients and withholding of intravenous pembrolizumab in 0.3% (9) of patients. All patients who were withheld reinitiated intravenous pembrolizumab after symptom improvement; of these, none had recurrence of hepatitis. Hepatitis resolved in 79% of the 19 patients. […]
Side effects (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 exposure to KEYTRUDA QLEX in combination with platinum doublet chemotherapy in a randomized, open-label, active-controlled trial (Study MK-3475A-D77), which enrolled 251 patients with NSCLC; intravenous pembrolizumab as a single agent in a randomized, placebo-controlled trial (KEYNOTE-091), which enrolled 580 patients with resected NSCLC; a non-randomized, open-label, multi-cohort trial (KEYNOTE-012), a non-randomized, open-label, single-cohort trial (KEYNOTE-055), and two randomized, open-label, active-controlled trials (KEYNOTE-040 and KEYNOTE-048 single agent arms), which enrolled 909 patients with HNSCC; in a randomized, open-label, active-controlled trial (KEYNOTE-048 combination arm), which enrolled 276 patients with HNSCC; in combination with axitinib in a randomized, active-controlled trial (KEYNOTE-426), which enrolled 429 patients with RCC; and in post-marketing use. Across all trials, patients were administered either KEYTRUDA QLEX 790 mg/9,600 units every 6 weeks or intravenous pembrolizumab at doses of 2 mg/kg every 3 weeks, 10 mg/kg every 2 weeks, 10 mg/kg every 3 weeks, or 200 mg every 3 weeks. Among the 2799 patients who received intravenous pembrolizumab, 41% were exposed for 6 months or more and 21% were exposed for 12 months or more. The most common adverse reactions (≥20%) in patients who received KEYTRUDA QLEX in combination with chemotherapy were nausea (25%), fatigue (25%), and musculoskeletal pain (21%). 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 (≥20%) in patients who received 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. 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. 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. in combination with axitinib : diarrhea, fatigue/asthenia, hypertension, hepatotoxicity, hypothyroidism, decreased appetite, palmar-plantar erythrodysesthesia, nausea, stomatitis/mucosal inflammation, dysphonia, rash, cough, and constipation. 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. in combination with belzutifan (reported in ≥25%) : decreased hemoglobin, increased alanine aminotransferase, fatigue, increased aspartate aminotransferase, decreased lymphocytes, and increased alkaline phosphatase. 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. in combination with sacituzumab govitecan-hziy : anemia, neutropenia, diarrhea, nausea, fatigue, alopecia, constipation, rash, vomiting, headache and abdominal pain. […]
Pregnancy, breastfeeding, children and older adults
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 Based on its mechanism of action, KEYTRUDA QLEX can cause fetal harm when administered to a pregnant woman [see Use in Specific Populations (8.1) ] . Pregnancy Testing Verify pregnancy status in females of reproductive potential prior to initiating KEYTRUDA QLEX [see Use in Specific Populations (8.1) ]. Contraception Advise females of reproductive potential to use effective contraception during treatment with KEYTRUDA QLEX and for 4 months after the last dose.
8.4 Pediatric Use The safety and effectiveness of KEYTRUDA QLEX for the treatment of pediatric patients 12 years and older who weigh greater than 40 kg have been established for: Stage IIB, IIC, or III melanoma following complete resection [see Indications and Usage (1.1) ] Unresectable or metastatic microsatellite instability high (MSI-H) or mismatch repair deficient (dMMR) solid tumors [see Indications and Usage (1.6) ] Recurrent locally advanced or metastatic Merkel cell carcinoma [see Indications and Usage (1.13) ] Unresectable or metastatic tumor mutational burden high solid tumors (TMB-H) [see Indications and Usage (1.16) ] Use of KEYTRUDA QLEX in pediatric patients for these indications is supported by evidence from adequate and well-controlled studies of intravenous pembrolizumab in adults and additional pharmacokinetic and safety data for intravenous pembrolizumab in pediatric patients 12 years and older [see Adverse Reactions (6.1) , Clinical Studies (14) ]. Pembrolizumab exposures in pediatric patients 12 years and older who weigh greater than 40 kg are predicted to be within range of those observed in adults at the same dosage [see Clinical Pharmacology (12.3) ]. The safety and effectiveness of KEYTRUDA QLEX have not been established in pediatric patients younger than 12 years of age for the treatment of melanoma, MCC, MSI-H or dMMR cancer, and TMB-H cancer. The safety and effectiveness of KEYTRUDA QLEX have not been established in pediatric patients for other approved indications [see Indications and Usage (1) ] . Intravenous pembrolizumab In KEYNOTE-051, 173 pediatric patients (including 108 pediatric patients aged 12 to 17 years) with advanced melanoma, lymphoma, or PD-L1 positive or MSI-H solid tumors received intravenous pembrolizumab 2 mg/kg every 3 weeks. The median duration of exposure was 2.1 months (range: 1 day to 25 months). Adverse reactions that occurred at a ≥10% higher rate in pediatric patients when compared to adults included pyrexia (33%), vomiting (29%), headache (25%), abdominal pain (23%), decreased lymphocyte count (13%), and decreased white blood cell count (11%). Laboratory abnormalities that occurred at a ≥10% higher rate in pediatric patients when compared to adults were leukopenia (30%), neutropenia (28%), thrombocytopenia (22%), and Grade 3 anemia (17%).
8.5 Geriatric Use Of the 251 patients treated with KEYTRUDA QLEX in combination with platinum doublet chemotherapy in Study MK-3745A-D77, 53% were 65 years and older and 16% were 75 years and older. No overall differences in safety or effectiveness of KEYTRUDA QLEX have been observed between patients aged 65 years or older and younger adult patients. The safety of KEYTRUDA QLEX as monotherapy or in combination with other antineoplastic drugs for its approved indications [see Indications and Usage (1) ] has been established in adequate and well-controlled studies of intravenous pembrolizumab as a single agent and in combination with other antineoplastic drugs. Below is a description of geriatric use information from the intravenous pembrolizumab studies. Of 3781 patients with melanoma, NSCLC, HNSCC, or urothelial carcinoma who were treated with intravenous pembrolizumab in clinical studies, 48% were 65 years and over and 17% were 75 years and over. Of 506 adult patients with Stage IB (T2a ≥4 cm), II, or IIIA NSCLC following complete resection and platinum-based chemotherapy who were treated with intravenous pembrolizumab in KEYNOTE-091, 242 (48%) were 65 years and over. […]
How it works
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.
Are there biosimilars to Pembrolizumab and Berahyaluronidase Alfa?
Yes. The FDA has approved 1 biosimilars; 1 of those approvals are active (not discontinued). As with generics, approval does not guarantee a product is stocked or covered.
- Keytruda Qlex Merck Sharp Dohme, approved 2025
Biologics have biosimilars rather than generics: highly similar versions with no clinically meaningful differences. Only biosimilars the FDA designates as interchangeable can be swapped at the pharmacy without asking the prescriber, where state law allows; the FDA Purple Book lists which ones are.
Source: Drugs@FDA (via openFDA), checked October 29, 2026. Marketing status is what companies report to the FDA; whether a pharmacy stocks a product, and what your insurance covers, can differ.
Dosage:
we do not reproduce dosing instructions. The right dose depends on the person and the condition and is set by the prescriber or pharmacist. Dosage section of the full label.
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Source: FDA structured product labeling, retrieved through openFDA. Label text is shown as published by the FDA, without editing; long sections are shortened, marked […]. openFDA data are not validated for clinical use — always check the current label and ask a doctor or pharmacist about your own treatment. Set ID 097d166f-b73b-41d3-9b37-7653cd2a0c41.