Keytruda Qlex
Pronunciation: key-TRUE-duh Q-lex
Generic name: pembrolizumab and berahyaluronidase alfa-pmph
Dosage form: subcutaneous injection
What is Keytruda Qlex?
Keytruda Qlex is the subcutaneous injection form of Keytruda infusion, an immunotherapy drug used to treat various cancers. The advantage of Keytruda Qlex is that it is much faster to administer (1-2 minutes compared to approximately 30 minutes) and can be administered in medical clinics or doctors' offices, instead of an infusion suite. Keytruda Qlex (pembrolizumab and berahyaluronidase alfa-pmph) works by helping the immune system's T-cells recognize and fight cancer cells.
Keytruda Qlex contains pembrolizumab, the active ingredient in Keytruda, with an additional ingredient, berahyaluronidase alfa-pmph, to help pembrolizumab rapidly disperse and absorb under the skin, so it can be given as a subcutaneous injection.
Keytruda Qlex is administered as a subcutaneous injection over one minute every three weeks or in two minutes every six weeks into the thigh or abdomen, avoiding the 5 cm area around the navel.
Keytruda Qlex FDA approval was granted on September 19, 2025, after positive results from Study 3475A-D77, a Phase 3 trial (ClinicalTrials.gov, NCT05722015) comparing subcutaneous Keytruda Qlex to IV pembrolizumab. Results demonstrated no notable differences in progression-free survival (PFS) and overall survival (OS) between the two groups, and the overall response rates (ORR) were similar, with 45% for the subcutaneous group and 42% for the IV infusion group.
How does Keytruda Qlex work?
Cancer cells can hide from the immune system by producing proteins such as PD-L1 and PD-L2. These proteins bind to PD-1 receptors on T-cells, leading to inhibition of T-cell activity and allowing the tumor to escape immune detection.
Keytruda Qlex active ingredient, pembrolizumab, works by binding to the PD-1 receptor on T-cells, blocking the interaction with PD-L1 and PD-L2. By preventing this binding, T-cell function is restored, enabling the immune system to detect and destroy cancer cells.
Keytruda is a PD-1 inhibitor that belongs to the drug class called immune checkpoint inhibitors.
Keytruda Qlex indications
Keytruda Qlex FDA-approved indications are:
Melanoma
- for the treatment of adult patients with unresectable or metastatic melanoma.
- for the adjuvant treatment of adult and pediatric patients 12 years and older with Stage IIB, IIC, or III melanoma following complete resection.
Non-Small Cell Lung Cancer
- in combination with pemetrexed and platinum chemotherapy, is indicated for the first-line treatment of adult patients with metastatic nonsquamous non-small cell lung cancer (NSCLC), with no EGFR or ALK genomic tumor aberrations.
- in combination with carboplatin and either paclitaxel or paclitaxel protein-bound, is indicated for the first-line treatment of adult patients with metastatic squamous NSCLC.
- as a single agent, is indicated for the first-line treatment of adult patients with NSCLC expressing PD-L1 [Tumor Proportion Score (TPS) ≥1%] as determined by an FDA-approved 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
- as a single agent, is indicated for the treatment of adult patients with metastatic NSCLC whose tumors express PD-L1 (TPS ≥1%) as determined by an FDA-approved 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.
- 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.
- as a single agent, is indicated as adjuvant treatment following resection and platinum-based chemotherapy for adult patients with Stage IB (T2a ≥4 cm), II, or IIIA NSCLC.
Malignant Pleural Mesothelioma
- in combination with pemetrexed and platinum chemotherapy, is indicated for the first-line treatment of adult patients with unresectable advanced or metastatic malignant pleural mesothelioma (MPM).
Head and Neck Squamous Cell Cancer
- in combination with platinum and fluorouracil (FU), is indicated for the first-line treatment of adult patients with metastatic or with unresectable, recurrent HNSCC.
- as a single agent, is indicated 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-approved test.
- as a single agent, is indicated for the treatment of adult patients with recurrent or metastatic HNSCC with disease progression on or after platinum-containing chemotherapy.
Urothelial Cancer
- in combination with enfortumab vedotin, is indicated for the treatment of adult patients with locally advanced or metastatic urothelial cancer.
- as a single agent, is indicated 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.
- as a single agent, is indicated 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.
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-approved test, that have progressed following prior treatment and who have no satisfactory alternative treatment options.
Microsatellite Instability-High or Mismatch Repair Deficient Colorectal Cancer
- for the treatment of adult patients with unresectable or metastatic MSI-H or dMMR colorectal cancer (CRC) as determined by an FDA-approved test.
Gastric Cancer
- in combination with trastuzumab, fluoropyrimidine- and platinum-containing chemotherapy, is indicated 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-approved test.
- in combination with fluoropyrimidine- and platinum-containing chemotherapy, is indicated 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-approved test.
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), 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-approved test.
Cervical Cancer
- in combination with chemoradiotherapy (CRT), is indicated 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).
- in combination with chemotherapy, with or without bevacizumab, is indicated 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-approved test.
- as a single agent, is indicated 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-approved test.
Hepatocellular Carcinoma
- for the treatment of adult patients with hepatocellular carcinoma (HCC) secondary to hepatitis B who have received prior systemic therapy other than a PD-1/PD-L1-containing regimen.
Biliary Tract Cancer
- in combination with gemcitabine and cisplatin, is indicated for the treatment of adult patients with locally advanced unresectable or metastatic biliary tract cancer (BTC).
Merkel Cell Carcinoma
- is indicated for the treatment of adult and pediatric patients 12 years and older with recurrent locally advanced or metastatic Merkel cell carcinoma (MCC).
Renal Cell Carcinoma
- in combination with axitinib, is indicated for the first-line treatment of adult patients with advanced renal cell carcinoma (RCC).
- in combination with lenvatinib, for the first-line treatment of adult patients with advanced RCC
- 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.
Endometrial Carcinoma
- in combination with carboplatin and paclitaxel, followed by KEYTRUDA QLEX as a single agent, is indicated for the treatment of adult patients with primary advanced or recurrent endometrial carcinoma.
- in combination with lenvatinib, for the treatment of adult patients with advanced endometrial carcinoma that is mismatch repair proficient (pMMR) or not MSI-H as determined by an FDA-approved test, who have disease progression following prior systemic therapy in any setting and are not candidates for curative surgery or radiation.
- as a single agent, is indicated for the treatment of adult patients with advanced endometrial carcinoma that is MSI-H or dMMR, as determined by an FDA-approved test, who have disease progression following prior systemic therapy in any setting and are not candidates for curative surgery or radiation.
Tumor Mutational Burden-High (TMB-H) Cancer
- for the treatment of adult and pediatric patients 12 years and older with unresectable or metastatic tumor mutational burdenhigh (TMB-H) [≥10 mutations/megabase (mut/Mb)] solid tumors, as determined by an FDA-approved test, that have progressed following prior treatment and who have no satisfactory alternative treatment options. This indication is approved under accelerated approval based on tumor response rate and durability of response. Continued approval for this indication may be contingent upon verification and description of clinical benefit in the confirmatory trials.
- Limitations of Use: The safety and effectiveness of KEYTRUDA QLEX in pediatric patients 12 years and older with TMB-H central nervous system cancers have not been established.
Cutaneous Squamous Cell Carcinoma
- for the treatment of adult patients with recurrent or metastatic cutaneous squamous cell carcinoma (cSCC) or locally advanced cSCC that is not curable by surgery or radiation.
Triple-Negative Breast Cancer
- for the treatment of adult patients with high-risk early-stage triple-negative breast cancer (TNBC) in combination with chemotherapy as neoadjuvant treatment, and then continued as a single agent as adjuvant treatment after surgery.
- in combination with chemotherapy, is indicated for the treatment of adult patients with locally recurrent unresectable or metastatic TNBC whose tumors express PD-L1 (CPS ≥10) as determined by an FDA-approved test.
Contraindications
Keytruda Qlex should not be use in patients with known hypersensitivity to berahyaluronidase alfa, hyaluronidase or any inactive ingredients.
Warnings and precautions
Immune-Mediated Adverse Reactions: This medicine may cause immune-mediated adverse reactions, which may be severe or fatal, can occur in any organ system or tissue, including the following:
- Immune-mediated pneumonitis, immunemediated colitis, immune-mediated hepatitis, immunemediated 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: Depending on the severity of the reaction Interruptinjection and resume upon symptom resolution, or permanently discontinue Kytruda Qlex.
Complications of Allogeneic hematopoietic stem cell transplantation (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. Follow patients closely for evidence of transplant-related complications and intervene promptly. Consider the benefit versus risks of treatment with a PD-1/PD-L1 blocking antibody prior to or after an allogeneic HSCT.
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.
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.
Keytruda Qlex side effects
The most common Keytruda Qlex side effects were nausea, fatigue, and musculoskeletal pain in 20% or more of patients when used in combination with chemotherapy.
Serious side effects and warnings
Keytruda can cause your immune system to attack normal organs and tissues in any area of your body and can cause serious side effects.
- These problems can sometimes become severe or life-threatening and can lead to death. You can have more than one of these problems at the same time.
- These problems may happen anytime during treatment or even after your treatment has ended
Call or see your healthcare provider right away if you develop any new or worsening signs or symptoms, including:
- Lung problems, such as cough, shortness of breath, or chest pain
- Intestinal problems, such as:
- diarrhea (loose stools) or more frequent bowel movements than usual
- stools that are black, tarry, sticky, or have blood or mucus
- severe stomach-area (abdomen) pain or tenderness.
- Liver problems such as
- yellowing of your skin or the whites of your eyes
- dark urine (tea colored)
- severe nausea or vomiting
- bleeding or bruising more easily than normal
- pain on the right side of your stomach (abdomen).
- Hormone gland problems, such as
- headaches that will not go away or unusual headaches
- urinating more often than usual
- eye sensitivity to light
- hair loss
- feeling cold
- eye problems
- rapid heartbeat
- constipation
- increased sweating
- your voice gets deeper
- extreme tiredness
- dizziness or fainting
- weight gain or weight loss
- changes in mood or behavior, such as decreased sex drive, irritability, or forgetfulness
- feeling more hungry or thirsty than usual.
- Kidney problems, such as
- a decrease in the amount of urine you produce
- swelling of your ankles
- blood in your urine
- loss of appetite.
- Skin problems, such as
- rash
- painful sores or ulcers in your mouth or your nose, throat, or genital area
- itching
- fever or flu-like symptoms
- skin blistering or peeling
- swollen lymph nodes.
- any new or worsening signs or symptoms in other organs, which may include:
- chest pain, irregular heartbeat, shortness of breath, swelling of ankles
- confusion, sleepiness, memory problems, changes in mood or behavior, stiff neck, balance problems, tingling or
- numbness of the arms or legs
- double vision, blurry vision, sensitivity to light, eye pain, changes in eyesight
- persistent or severe muscle pain or weakness, muscle cramps
- low red blood cells, and bruising.
- Infusion reactions can sometimes be severe or life-threatening. Signs and symptoms may include:
- chills or shaking
- dizziness
- itching or rash
- feeling like passing out
- flushing
- fever
- shortness of breath or wheezing
- back pain.
For people who have had an organ transplant, Keytruda may cause rejection of a transplanted organ or tissue. Your healthcare provider should tell you what signs and symptoms you should report and monitor you depending on the type of organ or tissue transplant that you have had.
Complications, including graft-versus-host-disease (GVHD), in people who have received a bone marrow (stem cell) transplant that uses donor stem cells (allogeneic). These complications can be serious and can lead to death.
- These complications may happen if you undergo transplantation either before or after being treated with Keytruda.
- Your healthcare provider will monitor you for these complications.
Get emergency medical help if you have signs of an allergic reaction to Keytruda (hives, difficulty breathing, swelling in your face or throat) or a severe skin reaction (fever, sore throat, burning eyes, skin pain, red or purple skin rash with blistering and peeling).
Keytruda may cause harm to an unborn baby. Females of reproductive potential should use effective contraception.
Getting medical treatment right away for these side effects may help keep these problems from becoming more serious. This is not a complete list of side effects, and others may occur. Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.
Related/similar drugs
Before taking this medicine
To make sure Keytruda is safe for you, tell your doctor if you have:
- an autoimmune disorder such as rheumatoid arthritis, Crohn's disease, ulcerative colitis, lupus, or psoriasis
- received or plan to receive a stem cell transplant that uses donor stem cells
- had an organ transplant
- had radiation to your chest
- a condition that affects your nervous system, such as myasthenia gravis or Guillain-Barré syndrome
- are pregnant or plan to become pregnant
- are breastfeeding.
Pregnancy
Keytruda may harm an unborn baby. Your healthcare provider will give you a pregnancy test to make sure you are not pregnant. Use effective birth control while using Keytruda and for at least 4 months after your last dose. Tell your healthcare provider right away if you think you may be pregnant or if you become pregnant during
treatment with Keytruda.
Breastfeeding
It is not known if Keytruda passes into breast milk. Do not breastfeed while using this medicine and for at least 4 months after your last dose.
How is Keytruda Qlex administered?
Keytruda Qlex is administered as a subcutaneous injection into the thigh or abdomen by our healthcare professional.
The usual recommended dose for adults and pediatric patients 12 years and older who weigh 40 kg or more is:
- Every 3-week dosing (395 mg/4,800 units): Inject 2.4 mL subcutaneously in the abdomen or thigh over 1 minute.
- Every 6-week dosing (790 mg/9,600 units): Inject 4.8 mL subcutaneously in the abdomen or thigh over 2 minutes.
Keytruda Qlex may be given as a single treatment or in combination with other medicines, depending on the cancer being treated and the individual's clinical situation.
What happens if I miss a dose?
Call your doctor for instructions if you miss an appointment for your Keytruda subcutaneous injection
What happens if I overdose?
In a medical setting, an overdose would be treated quickly.
What should I avoid while receiving this medicine?
Follow your doctor's instructions about any restrictions on food, beverages, or activity.
What other drugs will affect this medicine?
Other drugs may interact with your Keytruda infusion, including prescription and over-the-counter medicines, vitamins, and herbal products. Tell your doctor about all other medicines you use.
Ingredients
Active ingredients: pembrolizumab and berahyaluronidase alfa
Inactive ingredients: histidine, histidine hydrochloride monohydrate, methionine, polysorbate 80, sucrose, and water for Injection. The pH is 5.3-5.9.
Storage
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.
Company
Keytruda is manufactured by Merck & Co. (known as MSD outside the United States and Canada), with global headquarters in Rahway, New Jersey, USA.
References
More about Keytruda Qlex (berahyaluronidase alfa / pembrolizumab)
Related treatment guides
Further information
Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.