Keytruda Qlex: Dosage, side effects, uses, interactions, and more

The Food and Drug Administration (FDA) has approved Keytruda Qlex to treat certain cancers in adults. These include:

The FDA has also approved Keytruda Qlex to treat certain skin cancers and solid tumors in children ages 12 years and older.

Keytruda Qlex is a brand-name biologic drug. It isn’t available as a biosimilar.

Biologics are made using parts of living cells, while traditional drugs are made using chemicals. This allows traditional drugs to have generics that are exact copies of the brand-name form. However, biologics cannot be copied exactly, so they have biosimilars instead of generics.

As with generics, biosimilars are considered to be as safe and effective as the original brand-name drug. Biosimilars tend to cost less than brand-name drugs.

The following information describes dosages that are commonly used or recommended. However, your doctor will determine the best dosage to fit your needs.

To learn more about using Keytruda Qlex, see the “How it’s given” section.

Note: Berahyaluronidase alfa is an enzyme (a type of protein) that helps the body absorb pembrolizumab after it’s injected.

Keytruda Qlex is prescribed to treat several types of cancer in adults, including skin cancer, colorectal cancer, and others. (For details, see the “Keytruda Qlex uses” section.)

The recommended dosage of Keytruda Qlex is the same for all of the cancers it’s approved to treat. The typical dosage is one of the following:

Your doctor will recommend the Keytruda Qlex dosage and schedule that’s right for you.

Keytruda Qlex is prescribed to treat certain skin cancers and solid tumors in children ages 12 years and older.

For children in this age group who weigh at least 40 kilograms (kg), which is about 88 pounds (lb), the recommended dosage is the same as for adults. For details, see the “Dosage for certain cancers” section.

The drug manufacturer hasn’t provided a recommended dosage of Keytruda Qlex for children in this age group who weigh less than 40 kg.

If you have questions about the proper dosage of Keytruda Qlex for your child, talk with their doctor.

Keytruda Qlex is given as a subcutaneous injection under the skin of your abdomen or thigh. A healthcare professional will administer the injection in a hospital or clinic.

Each Keytruda Qlex injection typically takes about 1 to 2 minutes to complete, depending on your dosing schedule.

If you have other questions about receiving Keytruda Qlex, talk with your doctor.

Keytruda Qlex can cause mild or serious side effects. The following lists contain some of the key side effects that may occur while taking Keytruda Qlex. These lists do not include all possible side effects.

The side effects of Keytruda Qlex may vary depending on whether it’s used alone or with other cancer treatments.

For more information about the possible side effects of Keytruda Qlex, talk with your doctor or pharmacist. They can give you tips on how to manage any side effects that may be concerning or bothersome.

Note: After the Food and Drug Administration (FDA) approves a drug, it tracks and reviews side effects of the medication. Sharing your experience helps make medications safer for everyone by giving doctors and researchers more information about how the drug works in real life. If you develop a side effect while taking Keytruda Qlex and want to tell the FDA about it, visit MedWatch or call 800-FDA-1088.

Here is a partial list of mild side effects of Keytruda Qlex. To learn about other mild side effects, talk with your doctor or pharmacist, or view Keytruda Qlex’s prescribing information.

Most of these side effects may go away within a few days to a couple of weeks. However, if they become more severe or don’t go away, talk with your doctor or pharmacist.

Serious side effects from Keytruda Qlex aren’t common, but they can occur. Call your doctor right away if you have serious side effects. Call 911 or your local emergency phone number if your symptoms feel life threatening or you think you’re having a medical emergency.

Keytruda Qlex is approved to treat certain cancers in children ages 12 years and older. Most side effects of Keytruda Qlex reported in children are similar to those in adults.

However, certain side effects of the drug were reported more often in children than in adults. Examples include abdominal pain, fever, headache, and vomiting.

If you have questions about the side effects of Keytruda Qlex in children, talk with your child’s doctor or pharmacist.

For some people, Keytruda Qlex can cause an allergic reaction.

In general, symptoms of an allergic reaction can be mild or serious.

For mild allergic reaction symptoms, such as a mild rash, call your doctor right away. They may recommend treatments to help manage your symptoms. They’ll also let you know whether you should keep taking the medication.

For severe allergic reaction symptoms, such as swelling or trouble breathing, call 911 or your local emergency number right away. These symptoms require immediate medical care because they can become life threatening. If you’ve had a serious allergic reaction to Keytruda Qlex, your doctor may recommend a different medication instead.

The following information describes the FDA-approved use for Keytruda Qlex.

Keytruda Qlex is approved to treat several types of skin cancer. These include melanoma, Merkel cell carcinoma, and cutaneous squamous cell carcinoma.

Melanoma develops when pigment-producing cells in the skin grow and divide rapidly.

Doctors prescribe Keytruda Qlex for adults with melanoma that is metastatic (has spread to other areas of the body) or cannot be removed with surgery. It’s also prescribed for adults and children ages 12 years and older to help reduce the risk of melanoma returning after surgery to remove the cancer.

MCC is a rare skin cancer that affects the top layers of the skin.

Doctors prescribe Keytruda Qlex for adults and children ages 12 years and older with MCC that has come back after prior treatment.

cSCC affects the outermost layer of the skin.

To learn more about these cancers, visit our skin cancer hub.

Keytruda Qlex is approved to treat non-small cell lung cancer (NSCLC) in adults.

NSCLC is the most common type of lung cancer. It develops when lung cells grow and divide rapidly.

For this purpose, Keytruda Qlex may be prescribed alone or in combination with other drugs, depending on specific features of the cancer.

To learn more about NSCLC, visit our cancer hub.

Keytruda Qlex is approved to treat pleural mesothelioma in adults.

Pleural mesothelioma is a rare cancer that develops in the lining of the lungs.

Doctors prescribe Keytruda Qlex as a first treatment for pleural mesothelioma that is metastatic or cannot be removed with surgery.

For this purpose, Keytruda Qlex may be prescribed with pemetrexed (Axtle, Alimta, others) and platinum-based chemotherapy, such as cisplatin or carboplatin (Kyxata).

To learn more about pleural mesothelioma, visit our cancer hub.

Keytruda Qlex is approved to treat head and neck squamous cell cancer (HNSCC) in adults.

HNSCC is a cancer that develops in the cells lining the mouth, throat, or other areas of the head and neck.

For this purpose, Keytruda Qlex may be prescribed alone or in combination with other drugs, depending on specific features of the cancer.

To learn more about HNSCC, visit our cancer hub.

Keytruda Qlex is approved to treat bladder and urinary tract cancer in adults.

This type of cancer may also affect the ureters (tubes that carry urine from the kidneys to the bladder) or other nearby areas.

For this purpose, doctors may prescribe Keytruda Qlex with enfortumab vedotin-ejfv (Padcev) when the cancer has spread to other areas.

Doctors may prescribe Keytruda Qlex on its own for bladder and urinary tract cancer in the following situations:

To learn more about bladder and urinary tract cancer, visit our cancer hub.

Keytruda is approved to treat certain solid tumors with genetic changes in adults and children ages 12 years and older. These include microsatellite instability–high (MSI-H) tumors, mismatch repair-deficient (dMMR) tumors, and tumor mutation burden-high (TMB-H) cancers.

A solid tumor is a group of abnormal cells that can form in nearly any organ or tissue in the body. MSI-H tumors, dMMR tumors, and TMB-H cancers have unique genetic features that make them more likely to respond to treatment with Keytruda Qlex.

To learn more about these conditions, visit our cancer hub.

Keytruda Qlex is approved to treat colorectal cancer in adults.

Colorectal cancer develops in the colon or rectum, which are parts of the large intestine. It may start as small growths called polyps that can lead to cancer over time.

Doctors prescribe Keytruda Qlex for colorectal cancer with certain genetic features that make the cancer more likely to respond to treatment with Keytruda Qlex. It’s used when the cancer is metastatic (has spread to other areas of the body) or cannot be removed with surgery.

To learn more about this condition, view our list of colorectal cancer articles.

Keytruda Qlex is approved to treat stomach cancer in adults.

Stomach cancer develops when cells in the stomach grow and divide quickly. It can also occur where the stomach meets the esophagus, which is called gastroesophageal junction (GEJ) cancer.

For this use, Keytruda Qlex is given with certain chemotherapy drugs. If the cancer also tests positive for the HER2 protein, doctors may prescribe trastuzumab (Herceptin) as well.

To learn more about stomach cancer, visit our cancer hub.

Keytruda Qlex is approved to treat esophageal cancer in adults.

Esophageal cancer develops in the lining of the esophagus, which is the tube that connects your throat to your stomach. It can also occur near where the esophagus meets the stomach, called gastroesophageal junction (GEJ) cancer.

For this use, Keytruda Qlex may be prescribed on its own or with certain chemotherapy drugs. It’s typically used alone when the cancer is a type called “squamous cell” and has not improved with past treatments.

To learn more about esophageal cancer, visit our cancer hub.

Keytruda Qlex is approved to treat cervical cancer in adults.

Cervical cancer develops in the cells lining the cervix, which connects the uterus to the vagina.

To learn more about cervical cancer, visit our cancer hub.

Keytruda Qlex is approved to treat hepatocellular carcinoma (HCC) in adults.

HCC is a type of liver cancer. It often develops in people with long-term liver problems, such as hepatitis or liver damage.

Doctors prescribe Keytruda Qlex for HCC related to hepatitis B. It’s used when the cancer has been treated with another whole-body therapy that does not include specific immunotherapy drugs such as nivolumab (Opdivo) and atezolizumab (Tecentriq).

To learn more about HCC, view our list of articles about liver cancer.

Keytruda Qlex is approved to treat biliary tract cancer (BTC) in adults.

BTC is a type of cancer that affects the bile ducts and gallbladder.

Doctors prescribe Keytruda Qlex for BTC that has spread and cannot be removed with surgery. For this purpose, the drug is prescribed with gemcitabine (Avgemsi) and cisplatin.

To learn more about BTC, visit our cancer hub.

Keytruda Qlex is approved to treat renal cell carcinoma (RCC) in adults.

RCC develops when cells in the kidneys grow and divide more quickly than is typical.

To learn more about RCC, visit our cancer hub.

Keytruda Qlex is approved to treat endometrial cancer in adults.

Endometrial cancer is a type of cancer that begins in the lining of the uterus.

Doctors may also prescribe Keytruda Qlex with carboplatin and paclitaxel for endometrial cancer that has come back or has spread to other areas of the body.

To learn more about endometrial cancer, visit our cancer hub.

Keytruda Qlex is approved to treat triple-negative breast cancer in adults.

With this type of breast cancer, the cancer cells do not have progesterone or estrogen receptors and do not make large amounts of the HER2 protein.

To learn more about this condition, visit our breast cancer hub.

For details about these conditions, see the “Keytruda Qlex for skin cancers” and “Keytruda Qlex for solid tumors with genetic changes” sections.

To learn more about Keytruda Qlex for children, talk with your child’s doctor.

Keytruda Qlex is not known to interact with other medications, herbs, supplements, foods, or alcohol. The manufacturer did not list any interactions in the drug’s prescribing information.

However, this doesn’t mean that interactions won’t be recognized in the future. For example, new drugs could be approved that interact with Keytruda Qlex.

Before starting Keytruda Qlex treatment, talk with your doctor and pharmacist. Tell them about all prescription, over-the-counter, and other drugs you take. Also tell them about any vitamins, herbs, and supplements you take. Sharing this information can help you avoid potential interactions.

If you have questions about drug interactions that may affect you, talk with your doctor or pharmacist.

As with all medications, the cost of Keytruda Qlex can vary. The actual price you’ll pay depends on your insurance plan and your location.

Financial and insurance assistance: The Merck Access Program is available if you need financial support to pay for Keytruda Qlex or help understanding your insurance coverage. For more information and to find out if you’re eligible for support, call 855-257-3932 or visit the program website.

Generic version: Keytruda Qlex is not available in a biosimilar form. It’s a brand-name biologic drug made from parts of living cells. Biosimilars tend to cost less than brand-name biologic drugs. See the “Keytruda Qlex generic or biosimilar” section for more details.

Other subcutaneous immunotherapy injections can treat your condition. Examples include nivolumab/hyaluronidase (Opdivo Qvantig) and atezolizumab/hyaluronidase (Tecentriq Hybreza). Some may be a better fit for you than others.

If you’re interested in finding an alternative to Keytruda Qlex, talk with your doctor. They can tell you about other medications that may work well for you.

If you can become pregnant, consider the following information about pregnancy, birth control, and breastfeeding.

Keytruda Qlex should not be used during pregnancy. If you’re planning a pregnancy or can become pregnant, talk with your doctor before starting treatment. They’ll likely give you a pregnancy test and may suggest birth control options to use during treatment with Keytruda Qlex.

It may not be safe to receive Keytruda Qlex during pregnancy. If you’re sexually active and you or your partner can become pregnant, talk with your doctor about your birth control options during treatment with Keytruda Qlex.

Note: The use of binary terms such as “male” and “female” or “men” and “women” in this article reflects the language of the sources we’ve used. Unless otherwise noted, it’s unclear whether the research we reference included participants with expansive gender identities.

If you’re a female who can become pregnant, your doctor may advise you to use birth control during Keytruda Qlex treatment. They may recommend that you continue using birth control for at least 4 months after your final dose.

If you’re a male with a sexual partner who can become pregnant, talk with your doctor about your birth control needs during Keytruda Qlex treatment.

It may not be safe to receive Keytruda Qlex while breastfeeding. If you’re currently breastfeeding or planning to do so, talk with your doctor before starting treatment. They may advise you to avoid breastfeeding during treatment and for at least 4 months after your final dose.

Before taking Keytruda Qlex, discuss your health history with your doctor. Keytruda Qlex may not be right for you if you have certain medical conditions or other factors affecting your health. Be sure to talk with your doctor if any of the following apply to you:

Note: For more information about the potential negative effects of Keytruda Qlex, see the “Keytruda Qlex side effects” section.

Disclaimer: Medical News Today has made every effort to make certain that all information is factually correct, comprehensive, and up to date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or another healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.