Jemperli (dostarlimab-gxly) is a prescription drug used to treat certain cancers. Jemperli can cause side effects that range from mild to serious. Examples include anemia and infusion-related reactions.

Jemperli is used in adults to treat the following types of cancer in certain situations:

The active ingredient in Jemperli is dostarlimab-gxly.* (An active ingredient is what makes a drug work.) The drug comes as a liquid solution given as an intravenous (IV) infusion (an injection into your vein given over time).

Keep reading to learn about the common, mild, and serious side effects Jemperli can cause. For a general overview of the drug, including details about its uses, see this article.

* The reason “-gxly” appears at the end of the drug’s name is to show that the drug is distinct from similar medications that may be created in the future.

Below are just a few of the more common side effects reported by people receiving Jemperli treatment in studies. Side effects can vary depending on what condition the drug is being used to treat.

More common side effects in people using Jemperli for endometrial cancer include:

More common side effects in people using Jemperli for solid tumors include:

* To learn more about this side effect, see the “Side effects explained” section below.

Mild side effects have been reported with Jemperli. These can vary depending on what condition the drug is being used to treat.

Mild side effects that have been reported in people using Jemperli for endometrial cancer include:

Mild side effects that have been reported in people using Jemperli for solid tumors include:

  • fatigue (low energy)
  • digestive side effects, such as nausea, diarrhea, constipation, and vomiting
  • loss of appetite
  • fever
  • skin rash
  • itching
  • cough
  • anemia (low level of red blood cells)*
  • mild allergic reaction*†

In most cases, these side effects should be temporary. And some may be easily managed. But if you have symptoms that are ongoing or bothersome, talk with your doctor or pharmacist. And do not stop Jemperli treatment unless your doctor recommends it.

Jemperli may cause mild side effects other than those listed above. See the drug’s prescribing information for details.

* To learn more about this side effect, see the “Side effects explained” section below.
† An allergic reaction from Jemperli is possible, but this side effect wasn’t reported in studies.

Serious side effects have been reported with Jemperli. These include:

If you develop serious side effects during your treatment with Jemperli, call your doctor right away. If the side effects seem life threatening or you think you’re having a medical emergency, immediately call 911 or your local emergency number.

* To learn more about this side effect, see the “Side effects explained” section below.
† An allergic reaction from Jemperli is possible, but this side effect wasn’t reported in studies.

Note: After the Food and Drug Administration (FDA) approves a drug, it tracks and reviews side effects of the medication. If you’d like to notify the FDA about a side effect you’ve had with Jemperli, visit MedWatch.

Get answers to some frequently asked questions about Jemperli’s side effects.

How do side effects of Jemperli compare with those seen with Keytruda?

Many side effects of Jemperli are similar to those of Keytruda (pembrolizumab). But Keytruda may cause different side effects as well.

For example, both Jemperli and Keytruda may cause digestive side effects that include nausea, diarrhea, and constipation. Both drugs may also cause more serious side effects, including hormone problems, pneumonitis (inflammation of the lungs), and infusion-related reactions.*

But Keytruda may also cause hair loss and bone pain. These side effects aren’t known to occur with Jemperli.

For lists of possible side effects of Jemperli, see the sections above. To learn more about Keytruda’s side effects, see this article. You can also talk with your doctor or pharmacist.

* To learn more about this side effect, see the “Side effects explained” section below.

Does Jemperli cause long-term side effects?

It’s possible. Long-term side effects include those that may start at any time you’re taking a drug, even if you’ve taken it for a long time. They also include side effects that may not go away, even after you stop taking the drug.

Examples of long-term side effects reported in Jemperli’s studies include:

These are not all of the long-term side effects Jemperli may cause. Talk with your doctor to learn more about possible side effects of Jemperli and how long they may last.

Learn more about some of the side effects Jemperli may cause.

Anemia

Anemia (a low level of red blood cells) was a common side effect reported in studies of Jemperli. This side effect may cause symptoms such as:

What might help

Your doctor may order tests to check your red blood cell levels from time to time during your Jemperli treatment. If the tests show you have a low red blood cell count, your doctor may have you temporarily stop treatment. They may have you restart Jemperli once your red blood cell levels return to normal.

Infusion-related reactions

Infusion-related reactions were an uncommon side effect reported in studies of Jemperli. With this side effect, you may have certain symptoms during or after your Jemperli infusion.* In extreme cases, these reactions can be life threatening.

Symptoms of infusion-related reactions may include:

  • wheezing or shortness of breath
  • dizziness
  • fever or chills
  • neck or back pain
  • skin rash or itchiness

* The drug comes as a liquid solution given as an intravenous (IV) infusion (an injection into your vein given over time).

What might help

Your doctor will watch for infusion-related reactions while you’re receiving Jemperli infusions. If you have symptoms of a reaction, your doctor will recommend what to do.

For example, if you have a mild reaction, your doctor may slow down or temporarily stop your Jemperli infusion. But if you have a more severe reaction, your doctor may permanently stop your Jemperli treatment. If so, they’ll recommend alternative treatments for your condition.

Infusion-related reactions can still happen after your Jemperli infusion ends. If you have symptoms of an infusion-related reaction, tell your doctor right away. They’ll tell you whether it’s safe to keep receiving Jemperli infusions and can recommend ways to ease your symptoms.

Allergic reaction

Like most drugs, Jemperli can cause an allergic reaction in some people. But this side effect wasn’t reported in studies. Symptoms can be mild to serious and can include:

  • skin rash
  • itchiness
  • flushing (temporary warmth, redness, or deepening of skin color)
  • swelling under your skin, usually in your eyelids, lips, hands, or feet
  • swelling of your mouth, tongue, or throat, which can make it hard to breathe

What might help

If you have mild symptoms of an allergic reaction, such as a mild rash, call your doctor right away. They may suggest a treatment to manage your symptoms. Examples include:

  • an oral antihistamine, such as Benadryl (diphenhydramine)
  • a product you apply to your skin, such as hydrocortisone cream

If your doctor confirms you’ve had a mild allergic reaction to Jemperli, they’ll decide whether you should continue receiving infusions.

If you have symptoms of a severe allergic reaction, such as swelling or trouble breathing, call 911 or your local emergency number right away. These symptoms could be life threatening and require immediate medical care.

If your doctor confirms you’ve had a serious allergic reaction to Jemperli, they may have you switch to a different treatment.

Keeping track of side effects

During your Jemperli treatment, consider taking notes on any side effects you’re having. You can then share this information with your doctor. This is especially helpful when you first start taking a new drug or using a combination of treatments.

Your side effect notes can include things such as:

  • what dosage of the drug you were taking when you had the side effect
  • how soon you had the side effect after starting that dosage
  • what your symptoms were
  • how your symptoms affected your daily activities
  • what other medications you were taking
  • any other information you feel is important

Keeping notes and sharing them with your doctor will help them learn more about how Jemperli affects you. They can then use this information to adjust your treatment plan if needed.

Below is important information you should consider before starting Jemperli.

Warnings

Jemperli can sometimes cause harmful effects in people with certain conditions. This is known as a drug-condition interaction. Other factors may also affect whether Jemperli is a good treatment option for you.

Talk with your doctor about your health history before starting Jemperli. Be sure to tell them if any of the following factors apply to you:

Alcohol and Jemperli

There are no known interactions between alcohol and Jemperli. If you have questions about consuming alcohol during Jemperli treatment, talk with your doctor or pharmacist.

Pregnancy and breastfeeding with Jemperli

Jemperli is not usually prescribed for someone who’s pregnant or breastfeeding.

Pregnancy

Jemperli treatment is not safe during pregnancy. If you’re pregnant or planning to become pregnant, talk with your doctor about your treatment options.

If you’re able to become pregnant, your doctor may recommend using a form of birth control during your Jemperli treatment. And you may need to continue using birth control for 4 months after your Jemperli treatment ends.

Breastfeeding

Jemperli treatment is not safe while breastfeeding. Your doctor will likely recommend that you not breastfeed during your Jemperli treatment and for 4 months after treatment ends. If you’re breastfeeding or planning to do so, talk with your doctor about your options.

Like most drugs, Jemperli can cause a number of side effects that range from mild to serious. But most are temporary and go away after a few days to weeks. If you have questions about side effects Jemperli can cause, talk with your doctor. Examples to help get you started include:

  • If I’ve had an organ transplant, what should I watch for during Jemperli treatment?
  • Will I need any lab tests to check for side effects from Jemperli?
  • Are there any side effects of Jemperli that could make it unsafe to drive after my infusion appointment?

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Disclaimer: Healthline 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.