Talvey (talquetamab-tgvs) is a prescription drug used to treat multiple myeloma. Talvey can cause side effects that range from mild to serious, including the risk of cytokine release syndrome and neurologic damage.

Specifically, Talvey is used in adults to treat relapsed or refractory multiple myeloma. It’s used when at least four other treatments haven’t worked in the past.

The active ingredient in Talvey is talquetamab-tgvs.* (An active ingredient is what makes a drug work.) The drug comes as a liquid solution that’s injected under your skin.

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

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

Some people may experience mild to serious side effects during Talvey treatment. Examples of the drug’s commonly reported side effects include:

* Talvey has a boxed warning about this risk. A boxed warning is the most serious warning from the FDA. To learn more, see the “Side effects explained” section below.

Mild side effects have been reported with Talvey. These include:

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 Talvey treatment unless your doctor recommends it.

Talvey 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 Talvey is possible, but this side effect wasn’t reported in studies.

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

If you develop serious side effects during Talvey treatment, 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 Talvey is possible, but this side effect wasn’t reported in studies.

Note: After the 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 Talvey, visit MedWatch.

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

How do side effects of Talvey compare with those of Tecvayli?

Many side effects of Talvey are similar to those of Tecvayli (teclistamab-cqyv). But each drug can cause unique side effects as well.

For example, both Talvey and Tecvayli may cause fever, headache, and diarrhea. Both drugs also have boxed warnings for the risk of cytokine release syndrome and neurologic damage.* Boxed warnings are the most serious warnings from the FDA.

But Talvey may also cause severe skin and mouth problems that aren’t known to occur with Tecvayli. And Tecvayli may cause high blood pressure, while Talvey isn’t known to cause this side effect.

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

* To learn more about these warnings, see the “Side effects explained” section below.

Does Talvey 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. It also includes side effects that may not go away even after you stop taking the drug.

For example, cytokine release syndrome and neurologic toxicity* were reported in Talvey’s studies. These side effects can lead to organ damage, such as kidney failure or encephalopathy (brain damage). And these effects may cause long-term problems.

Talk with your doctor to learn more about possible side effects of Talvey and how long they may last.

* Talvey has boxed warnings about these risks. A boxed warning is the most serious warning from the FDA. To learn more, see the “Side effects explained” section just below.

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

Risk of cytokine release syndrome

Talvey has a boxed warning for the risk of cytokine release syndrome (CRS). A boxed warning is the most serious warning from the FDA. CRS was a common side effect reported in studies of Talvey.

CRS happens when cells in the immune system release certain proteins into the blood. In extreme cases, CRS can be life threatening. It may also lead to severe problems such as kidney failure and liver failure.

CRS may cause symptoms such as:

  • fast heart rate
  • fatigue
  • fever
  • headache
  • low blood pressure

Due to this risk, Talvey is only available through a risk evaluation and mitigation strategy (REMS) program. The FDA requires this program to make sure that Talvey is used safely.

What might help

Your doctor will follow certain steps to help prevent CRS. For example, they’ll slowly increase your Talvey dosage over your first three doses. Your doctor will also give you medications before these doses to help prevent CRS. These include:

Your doctor will monitor you for symptoms of CRS whenever you receive a dose of Talvey. You’ll stay in a healthcare facility for at least 48 hours after your first three doses of Talvey.

If you have symptoms of CRS, tell your doctor right away. They may prescribe treatments for your symptoms and will tell you whether it’s safe to continue Talvey treatment.

Risk of neurologic damage

Talvey has a boxed warning for the risk of neurologic damage. A boxed warning is the most serious warning from the FDA. Neurologic damage was a common side effect reported in studies of Talvey.

This side effect occurs when the drug damages your nervous system. In extreme cases, neurologic damage can be life threatening.

Neurologic damage may cause symptoms such as:

Due to this risk, Talvey is only available through a REMS program, which the FDA requires to be sure Talvey is used safely.

What might help

Your doctor will monitor you for symptoms of neurologic damage whenever you receive a dose of Talvey. You’ll stay in a healthcare facility for at least 48 hours after your first three doses of Talvey. It’s also important to avoid driving or operating machinery between the first three doses and for at least 48 hours after your third dose.

If you have symptoms of neurologic damage, tell your doctor right away. They may prescribe treatments for your symptoms and will tell you whether it’s safe to continue Talvey treatment.

Allergic reaction

Like most drugs, Talvey 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 Talvey, they’ll decide whether you should continue treatment.

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 Talvey, they may have you switch to a different treatment.

Keeping track of side effects

During your Talvey 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 dose of the drug you were taking when you had the side effect
  • how soon you had the side effect after starting that dose
  • 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 Talvey affects you. They can then use this information to adjust your treatment plan if needed.

Below is important information you should consider before starting Talvey treatment.

Boxed warnings

Talvey has boxed warnings for the risk of cytokine release syndrome and neurologic damage. Boxed warnings are the most serious warnings from the FDA.

Risk of cytokine release syndrome (CRS): Talvey may cause CRS. This condition happens when cells in the immune system release certain proteins into the blood. In extreme cases, CRS can be life threatening.

Risk of neurologic damage. Talvey may cause neurologic damage. This side effect occurs when the drug damages your nervous system. In extreme cases, neurologic damage can be life threatening.

To learn more, see the “Side effects explained” section above.

Other warnings

Talvey can sometimes cause harmful effects in people with certain conditions. This is known as a drug-condition interaction. Other factors may also affect whether Talvey is a good treatment option for you. Talk with your doctor about your health history before starting this drug. Be sure to tell them if any of the following factors apply to you:

  • current infection
  • previous allergic reaction to Talvey
  • pregnancy
  • breastfeeding

Alcohol and Talvey

There are no known interactions between alcohol and Talvey.

But keep in mind that drinking large amounts of alcohol may cause liver damage. Talvey may cause high levels of liver enzymes (proteins), which can be a sign of liver damage. So drinking large amounts of alcohol during Talvey treatment could raise your risk of liver damage.

If you have questions about consuming alcohol during Talvey treatment, talk with your doctor or pharmacist.

Pregnancy and breastfeeding with Talvey

Talvey is usually prescribed for someone who’s pregnant or breastfeeding only if the benefits of treatment outweigh the potential risks to the fetus or child.

Pregnancy

Talvey may not be safe to use 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 Talvey treatment. You may also need to continue taking birth control for 3 months after your Talvey treatment ends.

Breastfeeding

Talvey may not be safe to use while breastfeeding. Your doctor may advise you not to breastfeed during your Talvey treatment or for at least 3 months after your treatment ends.

If you’re breastfeeding or planning to do so, talk with your doctor about your options.

Like most drugs, Talvey 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 Talvey can cause, talk with your doctor. Examples to help get you started include:

  • Could other medications I take raise my risk of side effects from Talvey?
  • How do Talvey’s side effects compare with other drugs that treat my condition?
  • Do I have any health factors that increase my risk of side effects from Talvey?

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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.