Firmagon is a brand-name prescription drug. It's used to treat advanced prostate cancer in adult men.

Firmagon contains the active drug degarelix, which belongs to a class of drugs called gonadotropin-releasing hormone (GnRH) antagonists. It works by stopping testosterone production. This helps lower your levels of prostate-specific antigen (a protein produced by prostate cells) to stop the growth of prostate cancer cells.

Firmagon comes as powder that's mixed into a solution. It's given by your doctor as an injection under the skin (subcutaneous). The first dose is called a starting dose and is given as two 120-mg injections (so 240 mg at one time). After that, your doctor will give you an injection of 80 mg every 28 days.

Effectiveness

A 1-year clinical study involving 620 men with advanced prostate cancer compared maintenance doses of Firmagon (160 mg and 80 mg) with another prostate cancer drug called leuprolide (Lupron Depot). The study evaluated the drugs' ability to lower testosterone levels over the course of a year to below 50 nanograms per deciliter (ng/dL).

A testosterone level below 50 ng/dL caused by drugs is called chemical castration (virtually no testosterone in the blood). Normal testosterone levels in men ages 50 to 79 years old are usually between 219 and 929 ng/dL.

By the end of the 1-year study, 97.2% to 98.3% of men taking Firmagon had testosterone levels below 50 ng/dL. In comparison, 96.4% of men taking leuprolide achieved this testosterone level.

Firmagon is available only as a brand-name medication. It's not currently available in generic form.

A generic drug is an exact copy of a brand-name medication. Generics tend to cost less than brand-name drugs.

Firmagon contains the active drug degarelix, which belongs to a class of drugs called gonadotropin-releasing hormone (GnRH) antagonists.

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

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

Note: The Food and Drug Administration (FDA) tracks side effects of drugs they have approved. If you would like to report to the FDA a side effect you've had with Firmagon, you can do so through MedWatch.

More common side effects

The more common side effects of Firmagon can include:

  • increase in some liver enzymes
  • lowered sex drive
  • erectile dysfunction
  • fatigue (lack of energy)

Other common side effects, described in "Side effect details" below, can include:

  • hot flashes
  • weight gain
  • injection site pain, redness, and swelling

How long do Firmagon side effects last?

Some of these side effects may go away within a few days or a couple of weeks, but some may last throughout the duration of your treatment. If they're more severe or don't go away, talk with your doctor or pharmacist.

Serious side effects

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

Serious side effects can include:

  • Impotence (being unable to conceive a child).
  • Disorder of the heart's electrical activity. Medications like Firmagon have been shown to raise the risk of disrupting your heart's electrical activity (specifically, increasing the QT interval). A QT interval is a measure that shows up on an electrocardiogram (ECG). A long QT interval can put you at risk for an arrhythmia (abnormal heart beat). Your doctor may have to run tests during your Firmagon treatment to check your heart for any abnormal electrical signals, like long QT syndrome.
  • Allergic reactions. See "Side effect details" below.

Side effect details

You may wonder how often certain side effects occur with this drug. Here's some detail on several of the side effects this drug may cause.

Allergic reaction

As with most drugs, some people can have an allergic reaction after taking Firmagon. Symptoms of a mild allergic reaction can include:

  • skin rash
  • itchiness
  • flushing (warmth and redness in your skin)

A more severe allergic reaction is rare but possible. Some reports of severe allergic reactions with Firmagon have been reported. Symptoms of a severe allergic reaction can include:

  • swelling under your skin, typically in your eyelids, lips, hands, or feet
  • swelling of your tongue, mouth, or throat
  • trouble breathing

Call your doctor right away if you have a severe allergic reaction to Firmagon. Call 911 if your symptoms feel life threatening or if you think you're having a medical emergency.

Injection site reactions

After a Firmagon dose, some people may have injection site reactions, including pain, redness, or swelling. In clinical studies, 35% to 44% of people taking Firmagon experienced injection site reactions, compared with less than 1% of people taking Lupron Depot.

In the studies, the most common type of injection site reaction was pain, with 28% of people taking Firmagon reporting it. Other injection site reactions included redness (17%), swelling (6%), hardening of the skin (4%) and formation of a bump (3%). These reactions usually happened after the starting dose of Firmagon and didn't continue throughout the entire treatment.

Talk with your doctor if you're concerned about injection site reactions.

Hot flashes

Firmagon may cause hot flashes. In a clinical study, 26% of people taking Firmagon experienced hot flashes. In comparison, 21% of people taking Lupron Depot had hot flashes. Hot flashes are likely caused by hormonal changes in your body from using Firmagon.

If the hot flashes become bothersome, talk with your doctor. They may recommend making some changes, like avoiding spicy foods or hot beverages. They may also recommend treatments to help relieve the hot flashes.

Weight gain

Firmagon may cause weight gain. In a clinical study, 9% to 11% of people taking Firmagon gained weight. In comparison, 12% of people taking leuprolide (Lupron Depot) gained weight.

If you have concerns about weight gain while you're taking Firmagon, talk with your doctor.

Other drugs are available that can treat advanced prostate cancer. Some may be a better fit for you than others. If you're interested in finding an alternative to Firmagon, talk with your doctor. They can tell you about other medications that may work well for you.

Note: Some of the drugs listed here are used off-label to treat these specific conditions. Off-label use is when a drug that's approved to treat one condition is used to treat a different condition.

Alternatives for advanced prostate cancer

Examples of other drugs that may be used to treat advanced prostate cancer include:

You may wonder how Firmagon compares to other medications that are prescribed for similar uses. Here we look at how Firmagon and Lupron Depot are alike and different.

Ingredients

Firmagon and Lupron Depot both contain active drugs that belong to a class of medications called gonadotropin-releasing hormone (GnRH) antagonists. Firmagon contains the active drug degarelix, and Lupron Depot contains the active drug leuprolide.

Uses

Firmagon and Lupron Depot are both FDA-approved to treat advanced prostate cancer.

Lupron Depot is also FDA-approved to treat the following conditions:

  • endometriosis associated pain and endometriotic lesions
  • uterine fibroids, in combination with iron supplements in preparation for surgery

Drug forms and administration

Firmagon comes as powder that's mixed into a solution. It's given by your doctor as an injection under the skin (subcutaneous).

Lupron Depot comes in a powder inside a syringe that's mixed into a solution. It's given as an intramuscular injection (an injection into your muscle) either by your doctor or by you under your doctor's supervision.

Side effects and risks

Firmagon and Lupron Depot have some similar side effects and others that differ. Below are examples of these side effects.

More common side effects

These lists contain examples of more common side effects that can occur with Firmagon, with Lupron Depot, or with both drugs (when taken individually).

  • Can occur with Firmagon:
  • Can occur with Lupron:
    • body pain
    • swelling
    • testicular shrinkage
    • difficulty urinating
    • upset stomach
    • headache
  • Can occur with both Firmagon and Lupron:
    • lowered sex drive
    • fatigue (lack of energy)
    • hot flashes
    • injection site pain, redness, and swelling

Serious side effects

These lists contain examples of serious side effects that can occur with Lupron Depot or with both drugs (when taken individually).

  • Can occur with Lupron Depot:
  • Can occur with both Firmagon and Lupron:
    • serious allergic reactions
    • disorder of the heart's electrical activity
    • impotence (being unable to conceive a child)

Effectiveness

The only condition both Firmagon and Lupron Depot are used to treat is advanced prostate cancer. The use of Firmagon and Lupron Depot in treating advanced prostate cancer has been directly compared in a 1-year clinical study.

The study involved 620 men with advanced prostate cancer. It compared maintenance doses of Firmagon (160 mg and 80 mg) with another prostate cancer drug called leuprolide (Lupron Depot). The study evaluated the drugs' ability to lower testosterone levels over the course of a year to below 50 nanograms per deciliter (ng/dL).

A testosterone level below 50 ng/dL caused by drugs is called chemical castration (virtually no testosterone in the blood). Normal testosterone levels in men ages 50 to 79 years old are usually between 219 and 929 ng/dL.

By the end of the 1-year study, 97.2% to 98.3% of men taking Firmagon had testosterone levels below 50 ng/dL. In comparison, 96.4% of men taking leuprolide achieved this testosterone level.

Costs

Firmagon and Lupron are both brand-name drugs. There is currently no generic form of Firmagon. A generic version of Lupron called leuprolide acetate is available. Brand-name medications usually cost more than generics.

According to estimates on WellRx.com, Firmagon is significantly less expensive than Lupron Depot. The actual price you'll pay for either drug depends on your insurance plan and your location.

Like Lupron Depot (above), the drug Zoladex has uses similar to those of Firmagon. Here's a comparison of how Firmagon and Zoladex are alike and different.

Ingredients

Firmagon and Zoladex both contain active drugs that belong to a class of medications called gonadotropin-releasing hormone (GnRH) antagonists. Firmagon contains the active drug degarelix, and Zoladex contains the active drug goserelin.

Uses

Both Firmagon and Zoladex are FDA-approved to treat advanced prostate cancer.

Zoladex is also FDA-approved to treat an earlier stage of prostate cancer, as well as endometriosis and breast cancer.

Drug forms and administration

Firmagon comes as powder that's mixed into a solution. It's given by your doctor as an injection under the skin (subcutaneous).

Zoladex comes as an implant that is delivered through a syringe by your doctor. It's usually given in combination with radiotherapy and a drug called flutamide.

Side effects and risks

Firmagon and Zoladex have some similar side effects and others that differ. Below are examples of these side effects.

More common side effects

These lists contain examples of more common side effects that can occur with Firmagon, with Zoladex, or with both drugs (when taken individually).

Serious side effects

These lists contain examples of serious side effects that can occur with Firmagon, with Zoladex, or with both drugs (when taken individually).

  • Can occur with Firmagon:
    • impotence (being unable to conceive a child)
  • Can occur with Zoladex:
  • Can occur with both Firmagon and Zoladex:
    • serious allergic reactions
    • disorder of the heart's electrical activity (which may require testing of your heart's electrical signals)

Effectiveness

Firmagon and Zoladex have different FDA-approved uses, but they're both used to treat advanced prostate cancer.

These drugs have been directly compared in clinical studies, which have found both Firmagon and Zoladex to be effective for treating advanced prostate cancer.

Two clinical studies compared Firmagon to Zoladex over a 12-week period in men with advanced prostate cancer. In both studies, about half the men took Firmagon, and the rest took Zoladex plus bicalutamide. The effectiveness of the drugs was measured by how much they reduced total prostate volume (size). The studies also looked at how effective Firmagon and Zoladex were at relieving symptoms of urinary problems.

  • In one study of 244 men, total prostate volume was reduced by 36% in people taking Firmagon and 35% in people taking Zoladex. At the end of the study, 37% of men taking Firmagon reported symptom improvements. In comparison, 27% of those taking Zoladex had improvements in their symptoms.
  • In one study of 175 men, total prostate volume was reduced by 37% in people taking Firmagon and 39% in people taking Zoladex. At the end of the study, 61% of men taking Firmagon reported symptom improvements. In comparison, 44% of men taking Zoladex had symptom improvements.

Costs

Firmagon and Zoladex are both brand-name drugs. There are currently no generic forms of either drug. Brand-name medications usually cost more than generics.

According to estimates on WellRx.com, Firmagon generally costs less than Zoladex. The actual price you'll pay for either drug depends on your insurance plan and your location.

The Firmagon dosage your doctor prescribes will depend on several factors. These include:

  • the type and severity of the condition you're using Firmagon to treat
  • your age
  • other medical conditions you may have

Drug forms and strengths

Firmagon comes as powder that's mixed into a solution. It's given by your doctor as an injection under the skin (subcutaneous). It comes in two strengths: 120 mg and 80 mg.

Dosage for advanced prostate cancer

The first dose is called a starting dose and is given as two 120-mg injections (so 240 mg at one time). After that, your doctor will give you an injection of 80 mg every 28 days.

What if I miss a dose?

Because you'll get Firmagon injections at your doctor's office, they'll be sure to schedule the appointments when you're due for an injection.

How long do I need to take Firmagon?

Firmagon is meant to be used as a long-term treatment. If you and your doctor determine that Firmagon is safe and effective for you, you'll likely take it long term.

You should take Firmagon according to your doctor or healthcare provider's instructions.

Injection site

Firmagon is injected under the skin of your abdomen (belly area) by your doctor. After you receive your injection, you should not rub or scratch the injection site. You may feel a lump, redness, soreness, or discomfort at the injection site for a few days after getting a dose.

When to take

Your doctor will give you Firmagon injections at their office. A dose is usually given every 28 days.

The Food and Drug Administration (FDA) approves prescription drugs such as Firmagon to treat certain conditions. Firmagon may also be used off-label for other conditions. Off-label use is when a drug that's approved to treat one condition is used to treat a different condition.

Firmagon for advanced prostate cancer

Firmagon is a brand-name prescription drug. It is used to treat advanced prostate cancer in adult men. Firmagon contains the active drug degarelix, which belongs to a class of drugs called gonadotropin-releasing hormone (GnRH) antagonists.

Firmagon works by stopping testosterone production. This helps lower your levels of prostate-specific antigen (a protein produced by prostate cells) to stop the growth of prostate cancer cells.

Effectiveness

A 1-year clinical study involving 620 men with advanced prostate cancer compared maintenance doses of Firmagon (160 mg and 80 mg) with another prostate cancer drug called leuprolide (Lupron Depot). The study evaluated the drugs' ability to lower testosterone levels over the course of a year to below 50 nanograms per deciliter (ng/dL).

A testosterone level below 50 ng/dL caused by drugs is called chemical castration (virtually no testosterone in the blood). Normal testosterone levels in men ages 50 to 79 years old are usually between 219 and 929 ng/dL.

By the end of the 1-year study, 97.2% to 98.3% of men taking Firmagon had testosterone levels below 50 ng/dL. In comparison, 96.4% of men taking leuprolide achieved this testosterone level.

Off-label use for Firmagon

In addition to the use listed above, Firmagon may be used off-label. Off-label drug use is when a drug that's approved for one use is used for a different one that's not approved.

Gender dysphoria

Gender dysphoria occurs when a person feels they're a different gender than what corresponds with the sex they were assigned at birth based on biological organs. This is also called being transgender. Certain treatments, including hormone therapy, can help align the body with the gender identity the person feels is more accurate.

Firmagon is currently being studied as a part of a treatment regimen to balance out the hormonal aspect of transgender men with gender dysphoria.

Here are answers to some frequently asked questions about Firmagon.

How long does Firmagon stay in your system?

About half of Firmagon leaves your body in 53 days, with the rest being filtered out of your body over a longer period of time. Firmagon takes a while to release from the injection made under your skin, which is why it's only injected every 28 days. It's meant to stay in your body for a long period of time to continuously reduce the hormones that allow prostate cancer cells to grow.

Talk with your doctor for more information about how long Firmagon stays in your system.

Is Firmagon considered chemotherapy?

No, Firmagon is not a form of chemotherapy (a type of drug that interferes with a cancer cell's ability to multiply). Firmagon works differently in your body than chemotherapy drugs.

Chemotherapy targets rapidly growing cells in your body. Cancer cells are typically fast-growing cells, so they're affected by chemotherapy. However, some healthy cells in your body are also fast-growing cells. These healthy cells can also be affected by chemotherapy drugs.

Firmagon is a type of hormone therapy called gonadotropin-releasing hormone (GnRH) antagonists. It works by stopping testosterone production. This helps lower your levels of prostate-specific antigen (a protein produced by prostate cells) to stop the growth of prostate cancer cells.

Talk with your doctor to learn more about how Firmagon works in your body.

Does Firmagon cause erectile dysfunction?

It might, although this side effect is rare. In clinical studies, around 1% to 5% of men reported experiencing erectile dysfunction.

Talk with your doctor if you're concerned about erectile dysfunction.

Will Firmagon change my testosterone levels?

Yes. Testosterone is the main reason that prostate cancer tumors grow. Therefore, one of the main goals of prostate cancer treatment is to lower testosterone levels. This can help the tumor shrink in size or go away completely.

Normal testosterone levels in men ages 50 to 79 years old are usually between 219 and 929 nanograms per deciliter (ng/dL). By the end of a 1-year clinical study, 97.2% to 98.3% of men taking Firmagon had testosterone levels below 50 ng/dL. For more details, see the "Firmagon uses" section above.

Talk with your doctor to learn more about how Firmagon affects your testosterone levels.

Why does my doctor have to give me Firmagon? Can't I give myself the injections?

Firmagon is only available as an injection to be given by your doctor or other healthcare professional at your doctor's office.

When drugs are reviewed by the Food and Drug Administration (FDA) for safety and effectiveness, they're also evaluated on how easy it is to take them correctly. Firmagon powder comes in a vial that needs to be carefully mixed with sterile water for injection. Because of this, the FDA approved the product to only be given by a healthcare professional.

Talk with your doctor if you have questions about how Firmagon is given.

There are no known interactions between Firmagon and alcohol. However, both Firmagon and alcohol are broken down by your liver. Drinking too much alcohol while you're taking Firmagon may prevent your liver from breaking down Firmagon properly. This may increase your risk for side effects.

If you drink alcohol, talk with your doctor about how much alcohol is safe for you to drink while you're using Firmagon.

There are no known drug interactions between Firmagon and other medications. There are also no known interactions between Firmagon and herbal supplements or foods. However, Firmagon can affect certain lab test results.

Firmagon and other medications

Before taking Firmagon, 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 use. Sharing this information can help you avoid potential interactions.

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

Firmagon and herbs and supplements

There aren't any herbs or supplements that have been specifically reported to interact with Firmagon. However, you should still check with your doctor or pharmacist before using any of these products while taking Firmagon.

Firmagon and lab tests

Firmagon can affect lab test results of certain reproduction hormones, such as the luteinizing hormone and the follicle-stimulating hormone. This happens because Firmagon works to treat prostate cancer by blocking the production of certain steroid hormones, like testosterone. However, Firmagon does not block only the production of testosterone, so other steroid hormone levels will also be reduced.

Regular lab tests are recommended to measure your levels of prostate-specific antigen (a protein produced by prostate cells) or testosterone to make sure Firmagon is working. Other lab tests may be recommended to check for possible side effects.

You don't have to take other medications with Firmagon. However, your doctor may recommend other drugs to help treat your advanced prostate cancer. According to the National Comprehensive Cancer Network guidelines, other medications can be used with Firmagon to treat advanced prostate cancer in men who haven't had chemical castration (testosterone-lowering) treatments before.

Other medications include chemotherapy or anti-androgen medications (which decrease testosterone levels to kill cancer cells).

Examples of medications that can be used with Firmagon include:

  • docetaxel (Taxotere), a chemotherapy drug
  • anti-androgen medications, such as:

As with all medications, the cost of Firmagon can vary. To find current prices for Firmagon in your area, check out WellRx.com. The cost you find on WellRx.com is what you may pay without insurance. The actual price you'll pay depends on your insurance plan and your location.

Your insurance plan may require you to get prior authorization before approving coverage for Firmagon. This means that your doctor will need to send a request to your insurance company asking them to cover the drug. The insurance company will review the request and let you and your doctor know if your plan will cover Firmagon.

If you're not sure if you'll need to get prior authorization for Firmagon, contact your insurance company.

Firmagon contains the active drug degarelix, which belongs to a class of drugs called gonadotropin-releasing hormone (GnRH) antagonists. It works by blocking your body from creating certain steroid hormones, like testosterone. Prostate cancer cells need testosterone to grow, and Firmagon stops your body from making testosterone. This can help the tumor shrink in size or go away completely.

How long does it take to work?

Firmagon starts to lower your testosterone levels right away. In a clinical study, testosterone levels dropped by 88% 1 day after a Firmagon injection. By day 3, levels had dropped by 94%, and by 28 days after the injection, levels dropped by 98%.

Firmagon can harm a developing fetus. It's only approved for use in men and should not be taken by women, especially those who are pregnant or planning to become pregnant.

Firmagon has not been studied in women, but it has been studied in pregnant rats and rabbits. In these studies, Firmagon was shown to raise the risk of miscarriages and birth defects.

Firmagon is only approved for use in men and should not be taken by women, especially those who are pregnant or planning to become pregnant. This is because Firmagon can harm a developing fetus.

Although a man taking Firmagon will likely not be able to impregnate a woman, this is not always the case. If you are sexually active and your or your partner can become pregnant, talk with your doctor about your birth control needs while using Firmagon.

Firmagon is not FDA-approved for use in women, and it should not be used in women who are pregnant or breastfeeding. It's not known if Firmagon passes into breast milk because Firmagon has not been studied in women.

This drug comes with several precautions. Before taking Firmagon, talk with your doctor about your health history. Firmagon may not be right for you if you have certain medical conditions or other factors affecting your health. These include:

  • Heart conduction problems. If you have a problem with your heart's electrical activity, Firmagon may make it worse. Your doctor will likely monitor you for any abnormal electrical heart signals, like long QT syndrome, during your treatment.
  • Liver damage. If you have liver damage, you may have lower levels of Firmagon in your blood than healthy individuals, meaning that Firmagon may not work as well. Your doctor may monitor your testosterone levels more closely to make sure Firmagon is working for you.
  • Pregnancy. Firmagon is not approved for use in women and shouldn't be taken by women who are pregnant or could become pregnant. For more information, see the "Firmagon and pregnancy" section above.
  • Breastfeeding. Firmagon is not approved for use in women, and it should not be used in women who are pregnant or breastfeeding. For more information, see the "Firmagon and breastfeeding" section above.

Note: For more information about the potential negative effects of Firmagon, see the "Firmagon side effects" section above.

The following information is provided for clinicians and other healthcare professionals.

Indications

Firmagon is a gonadotropin-releasing hormone (GnRH) antagonist used to treat advanced prostate cancer in adult men.

Mechanism of action

Firmagon is a GnRH antagonist. It works by binding to GnRH receptors to reduce the secretion of gonadotropins, effectively eliminating the production of testosterone.

Pharmacokinetics and metabolism

Upon subcutaneous injection, Firmagon forms a depot from which degarelix is released into the bloodstream. Maximum concentrations were seen at 2 days post injection. Firmagon half-life is 53 days, with 20% to 30% excreted renally and 70% to 80% excreted from the hepatobiliary system.

Contraindications

Firmagon is contraindicated in patients with a history of hypersensitivity to degarelix. Firmagon is also contraindicated in pregnant women because it can cause fetal harm.

Storage

Store the carton at room temperature (77°F/25°C) with excursions of 59°F to 86°F (15°C to 30°C) allowed.

Once reconstituted, the drug must be administered within 1 hour of addition of sterile water for injection. Reconstituted drug should not be kept beyond 1 hour.

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 other 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.