As doctors and scientists have learned more about desmoid tumors, they’ve developed new treatments. These include targeted therapies, which work by targeting or blocking proteins in desmoid tumor cells.

Several treatments are available, most of which are used off-label. As of April 2026, only one targeted therapy for desmoid tumors has been approved by the U.S. Food and Drug Administration (FDA).

In this article, we’ll cover four facts about targeted therapies for desmoid tumors. We’ll discuss what these drugs are, how they work, and when you may be treated with one.

To learn more about how a targeted therapy may fit into your desmoid tumor treatment plan, talk to your doctor.

Targeted therapies are a type of systemic treatment used for some cancers and tumors, including desmoid tumors.

Desmoid tumors aren’t cancerous. However, they are caused by gene mutations (changes) that make cells grow uncontrollably. You may hear desmoid tumors referred to as “aggressive fibromatosis” for this reason.

Scientists have developed targeted therapies to target or block proteins in desmoid tumor cells. Without these proteins, the cells no longer receive signals telling them to grow and divide. This lack of signaling causes the desmoid tumors to stop growing or shrink.

Targeted therapies have the potential to have fewer side effects compared to chemotherapy drugs, which can affect healthy cells in addition to tumor cells.

Targeted therapies are considered systemic therapies because they can affect the entire body. Although these drugs are systemic, they are designed to target desmoid tumor cells specifically. They’re designed to affect specific targets involved in tumor growth, but they can still affect healthy cells and cause side effects.

This is why targeted therapies have the potential to have fewer side effects compared to chemotherapy drugs, which can affect healthy cells in addition to tumor cells.

Many people living with desmoid tumors are monitored carefully by their healthcare team. Before starting treatment, the team uses scans to see if the tumor grows. This approach is called active surveillance.

Your desmoid tumor care team may recommend treatment with targeted therapy if your tumor progresses or is causing symptoms or other problems. If your tumor progresses, your healthcare team will help you understand if targeted therapies are a good option for you.

In November 2023, the FDA approved nirogacestat (Ogsiveo) as the first treatment specifically for adults with progressing desmoid tumors. Nirogacestat is known as a gamma-secretase inhibitor.

Nirogacestat works by blocking the enzyme gamma-secretase, preventing it from activating another protein called Notch. Scientists believe desmoid tumor cells use Notch proteins to grow and divide.

Doctors prescribe nirogacestat to people with desmoid tumors who need systemic treatment. Nirogacestat is a pill that’s typically taken twice daily.

Your desmoid tumor care team may recommend treatment with targeted therapy if your tumor progresses or is causing symptoms or other problems.

Researchers studied nirogacestat in large, regulated studies known as clinical trials. They found that nirogacestat slowed desmoid tumor progression compared to a placebo (inactive treatment).

The clinical trial found that 41 percent of participants who took nirogacestat had significant desmoid tumor shrinkage by at least 30 percent. Only 8 percent of those who took the placebo had significant tumor shrinkage.

When choosing a desmoid tumor treatment option, your doctor or oncologist (cancer specialist) will weigh the benefits and risks. It’s important to discuss possible side effects and how the medication may affect your quality of life.

The most commonly reported side effects of nirogacestat treatment included:

• Diarrhea
• Hair loss
• Abdominal (stomach) pain and nausea
• Headache
• Cough, shortness of breath, and upper respiratory infections
• Fatigue (extreme tiredness that doesn’t improve with rest)
• Ovarian toxicity (for example, fertility issues)
• Rash
• Stomatitis (mouth sores)

This medication is not safe if you’re pregnant or trying to become pregnant.

Tyrosine kinase inhibitors (TKIs) are widely used targeted therapies for treating tumors and cancers. They block kinases — proteins that cells use to send growth signals. Blocking these proteins with TKIs may prevent desmoid tumors from growing.

Doctors treat desmoid tumors with several TKIs. It’s important to note that the FDA hasn’t approved any TKIs specifically for desmoid tumors. Instead, doctors prescribe them off-label, meaning they’re used for conditions other than what they were originally approved for.

Below are some TKIs that are used to treat desmoid tumors. Your healthcare team can help you understand why a specific drug might be recommended and the benefits and risks of the available treatments.

Sorafenib

Sorafenib (Nexavar) is a TKI approved for treating certain thyroid, kidney, and liver cancers. One study found that 33 percent of desmoid tumors had significant shrinkage (at least 30 percent) with sorafenib treatment. However, the authors noted that 20 percent of people who received a placebo also had their tumors significantly shrink.

Potential side effects of sorafenib include:

• Diarrhea
• Loss of appetite, nausea, and vomiting
• Hypertension (high blood pressure)
• Skin rashes or dry and itchy skin
• Mouth sores

Pazopanib

Another TKI, pazopanib (Votrient), is typically used to treat soft tissue sarcomas (cancers) and kidney cancer. One clinical trial from France assigned participants with desmoid tumors to pazopanib or the chemotherapy drugs vinblastine and methotrexate.

The authors found that more than 80 percent of people who received pazopanib and 54 percent of those who received chemotherapy were progression-free at six months. This means that their tumor didn’t grow or progress during this time.

Common side effects of pazopanib include:

• Fatigue
• Diarrhea
• High blood pressure
• Loss of color in your skin and hair

Imatinib and Nilotinib

Doctors also prescribe imatinib (Gleevec) to treat certain soft tissue sarcomas. A study found that imatinib treatment may slow and even stop disease progression for several months.

Side effects of imatinib treatment include:

• Fluid buildup in the body
• Nausea
• Fatigue
• Diarrhea
• Muscle aches

Imatinib treatment was unsuccessful for some participants. The researchers gave them the TKI nilotinib (Tasigna). Overall, seven of the eight participants had slowed or stopped desmoid tumor progression.

Nilotinib may cause:

• Itchy skin or rashes
• Headaches
• Easy bruising and bleeding
• Muscle aches
• Abdominal pain
• Fatigue

Sunitinib

Sunitinib (Sutent) is a TKI used to treat a certain type of soft tissue sarcoma, known as a gastrointestinal stromal tumor (GIST), in people who can’t take or progress on imatinib.

An older study included 19 people treated with sunitinib. They found that eight of the participants had stable disease. This means their desmoid tumors had only minor growth, minor shrinkage, or no change in growth.

Side effects of sunitinib include:

• Cough or shortness of breath
• Easy bruising and bleeding
• Loss of appetite
• Dizziness
• Headaches
• Diarrhea or constipation
• High blood pressure

Researchers are also studying new targeted therapies for treating desmoid tumors. This includes a drug called tegavivint and another called varegacestat.

Tegavivint is a new type of targeted therapy being studied for desmoid tumors.

Like nirogacestat, varegacestat is a gamma-secretase inhibitor. Phase 3 trial data reported in December 2025 showed positive topline results for varegacestat, which is an important step toward potential FDA review. However, it remains investigational unless and until it is FDA-approved.

New drugs are tested in clinical trials. These studies are critical to ensure new medications can become available for rare diseases like desmoid tumors. If you’re interested in joining a clinical trial studying a new treatment for desmoid tumors, talk to your desmoid tumor care team.

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