5 New Treatments for Chronic ITP

Living with chronic immune thrombocytopenia (ITP) means dealing with more than just low platelets (the cells that help blood clot). It often brings bruises that appear out of nowhere, fatigue, and the constant worry of serious complications. The good news is that, in recent years, researchers have made big strides in finding new treatments for ITP.

These options go beyond common treatments, like corticosteroids or intravenous immunoglobulin (IVIG). They’re designed to raise platelet counts in new ways, improve safety, and offer longer-lasting results. Some are already approved by the U.S. Food and Drug Administration (FDA). Others are being tested in ongoing clinical trials.

In this article, we’ll discuss the latest advances in the treatment of chronic ITP. These new therapies boost platelet count in unique ways and prevent severe bleeding events.

What Is Chronic ITP?

Chronic ITP is an autoimmune disease. Your body makes autoantibodies (immune proteins) that stick to your platelets. Once this happens, other immune cells, like macrophages, recognize the platelets as “foreign” and destroy them.

This process lowers your platelet count. If your platelet levels stay too low for more than 12 months, doctors call it chronic ITP. Since platelets are vital for clotting, people with ITP may bruise easily, have nosebleeds, or experience bleeding gums. In rare cases, bleeding inside the brain or other organs can occur. This can be life-threatening.

Traditional treatments — such as rituximab, steroids, or surgery — can help, but they don’t always work in the long term. Many people relapse after stopping therapy. That’s why scientists continue to study new therapies with better safety profiles, better platelet responses, and fewer side effects. Here, we’ll cover five of the most recent approaches.

1. Thrombopoietin Receptor Agonists

One of the biggest breakthroughs in the treatment of chronic ITP has been the use of thrombopoietin receptor agonists (TPO-RAs). These medicines work with your body’s own system for making platelets. In healthy people, the hormone thrombopoietin (TPO) tells megakaryocytes (special bone marrow cells) to make platelets. In chronic ITP, platelet destruction happens faster than new ones can be made. TPO-RAs step in to boost platelet production and restore balance.

Three TPO-RAs are FDA-approved for chronic ITP:

• Eltrombopag (Promacta) — This oral (pill) option was approved in 2008 for adults with chronic ITP who haven’t responded well to steroids, immunoglobulins, or surgery. In 2015, it gained approval for children aged 1 year or older who haven’t responded to other treatments.
• Romiplostim (Nplate) — This once-weekly injection was first approved for adults with chronic ITP in 2008. It is now also approved for children aged 1 year or older who haven’t responded to other treatments.
• Avatrombopag (Doptelet) — This oral option was approved in June 2019 for individuals with chronic ITP who haven’t responded to other treatments. This treatment increases platelet levels quickly and reduces the risk of bleeding events.

While not FDA-approved for chronic ITP specifically, lusutrombopag (Mulpleta) has also been studied for thrombocytopenia related to liver disease.

Studies show that many adults respond well to these medicines. Many people reach safe platelet counts and lower their risk for bleeding events. Treatment is usually long term. However, some studies report that about half of people who come off their medications may remain stable for years after ending treatment. The overall safety profile of these drugs is good, and serious side effects are rare.

2. Fostamatinib

Fostamatinib (Tavalisse) works by protecting the platelets you already have. In chronic ITP, macrophages “clean up” cells and break down platelets tagged by autoantibodies. Fostamatinib blocks a signal inside these macrophages. This prevents them from destroying platelets. In turn, your platelet counts rise, and the risk of bleeding is reduced.

The FDA approved fostamatinib in 2018 for adults with chronic ITP who have already tried other medicines without success. That means it’s not a first-line treatment (the approach that doctors try first). It may be a second-line treatment option when steroids, IVIG, or TPO-RAs don’t work well enough.

Most people tolerate fostamatinib well, but some may experience side effects. The most common side effects include diarrhea, elevated liver enzymes, neutropenia (a decrease in the cells that fight infections), high blood pressure, tiredness, and abdominal (belly) pain. Doctors usually check blood pressure and liver function during treatment.

3. Bruton’s Tyrosine Kinase Inhibitors

A newer type of drug being studied for chronic ITP is called a BTK inhibitor. BTK stands for Bruton’s tyrosine kinase — an enzyme that helps B cells grow and make antibodies. In chronic ITP, B cells make harmful autoantibodies that mistakenly tag platelets for destruction. By blocking BTK, these medicines reduce B-cell activity and help protect your platelets.

The first and only BTK inhibitor currently FDA-approved for chronic ITP is rilzabrutinib (Wayrilz). This medicine is taken by mouth and is being tested further in international clinical trials. One clinical trial showed that about 23 percent of adults with ITP showed a strong platelet response. This means their platelet counts rose to safer levels. Some even showed strong improvement after just a few weeks of treatment. Some people were also able to reduce their need for rescue therapies, like IVIG.

So far, rilzabrutinib has shown a good safety profile. Mild side effects may include nausea, diarrhea, or headache. Serious adverse (negative) events have been rare. Further clinical studies are underway to confirm these results. If successful, researchers believe this could become a major new treatment option for chronic ITP.

4. Neonatal Fc Receptor Blockers

Your immune system regulates your antibody levels using a protein known as the neonatal Fc receptor (FcRn). Blocking FcRn causes your body to clear out extra autoantibodies. This means your platelets are less likely to be destroyed, which can increase your count.

Scientists are currently studying efgartigimod (Vyvgart) as a treatment for chronic ITP. A 2022 study found that efgartigimod is a safe medication that significantly improves platelet counts.

Rozanolixizumab (Rystiggo) has also shown good results in phase 3 clinical trials in adults with chronic ITP. The studies showed meaningful improvement in platelet count. However, this medicine is not yet specifically approved by the FDA for ITP.

5. New Monoclonal Antibodies

Monoclonal antibodies are lab-made proteins that target specific parts of your immune system. For chronic ITP, scientists are studying new ones that may work better and last longer.

Ianalumab works by blocking a signal called B-cell activating factor (BAFF). The drug helps reduce harmful antibodies and allows platelet counts to rise. Studies show that ianalumab may increase platelet counts in people whose ITP didn’t improve with other therapies. Larger studies are now testing it against a placebo (sugar pill). This will help to confirm its long-term benefits.

Two treatments that show promise for chronic ITP are daratumumab (Darzalex) and mezagitamab. They work like rituximab to block cells and stop them from making autoantibodies that destroy platelets.

These new monoclonal antibodies aren’t yet approved for ITP, but the data looks promising so far. They may offer more treatment options in the future for people who haven’t responded to other therapies.

The Future of ITP Treatment: New and Upcoming Studies

Research into chronic ITP is moving quickly, and newer types of drugs are on the horizon. One promising area is complement inhibition. A drug called sutimlimab targets the complement system — a part of the immune system that can destroy platelets. In an early trial, some people had a rise in platelet counts in just 24 hours.

Another study is testing bortezomib — a medicine already used for multiple myeloma. Scientists are studying whether it can help reduce the long-lived plasma cells that make harmful antibodies in ITP. Finally, researchers are also studying sirolimus. This drug has shown success in other autoimmune blood disorders and could help people with hard-to-treat ITP.

Join the Conversation

On myITPcenter, people share their experiences with chronic immune thrombocytopenia, get advice, and find support from others who understand.

Have you tried a new treatment for your chronic ITP? How has it improved your symptoms or your quality of life? Let others know in the comments below.