Substrate Reduction Therapy

Substrate reduction therapy (SRT) is an oral medication for Gaucher disease (pronounced go-SHAY). SRT is not available for women who are pregnant or breastfeeding, nor is it approved for use in children. Learn more about Gaucher disease treatment options.

Substrate Reduction Therapy Drugs for Gaucher Disease

The U.S. Food and Drug Administration (FDA) approved the first oral SRT medication for Gaucher disease in 2003. There are currently 2 FDA-approved oral SRT drugs for patients with Gaucher disease:

These drugs act differently in the body and are only approved for use in certain patients. If you are eligible to receive SRT, a Gaucher specialist can help you identify which medication is right for you.

How Substrate Reduction Therapy Works

SRT partially blocks the body from producing glucocerebroside, the fatty chemical that builds up in the bodies of patients with Gaucher disease. The drug works differently from enzyme replacement therapy for Gaucher disease, which breaks down excess glucocerebroside.

If we think of this process as recycling, ERT helps the body recycle more waste (glucocerebroside), while SRT helps the body produce less of it to begin with. It does not completely shut down production, but it allows the enzymes you have to keep your body in balance.

Who Can Receive Substrate Reduction Therapy for Gaucher Disease?

SRT is approved only for certain patients. The drug is not approved for use in:

  • Children or teens
  • Pregnant or breastfeeding women
  • Very elderly patients
  • People with severe kidney or liver disease

To receive eliglustat, your metabolic profile (rate at which your body breaks down the drug) must fall within a certain range. Free testing is available from the pharmaceutical manufacturer to determine whether you are eligible. A Gaucher specialist can help you determine the treatment that is right for you, and you should always discuss any side effects with your physician. Learn more about creating a Gaucher disease treatment team.

Advantages and Disadvantages of Substrate Reduction Therapy for Gaucher Disease

Before you start taking oral SRT, it is important to consider the pros and cons compared with ERT. Pros of using SRT to treat Gaucher disease include:

  • Convenience: Many people find it more convenient to take a pill than to travel to an infusion center.
  • Less invasive: SRT doesn’t require an IV or port, a device installed under your skin for long-term use in delivering IV medication.
  • Consistent dosage: SRT provides a consistent dose over time. In comparison, patients receive ERT only every 2 weeks or so. As a result, some report feeling fatigued right before an infusion and feeling best right after one.

Cons of taking SRT as a Gaucher disease treatment include:

  •  Side effects:  Certain SRT drugs may have unpleasant side effects such as diarrhea, stomach problems and even neuropathy. Neuropathy causes numbness, pain and weakness in areas like your hands and feet.

  • Drug interactions: Some SRT drugs can interact with medications that include antibiotics, cardiac drugs and antidepressants. However, you can stop taking SRT to take antibiotics. Make sure your primary care physician and Gaucher specialist know about all the medications you take and whenever you change your medications.

  • Sticking to your drug regimen: Some people stop taking their oral medication or change the recommended dose due to the side effects. Some may also forget to take their medication simply because they feel better. It is very important for people with Gaucher disease to continue receiving the treatment to prevent permanent damage to their bodies.

Does My Insurance Cover Substrate Reduction Therapy?

If you have trouble getting your insurance company to pay for SRT, help is available. Pharmaceutical companies have dedicated case managers who can help you navigate your coverage. Find out more about financial support available for patients with Gaucher disease.

Nonprofits like the Patient Access Network, Patient Services, Inc. and NeedyMeds may also help people in need pay for their medications.

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