Your Guide to Duvyzat for Duchenne Muscular Dystrophy

Written by Kelli Garrison, PharmD, BCPS
Medically Reviewed by Jessica Swirble, PharmD on January 01, 2025
8 min read

Duchenne muscular dystrophy (DMD) is a genetic disease that causes progressive muscle weakness. DMD commonly affects boys, where symptoms are seen in early childhood. There is not a cure for DMD. Health care providers manage symptoms with steroids, physical therapy, and assistive devices (like braces and wheelchairs). New medicines are being studied to help slow the progression of DMD by targeting the abnormal gene or inflammatory processes. Duvyzat is the first nonsteroidal medicine for DMD that helps to slow down damage to your muscles. 

Your muscles need continuous maintenance to stay strong and healthy. Duchenne muscular dystrophy (DMD) happens when there is a change in a person's genetic instructions that affects the production of an important muscle protein called dystrophin. This change, or mutation, causes the body to make little or no dystrophin or to make a version that doesn't work properly. Without the right amount of functioning dystrophin, muscles become weak and can't repair themselves as they should, leading to progressive muscle weakness.

Enzymes in the body called histone deacetylases (HDAC) tell other proteins how to repair muscles. In addition to less dystrophin, people with DMD also have overactive HDAC enzymes, which cause chronic inflammation, decrease muscle repair, and replace muscle with fat or scar tissue. This uncontrolled inflammation can cause muscle damage and prevent muscles from repairing overtime. 

DMD is a progressive disease that is usually diagnosed in young children. This means that the symptoms are more noticeable as the child gets older. Since there is not a cure for DMD, health care providers manage the symptoms with medicines and physical therapy to help keep muscles strong.  

New medicines have been approved to target specific areas of these genetic mistakes or to provide a similar dystrophin protein directly to the muscle cells. This allows the body to start making a similar dystrophin protein. With more dystrophin, the muscles can stay strong longer. 

Duvyzat is the first nonsteroidal medicine that slows down the progression of muscle damage. It is thought to reduce the overactive HDAC enzymes, which reduces inflammation in muscle cells, slows down muscle breakdown, and increases the ability for the body to repair muscles.

Duvyzat is an oral medicine that is taken twice daily with food. It should be taken at the same time (morning and night) every day. Your health care provider may treat your DMD with Duvyzat alone or may also prescribe steroids. 

The medicine should not be mixed with water or any other liquid. Before taking Duvyzat, mix the medicine by turning the bottle up and down for at least 30 seconds. The dosing syringe that comes with the medicine should be used for each dose. 

One study has been done to look at the safety and efficacy of Duvyzat for the treatment of Duchenne muscular dystrophy (DMD) when compared with placebo. Placebo-controlled studies help researchers see differences in benefit or harm of a medicine when compared with no treatment.

All the people in the study were male (100%), had genetically confirmed DMD, and were at least 6 years of age, with an average age of 9. Most people in the study were White (91%), with 3% who identified as Asian, 1% as Black, and 4% as Other. Each person was taking a steroid medicine for at least six months before starting the study. 

To start the study, each person had to complete the following timed tests to measure mobility and strength in their legs. These tests are also used to track disease progression. 

  • Four-stair climb. This test measures the time (in seconds) it takes a person to walk up four stairs. The person climbs as quickly and safely as possible. To be in the study, the person must have an average of eight seconds or less. 
  • Time-to-rise. For this timed test, a person is lying on the floor with arms by their side and stands up without assistance. This test evaluates muscle weakness. To be in the study, the person must have a time-to-rise of at least three seconds but less than 10 seconds.

Efficacy in the study was based on changes in the four-stair climb test after 72 weeks of treatment. Other tests used to look at differences between Duvyzat and placebo included the following:

  • North Star Ambulatory Assessment (NSAA) score, which measures how well someone with DMD can move and do their everyday activities. 
  • Six-minute walk test, which measures how far you walk in six minutes
  • Muscle strength assessment, which includes bending the elbow and straightening the knee
  • Vastus lateralis fat fraction (VLFF), which uses an MRI image to measure changes in the muscle and fat ratios in the large muscles. As muscles weaken, there is an increased amount of fat in those areas. Therefore, a lower VLFF percentage shows healthier muscles to aid in movement.

With DMD, the ability to move will decrease over time. In this study, people taking Duvyzat saw a slower decline in their ability to move compared to people taking placebo. This means that after 72 weeks, the people taking Duvyzat saw less disease progression. 

Strength and ability to move.  In the study, the movement of each person was timed doing the four-stair climb and time-to-rise.

  • Patients taking Duvyzat took about 1.25 seconds longer to climb stairs at the end of the study compared to when they started, while patients taking placebo took about three seconds longer to climb stairs by the end. This means that Duvyzat helped to maintain stair-climbing about 40% more than the placebo.
  • Patients taking Duvyzat generally took less time for the time-to-rise test, with an average time of nine seconds, compared to 12 seconds for placebo.

Change in NSAA scores. At the end of the study, people taking Duvyzat failed fewer test items compared to people taking the placebo. The change in the overall NSAA score for Duvyzat was -2.66 points compared with -4.58 points for the placebo. This also shows a slower decline in the ability to move and muscle strength for people taking Duvyzat. 

Vastus lateralis fat fraction (VLFF). MRI images showed that people taking Duvyzat had smaller changes in the muscle-to-fat ratios (7.48% increase) compared to people taking placebo (10.89% increase). This may be another sign of slower disease progression. 

Your results may differ from what was seen in clinical studies. You and your health care provider should determine if the benefits outweigh any potential risks. 

It may take up to a year to see the small changes from Duvyzat. As the inflammation decreases, the muscles may slowly start to become stronger. You may have slight improvements in movement, like walking, climbing stairs, or getting up off the floor. However, you may not see improvements but may see a slower decline. It is important to track your progress and review with your health care provider. 

The most common side effects of Duvyzat are diarrhea, nausea/vomiting, abdominal pain, and fever. Tell your health care provider if you have any of these symptoms. They may give you medicine and guidance on possible diet changes to help ease the symptoms. Make sure that you stay hydrated, drinking plenty of water.

Other common side effects, which can be serious, are low platelet levels (thrombocytopenia) and high levels of fat in your blood (hypertriglyceridemia). Your health care provider may check your blood levels before starting Duvyzat and during treatment. 

  • Platelets help to form blood clots. Having a low level of platelets may increase your risk of bleeding. Tell your health care provider if there is more bruising or bleeding than normal, nosebleeds, or bleeding that does not stop.
  • If fat levels in your blood increase, talk to your health care provider about healthy diet options.

These are not all of the possible side effects. Talk with your health care provider if you are having symptoms that bother you. In the U.S., you can report side effects to the FDA at www.fda.gov/medwatch or by calling 800-FDA-1088. In Canada, you can report side effects to Health Canada at www.health.gc.ca/medeffect or by calling 866-234-2345.

Before starting Duvyzat, your health care provider may perform blood tests to monitor your platelet and fat levels or do an electrocardiogram (EKG) to check how your heart is beating. While you are taking Duvyzat, your health care provider may repeat these tests.

Duvyzat may affect the blood levels of some medicines. This may increase the risk of side effects of those medicines. Talk with your health care provider if you are using any of the following medicines. 

  • CYP3A4 substrates like atorvastatin, simvastatin, and other medicines
  • OCT2 transporter substrates like metformin 

Duvyzat may cause heart rhythm changes called QT prolongation and torsade de pointes. Tell your health care provider if you have taken any of the following medicines within the past two weeks.

  • Antiarrhythmics like amiodarone, disopyramide, procainamide, quinidine, and sotalol
  • Antibiotics like azithromycin, ciprofloxacin, clarithromycin, erythromycin, levofloxacin, and moxifloxacin
  • Antidepressants like amitriptyline, citalopram, and imipramine
  • Antipsychotic medicines, like droperidol, haloperidol, olanzapine, quetiapine, risperidone,  thioridazine, and ziprasidone
  • Other medicines that may cause changes in heart rhythm like methadone, ondansetron, and sumatriptan
  • Over-the-counter (OTC) medicines like diphenhydramine
  • Herbal supplements like echinacea

This is not a complete list of medicines that may interact with Opzelura. Tell your pharmacist or health care provider about all the prescription or OTC medicines, vitamins/minerals, herbal products, or other supplements you take or have recently taken. This will help them determine if there are any interactions or if you need a dosage adjustment.

Duvyzat is considered a specialty medicine, which is a high-cost medication that is taken for rare, complex, or long-term (chronic) diseases. It requires a different process than picking up a prescription at your local pharmacy. The manufacturer has a program to help support the process for you and your health care provider. You can find out more at www.Duvyzat.com or by calling 855-488-3272.  

Here are some differences that you may expect. 

Insurance approval. Your insurance may require approval for using this medicine, also called a prior authorization. The insurance company reviews the prescription from your health care provider to make sure it is covered and determines the process that needs to be followed. 

Financial assistance. There is a financial assistance program from the manufacturer. Whether you are eligible depends on whether you have prescription insurance and what type of insurance you have.