Dear DMD Community,

In September, ITF Therapeutics was pleased to announce new data from multiple analyses of DUVYZAT® (givinostat) in the treatment of DMD. The analyses were presented as posters during the 2025 Neuromuscular Study Group (NMSG) Annual Scientific Meeting held in Stresa, Italy.

hese new findings are descriptive only and cannot predict individual results. Please see Important Safety Information below and the full DUVYZAT Prescribing Information.

These analyses provide additional insights on many aspects of treatment with DUVYZAT that families and advocacy partners have often asked about, including updates on dosing flexibility, the risk and management of thrombocytopenia, correlation between vastus lateralis fat fraction (VLFF) and efficacy outcomes, and respiratory function. Through our continued focus on research, our goal is to provide information that can help members of the DMD community and their healthcare providers make informed decisions about treatment with DUVYZAT.

To learn more about our data announcements and to find the individual study abstracts, see our press release.

We are deeply grateful to all members of the DMD patient and treatment communities who continue to play important roles in helping us advance new research.

What is DUVYZAT?

DUVYZAT is a prescription medicine for the treatment of Duchenne muscular dystrophy (DMD) in people 6 years of age and older. It is not known if DUVYZAT is safe and effective in children under age 6.

Important Safety Information

What is the most important information I should know about DUVYZAT?

• Low platelet counts in your blood (thrombocytopenia). Platelets are important for blood clotting, so having fewer can increase your risk of bleeding or bruising. Your doctor will check your blood count before you start DUVYZAT and regularly during treatment for signs of thrombocytopenia. Call your doctor right away if you notice unusual bleeding or small red or purple spots on the skin.
• Increased levels of fat (triglycerides) in your blood. You may not have any symptoms, so your doctor will do blood tests before you start DUVYZAT and regularly during treatment to check your triglyceride levels.
• Frequent watery loose stools (diarrhea) and vomiting. DUVYZAT can cause vomiting and moderate to severe diarrhea. If diarrhea occurs, you should keep track of the frequency and severity of your diarrhea symptoms, drink plenty of fluids, and contact your doctor.
• If thrombocytopenia, increased triglycerides, or diarrhea cannot be managed, your doctor may change your dose or stop your treatment with DUVYZAT, if needed.

Before taking DUVYZAT, tell your doctor about all of your medical conditions, including:

• any heart problems or medicines you take that could increase your chance for irregular heart rhythms.
• any bleeding problems.

Tell your doctor about all of the medicines you take, including prescription and over-the-counter medicines, vitamins, and herbal supplements.

Taking DUVYZAT with certain other medicines may affect each other. Taking DUVYZAT with other medicines can cause serious side effects. Do not start or stop other medicines without talking to your doctor.

What are the possible side effects of DUVYZAT?

• DUVYZAT can cause serious side effects, including changes in the electrical activity of your heart called QT prolongation. QT prolongation can increase the risk of developing a type of irregular heart rhythm known as Torsades de Pointes. Call your doctor right away if you feel faint, have an irregular heartbeat, feel dizzy, or lose consciousness. See the section titled “What is the most important information I should know about DUVYZAT?” for more information about side effects.

The most common side effects (occurring in >5% of DUVYZAT-treated patients) included diarrhea, abdominal pain, low platelet levels, nausea/vomiting, high triglyceride levels, elevated temperature/fever, muscle aches, rash, joint pain, fatigue, constipation and decreased appetite.

These are not all of the possible side effects of DUVYZAT. For more information, ask your doctor or pharmacist.

Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Please see full Prescribing Information and Medication Guide.

DUVYZAT is a registered trademark of Italfarmaco S.p.A.

Warmly,
Caroline Allen
Head of Patient Advocacy, ITF Therapeutics

C-DUV-US-0588 09/2025