Dear DMD Community,

It was a busy and exciting week at the 2026 MDA Clinical and Scientific Conference. In our continued commitment to sharing data, we were grateful for the opportunity to present findings from our research in Duchenne muscular dystrophy (DMD).

The analyses we shared are descriptive only and cannot predict individual results. Please see Important Safety Information below and the full DUVYZAT Prescribing Information.

At this year’s meeting, we had a total of ten presentations from the givinostat clinical development program. These included four “de novo” poster presentations — meaning the findings were being presented publicly for the first time. We also delivered one oral and five “encore” poster presentations, which included data that were shared previously at other scientific meetings. These presentations covered a range of areas that community members have told us are important to them, including longer-term safety observations, dosing considerations, and analyses on disease progression in individuals treated with givinostat.

The content of the presentations is highly complex and, given that we are part of a regulated industry, we are not able to fully summarize the study findings in this letter. This is important to help ensure that information shared publicly is accurate, balanced, and does not unintentionally sound like a medical claim. However, what we can share is this: we remain fully focused on evaluating data from our Phase 3 clinical trial and ongoing open-label extension study to learn everything we can about treatment with DUVYZAT. We also prioritize opportunities to bring information to the Duchenne community that can support informed treatment decisions.

Our Medical Affairs team actively works with clinicians to ensure they have access to robust, up-to-date information about DUVYZAT. If you have any questions about treatment with DUVYZAT, we encourage you to speak with your healthcare provider.

For more information about the individual study abstracts presented at the 2026 MDA Clinical and Scientific Conference, you can read our press release here.

Thank you to the families, advocates, researchers, and clinicians whose contributions and perspectives have been essential in helping us better understand the evolving needs and priorities of the Duchenne community. Your feedback continues to shape our ongoing 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-ITF-US-0027 02/2026