Haematological changes
Duvyzat can cause dose-related thrombocytopenia and other signs of myelosuppression, including decreased hemoglobin and neutropenia.
In Study EPIDYS, thrombocytopenia occurred in 33% of patients treated with Duvyzat compared to no patients on placebo. The maximum decrease in platelets occurred within the first 2 months of therapy and remained low throughout the course of therapy. In a few patients, thrombocytopenia was associated with bleeding events including epistaxis, hematoma or contusions. Low platelet counts resulted in Duvyzat dose reduction in 28% of patients. Patients with baseline platelet counts below the lower limit of normal were excluded from the study.
Decreased hemoglobin and decreased neutrophils were also observed in patients treated with Duvyzat compared to placebo.
Blood counts should be monitored every 2 weeks for the first 2 months of treatment, at month 3, and then every 3 months thereafter. The dose of Duvyzat should be modified in case of confirmed thrombocytopenia. Treatment should be permanently discontinued if the abnormalities worsen despite dose modification. If a patient develops signs or symptoms of thrombocytopenia, a platelet count should be obtained as soon as possible, and dosing should be held until platelet count is confirmed.
Increased Triglycerides
Duvyzat can cause elevations in triglycerides.
In Study EPIDYS, hypertriglyceridemia occurred in 23% of patients treated with Duvyzat (one of whom had familial hypertriglyceridemia) compared to 7% of patients on placebo.
High triglycerides (i.e., levels greater than 3.42 mmol/L) resulted in discontinuation and led to dosage modification in 2% and 8%, respectively, of patients treated with Duvyzat.
Triglycerides level should be monitored at 3 months, 6 months, and then every 6 months thereafter. The dosage should be modified if fasting triglycerides are verified >3.42 mmol/L. Treatment with Duvyzat should be discontinued if triglycerides remain elevated despite adequate dietary intervention and dosage adjustment.
Gastrointestinal disturbances
Gastrointestinal disturbances, including diarrhoea, nausea/vomiting, and abdominal pain were common adverse reactions in Duvyzat clinical trials in DMD.
In Study EPIDYS, diarrhoea was reported in 37% of patients treated with Duvyzat (with 1 severe case reported) compared to 20% of patients on placebo. Diarrhoea usually occurred within the first few weeks of initiation of treatment with Duvyzat.
Vomiting and nausea, sometimes severe and usually occurring within the first 2 months of treatment, occurred in 32% of patients treated with Duvyzat compared to 18% of patients on placebo.
Abdominal pain occurred in 34% of patients treated with Duvyzat compared to 25% of patients on placebo. One case of abdominal pain was serious.
Antiemetics or antidiarrheal medications may be considered during treatment with Duvyzat. Fluid and electrolytes should be replaced as needed to prevent dehydration. The dosage of Duvyzat in patients with moderate or severe diarrhoea should be modified, and treatment should be discontinued if significant symptoms persist.
QTc prolongation
Duvyzat can cause prolongation of QTc. Avoid use of Duvyzat in patients who are at an increased risk for ventricular arrhythmias (including torsades de pointes), such as those with congenital long QT syndrome, coronary artery disease, electrolyte disturbance, concomitant use of other medicinal products known to cause QT prolongation. In patients with underlying cardiac disease or in patients who are taking concomitant medications that cause QT prolongation, obtain ECGs prior to initiating treatment with Duvyzat, during concomitant use and as clinically indicated.
Excipients with known effects
Patients with hereditary fructose intolerance (HFI) should not take this medicinal product.
This medicinal product contains 400 mg sorbitol in each mL which is equivalent to 40 mg/kg.
The additive effect of concomitantly administered products containing sorbitol (or fructose) and dietary intake of sorbitol (or fructose) should be taken into account.
The content of sorbitol in medicinal products for oral use may affect the bioavailability of other medicinal products for oral use administered concomitantly.
This medicinal product contains 4.4 mg sodium benzoate in each mL which is equivalent to 0.44 mg/kg.
This medicinal product contains less than 1 mmol sodium (23 mg) per dose and therefore, is essentially 'sodium-free'.