RAXONE® - Phase 3 Study Assessing the Efficacy, Safety and Tolerability of Idebenone in Patients with Duchenne Receiving Glucocorticoid Steroids (SIDEROS)


Frequently Asked Questions (FAQs) about this study:


What stage is this research?

  • This is a new Phase 3 trial which began recruiting participants in September 2016.


What was the goal or purpose of this study?

  • The primary objective of this study is to assess the efficacy and safety of Raxone® in slowing the loss of pulmonary function in  boys with Duchenne receiving glucocorticoid steroids. In a previous Phase 3 study (DELOS), idebenone was shown to slow the loss of respiratory function in boys with Duchenne not taking concomitant glucocorticoid steroids.


What is Raxone® and how does it work?

  • Raxone® is the brand name for Santhera’s 150 mg film-coated idebenone tablets. Idebenone works in Duchenne to increase the energy output of the cells’ mitochondria – the parts (“factories”) of the cell that generate all of a cells’ energy. Specifically, the drug acts as an electron Glossary Link carrier to provide additional electrons to the mitochondria, which use them to generate energy. Idebenone can carry and drop off electrons within the mitochondria numerous times. In addition to helping cells make extra energy, idebenone is a powerful antioxidant and can neutralize destructive free radicals in cells. All of these activities help dystrophic muscle cells to maintain their cellular energy supply, which is reduced as a result of the lack of dystrophin and protect cells from oxidative stress.


Who was funding this study?


Who is eligible to participate in this study?

  • To participate in this study, you must have stable use of glucocorticoid steroids continuously for at least 12 months with no dose adjustments for the past six months, with the exception of weight changes. This includes prednisone or deflazacort, and any dosing regimens. Changes between prednisone and deflazacort are allowed if dose is comparable.
  • Participants must have a baseline Forced Vital Capacity between 30%-80% and be able to provide reliable and reproducible pulmonary function testing.


What do I have to do if I decide to participate in this study?

  • This study involves a screening assessment, and boys will be randomized to receive either 900 mg/daily of idebenone (2 tablets, 3 times daily with food) or placebo for 18 months. Parents will be asked to keep a daily diary of medication intake.
  • Participants will complete safety assessments, pulse-oximetry, and pulmonary function tests at study site visits every three months, as well as be given a hand-held spirometry device to complete weekly pulmonary function assessments at home.
  • Funding will be provided to assist families with costs to participate in the study.


How long will this study last, and will I have access to the drug/treatment once the study has ended?

  • Patients’ active participation is up to 21-22 months (88-92 weeks) including screening and follow-up visits, and 18 months receiving study medication or placebo.
  • Patients completing the study through week 78 will be eligible to participate in an open-label extension study and will continue to receive medication until the trial is terminated or Raxone is approved.


Where can I learn more about this study?


 (Updated 5/11/2017)