Santhera Completes Enrollment of Phase 3 SIDEROS Study with Puldysa® (Idebenone) in Duchenne Muscular Dystrophy (DMD)
Pratteln, Switzerland, May 20, 2020
Santhera Pharmaceuticals announces the full recruitment of its Phase 3 SIDEROS study with idebenone in Duchenne muscular dystrophy (DMD). The sample-size and variability re-assessment performed according to study protocol demonstrated that with the currently enrolled patients the study has a very high power (>99%). Given the strong powering of SIDEROS, the Company is now assessing the potential of conducting an interim analysis to test for overwhelming efficacy with a view of completing the trial early.
With patient recruitment into the 18-month international SIDEROS trial in its final stages, Santhera performed the planned sample size and variability re-assessment in accordance with the study protocol to confirm adequate study power. This blinded analysis showed that variability is lower than anticipated per protocol and, with the current number of enrolled patients, the SIDEROS study has a very high power of over 99% to detect a treatment difference. On this basis, Santhera has taken the decision to complete enrollment into the SIDEROS trial. At present, approximately half of the recruited patients in SIDEROS have completed 18 months of treatment and about two-thirds of patients have completed 12 months of treatment.
Owing to the decision to complete enrollment of this advanced study, its very high power as well as the urgent unmet medical need, Santhera is assessing the potential of conducting an interim analysis to test for overwhelming efficacy with a view of completing the trial early. Such an interim analysis would be performed by the independent Data and Safety Monitoring Board (DSMB) to preserve the integrity of the study. If overwhelming efficacy is not established in the interim analysis, the study could continue as planned with the currently enrolled patients and the corresponding high power. However, if overwhelming efficacy is demonstrated, it would be considered unethical to continue with the blinded study and the Company would decide to end the study later this year. This would result in the acceleration of corresponding regulatory filings by approximately one year both in Europe and the US.
Gunnar Buyse, MD, Ph.D., Professor of Child Neurology at the University Hospitals Leuven (Belgium), SIDEROS Principal Investigator and Lead Investigator for Europe – “Santhera is the only company that has dedicated its clinical development program towards finding a treatment to preserve respiratory function in DMD. The large Phase 3 SIDEROS study was designed to confirm the efficacy of idebenone in patients with respiratory function decline who are concurrently taking glucocorticoids. We are truly excited that SIDEROS has completed recruitment and is on track to generate a comprehensive dataset in an area of such high unmet need.”
Oscar Henry Mayer, MD, Medical Director of the Pulmonary Function Testing Laboratory at the Children’s Hospital of Philadelphia and Lead Investigator for the US – “There are currently no approved treatments to slow the rate of respiratory function decline leading to respiratory failure, which remains a leading cause of premature death in young men at the advanced stages of DMD. By slowing the rate of respiratory function decline, we open the possibility of delaying the time to chronic respiratory failure and the need to assisted ventilation and reducing the risk of other life-threatening respiratory complications.”
Sjöblom Nygren, MD, Chief Medical Officer and Head of Development of Santhera – “We are delighted to have reached such an important milestone and wish to express our sincere thanks to patients and families, caregivers, physicians and study personnel for their support and commitment.”
About SIDEROS
SIDEROS, the largest currently ongoing clinical trial in DMD, is a double-blind randomized placebo-controlled Phase 3 study evaluating the efficacy of idebenone in delaying the loss of respiratory function in patients with DMD. Patients on any stable glucocorticoid treatment scheme and irrespective of the underlying dystrophin mutation or ambulatory status were randomized to receive oral idebenone (900 mg/day three times a day) or placebo for 18 months. The primary endpoint of the trial estimates the treatment difference in FVC%p (forced vital capacity % predicted). Patients completing the trial are offered the opportunity to enroll in an open-label extension study where all patients receive idebenone. The study is currently conducted in 62 sites in the United States, Europe and Israel. Further information is available at ClinicalTrials.gov NCT#02814019.
About idebenone
Idebenone is a synthetic molecular formula similar to coenzyme Q10. Chemically, it is an organic compound of the family of quinones that can slow the loss of respiratory function.
Mitochondria are specialized structures in the human body that serve as batteries, powering various functions of the cell and the organism as a whole.
Mitochondria produce the energy necessary for the cell functioning through a process called “cellular respiration” which requires oxygen and provides energy. During cellular respiration, some toxic forms of oxygen (called oxygen free radicals) can be produced. These free radicals must be neutralized by other substances to avoid cellular damage.
Idebenone is expected to act as a neutralizer of these toxic forms of oxygen. Thus, idebenone is expected to have an antioxidant effect, and consequently prevent cellular damage.
Idebenone is optimized to dissolve in water and lipids and able to cross the mitochondrial membrane.
Idebenone is a medicine that is under investigation for the treatment of DMD. It has not yet been approved by the U.S. FDA, and the safety and efficacy continue to be evaluated in clinical trials.
About Santhera Pharmaceuticals
Santhera Pharmaceuticals is a Swiss specialty pharmaceutical company focused on the development and commercialization of innovative medicines for rare neuromuscular and pulmonary diseases with a high unmet medical need. Santhera is building Duchenne muscular dystrophy (DMD) product portfolio to treat patients irrespective of causative mutations, disease stage or age. A marketing authorization application for Puldysa® (idebenone) is currently under review by the European Medicines Agency. Santhera has an option to license vamorolone, a first-in-class anti-inflammatory drug candidate with a novel mode of action, currently investigated in a pivotal study in patients with DMD to replace standard corticosteroids. The clinical-stage pipeline also includes lonodelestat (POL6014) to treat cystic fibrosis (CF) and other neutrophilic pulmonary diseases, as well as omigapil and an exploratory gene therapy approach targeting congenital muscular dystrophies. Santhera out-licensed ex-North American rights to its first approved product, Raxone® (idebenone), for the treatment of Leber’s hereditary optic neuropathy (LHON) to Chiesi Group. For further information, please visit www.santhera.com. Raxone® and Puldysa® are trademarks of Santhera Pharmaceuticals.
