Santhera to discontinue phase III SIDEROS study and development of Puldysa in Duchenne muscular dystrophy (DMD) and focus on vamorolone.

Santhera Pharmaceuticals announces the discontinuation of its Phase III SIDEROS study with Puldysa (idebenone) in patients with Duchenne muscular dystrophy (DMD) who are in respiratory decline and receive concomitant glucocorticoid treatment.

Data from an interim analysis conducted by the independent Data and Safety Monitoring Board (DSMB) concluded that the study was unlikely to meet its primary endpoint. As a consequence, Santhera will discontinue the study, withdraw the European marketing authorization application and end the global development program for Puldysa. The Company intends to initiate a restructuring plan for the business with a focus on retaining key functions for bringing DMD drug candidate vamorolone to patients and execute on its other pipeline programs. Based on the now completed interim analysis which tested for efficacy, the DSMB has recommended the SIDEROS study be discontinued due to futility. The interim analysis was based on the primary endpoint of the study, the change of forced vital capacity % predicted (FVC%p) from baseline to 18 months of treatment. The outcome revealed that the probability of reaching the primary endpoint at the end of the study is too small to merit the continuation of the study. There were no safety concerns noted by the DSMB. Santhera will stop the SIDEROS trial (including extension) and participants who are enrolled in the study will discontinue study medication and complete the study’s follow-up evaluations. Furthermore, following up on the recommendation from the DSMB, Santhera will discuss the impact of ending the SIDEROS study on ongoing expanded access programs with the corresponding regulatory bodies. In connection with this decision, Santhera intends to start a restructuring process, aligning its operations to focus on progressing vamorolone for DMD, lonodelestat for cystic fibrosis and other lung diseases and its discovery-stage gene therapy approach for congenital muscular dystrophy. .