Santhera Pharmaceuticals (SIX: SANN) announces that the EMA’s CHMP has granted a requested extension of the clock-stop in the regulatory procedure for its conditional marketing authorization (CMA) application for Puldysa (idebenone) in Duchenne muscular dystrophy (DMD). During this clock-stop, the Company is evaluating the potential of conducting an interim analysis to test for so-called overwhelming efficacy of its SIDEROS study with a view of including the data in the review procedure and potentially completing the trial early. This will result in a CHMP opinion in Q4 2020. A positive early completion of the SIDEROS study would allow acceleration of subsequent regulatory filings in the US and Europe by approximately one year.
During its May meeting the CHMP accepted a requested extended clock-stop to address the list of outstanding issues adopted at Day 180 of the ongoing review procedure of the conditional marketing authorization (CMA) application for Puldysa (idebenone) in DMD for patients not using concomitant glucocorticoids. This extends the review time into the fourth quarter 2020.
Santhera recently communicated that it has completed enrollment into its SIDEROS study. SIDEROS 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 using concomitant glucocorticoids. As previously announced, and given the strong powering of SIDEROS, Santhera now intends to pursue the conduct of an interim analysis by the independent Data and Safety Monitoring Board (DSMB) to test if the trial can be stopped early due to overwhelming efficacy.
Under the scenario that overwhelming efficacy is demonstrated, the outcome of the interim analysis would be added within the clock-stop to the dossier currently under review by the CHMP to further enhance the CMA data package. Furthermore, the study would be completed with the option for trial participants to transfer into the open label extension of SIDEROS, where all patients are treated with idebenone.
Positive interim data supporting overwhelming efficacy from the SIDEROS study and a potential early completion of the study would also allow acceleration of filings for a label including patients irrespective of their glucocorticoid use status. Such NDA filing with the US FDA could be accelerated by approximately one year. In Europe, subject to approval in the indication currently under CHMP review for patients not using concomitant glucocorticoids, such positive SIDEROS data could also shorten time to a label extension to include glucocorticoid using DMD patients by around one year.
“We are delighted about the completion of enrollment of the SIDEROS study and hope to now be able to proceed with an interim analysis which potentially paves the way for an earlier close of the trial,” said Dario Eklund, Chief Executive Officer of Santhera. “Despite the delay in our plans to get a CMA approved resulting from the clock-stop, we are convinced that this is the right strategy to both strengthen our current filing dossier and also to accelerate time to market in the US, and in the EU for patients using glucocorticoids.”