
Santhera kicks idebenone DMD program to the curb after PhIII trial fails interim analysis
An oft-troubled program at Santhera Pharmaceuticals {SWX: $SANN} is headed for the chopping block.
The Swiss biotech announced Tuesday morning that it is discontinuing a Phase III study for idebenone in patients with Duchenne muscular dystrophy and receiving steroid treatment. In a release, Santhera said that the trial failed an interim analysis, and as a result will pull its EMA application and end global development.
Santhera will also restructure its business plans to focus on a separate DMD candidate, vamorolone.
“While this is obviously not the outcome we expected, all our efforts in DMD will now be focused on progressing the promising drug candidate vamorolone, which we recently licensed from ReveraGen to its next inflection point,” CEO Dario Eklund said in a statement.
With the news, the biotech’s stock price cratered more than 43% as the Swiss stock exchange opened, but has since leveled off to falling about 25 to 30%.
Idebenone was designed to improve lung function in patients by energizing weakened muscle cells, and the primary endpoint for the Phase III trial sought to demonstrate an improvement in delaying the loss of respiratory function after 18 months. Though there were no safety concerns noted by the trial investigators, the likelihood of meeting that endpoint was deemed too small to merit continuing the trial. Santhera has not shared exactly what data prompted the shutdown.
Tuesday marks the end of an era as idebenone faced several setbacks in its eventual road to nowhere. Santhera originally applied for US approval back in 2016, but the FDA swatted down its application and asked for a confirmatory trial — the trial which has now been terminated. At the time, that move proved consistent with the agency’s history of pumping the brakes on companies like Sarepta seeking swift OKs in the DMD field.
But idebenone also ran into trouble in Europe when regulators shot down a label expansion into DMD in 2017 and an appeal in 2018. Approved on the continent as Raxone to treat Leber’s hereditary optic neuropathy, the drug also failed an NIH-backed multiple sclerosis trial in March 2018 after showing no difference from a placebo.
With a renewed focus on vamorolone, Santhera is not giving up its DMD efforts. The compound is currently in a Phase IIb trial looking to measure improvement in time to stand over baseline after 24 weeks. This trial enrolled DMD patients that are not taking steroid treatments, and Santhera says vamorolone has the potential to be an alternative to such therapies altogether by slowing disease progress without steroidal side effects.
In early September, Santhera picked up global rights to vamorolone after signing on to an option from ReveraGen and Idorsia in 2018.
The restructuring will also allow Santhera to focus on lonodelestat for cystic fibrosis and other lung diseases, as well as its discovery-stage gene therapy approach for congenital muscular dystrophy.