Idebenone
Idebenone, sold under the brand name Raxone among others, is a medication that was initially developed by Takeda Pharmaceutical Company for the treatment of Alzheimer's disease and other cognitive defects. This has been met with limited success. The Swiss company Santhera Pharmaceuticals has started to investigate it for the treatment of neuromuscular diseases. In 2010, early clinical trials for the treatment of Friedreich's ataxia and Duchenne muscular dystrophy have been completed. the drug is not approved for these indications in North America or Europe. It is approved by the European Medicines Agency for use in Leber's hereditary optic neuropathy and was designated an orphan drug in 2007.
Chemically, idebenone is an organic compound of the quinone family. It is also promoted commercially as a synthetic analog of coenzyme Q10.
Uses
Indications that are or were approved in some territories
Nootropic effects and Alzheimer's disease
Idebenone improved learning and memory in experiments with mice. In humans, evaluation of Surrogate endpoints like electroretinography, auditory evoked potentials and visual analogue scales also suggested positive nootropic effects, but larger studies with hard endpoints are missing.Research on idebenone as a potential therapy of Alzheimer's disease have been inconsistent, but there may be a trend for a slight benefit. In May 1998, the approval for this indication was cancelled in Japan due to the lack of proven effects. In some European countries, the drug is available for the treatment of individual patients in special cases.
Friedreich's ataxia (Sovrima)
Preliminary testing has been done in humans and found idebenone to be a safe treatment for Friedreich's ataxia, exhibiting a positive effect on cardiac hypertrophy and neurological function. The latter was only significantly improved in young patients. In a different experiment, a one-year test on eight patients, idebenone reduced the rate of deterioration of cardiac function, but without halting the progression of ataxia.The drug was approved for Friedreich's ataxia in Canada in 2008 under conditions including proof of efficacy in further clinical trials. However, in February 2013, Health Canada announced that idebenone would be voluntarily recalled as of April 2013 by its Canadian manufacturer, Santhera Pharmaceuticals, due to the failure of the drug to show efficacy in the further clinical trials that were conducted. In 2008, the European Medicines Agency refused a marketing authorisation for this indication. As of 2013 the drug was not approved for FA in Europe nor in the US, where, as of February 2023, there is only one approved treatment.
Leber's hereditary optic neuropathy (Raxone)
is a mitochondrially inherited degeneration of retinal ganglion cells and their axons that leads to an acute or subacute loss of central vision; this affects predominantly young adult males. Santhera completed a Phase III clinical trial in this indication in Europe with positive results, and submitted an application to market the drug to European regulators in July 2011. It is approved by EMA for this indication and was designated an orphan drug in 2007.Indications being explored
Duchenne muscular dystrophy (Catena)
After experiments in mice and preliminary studies in humans, idebenone has entered Phase II clinical trials in 2005 and Phase III trials in 2009.Other neuromuscular diseases
Phase I and II clinical trial for the treatment of MELAS was conducted. Phase I/II trial for primary progressive multiple sclerosis concluded that Idebenone did not inhibit disability progression.As of 2022, a phase III clinical trial is ongoing for the treatment of Parkinson's disease.