Santhera Pharmaceuticals (SIX: SANN), a Swiss based company focused on the treatment of mitochondrial and neuromuscular disease, has announced the receipt of marketing authorization for idebenone, the active pharmaceutical ingredient of Raxone, a synthetic short-chain benzoquinone compound and a cofactor for the enzyme NAD(P)H. According to the company, the authorisation represents “the first approved medicine available in all 28 member states of the European Union (EU), Norway, Iceland and Liechtenstein for the treatment of visual impairment in adolescent and adult patients with Leber’s Hereditary Optic Neuropathy (LHON)”.
Raxone will shortly be made available as an oral medication authorized at a daily dose of 900 mg (given as 2 tablets three times a day with food), for the treatment of visual impairment in adolescent and adult patients with LHON. A double-blind, randomized, placebo-controlled study reported in 2011 (entitled “Rescue of Hereditary Optic Disease Outpatient Study” or RHODOS), tested 900 mg idebenone/day (3 times 300 mg) against placebo in a cohort of 85 participants over a 24-week period. While the results indicated that idebenone was safe and well tolerated the primary end-points did not reach statistical significance in the intention to treat population. However, interest in the drug was maintained due to a post hoc interaction analysis suggesting a different response to idebenone in patients with discordant visual acuities at baseline. In such a group, all secondary end-points (including BCVA, changes in VA of the best eye at baseline and changes in VA for both eyes in each patient) appeared to be significantly different between tests and controls. Consequently, the data was interpreted as providing some evidence that patients with discordant visual acuities may benefit from the treatment.
LHON is a rare progressive disease with an estimated European prevalence of between 1 in 30,000 and 1 in 50,000. Over 95% of LHON patients carry one of three pathogenic mutations in their mitochondrial DNA causing a defect in the complex I subunit of the mitochondrial respiratory chain, causing progressive loss of visual acuity and blindness. Although small by pharma standards, the indication may represent an attractive market as it represents one of the most common mitochondrial (mtDNA) disorders. Securing market approval in one such mitochondrial disorder may leverage opportunities in other such disorders. Commenting on the achievement, Thomas Meier, PhD, Santhera’s CEO, stated that, “our data demonstrate that Raxone treatment can prevent patients from further vision loss and can promote clinically relevant recovery of vision. The European approval of Raxone as an efficacious treatment for LHON and as the first approved medication for a mitochondrial disease is a major milestone for Santhera as it marks our transition to a pharmaceutical company with a product on the market.”