Santhera's Marketing Authorization Application for Idebenone in LHON Accepted for Review by European Medicines Agency

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Liestal, Switzerland, July 22, 2011 - Santhera Pharmaceuticals (SIX: SANN) announced today that the European Medicines Agency (EMA) has validated the Marketing Authorization Application (MAA) for idebenone in the treatment of Leber's Hereditary Optic Neuropathy (LHON) and has started to review the Company's file. Santhera received orphan drug designation for idebenone in LHON from the European Commission in 2007. Currently, no therapy is available to prevent or reverse vision loss and blindness in patients with LHON.

The efficacy of Santhera's idebenone in LHON was shown in a randomized, placebo-controlled clinical study (the RHODOS study). Data were presented at the 2010 Meeting of the American Neurological Association and the 2011 Meeting of the European Neurological Society. According to scientific advice from the EMA's Committee for Medicinal Products for Human Use, the prespecified endpoint - change in best visual acuity - was the clinically most relevant endpoint and will be of special importance in the assessment. Here a difference between treatment groups at week 24 favored Santhera's idebenone in the intent-to-treat population (p=0.078) and reached statistical significance in the prespecified subgroup of patients with the G11778A or G3460A mitochondrial DNA mutations (p=0.037). Patients with either of these two mutations represent 70 to 80% of LHON patients in Europe and experience rapid and mostly irreversible vision loss. The filed MAA specifically asks for approval based on this subgroup's significant treatment effect with Santhera's idebenone as demonstrated by the RHODOS study.

"The MAA emphasizes the high consistency of the RHODOS results across all visual acuity endpoints and analyses favoring Santhera's idebenone over placebo, and the clinically meaningful benefit afforded to LHON patients," said Thomas Meier, Santhera's Chief Scientific Officer. "This is an important milestone in the development of a potential first treatment for this neuro-ophthalmological disease. Santhera's idebenone holds the promise to both protect against the loss of vision and to accelerate recovery."

In addition to the RHODOS study data, the MAA includes nonclinical data from a disease-relevant model of LHON which show that retinal ganglion cell death and other retinal pathologies induced by mitochondrial complex 1 inhibition (the mechanism by which LHON causes the blindness in humans), could be prevented with idebenone.

About Leber's Hereditary Optic Neuropathy

Leber's Hereditary Optic Neuropathy (LHON) is a maternally inherited loss of vision due to atrophy of the optic nerve. It typically present in young adults, mostly men, as painless acute or subacute visual failure of both eyes in quick succession. Blurring of central vision and color desaturation usually mark the beginning of the symptomatic phase of this neuro-ophthalmological disorder. The effects of LHON are rapid and severe, typically leading to blindness within a few months of the onset. While symptoms initially develop in one eye, the second eye is usually involved within a few months. Over 95% of patients harbor one of three pathogenic mutations of the mitochondrial DNA which cause a defect in complex I subunit of the mitochondrial respiratory chain. This defect leads to decreased ATP production, increased oxidative stress, retinal ganglion cell apoptosis and optic nerve atrophy which cause progressive and irreversible loss of visual acuity and blindness. A recent epidemiology meta-analysis estimates a LHON prevalence of approximately 1 in 50,000 in Europe.

About Santhera

Santhera Pharmaceuticals (SIX: SANN) is a Swiss specialty pharmaceutical company focused on the development and commercialization of innovative pharmaceutical products for the treatment of severe neuromuscular and neurodegenerative diseases, an area of high unmet medical need which includes many orphan and niche indications with no current therapy. Santhera's first product, Catena® to treat Friedreich's Ataxia is marketed in Canada. For further information, please visit

Catena® is a trademark of Santhera Pharmaceuticals.