Primary progressive multiple sclerosis

Primary progressive multiple sclerosis

Multiple sclerosis (also called muscle sclerosis or MS) is an inflammatory and neurodegenerative disorder of the central nervous system that causes a wide range of physical symptoms, such as impaired movement, fatigue, numbness, and pins and needles, as well as problems with memory and understanding.1–3 

There are two main types of MS – relapsing–remitting MS (RRMS) and primary progressive MS (PPMS):2,4,5

In RRMS, patients experience symptoms intermittently (called relapses) and symptoms may disappear completely between attacks, with a slower accumulation of permanent disability than in PPMS.4,6 RRMS is more common in women than in men.2,6,8PPMS is the more aggressive form of MS.6 Physical disability gets progressively worse over time and patients do not experience periods without symptoms.2,3 PPMS affects about 9–15% of patients with MS and is associated with a later age of onset than RRMS.2,6–8  PPMS affects similar proportions of men and women.2,6,8
Relapsing–Remitting Multiple Sclerosis
Primary Progressive Multiple Sclerosis

In MS, the outer coating of nerve fibers (called myelin) is damaged, preventing the nerves from functioning properly.2,3 The causes of MS are unknown, but research has established that dysfunction of the energy-producing mitochondria in nerve cells could play a major role, particularly in PPMS.3,9 

Extensive research has led to the successful development and approval of a range of treatments for patients with RRMS.10 In contrast, there are currently no approved treatments for PPMS and research is urgently needed to find new effective treatments for this condition.1,2

Santhera and PPMS

In collaboration with Santhera, the National Institutes of Health (NIH) are currently conducting a phase I/II clinical trial to investigate the safety, therapeutic efficacy and mechanism of action of idebenone in primary progressive multiple sclerosis (PPMS) patients. 
If you are a registered healthcare professional, please click here to find out more about clinical trials of idebenone in PPMS.



EMA Guideline on clinical investigation of medicinal products for the treatment of multiple sclerosis, March 2015; Available here. Accessed December 2015.


Miller DH & Leary SM. Lancet Neurol 2007; 6:903–912.


Lassmann H, et al. Nat Rev Neurol 2012; 8:647–656.


Relapsing-remitting MS (RRMS). NMSS website. Available here. Accessed December 2015.


Lublin FD, et al. Neurology 1996; 46;907–911.


Cottrell DA, et al. Brain 1999; 122: 625–639.


Confavreuz C & Vukusic  S. Brain 2006; 129:606–616.


McKay KA, et al. Biomed Res Int 2015; Article ID 817238.


Mahad D, et al. Neuropathol Appl Neurobiol 2008; 34: 577–589.


Torkildsen Ø, et alEur J Neurol 2016; 23 (Suppl. 1):18–27.