SECONDARY PROGRESSIVE MS

SPMS is a natural progression of any relapsing and remitting MS. There is no secondary progressive MS from the start, hence, the current classification of MS which considers SPMS as a separate class similar to RRMS and PPMS is not right. SPMS is a sub-class, but can never be a class on its own. Nearly 95% of RRMS will be SPMS in 10-15 years from the first symptoms. The other 5% will remain very benign during the life span of the affected.

The diagnosis of SPMS is clinical, but there is currently no test that distinguishes RRMS from SPMS. In fact, there is no test that can distinguish between SPMS and PPMS. 

SPMS can be subdivided into two groups:

1. SPMS with relapses.
2. SPMS without relapses.

This sub classification is very important when it comes to disease modifying therapy. MRI imaging might help to support the clinical diagnosis with the presence of disease activity on gadolinium enhanced imaging.

MANAGEMENT OF SPMS

Few treatment options are available for patients with progressive multiple sclerosis.

• Anti-inflammatory drugs have little effect.
• Some clinical manifestations, such as cognitive impairment and neuropsychiatric dysfunction, have a dramatic effect on quality of life.
• Preservation of functional and social independence are perhaps the main therapeutic goals in these patients at least for the time being.

For SPMS with relapses, there are criteria for selecting patients who are legible for DMT. Relapses will be treated as usual i.e steroids, or plasma exchange, or IV immunoglobulins. 

For SPMS, there is currently no licenced DMT for this group of patients. However, Siponimod(Mayzent) has been approved by European Medicines Agency for SPMS with disease activity either in the form of relapses or evidence of disease activity on the MRI. NICE in UK has not recommended siponimod to treat patients who have SPMS despite expectations that the drug would soon be available on the NHS in the UK. NICE mentioned that: Clinical trial results show that siponimod reduces the number of relapses and slows disability progression compared with placebo. However, it is uncertain how effective siponimod is compared with interferon beta-1b because there is no evidence directly comparing them. NICE says that due to the limited clinical evidence, the cost-effectiveness estimates are uncertain, and none of the analyses reflect the committee’s preferred assumption that it cannot be recommended. The committee has requested further analyses to be included in the company’s economic model. These include comparing siponimod with best supportive care and assuming that there is a reduction in its treatment effect over time.

Drugs under trial for SPMS:

These drugs are being tested as part of a phase II trial, called MS SMART, which will study 440 participants over two years.

• Amiloride. 
• Ibudilast: phosphodiesterase inhibitor. Used in the treatment of asthma, stroke, and ? multiple sclerosis.
• Riluzole.

Drugs trialled for SPMS: 

• Masitinib: Tyrosine kinase inhibitor that targets mast cells and macrophages.  
• Natalizumab.
• Siponimod(recently approved for SPMS with relaoses).