Multiple Sclerosis (MS) is a chronic, unpredictable disease of the central nervous system (the brain, optic nerves, and spinal cord). It is believed to be an autoimmune disorder, meaning the immune system incorrectly attacks the person’s healthy tissue.¹

Symptoms of MS are unpredictable and vary from person to person, and from time to time in the same person. The most common characteristics of MS include fatigue, weakness, spasticity, balance problems, bladder and bowel problems, numbness, vision loss, tremor and vertigo. Not all symptoms affect all MS patients and symptoms and signs may be persistent or may cease from time to time.^1,2

While the cause of MS is still unknown, it is generally accepted that MS is a chronic, progressive inflammatory disease in which the body’s own defense system attacks myelin, the fatty substance that surrounds and protects the nerve fibers in the central nervous system. The nerve fibers themselves can also be damaged. The damaged myelin forms scar tissue (sclerosis), which gives the disease its name. When any part of the myelin sheath or nerve fiber is damaged or destroyed, nerve impulses traveling to and from the brain and spinal cord are distorted or interrupted, producing the variety of symptoms that can occur.¹

MS is the most common neurological disorder diagnosed in young adults. It is estimated that MS affects approximately 2.5 million individuals worldwide, with two-thirds of those being women. In the United States today, there are approximately 400,000 people with MS, with 200 more people diagnosed every week. MS appears more frequently in whites than in Hispanics or African Americans and is relatively rare among Asians and certain other groups. Ninety percent of MS patients diagnosed are between the ages of 16 and 60, but MS can make its first appearance in early childhood or after age 60. Studies suggest that genetic factors make certain individuals more susceptible than others, but there is no evidence that MS is directly inherited.^1,2

Since the symptoms of early MS can come and go, diagnosing MS is often difficult. While no single laboratory test is yet available to prove or rule out MS, magnetic resonance imaging (MRI) plays a critical role in reaching a definitive diagnosis.¹

There is no cure for MS, and currently approved MS therapeutics addresses only the symptoms of the disease and not its underlying cause(s). As such, these treatments are only able to slow the progression of MS. Currently available MS treatments possess only modest efficacy and are limited by significant compliance issues related to severe side effect profiles and cumbersome administration approaches/schedules. Moreover, the patients perceived clinical benefit in relation to the side effects experienced by these drugs result in approximately 43% of MS patients choosing not to initiate treatment or fail to continue treatment with the currently approved disease modifying drugs (National MS Society-funded Sonya Slifka Longitudinal MS Study, unpublished Data).

A significant unmet medical need currently exists in connection with the treatment of MS, and there are several therapies in development geared toward meeting this need. One of these therapies, Tcelna, developed by Opexa Therapeutics, has completed a land mark Phase 2b clinical trial. Tcelna is a novel T-cell vaccine for the treatment of MS that is specifically tailored to each patient’s disease profile. Clinical results to date have demonstrated that Tcelna may offer enhanced efficacy, safety and tolerability as compared to most MS therapies currently on the market or in development.

The stages of MS are as follows: High-Risk Clinically Isolated Syndrome (CIS) - The term “clinically isolated syndrome” (CIS) has been used to describe a first neurologic episode that lasts at least 24 hours. The person has a high risk of a second neurologic event, and therefore, a diagnosis of clinically definite MS within several years.

Relapsing-Remitting Multiple Sclerosis (RRMS) – RRMS is the most common form of MS. Approximately 85 percent of patients are initially diagnosed with RRMS. With RRMS, patients experience relapses during which new symptoms may appear and old symptoms resurface or worsen. Relapses are followed by periods of remission, characterized by full or partial recovery. All currently approved therapies for MS are indicated for the treatment of RRMS.

Secondary-Progressive Multiple Sclerosis (SPMS) – After a number of years many people (approximately 50 percent) who have had relapsing-remitting MS eventually progress to SPMS, a secondary progressive phase of the disease. SPMS is characterized by a gradual worsening of the disease between relapses. In SPMS, relapses merge into a general disease progression and the resulting damage cannot be reversed.

Primary-Progressive Multiple Sclerosis (PPMS) – The most severe stage of MS, PPMS involves a rapid decline in overall neurological function. PPMS does not involve periods of either relapse or improvement. There is presently no cure for PPMS.

Progressive-Relapsing Multiple Sclerosis (PRMS) – People with this type of MS experience a steadily worsening disease from the onset but also have clear acute relapses (attacks or exacerbations), with or without recovery. In contrast to relapsing-remitting MS, the periods between relapses are characterized by continuing disease progression. About five percent of MS patients have PRMS.¹

Market reports approximate the number of MS patients in North America and Canada at 500-550,000 and worldwide at 2.5 million (85% Relapse Remitting, 50% converting to Secondary Progressive within 10 years of diagnosis, 10% Primary Progressive and 5% Progressive Relapsing). This estimate suggests that approximately 200 new cases are diagnosed each week primarily effecting young adults between the ages of 20-60 years of age, who have a virtually normal life expectancy. Consequently, the economic, social, and medical costs associated with this incurable disease are significant. Estimates place the annual cost of MS in the United States in the billions of dollars. The MS market is estimated to be worth almost $9 billion in 2008.^3,4,5