A Canadian Study Assessing the Utility of the Treatment Optimization Recommendations in Multiple Sclerosis (CanTOR)

Multiple sclerosis (MS) is a chronic, inflammatory, demyelinating disease of the central nervous system (CNS) and is one of the most common causes of neurological disability in young adults. The neuropathology of the disease is marked by accumulation of leukocytes in the CNS, oligodendrocyte loss, demyelination, axonal atrophy, and neuronal loss. Clinically it is characterized by multi-focal recurrent attacks of neurological symptoms and signs with variable recovery and eventually, the majority of subjects develop a progressive clinical course of MS. The exact cause of MS is unknown, although an autoimmune process has been implicated. Genetic susceptibility plays a role in disease initiation but unidentified environmental factors may also be involved. Three clinical forms of MS are recognized: primary progressive multiple sclerosis (PPMS), secondary progressive multiple sclerosis (SPMS) and RRMS. Primary progressive subjects are characterized by slow and steady accumulation of neurological deficits from onset without superimposed attacks. Subjects with RRMS have exacerbations or relapses with subsequent variable recovery (remission). Secondary progressive multiple sclerosis is characterized by the steady accumulation of significant and persistent neurological deficit with or without superimposed relapses.

In approximately 90% of subjects, the first presentation of MS is an acute, usually reversible episode of CNS dysfunction, referred to as Clinically Isolated Syndrome (CIS). With the advent of MRI, it has become possible to reasonably predict the clinical course of CIS subjects presenting with abnormal MRI findings. The first 5 year follow up study of CIS subjects presenting with abnormal MRI demonstrated a trend for those with more lesions to develop clinically definite MS (CDMS) more frequently, with 92% of those with 4-10 T2 lesions developing CDMS compared to 67% of those with 2-3 T2 lesions. It is also well established that the vast majority of CIS subjects continue to experience ongoing demyelinating disease activity, as evidenced by MRI, even in the absence of a clinical conversion to CDMS.

The introduction of the disease modifying drugs (DMDs) for MS has had a significant impact on the management of those living with this disease. These DMDs are the first agents that have been shown to alter the natural course of relapsing MS. Although there is evidence that the DMDs significantly reduce disease activity, these agents are not "cures" for MS. Thus, many subjects with MS continue to experience disease activity, in spite of treatment with DMDs, including continued relapses, progressive impairment, and ongoing accumulation of MRI disease burden.

OBJECTIVES

Primary objectives:

• To assess if application of the TOR influences clinicians' decisions regarding DMD treatment in the Canadian clinic setting
• To evaluate the perceived utility of the TOR in the DMD treatment decision making process in the Canadian clinic setting

Secondary objective:

• To determine the proportion of subjects meeting a medium or high level of concern according to the TOR in the Canadian Clinic setting.

This was a non-interventional, open-label, observational, multicentric, phase IV study. Subjects were assessed according to the TOR on two occasions over a prospective 12 month observation period. All subjects were assessed according to the TOR at baseline. Subjects were subsequently assessed according to the TOR either at a time-point within the 12-month period when treatment modification is being considered for reasons other than intolerance or at the end of the 12-month observational period. Treatment decisions after each TOR assessment was noted, and perceptions on the utility of the TOR in the decision making process was captured. Additional feedback on the TOR was collected at the end of the observational period through a separate evaluation questionnaire. The assessments that were carried out at baseline and subsequent visits included EDSS history/current status, relapse history/current status, MRI history/current status, cognitive history/current status (if done) and neutralizing antibody (NAb) history/current status (if done).