Maximising therapeutic outcomes in patients failing on current therapy.

The different immunomodulatory treatments available to patients with relapsing remitting multiple sclerosis are only partially effective. Since these treatments are most effective in the early relapsing stage of the disease, it is important to adjust therapy in a timely fashion in order to fall within the window of opportunity when maximal benefit can be gained from a second-line treatment. Consensus guidelines have been established to define a sub-optimal treatment response. Switching to another class of immunomodulatory therapy represents a logical treatment strategy in patients who fail to respond adequately to first line treatments. Several observational studied have now shown such a strategy to be beneficial. Disease control can be improved following switching in patients with persistent relapse activity on first-line treatment. In patients experiencing intolerable side-effects to first- line-treatment, tolerability can be improved by switching without loss of disease control. In particular, a switch between different classes of immunomodulatory treatments seems to be more beneficial than switching within the same class. Formal switching algorithms need to be developed in order to ensure that all patients who could benefit from such an approach are managed in a timely and optimal manner.