Disease activity-free status: the new gold standard?

Could we use disease-activity free status to determine the effectiveness of new MS disease-modifying therapies? It may make it easier to do head-to-head studies.

Please see the following links:
Coles et al. Lancet Neurol. 2011 Apr;10(4):338-48.

Giovannoni et al. Lancet Neurol. 2011 Apr;10(4):329-337.