DSMC will look at the interim data (including analysis by a statistician) and come to a conclusion on submittal to the FDA. They send a report to Cytodyn with their conclusion and broad reasoning for why. Cytodyn does not have to abide by their conclusion. If the reasoning seems specious Cytodyn can have the raw data turned over do their own analysis and submit to the FDA. The trial can still continue but if not approved at interim the FDA will look doubly close at data from the second half to see if it's tainted.