I am not sure if this is a 2 step process ie AVXL sells to Cantor, it shows as share issued on AVXL books and Cantor sells to final buyer. In this case Cantor will make profit and show as separate transaction.
F1 explained is better - the shares are sold by Cantor directly to end buyer and they get commission 3% on the selling amount.
In the end they make 3% on all 50 million but the number of shares issued based on timing.
So it seems they issued 1st lot before the trial news and at 2.62/2.66 which is much lower that current market price.