This is the third time MITI dropping from $8+ to $5 or sub $5 in short period of time. Each time, I heard the same thing about the concern of neurotoxicity. I haven't seen any evidence it is an issue in ALL. In 60 ug MTD dose for NHL, it is a concern for those with B:T ratio less than 1:8 which is why they are enrolling more patients to find best mitigating strategy before moving to phase II.
In small biotech, focus on the data, not noise, expect the fluctuation of share price during lull period. I loaded up the last two times, lighten up some at the top, I am doing the same thing this time. Each time, people would say later on they wished they had done so, but when the moment came, they couldn't pull the trigger.