ZGEN has been at 66-68M shares for almost 5 years. In biotechland that is forever.
I believe that what they are doing it trying to get enough cash to get them through a moderately worst case ramp for reco to self sustaining while being able to prosecute their pipeline (i.e. making this the last dillution for another 4.5 years). Personally I'd have preferred that they make this secondary 50% larger and keep more of their research staff.