Ann: PAA completes Phase 1 and files for Orphan Drug Designation, page-329

Yes one would still need to pay the 15c to convert the options into shares.
If you don't want to pay all that money, you can just sell the options on market. As the exercise date draws nearer, it is likely that the value of the options and the shares will very closely reflect eachother.
I personally would wait longer before selling or converting the options. If the share price tanks at somepoint, then you only lose the value of the options, so why take the risk before you need to.
That being said, PAA is potentially a takeover target, so this should be considered before waiting too long to exercise.
DYOR