That BAX and MNTA are now working on the third FoB in the collaboration means that BAX has exercised the option to develop compounds #3-#6, which results in a $28M milestone payment to MNTA—see #msg-70258421.
BAX's exercise of the option on compounds #3-#6 presumably means that the BAX-MNTA collaboration is producing results ahead of schedule. I wasn't expecting BAX to exercise the option on compounds #3-#6 until 2013 at the earliest (although I noted in #msg-78079512 that it could happen at any time).
“The efficient-market hypothesis may be the foremost piece of B.S. ever promulgated in any area of human knowledge!”