The FDA have made it clear that they require an RCT, whereas...

The FDA have made it clear that they require an RCT, whereas Mesoblast have consistently attempted to bypass this requirement. IMO there is no doubt that the need for an RCT was included as part of the CRL, which might explain why it took longer than 14 days for the FDA to respond. The FDA may have been weighing up Mesoblast's response to bypassing the need for an RCT to determine if the response was complete or incomplete, since no RCT had been performed.

Now the fun really starts, where the strength of the response will be evaluated. I am 50:50 on this one since it will probably come down to whether the FDA require or simply recommend that a RCT is performed. There are ways to bypass the need for a RCT, so it will be interesting to see how the FDA responds.

PDUFA date is always 6 months after the applicant marks the resubmission as complete, irregardless of whether fast-track status was given or not. I don't think fast-track applies to resubmissions, only to the original submission.