Thanks TechGuru. That FDA guidance makes clear

Thanks TechGuru.

That FDA guidance makes clear that either the 75% interim analysis or the 42 day mortality endpoint modification could be the results of an adaptive trial design.

Anyone know if "adaptive trial design" has been spoken by any CYDY representative?

It appears that if a trial modification was not prospectively planned, then that modification is "strongly discouraged":

When trial data are examined in a comparative interim analysis, data analyses that were not prospectively planned as the basis for adaptations may unexpectedly appear to indicate that some specific design change (e.g., restricting analyses to some population subset, dropping a treatment arm, adjusting sample size, modifying the primary endpoint, or changing analysis methods) is ethically important or might increase the potential for a statistically significant final trial result...Sponsors are strongly discouraged from implementing such changes without first meeting with FDA to discuss the changes being considered, provided patient safety is not compromised.

It would be very easy to prospectively define an efficacy stop condition as a function of the number of patients in the trial, so planning for an efficacy stop at a 75% interim analysis would be quite easy to do.

Seem like a modification to a primary endpoint would not be possible without an FDA meeting.