NorthWest Biotherapeutics Inc (NWBO)

[Doktornolittle]

The PFS threshold for approval dropped from 6 months to 4 months, a factor of 1.5. (if the PEI approves).

The number of data points was increased 2.25 fold from 110 to 248. The RMS noise in that data dropped by the square root of 2.25 or 1.5.

If the way the FDA works is to want a mean efficacy and confidence such that some common threshold of likelyhood for the "true" mean is above / at 0 efficacy, then the 2.25 fold increase in data points corresponds directly with the 1.5 fold decrease in the required PFS.

Does anyone know if that is how the policies work. In the end, is the net measure of sufficient efficacy such that there is simply net positive efficacy with X certainty, where that X is always the same. Ie, for all trials?