NorthWest Biotherapeutics Inc (NWBO)

[exwannabe]

It is more common than not for trials to unblind patients after a PFS primary endpoint in order to facilitate selection of subsequent treatment.

My guess is that this trial maintained the blind to reduce the issue with the cross over election possibly biasing the follow-up selection, and therefore the OS endpoint.

But this bias is marginal anyway. So this is a minor blind fail on a minor bias which makes it "minor squared" and thus simply not relevant.