S.J (asker) Mar 20, 2020:

Thank you all for your efforts.

S.J (asker) Mar 19, 2020:

To be honest, I don't know much, what I know it is clinical trial.

philgoddard Mar 19, 2020:

Just out of interest What kind of trial is this, and who are the participants?

S.J (asker) Mar 19, 2020:

Can we say "in the office" for example?

Tony M Mar 19, 2020:

@ Asker As usual, without knowing properly what the wider context is, it is rather difficult for the rest of us to understand what is actually going on here.
However, I believe that here it is not 'point-of-sale' as in the retailing context, but rather 'at the moment of sale' — i.e. a 'point' in time. Though of course, it may not actually literally be a 'moment', which is possibly why the writer rather misguidedly used 'point" instead!