Please, I have a medical-pharmaceutical study that says:

SPRT (something to do with Secuential and Truncated).

Do You know what it means S.P.R.T. and what it is?

SPRT is the Sequential Probability Ratio Test. You can find some information on this test at http://www.agrsci.dk/plb/bembi/africa/sampling/samp_spr.html