The present invention relates to a titrated extract of Cynara scolymus, to titrated fractions of extract of Cynara scolymus or titrated mixtures of said extract with one or more of said titrated fractions or mixtures of said fractions, and to compositions and kits comprising them, for the prevention and/or the treatment of a pathological condition characterised by a constitutive activation of the STAT3 transcription factor,