The present invention relates to a combined preparation comprising (i) a modulator of pyruvate kinase M2 (PKM2) activity, and (ii) an agent providing high mobility group box 1 (HMGB1) polypeptide or a derivative thereof. The present invention also relates to the aforesaid combined preparation for use as a medicament and for use in the treatment of inappropriate cellular proliferation, preferably in the treatment of cancer. Moreover, the present invention relates to a method for determining whether a subject suffering from inappropriate cellular proliferation is amenable to a treatment comprising administration of a modulator of PKM2 activity as the only PKM2 inhibitor and to treatment methods related thereto.