The present invention describes the new use in the oncologic field ofbioconjugates as differentiating agentsob-tained by the conjugation between hyaluronic acid (HA) and achemotherapeutic product (identified hereafter with the trade-nameONCOFID®) among which, in particular, Irinotecan, Doxorubicin, Paclitaxel,Cis-platinum and 5-Fluorouracyl (5-FU) fortreat-ing primary tumors and metastasis. In particular, the biologicalbehaviour is described in terms of action mechanism, efficacy andtolerability of pharmaceutical preparations of derivative of ONCOFID®soluble in water. More specifically, the invention relatesto the surprising biological and pharmacological effect demonstrated byformulations based on ONCOFID-S (HA-SN38conju-gates) and ONCOFID-D (HA-Doxorubicin conjugates) in promoting thedifferentiation of tumoral cells towards a untransformedphenotype, compared with the reference drug Irinotecan (or CPT11 whose activeform is represented by SN38) and Doxorubicin.
