Alpha1-acid glycoprotein expressed in the plasma of chronic myeloid leukemia patients does not mediate significant in vitro resistance to STI571.

Despite the efficacy of STI571 (Glivec, Novartis, Basle, Switzerland) in treating chronic myeloid leukemia (CML), drug resistance has already been noted both in vitro and in vivo. As plasma proteins, including alpha-1-acid glycoprotein (AGP), may reduce drug efficacy through binding, AGP was investigated for its ability to interact with STI571. At all stages of CML, AGP plasma level was significantly higher than in normal controls (P <.