To improve anti-leukemia efficacy of a small molecule inhibitor (apoptozole, Az) of Hsp70 proteins, Az was linked to Hsp90 (geldanamycin) or Abl kinase (imatinib) inhibitors. Hybrid of Az with geldanamycin significantly enhanced the anti-leukemia activity compared to individual inhibitors. However, hybrid of Az with imatinib showed lower cytotoxicity on leumekia cells compared to individual treatment. These findings suggest that hybrid of Az with geldamamycin could be utilized as potential anti-leukemia agents.