PALO ALTO, Calif., Dec. 6, 2010 /PRNewswire/ -- Telik, Inc. (Nasdaq: TELK) today announced positive results from a Phase 2 multicenter trial of oral ezatiostat hydrochloride (TELINTRA, TLK199) in patients with an International Prognostic System Score (IPSS) of low to intermediate-1 risk myelodysplastic syndrome (MDS). The presentation entitled Phase 2 Randomized Multicenter Study of Extended Dosing Schedules of Oral Ezatiostat HCl (Telintra), a Glutathione Analog, Glutathione-S-transferase P1-1 (GSTP1-1) Inhibitor, In Low to Intermediate-1 Risk Myelodysplastic Syndrome (MDS), Raza, A., Galili, N., Smith, S., Godwin, J., Boccia, R., Myint, H., Mhadevan, D., Mulford, D., Rarick, M., Allison, M A., Melnyk, O., Meng, L., Jones, M., Brown, G., Young, S., List, A., Komrokji, R., Sekeres, M., was given at the 52nd Annual Meeting of the American Society of Hematology in Orlando, FL. MDS is a heterogeneous group of clonal hematopoietic stem cell disorders characterized by ineffective hematopoiesis (blood cell production) involving one or more cell lineages (red blood cells, white blood cells or platelets) and a variable risk of developing acute myeloid leukemia (AML). Ezatiostat is an inhibitor of the enzyme glutathione S-transferase P1-1 (GST P1-1), a validated clinical target in MDS. Inhibition of this enzyme results in the activation of the signaling molecule Jun kinase resulting in cell death (apoptosis) of leukemic and pre-leukemic cells, and the growth and maturation of normal blood progenitor cells. "We are very pleased to present the positive results of this study that was conducted at 22 clinical sites," stated Dr. Azra Raza, Professor of Medicine and Director, MDS Center at Columbia University Medical Center. "Telintra is the first GSTP1-1 enzyme inhibitor-based treatment for low to intermediate-1 risk MDS patients. In addition to advancing our understanding of this disease, we have the opportunity to develop a new targeted agent that potentially, can transform the treatment of MDS in these low to intermediate-1 risk MDS patients." The primary objective of the study was to determine the efficacy of ezatiostat, defined by Hematologic Improvement (HI) rate according to the International Working Group criteria (IWG, 2006), as well as its safety and tolerability. An additional goal of this study was to identify those patients whose disease characteristics may allow us to prospectively target patients most likely to respond to Telintra treatment. A multivariate logistic regression analysis was conducted to identify significant MDS disease factors associated with HI-E rates, including prior MDS treatment, age, gender, IPSS risk, Eastern Cooperative Group (ECOG) performance status, years from MDS diagnosis, MDS World Health Organization (WHO) subtypes, anemia only versus anemia plus other cytopenias, dose schedule and starting dose.