Aeterna Zentaris Presents Positive Preclinical Data in Breast Cancer on AEZS-131, a Highly Selective Erk 1/2 Inhibitor, at San Antonio Breast Cancer Symposium

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[{"type":"text","content":"\n\n\n\n\n\nQUEBEC CITY, Dec. 9, 2011 /CNW Telbec/ - Aeterna Zentaris Inc. (NASDAQ:\n AEZS) (TSX: AEZ) (the \"Company\") today announced positive preclinical\n data in triple-negative breast cancer (TNBC) for its highly selective\n Erk 1/2 inhibitor anticancer compound, AEZS-131. Data showed that\n AEZS-131 selectively inhibits Erk at low nanomolar (nM) concentrations\n and induces G1 arrest. Accordingly, the cytotoxic effect of AEZS-131\n was most pronounced in TNBC cell lines with mutations in the MAPK\n pathway. Data were presented yesterday by Dr. Jörg B. Engel, Medical\n University of Regensburg, Department of Gynaecology and Obstetrics,\n Germany, during a poster session at the CTRC - AACR San Antonio Breast\n Cancer Symposium, in San Antonio, Texas.\n\n\n\n\n\nPoster #P3-18-06: \n\n\n\"AEZS- 131 - a highly selective ERK-inhibitor: Characterization and\n preclinical testing in triple-negative breast cancer (TNBC)\", Engel Jörg B., Seipelt Irene, Hönig Arnd, Hahne Jens C., Teifel Michael.\n\n\nThe Study\n\n\nAEZS-131 was tested to check for selectivity, inhibition of\n Rsk-phosphorylation (cellular substrate of Erk), mode of action and\n cleavage of PARP. Cytotoxic efficacy was evaluated in a selection of\n TNBC cell lines, with or without mutations in the MAPK signal\n transduction pathway, by MTT assay.\n\n\nResults\n\n\nThe study showed that AEZS-131 selectively inhibited ERK with an IC50<4nM. Phosphorylation of Rsk-1, the cellular substrate of Erk, was\n inhibited with an IC50 of 158 nM. AEZS-131 induced cell cycle arrest in G1 dose-dependently\n and cleavage of PARP. EC50 values were below 1µM for cell lines with mutations in the MAPK\n pathway. TNBC cell lines without mutations in the MAPK pathway were\n less responsive.\n\n\nDr. Jörg B. Engel, of the Medical University of Regensburg, commented,\n \"Over-expression of MAPK has been detected in 34% of triple-negative\n breast cancer and has been found to be associated with an increased\n risk for recurrence in patients with this type of breast cancer. Since\n preclinical data suggest that AEZS-131's cytotoxic effect was most\n pronounced in triple-negative breast cancer cell lines with mutations\n in the MAPK pathway, we, therefore, believe this compound should be\n further explored in triple-negative breast cancer with over activa...

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