Telik Announces the Results of Genetic Signature Studies of Myelodysplastic Syndrome Patients Likely to Respond to Telintra® (Ezatiostat Hydrochloride, TLK199) at the Annual Meeting of the American Society of Hematology

PALO ALTO, Calif., Dec. 13, 2011 /PRNewswire/ -- Telik, Inc. (Nasdaq: TELK) announced today the results of gene expression analyses conducted during a Phase 2 clinical trial of Telintra in myelodysplastic syndrome (MDS), which may identify patients more likely to respond to Telintra therapy.  This work was conducted in collaboration with investigators at Columbia University Medical School and at the Broad Institute of MIT and Harvard University.  The presentation was made during the 53rd Annual Meeting of the American Society of Hematology in San Diego, California (Proceedings #2779).

Pre-therapy bone marrow mononuclear cells of Low to Intermediate-1 Risk MDS patients treated with Telintra who demonstrated hematologic improvement by International Working Group (IWG 2006) criteria were collected and analyzed for gene expression by whole genome array.   RNA isolated from the marrow mononuclear cells was available on 9 responders and 21 non-responders.  The top 100 differentially expressed genes of responders and non-responders were identified and revealed a number of genes and unidentified transcripts that may play a role in the MDS patient response to Telintra treatment.  

Pathway analysis of the expression data confirmed that a c-Jun N-terminal kinase (JNK) gene set was consistently under-expressed in the pre-therapy bone marrow mononuclear cells of responders and over-expressed in non-responders.  Importantly, this result was consistent with the proposed Telintra mechanism of action: patients whose pre-therapy marrow showed under-expression of the JNK gene set were those who benefited from Telintra; while those patients who over-expressed these genes were unlikely to respond to Telintra.  In addition, it may be possible to use gene expression signatures to enable selection of MDS patients that are most likely to benefit from Telintra.

Background on MDS and Telintra

The myelodysplastic syndrome 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 transformation to acute myeloid leukemia.  It is estimated that MDS affects approximately 300,000 people worldwide. According to a study published in the Journal of Clinical Oncology by Goldberg et al. (June 2010), 45,000 new cases of MDS are diagnosed each year in the United States, with survival rates ranging from six months to six years. MDS patients often require multiple blood transfusions to manage their disease.

Telintra has a novel mechanism of action that inhibits an enzyme called glutathione S-transferase P1-1, which leads to activation of Jun kinase, a key regulator of cellular growth and differentiation of blood precursor cells; and induces cancer cell death, or apoptosis, in human leukemia cell lines. Telintra is currently being evaluated in a Phase 2 clinical study in Revlimid® refractory and resistant deletion (5q) MDS patients; and in a Phase 2b clinical study in non-deletion (5q) MDS patients.  Additional information about Telintra is available at www.telik.com .

About Telik

Telik, Inc. of Palo Alto, CA, is a clinical stage drug development company focused on discovering and developing small molecule drugs to treat cancer.  The company's most advanced drug candidate is Telintra®, a modified glutathione analog intended for the treatment of hematologic malignancies including myelodysplastic syndrome; followed by Telcyta®, a cancer activated prodrug for the treatment of a variety of cancers. Telik's product candidates were discovered using its proprietary drug discovery technology, TRAP®, which enables the rapid and efficient discovery of small molecule drug candidates.

This press release contains "forward-looking" statements regarding the future development of Telintra, the safety and effectiveness of Telintra in treating MDS and the potential use of gene expression signatures to identify patients more likely to respond to Telintra therapy. These forward-looking statements are based upon Telik's current expectations and there are important factors that could cause actual results to differ materially from those indicated by these forward-looking statements. Detailed information regarding factors that may cause actual results to differ materially from the results expressed or implied by statements in this press release may be found in Telik's periodic filings with the Securities and Exchange Commission, including the factors described in the section entitled "Risk Factors" in its quarterly report on Form 10-Q for the period ending September 30, 2011. Telik does not undertake any obligation to update forward looking statements contained in this press release.

Telik, the Telik logo, TELINTRA, TELCYTA and TRAP are trademarks or registered trademarks of Telik, Inc.

SOURCE Telik, Inc.