Cylene Pharmaceuticals Reports Data for New Class of Cancer Therapeutics and Selects Clinical Candidate; Company Presents Late-Breaking Abstract at AACR Annual Meeting.

Business Editors/Health/Medical Writers

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SAN DIEGO--(BUSINESS WIRE)--March 31, 2004

Cylene Pharmaceuticals, Inc., an oncology drug discovery and development company, reported strong preclinical data for one of its Oncogene Inhibitors, a new class of cancer therapeutics. The small molecule, CX-3543, effectively reduced expression of the c-Myc oncogene and inhibited tumor growth in colorectal tumor animal models. The compound also inhibited growth of prostate and pancreatic tumor models in mice. c-Myc is an oncogene implicated in tumor proliferation and is known to be produced in high levels in these tumor cell types. Based on data compiled to date, Cylene has selected CX-3543 as the first of its Oncogene Inhibitors that it will advance toward clinical trials. The data were highlighted at a press conference today and presented in a late-breaking abstract during the 95th Annual Meeting of the American Association for Cancer Research (AACR) in Orlando, Florida.

"We are very excited about moving forward with CX-3543, as it is the first true small molecule approach to the selective regulation of oncogene expression," said William G. Rice, Ph.D., Cylene President and Chief Executive Officer. "We look forward to further preclinical and clinical trials. We see this application of our technology as a major step forward in oncology and intend to advance several products into the clinic over the next few years."

Cylene recently demonstrated that G-quadruplexes -- highly ordered three-dimensional DNA structures that regulate expression of certain oncogenes -- can be targeted with small molecules, leading to selective suppression of oncogene expression and tumor cell death. CX-3543 selectively suppresses c-Myc activity by specifically binding to the c-Myc quadruplex. The compound also targets the structurally similar quadruplex regulatory element of VEGF (vascular endothelial growth factor), a validated target of other cancer drugs including Avastin(TM).

Cylene Pharmaceuticals, Inc. is a privately-held pharmaceutical company dedicated to the discovery, development and commercialization of first-in-class small molecule drugs to treat life-threatening diseases, with a particular emphasis in oncology. Cylene's pipeline is led by CX-3543, a c-Myc/VEGF Oncogene Inhibitor which demonstrates potent in vivo efficacy in xenograft models of human solid tumors and is currently in preclinical development. CX-3543 and other molecules in the pipeline originate from the company's proprietary platform, which directs small molecules at molecular targets that regulate the expression of key oncogenes and other disease-related proliferation genes. The company is establishing its leadership position in small molecule regulation of oncogene expression by commercializing the pioneering work of two Cylene founders, Professors Laurence Hurley and Daniel Von Hoff.

Avastin(TM) is a trademark of Genentech.

Editor's Note: Copies of the abstract can be obtained by contacting Kathy Witz Sweeney at 858-455-5500, ext. 212 or [e-mail].