09/08/2008

Proteolix Raises $79 Million Series C Financing

Funds to Support Clinical Development of Carfilzomib Paul Hastings Appointed to Board of Directors

South San Francisco, California, September 8, 2008 -- Proteolix, Inc., a leader in the discovery and development of novel therapeutics that target protein degradation pathways in cancer and autoimmune diseases, today announced the successful completion of a new financing round of $79 million. The Series C round was led by new investor Nomura Phase4 Ventures. New investor Westfield Capital Management and existing investors, Advanced Technology Ventures, Delphi Ventures, Latterell Venture Partners, U.S. Venture Partners and The Vertical Group, all participated in the financing.

Proceeds from the financing will primarily support the completion of the company's ongoing Phase 2 clinical trials of carfilzomib, and the advancement of this anti-cancer therapeutic into Phase 3 clinical trials for the treatment of multiple myeloma. Proteolix will also use the funds to advance candidates in the company’s earlier stage pipeline of proteasome inhibitors.

"We are pleased to have completed this significant financing with participation from such highly-regarded new and existing investors," said Susan Molineaux, Ph.D., Proteolix's Chief Executive Officer. "Our lead candidate, carfilzomib, has demonstrated promising results in clinical and preclinical studies in multiple myeloma and a variety of other tumor types. Proceeds from this financing will enable us to advance carfilzomib to registration studies for multiple myeloma while continuing to cultivate select early-stage assets in our pipeline."

"We have been impressed by Proteolix's team, pipeline and proprietary expertise in the area of proteasome drug discovery and development. In particular, carfilzomib has been designed to be a highly selective candidate against a validated target and has demonstrated promising clinical data in hematologic malignancies," said Denise Pollard-Knight, Ph.D., Managing Director of Nomura Phase4 Ventures. Carfilzomib is currently in Phase 2 clinical studies to evaluate its safety and efficacy in hematologic and solid tumor malignancies. In non-clinical studies, carfilzomib has consistently exhibited a high level of selectivity for a single active site in the proteasome, and the reported clinical data to-date indicate the drug is well tolerated. The company's most advanced clinical trials of carfilzomib are evaluating the compound’s activity among multiple myeloma patients who have failed or relapsed following prior therapy. In addition to carfilzomib, Proteolix has generated a rich pipeline, including an oral anti-cancer proteasome inhibitor as well as a selective inhibitor targeting the proteasome in the cells of the immune system.

New Board Member Announced

Proteolix is also pleased to announce that Paul Hastings, President and Chief Executive Officer of OncoMed Pharmaceuticals, Inc., has joined its Board of Directors. Mr. Hastings brings more than 20 years of biotechnology and pharmaceutical industry experience as a senior-level executive in public and private companies. "Proteolix has made great progress in advancing its lead cancer therapeutic through clinical trials and developing an earlier stage pipeline of proteasome inhibitors," said Mr. Hastings on behalf of Proteolix’s Board of Directors. "I personally look forward to working closely with the team on their continued success."

About Proteolix

Proteolix, Inc. is a privately-held biopharmaceutical company, headquartered in South San Francisco, dedicated to discovering, developing and commercializing novel therapeutics that target protein degradation pathways for cancer and autoimmune diseases. Proteolix’s lead product, carfilzomib (PR-171), is currently in multiple Phase 2 clinical studies to evaluate its safety and efficacy in hematologic and solid tumor malignancies. Proteolix is also developing a pipeline of novel proteasome inhibitors, including an oral proteasome inhibitor and a selective immunoproteasome inhibitor.

Contacts:
Investors
Matthew Ferguson
Chief Financial Officer
650-266-2825
Contacts:
Media Inquiries
Karen L. Bergman or Michelle Corral
650-575-1509 or 415-794-8662