Berkeley, CA - September 30, 2009 - Plexxikon Inc. announces that enrollment has been initiated and the first patient has been treated in the first of two pivotal trials of PLX4032 (RG7204) in patients with metastatic melanoma. PLX4032 is a novel, oral and highly selective drug that targets the BRAFV600E cancer-causing mutation occurring in about 50 percent of melanomas and about eight percent of all solid tumors. This single arm Phase 2 B-Raf Inhibitor in Melanoma (BRIM2) trial for previously-treated metastatic melanoma patients, along with a randomized, controlled Phase 3 trial (BRIM3) expected to start by the end of 2009 in first-line patients, are part of the planned registration program for PLX4032. The initiation of the Phase 2 trial has triggered a significant milestone payment to Plexxikon from Roche. Plexxikon is entitled to receive additional payments for milestone achievements as well as royalties on sales of PLX4032. Plexxikon and Roche are co-developing PLX4032 under their 2006 license and collaboration agreement.

 
Berkeley, CA and Basel, Switzerland - January 8, 2009 -- Plexxikon Inc. and Roche (SWX:ROG), today announced that they have entered into an agreement to develop and commercialize a second novel kinase inhibitor, PLX5568. The main focus of this partnership will be the development of this small molecule inhibitor of Raf kinase as an oral therapeutic treatment for polycystic kidney disease (PKD). There is currently no registered treatment for PKD which affects over 600,000 patients in the U.S and is the most common life- threatening genetic disease.

 
BERKELEY, Calif., September 3, 2008--(Business Wire)--Plexxikon Inc. today announced that it has initiated a Phase 1 human clinical trial for PLX5568, a novel kinase inhibitor targeted for the treatment of at least two major indications with unmet medical needs: pain as well as polycystic kidney disease (PKD). PLX5568 has demonstrated robust preclinical efficacy in multiple pain models, including neuropathic pain as well as acute and inflammatory pain. In addition, PLX5568 has demonstrated compelling efficacy in multiple preclinical models of PKD.

 
BERKELEY, Calif., May 21, 2008 --(BUSINESS WIRE)-- Plexxikon Inc. today announced data from preclinical studies of Polycystic Kidney Disease (PKD) demonstrating significantly reduced kidney disease following treatment with Plexxikon’s novel drug candidate. Plexxikon’s novel small molecule kinase inhibitor is a highly selective and potent inhibitor of Raf kinase, a critical mediator of PKD pathology. These data were recently presented at the ISN Forefronts Symposium on Polycystic Kidney Disease in Montreal, Canada by Stefan Somlo, M.D., CNH Long Professor of Internal Medicine and Genetics and Chief of Nephrology at the Yale University School of Medicine.