Study Meets Co-Primary Endpoints: Overall Survival and Progression-Free Survival Benefit

Plexxikon's U.S. Patent for PLX4032 Issues

Berkeley, CA — January 18, 2011 - Plexxikon Inc. today announced positive data from an interim analysis of the BRIM3 trial, a large multi‐ center Phase 3 clinical study of PLX4032 (RG7204) in patients with previously untreated metastatic melanoma with the BRAF mutation. Patients treated with PLX4032 had an improved overall survival (OS) compared to patients treated with dacarbazine, the current standard of care. In addition, these patientslived longer on average without their disease getting worse, as measured by progression‐free survival (PFS). PLX4032 is an oral, novel kinase inhibitor that targets the oncogenic BRAF mutation.

 
September 15, 2010

With pharma focused on new frontline therapies, developers are relying on new technology to advance a fresh series of best-in-class therapies--anything that looks like a me-too approach won't get pushed. And Plexxikon hit paydirt when it collected a $60 million upfront from Roche in early 2009 pact covering its PLX-5568, an experimental therapy for a rare genetic kidney disease as well as additional undisclosed programs. Altogether the developer has rounded up a whopping $185 million in non-dilutive partnership funding, a stellar record in an industry that thrives on that kind of cash.

BERKELEY, Calif. – August 25, 2010 - Plexxikon today announced publication of data from the Phase 1 clinical trial of PLX4032 (RG7204), confirming that treatment of metastatic melanoma patients with the BRAF V600E mutation resulted in significant tumor shrinkage in the majority of patients. Specifically, in the melanoma extension cohort of the study, nearly all patients showed some response; 81 percent of patients had tumor shrinkage of at least 30 percent. The data were published in the August 26, 2010 issue of the New England Journal of Medicine, based on an analysis as of January 31, 2010. These results further support the current PLX4032 development strategy, which includes parallel and ongoing Phase 2 (BRIM2) and Phase 3 (BRIM3) studies to support registration. PLX4032 is a novel, orally administered, targeted agent that is selective for a key oncogenic driver in melanoma and other cancers.

 
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.