ArQule and Daiichi Sankyo Announce Discontinuation of Phase 3 MARQUEE Clinical Trial in Non-Small Cell Lung Cancer

DMC Recommends Discontinuation of Study for Futility

No Unexpected Safety Findings from Interim Analysis

ArQule and Daiichi Sankyo Announce Discontinuation of Phase 3 MARQUEE Clinical Trial in Non-Small Cell Lung Cancer

ArQule, Inc.William B. Boni, 781-994-0300VP, Investor Relations/Corp. CommunicationsorDaiichi Sankyo, Inc. (US)Tara Camp, 973-944-2393/908-577-4531orDaiichi Sankyo, Co., Ltd.Michaela Paudler-Debus, PhD, +81-3-6225-1338

ArQule, Inc. (Nasdaq: ARQL) and Daiichi Sankyo, Co., Ltd. (TSE 4568) today announced that the independent Data Monitoring Committee (DMC) of the Phase 3 MARQUEE (et inhibitor 197 plus rlotinib vs rlotinib plus placebo in NSCLC) trial recommended the study be stopped early following a planned interim analysis, when they concluded that the study would not meet its primary endpoint of improved overall survival. Although the interim analysis showed a statistically significant improvement in progression-free survival (PFS) in the intent-to-treat (ITT) population, this benefit did not carry over to overall survival. There were no safety concerns identified by the DMC to Daiichi Sankyo or ArQule during this interim analysis.

MARQUEE is a randomized, double-blind, controlled pivotal trial to evaluate the investigational selective MET inhibitor, tivantinib (ARQ 197), in combination with erlotinib in previously treated patients with locally advanced or metastatic, non-squamous NSCLC.

ArQule and Daiichi Sankyo are providing information regarding the study discontinuation to health authorities and those clinical investigators participating in studies of tivantinib. Data from this study will be presented at an upcoming scientific meeting.

“We are disappointed that the MARQUEE trial did not provide statistically significant results for overall survival in a disease and treatment setting which remains a major unmet medical need,” said Paolo Pucci, chief executive officer of ArQule.

“Fighting cancer is a complex process in that therapies work differently in different tumor settings, so we will continue to investigate tivantinib in other tumor types,” said Glenn Gormley, MD, PhD, global head, R&D and senior executive officer, Daiichi Sankyo Co., Ltd.

Approximately 1,000 patients were recruited in MARQUEE from more than 200 clinical sites worldwide. The primary endpoint in the trial is overall survival (OS) in the overall intent-to-treat population. Secondary endpoints include OS in the subpopulation of patients with epidermal growth factor receptor (EGFR) wild type, progression-free survival (PFS) in the ITT population, and further assessment of the safety of tivantinib in combination with erlotinib. Tivantinib has not been approved for any indication in any country.

In December 2008, ArQule and Daiichi Sankyo signed a license, co-development and co-commercialization agreement to co-develop tivantinib in the U.S., Europe, South America and the rest of the world, excluding Japan, China (including Hong Kong), South Korea and Taiwan.

A replay of the conference call will be available for seven days following the call and can be accessed by dialing toll-free (855) 859-2056 and outside the U.S. (404) 537-3406. The replay access code is 37426625.

ArQule is a biotechnology company engaged in the research and development of next-generation, small-molecule cancer therapeutics. The Company’s targeted, broad-spectrum products and research programs are focused on key biological processes that are central to human cancers. ArQule’s lead product candidate, in Phase 2 and Phase 3 clinical development together with development and commercialization partner, Daiichi Sankyo, Co. Ltd., is tivantinib, an oral, selective inhibitor of the MET receptor tyrosine kinase. The Company’s pipeline consists of ARQ 621, designed to inhibit the Eg5 kinesin motor protein, and ARQ 736, designed to inhibit the RAF kinases. ArQule’s current discovery efforts, which are based on the ArQule Kinase Inhibitor Platform (AKIP™), are focused on the identification of novel kinase inhibitors that are potent, selective and do not compete with ATP (adenosine triphosphate) for binding to the kinase.

The Daiichi Sankyo Group is dedicated to the creation and supply of innovative pharmaceutical products to address the diversified, unmet medical needs of patients in both mature and emerging markets. While maintaining its portfolio of marketed pharmaceuticals for hypertension, hyperlipidemia, and bacterial infections, the Group is engaged in the development of treatments for thrombotic disorders and focused on the discovery of novel oncology and cardiovascular-metabolic therapies. Furthermore, the Daiichi Sankyo Group has created a "Hybrid Business Model," which will respond to market and customer diversity and optimize growth opportunities across the value chain. For more information, please visit .