By Matthew Willett

ArQule Inc. completed an increased follow-on offering, tacking 420,000 shares onto the 2.5 million it originally planned to offer, for total proceeds of $65.7 million.

Lead underwriter UBS Warburg LLC, of Stamford, Conn., and underwriters CIBC World Markets Corp., of New York; Gerard Klauer Mattison & Co. LLC, of New York; and Legg Mason Wood Walker Inc., of Baltimore, were granted an option to purchase another 438,000 shares to cover overallotments.

ArQule focuses on synthesized compound arrays for use in lead compound generation and optimization. The company, which also provides research and development services, has established a number of joint ventures for drug discovery, and it pursues a pipeline of internal development.

The core of its technology is the AMAP Chemistry Operating System, a highly automated and integrated series of chemistry workstations and processes designed to enable rapid, parallel generation of thousands of novel, pure, diverse and spatially addressed arrays of compounds.

The company uses its proprietary Parallel Track Drug Discovery program, which integrates high-throughput and automated small-molecule synthesis technologies.

As a provider of mapping arrays and directed array libraries, ArQule collaborates with a number of pharmaceutical companies, including Pfizer Inc., of New York; Bayer AG, of Leverkusen, Germany; Wyeth-Ayerst Laboratories, a division of American Home Products Corp., of Madison, N.J.; and Abbott Laboratories, of Abbott Park, Ill.

As a drug discovery company, ArQule partners with players in the biotech sector such as Genome Therapeutics Inc., of Waltham, Mass. That deal centers on anti-infectives using compounds derived from GTI's PathoGenome Database.

ArQule will receive an equal share of any revenue generated through that deal, entered in October.

ArQule's stock (NASDAQ:ARQL) dropped 56.2 cents Tuesday, closing at $22.875. n