By Brady Huggett

Array Biopharma Inc. filed a registration statement with the SEC for an initial public offering of common stock, putting 6 million shares on the block and looking to pull in $66 million.

In August, Array sold 1.67 million shares of preferred stock in a Series C offering, raising roughly $10 million, and generated $8 million in a second round of private equity financing in December 1999.

The public offering is being made by co-lead managers Lehman Brothers Inc. and Deutsche Banc Alex. Brown, and Legg Mason Wood Walker Inc. is co-manager. They have an overallotment option on 800,000 shares. Array estimated the shares would sell between $10 and $12 apiece.

Array, of Boulder, Colo., has been expanding collaborations and coupling up with other companies during the past year. Array last week grew its existing agreement with Merck & Co. Inc. to continue designing and synthesizing lead-generation libraries for Merck's drug discovery activities, and Array and ICOS Corp. in August expanded their previous drug discovery collaboration, also entering into a process research and manufacturing agreement. In May, Array and Tularik Inc. agreed to design and synthesize a small-molecule-focused library targeting orphan nuclear receptors, and Eli Lilly and Co. has 30 Array scientists working alongside its own on several drug discovery projects.

Array is a discovery research company providing services in chemistry, high-throughput screening, structural biology and information management. Its trademark technology is Optimers - drug-relevant building block sets designed to explore structure-activity relationships (SAR) of leads. Optimers are based on criteria of how to facilitate rapid SAR exploration, and Array performed a retro-synthetic analysis of all the small molecules that have entered into clinical trials to develop Optimers.

Array opened for business in July 1998. The four founders, Kevin Koch, David Snitman, Anthony Piscopio and KC Nicolaou, three of them formerly with Amgen Inc., gave the company its start by leasing part of Amgen's old building in Boulder and recruiting 20 ex-Amgen scientists.

In July, Array doubled its lab space to 50,000 square feet by building a new facility in nearby Longmont for new chemists, and the company now has over 100 employees.

After the sale, all directors and executives combined will hold a 38 percent share in the company, down from a controlling 51.1 percent before, and Array will have 21.37 million shares outstanding. Investors holding between 11.5 percent and 15 percent before the IPO are ARCH Venture Fund III LP, of Chicago; Boulder Ventures II LP, of Boulder; Falcon Technology Partners LP, of Devon, Pa.; and Frazier Healthcare II LP, of Seattle.