Array BioPharma Inc. (NASDAQ: ARRY) announced today that it is offering to sell, subject to market and other conditions, shares of its common stock pursuant to an effective shelf registration statement in an underwritten public offering. Array also intends to grant the underwriters a 30-day option to purchase additional shares of common stock to cover over-allotments, if any. All of the shares to be sold in the offering are to be sold by Array, with the proceeds to be used to fund research and development activities and for general corporate purposes. Jefferies & Company, Inc. and Leerink Swann LLC are acting as joint book-running managers of the proposed offering. Stifel Nicolaus Weisel is acting as co-manager of the offering.

A shelf registration statement relating to the shares was filed with the Securities and Exchange Commission and is effective. Information about the offering is available in the preliminary prospectus supplement to be filed with the Securities and Exchange Commission. This press release does not constitute an offer to sell, or the solicitation of an offer to buy, these securities, nor will there be any sale of these securities in any state or other jurisdiction in which such offer, solicitation or sale is not permitted. Any offer, if at all, will be made only by means of a prospectus, including a prospectus supplement, forming part of the effective shelf registration statement.

Copies of the preliminary prospectus supplement and accompanying prospectus may be obtained from Jefferies & Company, Inc., Attention: Equity Syndicate Prospectus Department, 520 Madison Avenue, 12th Floor, New York, New York 10022, or by calling (877) 547-6340, and Leerink Swann LLC, Attention: Syndicate Department, One Federal Street, 37th Floor, Boston, Massachusetts 02110, or by calling (800) 808-7525.

About Array BioPharma

Array BioPharma Inc. is a biopharmaceutical company focused on the discovery, development and commercialization of targeted small-molecule drugs to treat patients afflicted with cancer and inflammatory diseases. Array has four core proprietary clinical programs: ARRY-614 for myelodysplastic syndromes, ARRY-520 for multiple myeloma, ARRY-797 for pain and ARRY-502 for asthma. In addition, Array has 10 partner-funded clinical programs including two MEK inhibitors in Phase 2: selumetinib with AstraZeneca and MEK162 with Novartis.

Forward-Looking Statements

This press release contains forward-looking statements that are made pursuant to the safe harbor provisions of the Private Securities Litigation Reform Act of 1995. Such forward-looking statements include statements concerning the completion, timing and size of the proposed offering and other statements that are other than statements of historical facts. These statements involve significant risks and uncertainties. Because these statements reflect our current expectations concerning future events, our actual events could differ materially from those anticipated in these forward-looking statements as a result of many factors. These factors include, but are not limited to: the risk that the financing may be delayed or may not occur due to market or other conditions and the satisfaction of customary closing conditions related to the proposed public offering. Additional information concerning these and other factors that may cause actual events to differ materially from those anticipated in the forward-looking statements is contained in the “Risk Factors” section of Array’s most recent Annual Report on Form 10-K, in our other periodic reports and filings with the Securities and Exchange Commission and in the prospectus supplement related to the offering. We caution investors not to place undue reliance on the forward-looking statements contained in this press release. All forward-looking statements are based on information currently available to Array on the date hereof, and we undertake no obligation to revise or update these forward-looking statements to reflect events or circumstances after the date of this press release, except as required by law.