SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities and Exchange Act of 1934 Date of report (Date of earliest event reported): July 14, 2000 VERTEX PHARMACEUTICALS INCORPORATED (Exact name of registrant as specified in its charter) Massachusetts (State of incorporation) 000-19319 04-3039129 (Commission File No.) (IRS Employer Identification No.) 130 Waverly Street Cambridge, MA 02139 (Address of principal executive offices and zip code) Registrant's telephone number, including area code: (617) 577-6000

Item 5. OTHER EVENTS On July 14, 2000, the Board of Directors of Vertex Pharmaceuticals Incorporated declared a two-for-one split of its common stock. The stock split will be in the form of a stock dividend, and new shares will be distributed on August 23, 2000 to holders of record as of the close of business on August 9, 2000. A press release relating to the stock split is attached hereto as Exhibit 99.1. Item 7. FINANCIAL STATEMENTS, PRO FORMA FINANCIAL INFORMATION AND EXHIBITS (c) Exhibits 99.1 Press Release dated July 14, 2000. SIGNATURES Pursuant to the requirements of the Securities Exchange Act of 1934, the Registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized. VERTEX PHARMACEUTICALS INCORPORATED Dated: August 1, 2000 By: /s/ Richard H. Aldrich ----------------------------------- Richard H. Aldrich Senior Vice President and Chief Business Officer -2-

EXHIBIT INDEX Exhibit Number Description - ------- ----------- 99.1 Press Release dated July 14, 2000, titled, "Vertex Announces Two-For-One Stock Split."


EXHIBIT 99.1 FOR IMMEDIATE RELEASE VERTEX PHARMACEUTICALS ANNOUNCES TWO-FOR-ONE STOCK SPLIT CAMBRIDGE, MA, JULY 14, 2000 -- Vertex Pharmaceuticals Incorporated (Nasdaq: VRTX) announced today that its Board of Directors has approved a two-for-one stock split of its common stock. The stock split will be in the form of a stock dividend, and new shares will be distributed on August 23, 2000 to holders of record as of the close of business on August 9, 2000. The stock split will increase the number of shares currently issued and outstanding from approximately 26.7 million shares to approximately 53.4 million shares. "Through this stock split, our goal is to increase the liquidity of Vertex common stock and to broaden our shareholder base," stated Joshua Boger, Ph.D., Chairman, President and CEO. "This stock split reflects our commitment to building shareholder value as well as our enthusiasm for Vertex's opportunities for continued growth." Vertex Pharmaceuticals Incorporated discovers, develops and markets small molecule drugs that address major unmet medical needs. Vertex has eight drug candidates in clinical development to treat viral diseases, inflammation, cancer, autoimmune diseases and neurological disorders. Vertex has created its pipeline using a proprietary, information-based approach to drug design that integrates multiple technologies in biology, chemistry and biophysics, aimed at increasing the speed and success rate of drug discovery. Vertex's first approved product is Agenerase(TM) (amprenavir), an HIV protease inhibitor, which Vertex co-promotes with Glaxo Wellcome.

The foregoing information regarding Vertex's business strategy is forward looking. While management will make its best efforts to be accurate in making forward-looking statements, any such statements are subject to risks and uncertainties that could cause Vertex's actual results to vary materially. Investors are directed to consider risks and uncertainties discussed in Vertex documents filed with the Securities and Exchange Commission. Vertex's press releases are available at www.vpharm.com, or by fax-on-demand at (800) 758-5804 -- Code: 938395. # # # VERTEX CONTACTS: Lynne H. Brum, Vice President, Corporate Communications, (617) 577-6614 or Michael Partridge, Associate Director, Corporate Communications (617) 577-6108 or Katie Burns, Manager, Investor Relations, (617) 577-6656