SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 -------------- FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE ACT OF 1934 -------------- Date of Report (Date of earliest event reported): August 14, 2002 Vertex Pharmaceuticals Incorporated (Exact name of registrant as specified in its charter) MASSACHUSETTS 000-19319 04-3039129 (state or other jurisdiction of (Commission File Number) (IRS Employer incorporation) Identification No.) 130 WAVERLY STREET CAMBRIDGE, MA 02139 --------------------------------------------------- (Address of principal executive offices) (Zip Code) Registrant's telephone number, including area code: (617) 444-6100 ---------------------------------------------------- ITEM 9. REGULATION FD DISCLOSURE. The Quarterly Report on Form 10-Q for the period ending June 30, 2002 by Vertex Pharmaceuticals Incorporated was accompanied by certifications by the company's principal executive officer, Joshua S. Boger, and principal financial officer, Ian F. Smith, pursuant to Section 906 of the Sarbanes-Oxley Act of 2002.

A copy of the certifications is attached hereto as Exhibit 99.1. EXHIBIT INDEX Exhibit 99.1 Certification pursuant to Section 906 of the Sarbanes-Oxley Act of 2002. 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 (Registrant) Date: August 14, 2002 /s/Ian F. Smith ----------------------- Ian F. Smith Vice President and Chief Financial Officer


                                                                  EXHIBIT 99.1

                                 CERTIFICATION
           PURSUANT TO SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002
                   (SUBSECTIONS (A) AND (B) OF SECTION 1350,
                  CHAPTER 63 OF TITLE 18, UNITED STATES CODE)

    Pursuant to section 906 of the Sarbanes-Oxley Act of 2002 (subsections
(a) and (b) of Section 1350, Chapter 63 of Title 18, United States Code), each
of the undersigned officers of Vertex Pharmaceuticals Incorporated, a
Massachusetts corporation (the "Company"), does hereby certify, to such
officer's knowledge, that the Quarterly Report on Form 10-Q for the quarter
ended June 30, 2002 (the "Form 10-Q") of the Company fully complies with the
requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934,
and the information contained in the Form 10-Q fairly presents, in all material
respects, the financial condition and results of operations of the Company.



                                         
Dated:  August 14, 2002                                         /s/ JOSHUA S. BOGER
        ----------------------------                -------------------------------------------
                                                                 Joshua S. Boger,
                                                                 CHAIRMAN AND CEO
                                                           (PRINCIPAL EXECUTIVE OFFICER)

Dated:
        August 14, 2002                                          /s/ IAN F. SMITH
        ----------------------------                -------------------------------------------
                                                                   Ian F. Smith,
                                                    VICE PRESIDENT AND CHIEF FINANCIAL OFFICER
                                                           (PRINCIPAL FINANCIAL OFFICER)
The foregoing certification is being furnished solely pursuant to section 906 of the Sarbanes-Oxley Act of 2002 (subsections (a) and (b) of Section 1350, Chapter 63 of Title 18, United States Code) and is not being filed as part of a separate disclosure document.