UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. Initial )* VERTEX PHARMACEUTICALS INCORPORATED (Name of Issuer) COMMON SHARES (Title of Class of Securities) 92532F100 (CUSIP Number) Check the following box if a fee is being paid with this statement [ ]. (A fee is not required only if the filing person: (1) has a previous statement on file reporting beneficial ownership of more than five percent of the class of securities described in Item 1; and (2) has filed no amendment subsequent thereto reporting beneficial ownership of five percent or less of such class.) (See Rule 13d-7). *The remainder of this cover page shall be filled out for a reporting person's initial filing on this form with respect to the subject class of securities, and for any subsequent amendment containing information which would alter the disclosures provided in a prior cover page. The information required in the remainder of this cover page shall not be deemed to be "filed" for the purpose of Section 18 of the Securities Exchange Act of 1934 ("Act") or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes). Page 1 of 4 PagesCUSIP No. 92532F100 Schedule 13G Page 2 of 4 1. NAME OF REPORTING PERSON S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON Mackenzie Financial Corporation 2. CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP* (a) (b) X 3. SEC USE ONLY 4. CITIZENSHIP OR PLACE OF ORGANIZATION Toronto, Ontario, Canada 5. NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH: SOLE VOTING POWER 1,351,200 Shares 6. SHARED VOTING POWER Nil 7. SOLE DISPOSITIVE POWER 1,351,200 Shares 8. SHARED DISPOSITIVE POWER Nil 9. AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 1,351,200 Shares 10. CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES.* 11. PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9 5.4% 12. TYPE OF REPORTING PERSON * IA Schedule 13G Page 3 of 4 Item 1(a) Name of Issuer Vertex Pharmaceuticals Incorporated Item 1(b) Address of Issuer's Principal Executive Offices 130 Waverly Street Cambridge, MA 02139-4211 Item 2(a) Name of Person Filing Mackenzie Financial Corporation Item 2(b) Address of Principal Business Office 150 Bloor Street West, Suite M111 Toronto, Ontario M5S 3B5 Item 2(c) Citizenship Organized in Toronto, Ontario, Canada Item 2(d) Title of Class of Securities Common Stock Item 2(e) CUSIP Number 92532F100 Item 3 If this statement is filed pursuant to Rules 13d-1 (b) or 13d-2 (b), check whether the person filing is a: (a) [ ] Broker or Dealer (b) [ ] Bank (c) [ ] Insurance Company (d) [ ] Investment Company (e) [ X ] Investment Adviser (f) [ ] Employee Benefit Plan, Pension Fund or Endowment Fund (g) [ ] Parent Holding Company (h) [ ] Group Item 4 Ownership (a) Amount Beneficially Owned 1,351,200 Shares (b) Percent of Class 5.4% (c) Number of shares as to which such person has: (i) sole power to vote 1,351,200 Shares (ii) shared power to vote Nil (iii) sole power to dispose 1,351,200 Shares (iv) shared power to dispose Nil Schedule 13G Page 4 of 4 Item 5 Ownership of Five Percent or Less of a Class If this statement is being filed to report the fact that as of the date hereof the reporting person has ceased to be the beneficial owner of more than five percent of the class of securities, check the following [ ]. [ X ] Not applicable Item 6 Ownership of More than Five Percent on Behalf of Another Person Several accounts managed by Mackenzie Financial Corporation have the right to receive dividends and the proceeds from the sale of these securities, none of which own more than 5% of the common stock of Vertex Pharmaceuticals Incorporated. Item 7 Identification and Classification of the Subsidiary Which Acquire the Security Being Reported on By the Parent Holding Company N/A Item 8 Identification and Classification of Members of the Group N/A Item 9 Notice of Dissolution of Group N/A Item 10 Certification By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were acquired in the ordinary course of business and were not acquired for the purpose of and do not have the effect of changing or influencing the control of the issuer of such securities and were not acquired in connection with or as a participant in any transaction having such purposes or effect. After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct. Harold P. Hands Executive Vice President, Legal March 23, 1998