<PAGE>
PURSUANT TO RULE 424(B)(3)
REGISTRATION NO. 333-51879
PROSPECTUS SUPPLEMENT
(TO PROSPECTUS DATED JUNE 18, 1998)
SEPRACOR INC.
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$189,475,000 PRINCIPAL AMOUNT OF 6 1/4% CONVERTIBLE
SUBORDINATED DEBENTURES DUE 2005
(Interest payable August 15 and February 15)
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4,012,617 Shares of Common Stock
($0.10 par value per share)
---------------------
The information in this Prospectus Supplement concerning the Selling
Securityholders supplements the statements set forth under the caption "Selling
Securityholders" in the Prospectus. Capitalized items used and not defined
herein shall have the meanings given to them in the Prospectus. The information
set forth under the caption "Selling Securityholders" in the Prospectus is
supplemented as follows:
SELLING SECURITYHOLDERS
The Debentures were originally acquired on February 10, 1998 from the
Company by the Initial Purchasers. The Initial Purchasers advised the Company
that the Initial Purchasers have resold the Debentures in transactions exempt
from the registration requirements of the Securities Act to "qualified
institutional buyers" (as defined in Rule 144A of the Securities Act) and
certain institutional "accredited investors" (as defined in Rule 501(a)(1), (2,
(3), or (7) under the Securities Act). These subsequent purchasers, or their
transferees, pledgees, donees or successors, may from time to time offer and
sell any or all of the Debentures and/or Conversion Shares pursuant to this
Prospectus.
The Debentures and the Conversion Shares have been registered pursuant to
the Registration Rights Agreement which provides that the Company file a
Registration Statement with regard to the Debentures and the Conversion Shares
within 90 days of the date of original issuance of the Debentures and keep such
Registration Statement effective until the earlier of (i) the sale pursuant to
the Registration Statement of all the securities registered pursuant to the
Registration Rights Agreement thereunder and (ii) the expiration of the holding
period applicable to such securities under Rule 144(k) under the Securities Act
or any successor provision.
In addition, 12,639 Additional Shares are being registered pursuant to the
Registration Statement for the account of certain securityholders of the
Company. The Selling Securityholders may choose to sell Debentures and/or
Sharesfrom time to time. See "Plan of Distribution."
DEBENTURES AND CONVERSION SHARES. The following table sets forth the name
of each Selling Securityholder who has provided the Company with notice as of
the date of this Prospectus pursuant to the Registration Rights Agreement of
such Selling Securityholder's intent to sell or otherwise dispose of Debentures
and/or Conversion Shares pursuant to the Registration Statement, the principal
amount of Debentures and the number of Conversion Shares which may be sold from
time to time by such Selling Securityholder pursuant to the Registration
Statement and the amount of outstanding Debentures and Common Stock
beneficially owned by such Selling Securityholder prior to the offering
(assuming no
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conversion of the Debentures). No such Selling Securityholder nor any of its
affiliates has held any position or office with, been employed by or otherwise
has had any material relationship with, the Company or any of its affiliates
during the three years prior to the date of this Prospectus. Because the
Selling Securityholder may offer all or some portion of the Debentures and
Conversion Shares, no estimate can be given as to the amount or percentage of
Debentures or Common Stock that will be held by the Selling Securityholders
upon termination of sales pursuant to this Prospectus. In addition, the Selling
Securityholders identified below may have sold, transferred or disposed of all
or a portion of their Debentures since the date on which they provided the
information regarding their holdings in transactions exempt from the
registration requirements of the Securities Act.
<TABLE>
<CAPTION>
Amount of Shares of
Amount of Debentures Common Stock
Debentures Owned Before Shares That May Owned Before
Name (1) May Be Sold Offering Be Sold (2) Offering
-------- ------------- ---------- ------------ -----------
<S> <C> <C> <C> <C>
ICI American Holdings
Trust $425,000 $425,000 8,972 0
Zeneca Holdings Trust 425,000 425,000 8,972 0
State of Delaware PERS 1,000,000 1,000,000 21,110 0
Starvest Fund-
Discretionary 500,000 500,000 10,555 0
State of Oregon/SAIF
Corporation 4,000,000 4,000,000 84,443 0
State of Oregon PERS 4,500,000 4,500,000 94,998 0
Nalco Chemical Corp.
Retirement 225,000 225,000 4,749 0
Kapiolani Medical
Center for Women and
Children 100,000 100,000 2,111 0
Hawaiian Airlines
Pension for Salaried
Employees 15,000 15,000 316 0
Hawaiian Airlines
Pilots' Retirement Plan 70,000 70,000 1,477 0
Hawaiian Airlines
Pension Plan - IAM 50,000 50,000 1,055 0
Allstate Insurance
Company 2,000,000 2,000,000 42,221 0
Shepard Investments
International Inc. 14,875,000 14,875,000 314,023 0
</TABLE>
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<TABLE>
<CAPTION>
<S> <C> <C> <C> <C>
Silverton International
Fund Limited 4,250,000 4,250,000 89,721 0
Nomura Securities
(Bermuda) Ltd. 10,000,000 10,000,000 211,108 0
Paloma Securities L.L.C.
4,475,000 4,475,000 94,471 0
Ell & Co., as nominee
for The Northern Trust
Company of New York 580,000 580,000 12,244 0
Salkeld & Co., as
nominee for Bankers
Trust Company 615,000 615,000 12,983 0
Bankers Trust Company
1,500,000 1,500,000 31,666 0
Bear Stearns Securities
Corp. 1,500,000 1,500,000 31,666 0
The Income Fund of
America, Inc. 7,350,000 7,350,000 155,164 0
The TCW Group, Inc. 12,315,000 12,315,000 259,980 0
Deutsche Bank AG 12,105,000 12,105,000 255,546 0
Morgan Stanley Dean
Witter 2,045,000 2,045,000 43,171 0
Colonial Penn Life
Insurance Company 2,000,000 2,000,000 42,221 0
OCM Convertible Trust 3,575,000 3,575,000 75,471 0
OCM Convertible
Limited Partnership 100,000 100,000 2,111 0
Delta Air Lines Master
Trust 1,025,000 1,025,000 21,638 0
State Employees'
Retirement Fund of the
State of Delaware 840,000 840,000 17,733 0
State of Connecticut
Combined Investment
Funds 3,210,000 3,210,000 67,765 0
Vanguard Convertible
Securities Fund, Inc. 2,200,000 2,200,000 46,443 0
</TABLE>
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<TABLE>
<CAPTION>
<S> <C> <C> <C> <C>
Partner Reinsurance
Company Ltd. 280,000 280,000 5,911 0
Chrysler Corporation
Master Retirement Trust
2,405,000 2,405,000 50,771 0
Raytheon Company
Master Pension Trust 1,115,000 1,115,000 23,538 0
Mainstay Convertible
Fund 4,750,000 4,750,000 100,276 0
Century National
Insurance Company 425,000 425,000 8,972 0
Chrysler Insurance
Company -Total Return 30,000 30,000 633 0
AAM/Zazove
Institutional Income
Fund L.P. 2,500,000 2,500,000 52,777 0
Zazove Convertible
Fund L.P. 745,000 745,000 15,727 0
McMahan Securities
Company L.P. 390,000 390,000 8,233 0
Stephenson Ventures 500,000 500,000 10,555 0
Delaware State
Employees' Retirement
Fund 3,300,000 3,300,000 69,665 0
Declaration of Trust for
the Defined Benefit
Plans of ICI American
Holdings, Inc. 1,030,000 1,030,000 21,744 0
Declaration of Trust for
the Defined Benefit
Plans of Zeneca
Holdings Inc. 700,000 700,000 14,777 0
Thermo Electron
Balanced Investment
Fund 950,000 950,000 20,055 0
Hillside Capital
Incorporated Corporate
Account 330,000 330,000 6,966 0
</TABLE>
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<TABLE>
<CAPTION>
<S> <C> <C> <C> <C>
General Motors
Employees Domestic
Group Trust 11,630,000 11,630,000 245,519 0
Summer Hill Global
Partners L.P. 80,000 80,000 1,688 0
The J.W. McConnell
Family Foundation 380,000 380,000 8,022 0
TQA Vantage Fund Ltd.
1,000,000 1,000,000 21,110 0
TQA Arbitrage Fund,
L.P. 750,000 750,000 15,833 0
California Public
Employees' Retirement
System 4,000,000 4,000,000 84,443 0
Millennium Trading
Co., L.P. 185,000 185,000 3,905 0
Donaldson, Lufkin &
Jenrette Securities Corp.
220,000 220,000 4,644 0
Fidelity Financial Trust:
Fidelity Convertible
Securities Fund (3) 7,815,000 7,815,000 164,981 0
Fidelity Securities Fund:
Fidelity OTC Portfolio
(3) 14,500,000 14,500,000 306,107 0
MFS Series Trust I-
MFS Convertible
Securities Fund 2,000 2,000 42 0
MFS Series Trust V-
MFS Total Return Fund 1,998,000 1,998,000 42,179 0
J. P. Morgan & Co. 3,000,000 3,000,000 63,332 81,500
General Motors
Employees Domestic
Group Pension
Trust (4) 8,679,000 8,679,000 183,221 47,600
Motors Insurance
Corporation (4) 2,002,000 2,002,000 42,263 0
General Motors
Foundation, Inc. (4) 319,000 319,000 6,734 0
</TABLE>
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<TABLE>
<CAPTION>
<S> <C> <C> <C> <C>
Nicholas-Applegate
Convertible Fund 2,157,000 2,157,000 45,536 0
Nicholas-Applegate
Global Holdings
Company LP 70,000 70,000 1,477 0
Baptist Health of South
Florida 118,000 118,000 2,491 0
Boston Museum of
Fine Arts 59,000 59,000 1,245 0
Engineers Joint Pension
Fund 218,000 218,000 4,602 0
Physicians Life 450,000 450,000 9,499 0
Wake Forest University 466,000 466,000 9,837 0
Dunham &
Associates II 41,000 41,000 865 0
Dunham &
Associates III 22,000 22,000 464 0
San Diego City
Retirement 589,000 589,000 12,434 0
San Diego County
Convertible 1,800,000 1,800,000 37,999 0
TQA Leverage
Fund, L.P. 565,000 565,000 11,927 0
Anchor Pathway
Growth-Income Series 3,650,000 3,650,000 77,054 0
GLG Market
Neutral Fund 2,000,000 2,000,000 42,221 0
Putnam Convertible
Income-Growth Trust 4,880,000 4,880,000 103,020 0
Putnam Balanced
Retirement Fund 300,000 300,000 6,333 0
Putnam Convertible
Opportunities and
Income Trust 390,000 390,000 8,233 0
Museum of Fine Arts,
Boston 60,000 60,000 1,266 0
Boston College 100,000 100,000 2,111 0
</TABLE>
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<TABLE>
<CAPTION>
<S> <C> <C> <C> <C>
ProMutual 500,000 500,000 10,555 0
Employers' Reinsurance
Corporation 550,000 550,000 11,610 0
University of Rochester 120,000 120,000 2,533 0
Rhone-Poulenc Rorer
Pension Plan 120,000 120,000 2,533 0
Parker-Hannifin
Corporation 140,000 140,000 2,955 0
New Hampshire
Retirement System 600,000 600,000 12,666 0
Norwest Bank
Nevada, N.A. 300,000 300,000 6,333 0
Sage Capital 2,750,000 2,750,000 58,054 0
Bristol Bay Native
Corporation 500,000 500,000 10,555 0
Foundation for
Research 300,000 300,000 6,333 0
Maria Newman 50,000 50,000 1,055 0
Roberta Goodman 100,000 100,000 2,111 0
Stephen H. Weiss
Trustee U/A 5/26/76
Jerome K. Ohrbock
Grantor 125,000 125,000 2,638 0
SoundShore Holdings
Ltd. 250,000 250,000 5,277 0
</TABLE>
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(1) Certain of the Debentures are currently evidenced by a global Debenture
which has been deposited with DTC and registered in the name of Cede & Co.
as DTC's nominee. Therefore, the Company is unable to provide the names of
any remaining Selling Stockholders.
(2) Assumes conversion of full amount of Debentures held by such holder at the
initial rate of $47.369 in principal amount of Debentures per share of
Common Stock.
(3) Debentures are held in the nominee name of Mag & Co. The entity is either
an investment company or a portfolio of an investment company registered
under Section 8 of the Investment Company Act of 1940, as amended, or a
private investment account advised by Fidelity Management & Research
Company ("FMR Co."). FMR Co. is a Massachusetts corporation and an
investment advisor registered under Section 203 of the Investment Advisers
Act of 1940, as amended, and provides investment advisory services to each
of such Fidelity entities identified above, and to other registered
investment companies and to certain other funds which are generally
offered to a limited group of investors.
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FMR Co. is a wholly-owned subsidiary of FMR Corp. ("FMR"), a Massachusetts
corporation. The holdings are as of September 2, 1998.
(4) General Motors Investment Management Corporation, a wholly owned subsidiary
of General Motors Corporation ("GM"), provides investment advice and
investment management services with respect to the assets of certain
employee benefit plans of GM and its subsidiaries, including the General
Motors Employees Domestic Group Pension Trust, and with respect to the
assets of certain direct and indirect subsidiaries of GM and associated
entities, including Motors Insurance Corporation and the General Motors
Foundation, Inc.
ADDITIONAL SHARES. Set forth below are the names of certain other Selling
Securityholders who acquired shares of Common Stock in certain transactions not
related to the sale of Debentures and the maximum number of Additional Shares
that may be sold by each such Selling Securityholder from time to time
hereunder. No such Selling Securityholders nor any of their affiliates has held
any position or office with, been employed by or otherwise have had any material
relationship with, the Company or any of its affiliates during the three years
prior to the date of this Prospectus. The percentage of Common Stock
beneficially owned by each of the Selling Securityholders identified below both
prior to and after giving effect to the offering being made hereby is less than
1%.
<TABLE>
<CAPTION>
NUMBER OF SHARES OF NUMBER OF SHARES OF
COMMON STOCK NUMBER OF SHARES OF COMMON STOCK
BENEFICIALLY OWNED COMMON STOCK TO BE BENEFICIALLY OWNED
NAME PRIOR TO THIS OFFERING OFFERED HEREUNDER AFTER THIS OFFERING
------ ----------------------- ------------------- --------------------
<S> <C> <C> <C>
Robash Inc. 243 243 0
Beincke Investment
Fund L.P. 1,944 1,944 0
Theodore H. Ashford 4,243 243 4,000
Bedrock Asset Trust I 7,778 7,778 0
Bankers Trust
Company, as Trustee of
the Hughes Aircraft
Company Retirement
Plans 80,539 2,431 78,108
</TABLE>
The date of this Prospectus Supplement is
August 27, 1999
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