<PAGE>
FILED PURSUANT TO RULE 424(B)(3)
REGISTRATION NO. 333-75561
PROSPECTUS SUPPLEMENT
(TO PROSPECTUS DATED JULY 28, 1999)
SEPRACOR INC.
-------------------------------------------------------------------
$300,000,000 PRINCIPAL AMOUNT OF 7% CONVERTIBLE
SUBORDINATED DEBENTURES DUE 2005
-------------------------------------------------------------------
2,402,402 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
We originally sold the debentures on December 15, 1998 to Morgan
Stanley Dean Witter and Salomon Smith Barney. These initial purchasers of the
debentures have advised us that the debentures were resold in transactions
exempt from the registration requirements of the Securities Act to "qualified
institutional buyers," defined in Rule 144A of the Securities Act. These
subsequent purchasers, or their transferees, pledges, donees or successors, may
from time to time offer and sell any or all of the debentures and/or shares of
the common stock issuable upon conversion of the debentures pursuant to this
prospectus.
The debentures and the shares of common stock issuable upon conversion
of the debentures have been registered pursuant to the registration rights
agreement. Pursuant to the registration rights agreement, we are required to
file a registration statement with regard to the debentures and the shares of
our common stock issuable upon conversion of the debentures and to keep the
registration statement effective until the earlier of:
(1) the sale of all the securities registered pursuant to the
registration rights agreement, and
<PAGE>
(2) the expiration of the holder period applicable to these
securities under Rule 144(k) under the Securities Act or any
successor provision.
The selling securityholders may choose to sell debentures and/or the
shares of common stock issuable upon conversion of the debentures from time to
time. See "Plan of Distribution."
The following table sets forth:
(1) the name of each selling securityholder who has provided us
with notice as of the date of this prospectus pursuant to the
registration rights agreement of their intent to sell or
otherwise dispose of debentures and/or shares of common stock
issuable upon conversion of the debentures pursuant to the
registration statement,
(2) the principal amount of the debentures and the number of
shares of our common stock issuable upon conversion of the
debentures which they may sell from time to time pursuant to
the registration statement, and
(3) the amount of outstanding debentures and our common stock
beneficially owned by the selling securityholder prior to the
offering, assuming no conversion of the debentures.
To our knowledge, no selling securityholder nor any of its affiliates
had held any position or office with, been employed by or otherwise has had any
material relationship with Sepracor or Sepracor's affiliates, during the three
years prior to the date of this prospectus.
A selling securityholder may offer all or some portion of the
debentures and shares of the common stock issuable upon conversion of the
debentures. Accordingly, no estimate can be given as to the amount or percentage
of debentures or our 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.
The information contained under the column heading "Shares That May be
Sold" assumes conversion of full amount of the debentures held by the holder at
the initial rate of $124.875 in principal amount of the debentures per share of
the common stock.
<PAGE>
<TABLE>
<CAPTION>
SHARES OF
AMOUNT OF 7% AMOUNT OF 7% COMMON
DEBENTURES THAT MAY DEBENTURES OWNED SHARES THAT STOCK
NAME BE BEFORE MAY BE OWNED
SOLD OFFERING SOLD BEFORE
OFFERING
-------------------- ---------------- ----------- ----------
<S> <C> <C> <C> <C>
Aloha Airlines Non-Pilots Pension Trust ............ $ 250,000 $ 250,000 2,002 0
Aloha Airlines Pilots Retirement Trust ............. 125,000 125,000 1,001 0
Aloha Airlines Non-Pilots Pension Trust ............ 185,000 185,000 1,481 0
Amoco Corporation Master Trust for Employee Pension Plans 962,000 962,000 7,703 0
Arkansas Teachers Retirement ....................... 3,605,000 3,605,000 28,868 0
Associated Electric & Gas Services Limited ......... 1,200,000 1,200,000 9,609 0
Baptist Health of South Florida .................... 368,000 368,000 2,946 0
Bank of America .................................... 250,000 250,000 2,002 0
Bankroft Convertible Fund, Inc. .................... 1,000,000 1,000,000 8,008 0
Bear Stearns & Co. ................................. 4,000,000 4,000,000 32,032 0
Boston Museum of Fine Arts ......................... 255,000 255,000 2,042 0
BNP Arbitrage SNC .................................. 50,000 50,000 400 24,850
CA Public Employees' Retirement System ............. 4,000,000 4,000,000 32,032 0
Castle Convertible Fund, Inc. ...................... 250,000 250,000 2,002 0
C&H Sugar Company, Inc. ............................ 300,000 300,000 2,402 0
Capital Market Transactions Inc. ................... 4,000,000 4,000,000 32,032 0
Chrysler Corporation Master Retirement 5,665,000 5,665,000 45,365 0
Trust ..............................................
Declaration of Trust for the Defined Benefit Plans of ICI 1,050,000 1,050,000 8,408 0
American Holdings Inc. .............................
Declaration of Trust for the Defined Benefit Plans of 710,000 710,000 5,685 0
Zeneca Holdings Inc. ..............................
Delaware PERS ...................................... 1,575,000 1,575,000 12,612 0
Delaware State Employees' Retirement Fund .......... 1,430,000 1,430,000 11,451 0
Delta Air Lines Master Trust ....................... 2,495,000 2,495,000 19,979 0
Deutsch Bank Securities ............................ 24,000,000 24,000,000 192,192 0
Dunham & Associates III ............................ 216,000 216,000 1,729 0
Ellsworth Convertible Growth and Income Fund, Inc. . 1,000,000 1,000,000 8,008 0
</TABLE>
<PAGE>
<TABLE>
<CAPTION>
<S> <C> <C> <C> <C>
Engineers Joint Pension Fund ....................... 694,000 694,000 5,557 0
Greyhound Lines .................................... 100,000 100,000 800 0
Hamilton Partners Limited .......................... 2,000,000 2,000,000 16,016 0
Hawaiian Airlines Employees Pension Plan - IAM ..... 200,000 200,000 1,601 0
Hawaiian Airlines Pension Plan for Salaried Employees 50,000 50,000 400 0
Hawaiian Airlines Pilots Retirement Plan ........... 275,000 275,000 2,202 0
Highbridge Capital Corporation ..................... 7,000,000 7,000,000 56,056 0
Hotel Union & Hotel Industry of Hawaii ............. 290,000 290,000 2,322 0
ICI American Holdings Trust ........................ 680,000 680,000 5,445 0
Island Holdings .................................... 20,000 20,000 160 0
Jackson Investment Fund Ltd. ....................... 2,000,000 2,000,000 16,016 0
Jeffries & Company Inc. ............................ 8,000 8,000 64 0
J.M. Hull Associates, L.P. ......................... 250,000 250,000 2,002 0
Julius Baer Securities ............................. 675,000 675,000 5,405 0
J.W. McConnell Family Foundation ................... 400,000 400,000 3,203 0
Kapiolani Health ................................... 50,000 50,000 400 0
Kapiolani Medical Center ........................... 400,000 400,000 3,203 0
LDG Limited ........................................ 250,000 250,000 2,002 0
Lincoln National Convertible Securities
Fund ............................................. 1,500,000 1,500,000 12,012 0
Lipper Convertibles L.P. ........................... 2,000,000 2,000,000 16,016 0
Lipper Convertibles Series II, L.P. ................ 3,000,000 3,000,000 24,024 0
Lipper Offshore Convertibles, L.P. ................. 3,000,000 3,000,000 24,024 0
Mag & Co., as Nominee for Fidelity Financial Trust:
Fidelity Convertible Securities (1) ............. 11,000,000 11,000,000 88,088 0
MainStay Convertible Fund .......................... 3,000,000 3,000,000 24,024 500
Major League Baseball .............................. 2,700,000 2,700,000 21,621 0
Minnesota Power Inc. ............................... 2,000,000 2,000,000 16,016 0
Morgan Stanley Dean Witter ......................... 30,000,000 30,000,000 240,240 0
Motion Picture Industry Health Plan-Active Member Fund 645,000 645,000 5,165 0
</TABLE>
<PAGE>
<TABLE>
<CAPTION>
<S> <C> <C> <C> <C>
Motion Picture Industry Health Plan-Retiree Member Fund 330,000 330,000 2,642 0
Museum of Fine Arts, Boston ........................ 51,000 51,000 408 0
Nalco Chemical Company ............................. 350,000 350,000 2,802 0
New Hampshire Retirement System .................... 305,000 305,000 2,442 0
Nicholas Applegate Convertible Fund ................ 6,920,000 6,920,000 55,415 0
OCM Convertible Limited Partnership ................ 165,000 165,000 1,321 0
OCM Convertible Trust .............................. 2,910,000 2,910,000 23,303 0
Paloma Securities LLC .............................. 250,000 250,000 2,002 0
Parker-Hannifin Corporation ........................ 64,000 64,000 512 0
Paloma Strategic Securities Limited ................ 250,000 250,000 2,002 0
Partner Reinsurance Company Ltd. ................... 640,000 640,000 5,125 0
Pell Rudman Trust Co., N.A. ........................ 1,375,000 1,375,000 11,011 0
Pepperdine University PoolA#1 ...................... 95,000 95,000 760 0
Physicians Life .................................... 640,000 640,000 5,125 0
Putnam Balanced Retirement Fund .................... 144,000 144,000 1,153 0
Putnam Convertible Income-Growth Trust ............. 7,250,000 7,250,000 58,058 0
Putnam Convertible Opportunities and Income Trust .. 147,000 147,000 1,177 0
Putnam High Income Convertible and Bond Fund ....... 750,000 750,000 6,006 0
Queens Health Plan ................................. 80,000 80,000 640 0
Raytheon Company Master Pension Trust .............. 2,660,000 2,660,000 21,301 0
Rhone-Poulenc Rorer Pension Plan ................... 23,000 23,000 184 0
Sage Capital ....................................... 1,600,000 1,600,000 12,812 0
Salomon Smith Barney ............................... 806,000 806,000 6,454 0
San Diego City Retirement .......................... 1,942,000 1,942,000 15,551 0
S.G. Cowen Securities Corporation .................. 3,000,000 3,000,000 24,024 0
San Diego County Convertible ....................... 5,649,000 5,649,000 45,237 0
Southern Farm Bureau Life Insurance - - 875,000 875,000 7,007 0
FRIC ...............................................
Starvest Combined Portfolio ........................ 250,000 250,000 2,002 0
Starvest Managed Portfolio ......................... 145,000 145,000 1,161 0
</TABLE>
<PAGE>
<TABLE>
<CAPTION>
<S> <C> <C> <C> <C>
State Employees' Retirement Fund of the State of Delaware 1,985,000 1,985,000 15,895 0
State of Connecticut Combined Investment Funds ..... 6,810,000 6,810,000 54,534 0
State of Oregon Equity ............................. 7,875,000 7,875,000 63,063 0
Summers Hill Global Partners L.P. .................. 125,000 125,000 1,001 0
TQA Arbitrage Fund, L.P. ........................... 1,150,000 1,150,000 9,209 0
TQA Leverage Fund, L.P. ............................ 1,800,000 1,800,000 14,414 0
TQA Vantage Fund, Ltd. ............................. 4,200,000 4,200,000 33,633 0
TQA Vantage Plus Fund, Ltd. ........................ 500,000 500,000 4,004 0
Tracor Inc., Employee Retirement Plan .............. 145,000 145,000 1,161 0
Transamerica Insurance Corporation of California ... 3,000,000 3,000,000 24,024 0
Transamerica Life Insurance & Annuity Company ...... 12,000,000 12,000,000 96,096 0
University of Rochester ............................ 49,000 49,000 392 0
Vanguard Convertible Securities Fund, Inc. ......... 4,120,000 4,120,000 32,992 0
Viacom Pension Plan Master Trust ................... 50,000 50,000 400 0
Wake Forest University ............................. 1,515,000 1,515,000 12,132 0
Zeneca Holdings Trust .............................. 680,000 680,000 5,445 0
Unknown (2) ........................................ 81,202,000 81,202,000 650,267 --
</TABLE>
(1) The entity is either an investment company or 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, or 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 industry advisory
services to each of the 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. FMR Co. owns 10.34% of
Sepracor's outstanding common stock. FMR Co. is a wholly owned subsidiary
of FMR Corp., a Massachusetts corporation.
(2) The name "Unknown" represents the remaining selling securityholders. We are
unable to provide the names of these securityholders because 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.
The date of this Prospectus Supplement is August 10, 1999.
