<PAGE>
Filed Pursuant to Rule 424(b)(3)
REGISTRATION NO. 333-32756
PROSEPECTUS SUPPLEMENT NO. 1 DATED AUGUST 7, 2000 TO THE
PROSPECTUS DATED JUNE 30, 2000 OF
CURAGEN CORPORATION
This Prospectus Supplement No. 1 amends the information in the table under
the caption "Selling Holders" in the Prospectus dated June 30, 2000 by deleting
the information contained in the table regarding the Selling Securityholders
with respect to the principal amount of debentures and common stock of CuraGen
Corporation and substituting therefor the following table:
<TABLE>
<CAPTION>
Name of Security Holder Principal Amount of Common Stock Owned Common Stock Offered Common Stock Owned
Debentures Beneficially After Completion of
Owned and Offered (in The Offering
thousands)
<S> <C> <C> <C> <C>
AIG SoundShore Holdings, $ 8,725 136,696 136,696 0
LTD
AIG SoundShore $ 2,500 39,168 39,168 0
Opportunity Holdings
Fund LTD
AIG SoundShore Strategic $ 1,106 17,328 17,328 0
Holding
Fund LTD
Argent Classic $ 5,875 92,045 92,045 0
Convertible Arbitrage
Fund (Bermuda) L.P.
BNP Arbitrage SNC $ 3,750 58,752 58,752 0
BNP Cooper Neff $ 250 3,917 3,917 0
Convertible Strategies
Fund, L.P.
Chartwell Investment $ 1,000 15,667 15,667 0
Partners
CLSP, L.P. -- 534,079 226,913 307,166
CLSP-SBS I, L.P. -- 81,034 81,034 0
CSLP-SBS II, L.P. -- 30,397 30,397 0
CLSP II, L.P. -- 36,656 36,656 0
Credit Research and $ 680 10,654 10,654 0
Trading LLC
</TABLE>
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<TABLE>
<S> <C> <C> <C> <C>
Credit Suisse First $ 2,200 34,468 34,468 0
Boston Corporation
Deephaven Domestic $ 3,500 54,835 54,835 0
Convertible Trading LTD
Depository Trust Company $45,794 717,465 0
Deutsche Bank $11,000 172,339 172,339 0
Securities, Inc.
Donaldson, Lufkin and $ 4,125 64,627 64,627 0
Jenrette Securities
Corporation
Family Services Life $ 300 4,700 4,700 0
Insurance Co.
Fidelity Financial Trust $ 6,000 94,003 94,003 0
Fir Tree Value Fund LP $ 7,405 116,012 116,012 0
Fir Tree Institutional $ 2,611 40,902 40,902 0
Value Fund LP
Fir Tree Value Partners $ 725 11,352 11,352 0
LDC II
Fir Tree Value Fund LP #2 $ 1,000 15,667 15,667 0
Guardian Life $ 6,500 101,837 101,837 0
Insurance Co.
Guardian Pension Trust $ 200 3,133 3,133 0
JMG Capital Partners LP $ 4,688 73,448 73,448 0
JMG Convertible $ 500 7,834 7,834 0
Investments LP
JMG Triton Offshore Fund $ 8,207 128,581 128,581 0
LTD
KBC Financial Products $ 200 3,133 3,133 0
Lyxor Master Fund $ 2,750 43,085 43,085 0
Merrill Lynch Convertible $ 250 3,917 3,917 0
Fund, Inc.
Michael Angelo, LP $ 3,250 50,918 50,918 0
Paloma Securities LLC $ 1,000 15,667 15,667 0
</TABLE>
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<TABLE>
<S> <C> <C> <C> <C>
Pequot Partners -- 3,638,000 1,500,000 2,138,000
Fund, LP
Pequot International -- 1,500,000 1,500,000 0
Fund, Inc.
Quantum Industrial -- 3,626,517 281,250 3,345,267
Partners LDC
Quantum Partners LDC -- 281,250 281,250 0
R2 Investments LDC $ 6,500 101,837 101,837 0
Sagamore Hill Hub $ 250 3,917 3,917 0
Fund Ltd.
St. Thomas Trading, Ltd. $ 50 783 783 0
Tribeca Investments LLC $29,825 467,275 467,275 0
Value Line Convertible $ 500 7,834 7,834 0
Fund, Inc.
Warburg Dillon $ 30 470 470 0
Read LLC
</TABLE>
This Prospectus Supplement No. 1 should be read in conjunction with the
Prospectus dated June 30, 2000
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