<PAGE>
FILED PURSUANT TO RULE 424(B)(2)
FILE NUMBER 333-39275
PRICING SUPPLEMENT NO. 4
(To Prospectus Dated November 12, 1997, and
Prospectus Supplement dated April 28, 2000)
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$1,390,685
CYGNUS, INC.
Common Stock
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<TABLE>
<S> <C>
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DATE OF PURCHASE....................................................................... SEPTEMBER 19, 2000
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NUMBER OF SHARES....................................................................... 123,600
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PRICE PER SHARE........................................................................ $11.2515
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PROCEEDS TO CYGNUS..................................................................... $1,390,685.00
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</TABLE>
The date of this Pricing Supplement is September 19, 2000.
