EXHIBIT 1.5

                                 AMENDMENT NO. 4
                                     TO THE
             STRUCTURED EQUITY LINE FLEXIBLE FINANCING-SM- AGREEMENT

         THIS AMENDMENT NO. 4 to the STRUCTURED EQUITY LINE FLEXIBLE
FINANCING-SM- AGREEMENT ("Amendment") is dated as of October 27, 2000 between
Cripple Creek Securities, LLC, a limited liability company organized and
existing under the laws of the state of New York (the "Investor"), and Cygnus,
Inc., a corporation organized and existing under the laws of the State of
Delaware (the "Company"). Capitalized terms not defined herein shall have the
meanings assigned to them in that certain Structured Equity Line Flexible
Financing-SM- Agreement dated as of June 30, 1999, as amended September 29,
1999, March 27, 2000 and May 9, 2000 (the "Agreement").

                              W I T N E S S E T H:

         WHEREAS, the Company and the Investor entered into the Agreement,
pursuant to which the Company may issue to the Investor, and the Investor shall
purchase from the Company, from time to time as provided therein, shares of the
Company's common stock, par value $.001 per share, for a maximum aggregate
Purchase Price of $60,000,000; and

         WHEREAS, the Company and the Investor desire to amend the Agreement in
certain respects.

         NOW, THEREFORE, in consideration of the foregoing premises and other
good and valuable consideration, the receipt and sufficiency of which are hereby
acknowledged, the parties hereto agree as follows:

                                   ARTICLE I

                                   AGREEMENT

Section 1.1  Section 2.2(b) of the Agreement is hereby amended and restated in
             its entirety as follows:

             "(b) INVESTMENT PERIOD LIMITS. Notwithstanding the obligations
and rights of the Investor to purchase shares of Common Stock pursuant to
Section 2.1(b), (c) and (d), the aggregate Investment Amount for any
Investment Period (whether pursuant to a Minimum Obligation, an Additional
Purchase Notice or an Investor Call Purchase Notice or any combination
thereof) shall not at the option of the Investor exceed the lesser of (x) the
Minimum Obligation plus the amount set forth in any Additional Purchase
Notice and Investor Call Purchase Notice with respect to such Investment
Period, if any, or (y) an amount equal to 8% of the aggregate Value of Open
Market Trading of the Common




Stock on the Principal Market for each Trading Day during the Investment
Period immediately preceding such Investment Period on which the Stock Price
is above the Floor Price for such preceding Investment Period (rounded up to
the next increment of $10,000), or (z) an amount equal to 8% of the aggregate
Value of Open Market Trading of the Common Stock on the Principal Market for
each Trading Day during such Investment Period on which the Stock Price is
above the Floor Price (rounded up to the next increment of $10,000) (the
lower of the amounts referred to in clauses (y) and (z), the "8% Limit");
provided, however, that the Investor may waive, in whole or in part, the 8%
Limit in any Investment Period."

                                   ARTICLE II

                                  MISCELLANEOUS

         Section 2.1  NO THIRD PARTY BENEFICIARIES. This Amendment is
intended for the benefit of the parties hereto and their respective permitted
successors and assigns and is not for the benefit of, nor may any provision
hereof be enforced by, any other person.

         Section 2.2  GOVERNING LAW. This Amendment shall be governed by and
construed and enforced in accordance with the internal laws of the State of
New York without regard to such state's principles of conflict of laws.

         Section 2.3  EXECUTION. This Amendment may be executed in two or
more counterparts, all of which shall be considered one and the same
agreement, it being understood that all parties need not sign the same
counterpart.

         Section 2.4  AGREEMENT OTHERWISE UNCHANGED. Except as amended hereby
and previously, the Agreement shall remain unchanged and in full force and
effect.

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         IN WITNESS WHEREOF, the parties hereto have caused this Amendment No. 4
to the Structured Equity Line Flexible Financing-SM- Agreement to be duly
executed by their respective authorized officers as of the date hereof.

CRIPPLE CREEK SECURITIES, LLC      CYGNUS, INC.

By: /s/ Robert L. Chender       By: /s/ Craig W. Carlson
   --------------------------      --------------------------------------------
   Name:  Robert L. Chender        Name: Criag W. Carlson
   Title:  Principal               Title: Senior VP, Finance and CFO



        [SIGNATURE PAGE TO AMENDMENT NO. 4 TO THE STRUCTURED EQUITY LINE
                          FLEXIBLE FINANCING AGREEMENT]

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