<PAGE>
Prospectus Supplement Filed Pursuant to Rule 424(b)(3)
to Prospectus Dated April 3, 1998 File No. 333-09927
2,206,650 Shares
MAGAININ PHARMACEUTICALS INC.
Common Stock
This prospectus supplement supplements information contained in that
certain prospectus of Magainin Pharmaceuticals Inc. originally dated September
18, 1996, as amended on May 8, 1997 and April 3, 1998 (the "Prospectus")
covering the resale from time to time of up to 2,206,649 shares of common stock,
$.002 par value (the "Common Stock"), of Magainin Pharmaceuticals Inc., a
Delaware corporation (the "Company") by certain selling stockholders of the
Company.
The information set forth in this Prospectus Supplement is hereby
added to and deemed to be included in the Prospectus and replaces, in its
entirety, the information set forth in the Prospectus dated April 3, 1998 in the
first paragraph of the prospectus cover and under the heading "Selling
Stockholders". This Prospectus Supplement does not contain complete information
about the offering of the Common Stock, and may not be delivered or utilized
except in connection with the Prospectus dated April 3, 1998, including any
amendments or supplements thereto.
THE DATE OF THIS PROSPECTUS IS JUNE __, 2000
<PAGE>
The shares offered hereby consist of (i) 1,037,842 shares (the "Original
Shares") of common stock, $.002 par value per share ("Common Stock"), of
Magainin Pharmaceuticals Inc., a Delaware corporation ("Magainin" or the
"Company"), which are owned by the selling stockholders listed herein under
"Selling Stockholders" (collectively, the "Selling Stockholders") and (ii)
1,168,808 shares (the "Warrant Shares" and, together with the Original Shares,
the "Shares") of Common Stock which will be owned by the Selling Stockholders
upon exercise of warrants issued by the Company (the "Warrants"). The Original
Shares may be offered from time to time by the Selling Stockholders and the
Warrant Shares may be offered from time to time by the Selling Stockholders
following exercise of their Warrants. All expenses of registration incurred in
connection herewith are being borne by the Company, but all selling and other
expenses incurred by a Selling Stockholder will be borne by the Selling
Stockholder. The Company will not receive any of the proceeds from the sale of
the Shares by the Selling Stockholders.
SELLING STOCKHOLDERS
The following table sets forth certain information regarding the beneficial
ownership of the Common Stock of each Selling Stockholder and as adjusted to
give effect to the sale of the Shares offered hereby. The Shares are being
registered to permit public secondary trading of the Shares, and the Selling
Stockholders may offer the Shares for resale from time to time. See "Plan of
Distribution."
The Original Shares being offered hereby by the Selling Stockholders were
acquired by them from the Company in private placement transactions pursuant to
purchase agreements, dated as of August 6, 1996 (the "Purchase Agreements"),
pursuant to which the Selling Stockholders acquired an aggregate of 1,556,763
Units, at a purchase price of $7.7083 per Unit, consisting of (i) an aggregate
of 1,556,763 Shares of Common Stock, including the Original Shares, and (ii) the
Warrants to purchase 1,011,896 Warrant Shares, at an exercise price, subject to
adjustment, of $8.4791 per Warrant Share (the "Exercise Price"). An aggregate of
518,921 of such shares have previously been resold by certain of the Selling
Stockholders. The Warrant Shares being offered hereby may be acquired, from time
to time, by the Selling Stockholders upon exercise of the Warrants.
Subject to certain exceptions, the Exercise Price per Warrant Share is
subject to adjustment, on a weighted average basis, upon the following events:
(i) the issuance or sale of shares of Common Stock for a consideration per share
of Common Stock less than the then current Exercise Price, (ii) the grant or
sale by the Company of options for which the exercise price per share of Common
Stock is less than the then current Exercise Price, (iii) the issuance or sale
by the Company of any securities convertible into shares of Common Stock for
which the conversion price per share of Common Stock is less than the then
current Exercise Price, (iv) a change in any exercise price or conversion price
for options or convertible securities to a price below the then current Exercise
Price and (v) the subdivision or combination of shares of Common Stock. In such
events, the number of Warrant Shares issuable upon exercise of the Warrants is
subject to a corresponding adjustment.
In connection with the public offering of 2,250,000 shares of Common Stock
at $8.00 per share completed by the Company on November 20, 1997, the Warrants
were adjusted to be exercisable for 1,017,872 shares at an exercise price of
$8.4352 per share.
In addition, the Exercise Price per Warrant was subject to a one-time
adjustment per Warrant, at the option of the holder of such Warrant, in the
event that the average of the closing prices for the Common Stock on the Nasdaq
National Market in any calendar month prior to August 1999 is less than $7.7083.
Several shareholders exercised their option to reset the exercise price,
resulting in 254,468 Warrant Shares being adjusted to an exercise price of
$6.9642 on March 10, 1998, and 339,290 Warrant Shares being adjusted to an
exercise price of $6.0600 on July 6, 1998.
In connection with the private placement of 620,540 shares of Common Stock
at $3.22 per share completed by the Company on December 30, 1998, the Warrants
were adjusted to be exercisable for 1,030,905 Warrant Shares at exercise prices
ranging from $5.9945-$8.3091 per share.
<PAGE>
In connection with the public offering of 4,000,000 shares of Common Stock
at $1.00 per share to selected institutional investors and $1.13 per share to
directors of the Company completed by the Company on October 21, 1999, the
Warrants were adjusted to be exercisable for 1,158,210 Warrant Shares at
exercise prices ranging from $5.3548-$7.3727 per share.
In connection with the private placement of 1,085,973 shares of Common
Stock at $4.60 per share completed by the Company on May 8, 2000, the Warrants
were adjusted to be exercisable for 1,168,808 Warrant Shares at exercise prices
ranging from $5.3292-$7.2783 per share.
In recognition of the fact that investors may wish to be legally permitted
to sell their Shares when they deem appropriate, the Company has filed with the
Commission, under the Securities Act, a Registration Statement on Form S-3, of
which this Prospectus forms a part, with respect to the resale of the Shares
from time to time on the Nasdaq National Market of The Nasdaq Stock Market or in
privately-negotiated transactions and has agreed to prepare and file such
amendments and supplements to the Registration Statement as may be necessary to
keep the Registration Statement effective until the Shares are no longer
required to be registered for the sale thereof by the Selling Stockholders.
<TABLE>
<CAPTION>
Beneficial Ownership
After Offering
----------------------------------
Number of Shares
Beneficially Owned Number of Shares Number of Shares
Name of Selling Stockholder Prior to Offering Being Offered Shares Percent
--------------------------- ------------------- ----------------- ------------------- ------------
<S> <C> <C> <C> <C>
T. Rowe Price New Horizons Fund, Inc. 911,867 911,867 0 --
Vector Later-Stage Equity Fund, L.P. 680,999 680,999 0 --
Goodland International Investments, Ltd.* 1,586 1,586 0 --
Weyburn Overseas Ltd.* 680 680 0 --
T. Rowe Price Health Sciences Fund, Inc. 227,967 227,967 0 --
Bear, Stearns & Co. Inc.* 383,551 383,551 0 --
</TABLE>
*On November 25, 1998 Goodland International Investments, Ltd. and Weyburn
Overseas Ltd. transferred 236,109 and 101,189 Warrant Shares, respectively, to
Bear, Stearns & Co. Inc.
