N E W S   R E L E A S E

               APHTON AGREES TO SELL NOTES FOR $20 MILLION IN TWO
                  TRANCHES AND CLOSES FIRST $15 MILLION TRANCHE

                                 March 31, 2003

               Miami, FL - Aphton Corporation (Nasdaq: APHT) announced it issued
and sold in a private placement convertible, redeemable, 5-year,
interest-bearing notes and warrants to three institutional investors, including
a substantial participation by two existing investors in the Company, for
proceeds of $15 million in the first tranche closing; the proceeds will be wired
tomorrow. The Notes are convertible at a fixed price of $2.50 per share; as part
of the transaction Aphton also issued to the investors five year warrants with a
fixed exercise price of $2.70 per share (both are at a premium to the market
price of the common stock as of the last closing price), unless otherwise
adjusted prior to conversion pursuant to the provisions of the notes and
warrants. We have the right and obligation to redeem the notes under certain
conditions at any time after the third year from the issuance date. The
securities have registration rights. In addition, and subject to certain
conditions, we are obligated to sell and one of the investors is obligated to
purchase an additional $5 million of such notes and warrants convertible into
shares of our common stock, also with registration rights, in the second
tranche. In compliance with regulatory requirements, Aphton intends to hold a
shareholder's meeting to approve certain aspects of the transaction; in
connection with the shareholder's meeting, Aphton has already secured
irrevocable proxies from certain of its existing shareholders to vote in favor
of the transaction and believes that it will have a strong favorable majority
vote.

               Aphton Corporation is a biopharmaceutical company developing
products using its innovative targeted immunotherapy technology for neutralizing
hormones that participate in gastrointestinal system and reproductive system
cancer and non-cancer diseases. Aphton has strategic alliances with Aventis
Pasteur for treating gastrointestinal system and other cancers with G17DT in
North America and Europe; GlaxoSmithKline for reproductive system cancer and
non-cancer diseases worldwide; and others.

               The securities have not been registered under the Securities Act
of 1933, as amended, and may not be offered or sold in the United States absent
registration or an exemption from the registration requirements.

               Except for the historical information herein, the matters
discussed herein are forward-looking statements that involve a number of risks
and uncertainties and are not a guarantee of future performance. Future results
may vary significantly based on a number of factors including, but not limited
to, intellectual property risks, risks in regulatory and market acceptance of
new products and continuing demand for same, the impact of competitive products
and pricing, changing economic conditions and other

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risk factors that are inherent in the drug development process and the company's
business including those set forth in Aphton's filings with the Securities and
Exchange Commission. It is not possible to predict or identify all such risk
factors that could cause actual results to differ from expected or historical
results. The company's actual results could differ from these forward-looking
statements and the company undertakes no obligation to update publicly any
forward-looking statement.

Contact: Aphton Corporation; Investor Relations, J.L. Whitmore, 305-374-7338.

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