Exhibit 99.1
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                              N E W S R E L E A S E

                FURTHER IMPRESSIVE INTERIM RESULTS FROM APHTON'S
        PHASE II CLINICAL TRIAL WITH 72 STOMACH CANCER PATIENTS EVALUATED

                                  July 31, 2002

Miami, FL - Aphton  Corporation  (NASDAQ:  APHT) - Aphton reported today further
impressive  interim  results from its phase II clinical trial with patients with
metastatic  stomach cancer who were treated with Aphton's G17DT and chemotherapy
consisting of cisplatin and 5FU. Today's report updates results reported on June
12, 2002 for 58 evaluable patients,  where 28 patients had either a partial or a
complete tumor response for an overall tumor response rate of 48.3%.

Of 72 evaluable  patients  reported upon this time, 37 had either a partial or a
complete tumor response for an overall tumor response rate of 51.4%. One patient
had a complete  response  (no  detectable  residual  tumor) and 36 had a partial
response  (tumor  shrinkage  by 50% or  more).  Furthermore,  an  additional  20
patients had stable disease.

There is only one  large,  randomized,  phase III  clinical  trial that has been
reported in the medical  literature  with  cisplatin plus 5 FU for patients with
advanced gastric cancer.  Of 399 total patients  enrolled in the trial, 245 were
evaluable.  For the patients treated with cisplatin plus 5FU, the tumor response
rate  was 20%,  as  reported  by the  European  Organization  for  Research  and
Treatment of Cancer  (EORTC) who  conducted the trial.  The results  reported by
Aphton  today  compare  favorably  with those  results.  They  represent  a 157%
improvement relative to the 20% results reported in the EORTC clinical trial.

It is  estimated  that there are  approximately  570,000  patients  with gastric
cancer in the US, Europe and Japan alone.  The  prognosis  for the  overwhelming
majority of these  patients is very poor.  Patients  diagnosed  with  metastatic
disease have five-year  survival rates of only about three percent.  Surgery and
chemotherapy are the primary  treatment options  currently,  but have shown only
very limited  benefit.  Aphton believes that its  anti-gastrin  approach has the
potential to extend life without adding toxicity to the therapeutic regimen.

Aphton is conducting one Phase III and three Phase II clinical trials.  Aphton's
anti-gastrin  targeted therapy induces  antibodies in patients that bind to both
gastrin 17 and gly-gastrin and remove them from circulation before they can bind
to the cancer  cell and  initiate  cell  growth.  (Aphton  believes  this is the
optimum  method  for  achieving  "growth  factor  inhibition.")  Gastrin  17 and
gly-gastrin  are  believed  to be  central  growth  factors,  or

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the  initiating  signals,  for cell growth,  cell  proliferation  and metastasis
(spread) in gastric, i.e. stomach, pancreatic,  esophageal, colorectal and other
gastrointestinal  (GI) system cancers. This signaling program is accomplished by
gastrin binding to the large numbers of gastrin receptors which appear, de novo,
in  the  great  majority  of  cases,  on  tumor  cell  surfaces  throughout  the
gastrointestinal  system.  Interrupting  this process by immunizing  the patient
with Aphton's  anti-gastrin  immunogen is a precisely "targeted"  immunotherapy.
This  specificity of targeting  only cancer cells occurs because  gastrin is not
normally  secreted and gastrin  receptors  are not  normally  found on "healthy"
cells in the GI system, unless they are malignant,  or on the path to malignancy
(except for cells involved with normal acid secretion).

Recent  findings  have shown that  inhibiting  gastrin  not only  inhibits  cell
growth,  proliferation  and metastasis  directly,  but also "unblocks" a central
pathway leading to cell-suicide  (apoptosis).  This tilts the balance, from cell
growth, to cell suicide. This effect is amplified  synergistically when Aphton's
drug is given  together with a  chemotherapeutic.  Gastrin also  stimulates  the
secretion and expression of other important  growth factors and receptors within
and on the  surfaces  of the  cancer  cells  involved  in tumor  growth.  Hence,
inhibiting  gastrin inhibits all of the foregoing factors  contributing to tumor
growth  and  spread,  while  simultaneously  opening a central  pathway  to cell
suicide.  Aphton's  anti-gastrin targeted therapy adds a biological dimension to
the treatment of gastrointestinal cancers.

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;  and the  prevention  of  pregnancy.  Aphton has strategic
alliances with Aventis Pasteur (NYSE: AVE) for treating  gastrointestinal system
and other  cancers  with G17DT;  GlaxoSmithKline  (NYSE:  GSK) for  reproductive
system cancer and non-cancer diseases; and others.

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 risk  factors that are inherent in the
drug development process and the company's business including those set forth in
Aphton's  most recent 10-K and other  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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