EXHIBIT 99.1

                                [EPIMMUNE LOGO]
               5820 Nancy Ridge Drive, San Diego, California 92121
                   Phone: (858) 860-2500- Fax: (858) 860-2600


FOR FURTHER INFORMATION


                                                                 
AT EPIMMUNE:                  AT FINANCIAL RELATIONS BOARD:
Robert De Vaere               Lars Glassen                             Tricia Ross
VP, Finance & Admin.          General Information                      Investor/Analyst Information
& CFO                         (310) 854-8313                           (617) 520-7064
(858) 860-2500                lglassen@financialrelationsboard.com     tross@financialrelationsboard.com


FOR IMMEDIATE RELEASE
MAY 12, 2005

              EPIMMUNE REPORTS FIRST QUARTER 2005 FINANCIAL RESULTS

SAN DIEGO, MAY 12, 2005 - EPIMMUNE INC. (NASDAQ: EPMN) today announced its
financial results for the first quarter ended March 31, 2005.

Revenue for the first quarter of 2005 was $1.8 million compared to $2.6 million
in the first quarter of 2004. The decrease in 2005 was primarily due to a
decrease in related party revenue, mainly as a result of lower milestone revenue
than during the 2004 period when the Company received a milestone payment from
its partner at the time, Genencor International, when Genencor filed an
Investigational New Drug (IND) application for a Hepatitis B vaccine candidate
on which the Company collaborated. Payments received from the Company's previous
collaboration with Genencor, which owns an equity position in Epimmune, were
recorded as related party revenue. In March 2004, Genencor assigned its rights
under the collaboration agreement to Innogenetics. Innogenetics does not own an
equity position in Epimmune and, therefore, is not a related party and
reimbursements under the collaboration agreement are now recorded as contract
revenue.

Research and development expenses increased to $2.7 million in the first quarter
of 2005 from $2.4 million in the first quarter of 2004. The increase relates
primarily to increases in subcontract and other outside costs incurred under
grants and contracts from the National Institutes of Health (NIH) and to costs
related to the Company's ongoing Phase II clinical trial in non-small cell lung
cancer (NSCLC) patients which began in late 2004.

General and administrative expenses decreased to $0.5 million in the first
quarter of 2005 from $0.7 million in the first quarter of 2004, primarily as a
result of lower non-cash, stock based compensation charges during 2005. The
Company also recorded $1.1 million in transaction expenses during the first
quarter of 2005 associated with the proposed business combination with IDM.
These expenses included investment banking advisory fees and accounting and
legal fees.

Net loss for the first quarter of 2005 was $2.4 million, or $0.15 per basic and
diluted share compared with a net loss of $0.5 million, or $0.04 per basic and
diluted share for the same period in 2004.

During the quarter, cash and cash equivalents declined by $1.3 million to an
ending balance of $5.7 million. Financial details appear in the accompanying
schedules.

                                    - more -


Financial Relations Board serves as financial relations counsel to this company,
is acting on the company's behalf in issuing this bulletin and is receiving
compensation therefor. The information contained herein is furnished for
informational purposes only and is not to be construed as an offer to buy or
sell securities.

Epimmune Inc.
Page 2 of 4


ABOUT EPIMMUNE INC.

EPIMMUNE INC., based in San Diego, is focused on the development of vaccines
using multiple epitopes to specifically activate the body's immune system.
Epitopes, critical signaling molecules, stimulate the T cell arm of the immune
system to respond to specific regions of cancer cells or infectious agents. By
combining multiple, selected epitopes into a single vaccine candidate, the
immune response can be both targeted and optimized for strength. Epimmune's
therapeutic vaccine candidates have been designed to treat disease by
stimulating the body's immune system to respond aggressively to infections such
as HIV, hepatitis C virus and hepatitis B virus, and tumors such as breast,
colon, lung and prostate. The Company's prophylactic vaccine candidates have
been designed to protect against disease by teaching the body's immune system to
react quickly when exposed to infectious agents. Epimmune's technology can also
be used to identify and potentially eliminate undesirable reactions to
therapeutic drugs or consumer products by modifying specific epitopes to
suppress the unwanted immune response without degrading product efficacy. For
more information on Epimmune, visit www.epimmune.com.

WHERE YOU CAN FIND ADDITIONAL INFORMATION ABOUT EPIMMUNE'S PROPOSED COMBINATION
WITH IDM

Epimmune has filed a proxy statement concerning its proposed combination with
IDM with the Securities and Exchange Commission (SEC). Investors and security
holders are advised to read the proxy statement related to the proposed
transaction because it contains important information related to the
transaction. Investors and security holders may obtain a free copy of the proxy
statement and other documents filed by Epimmune with the SEC at the SEC's
website at http://www.sec.gov. The proxy statement and any other documents filed
by Epimmune with the SEC may also be obtained free of charge from Epimmune by
directing such request to Epimmune's Secretary at the following address: 5820
Nancy Ridge Drive, San Diego, California 92121.

INFORMATION CONCERNING PARTICIPATION IN EPIMMUNE'S PROXY SOLICITATION

Epimmune and IDM and their respective executive officers and directors may be
deemed to be participants in the solicitation of proxies from the shareholders
of Epimmune with respect to the proposed transaction between Epimmune and IDM.
Information regarding Epimmune's executive officers and directors is included in
Epimmune's Annual Report on Form 10-K filed with the SEC for the year ended
December 31, 2004. This document is available free of charge at the SEC's
website at http://www.sec.gov and from Epimmune at http://www.epimmune.com.
Investors and security holders may obtain additional information about the
interests of the respective executive officers and directors of Epimmune and IDM
in the proposed transaction between Epimmune and IDM by reviewing the proxy
statement related to the transaction filed with the SEC.

FORWARD-LOOKING STATEMENTS

This press release includes forward-looking statements that reflect management's
current views of future events, including statements regarding the potential
closing of the proposed transaction between Epimmune and IDM and the expected
advantages of combining Epimmune and IDM. Actual results may differ materially
from the above forward-looking statements due to a number of important factors,
including but not limited to the possibility that the proposed transaction with
IDM may not ultimately close for any of a number of reasons, including, but not
limited to, Epimmune not obtaining shareholder approval of the transaction, the
increase in its authorized capital or the reverse


                                    - more -

Epimmune Inc.
Page 3 of 4


split of Epimmune common stock; the possibility that IDM shareholders who have
not become parties to the definitive agreement make an alternative bid regarding
a transaction involving IDM to the IDM shareholders pursuant to rights under the
shareholders agreement among the IDM shareholders and, if so, that the IDM
shareholders accept that bid instead of the transaction with Epimmune; the
possibility that NASDAQ will not approve the listing of the combined company's
shares for trading on the NASDAQ National Market or that the combined company
will not be able to meet the continued listing requirements after the closing of
the transaction; that Epimmune will forego business opportunities while the
transaction is pending; that prior to the closing of the proposed transaction,
the business of the Company, including the retention of key employees, may
suffer due to uncertainty; and even in the event the transaction is completed,
that combining Epimmune and IDM may not result in a stronger company, that the
technologies and clinical programs of the two companies may not be compatible
and that the parties may be unable to successfully execute their integration
strategies or realize the expected benefits of the transaction. Additional
factors that may cause actual results to differ materially include risks
regarding whether the company or any of its collaborators will be able to
develop pharmaceutical products using the technologies of the company, risks
associated with completing clinical trials of product candidates, the risks
involved in the regulatory approval process for the company's product
candidates, the possibility that clinical testing may reveal undesirable and
unintended side effects or other characteristics that may prevent or limit the
commercial use of proposed products; whether the cash resources of the company
will be sufficient to fund operations as planned, reliance on key employees,
especially senior management; the uncertainty of the company's future access to
capital; the risk that the company may not secure or maintain relationships with
collaborators, and the company's dependence on intellectual property. These
factors are more fully discussed in Epimmune's Annual Report on Form 10-K filed
with the SEC for the year ended December 31, 2004, in the proxy statement
concerning Epimmune's proposed business combination with IDM filed with the SEC
on April 22, 2005, and other periodic reports filed with the Securities and
Exchange Commission. Epimmune expressly disclaims any intent or obligation to
update these forward-looking statements, except as required by law.

Epimmune Inc.
Page 4 of 4



                                  EPIMMUNE INC.
                 CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS
                                   (unaudited)
                    (in thousands, except per share amounts)



                                                           Three months ended March 31,
                                                           2005                   2004
                                                         --------               -------
                                                                          
Revenues:
   License fees and milestones                            $   114               $    97
   Research grants and contract revenue                     1,719                 1,454
   Related party revenue                                       --                 1,026
                                                          -------               -------
Total revenues                                              1,833                 2,577

Costs and expenses:
   Research and development                                 2,686                 2,407
   General and administrative                                 467                   658
   Business combination transaction costs                   1,089                    --
                                                          -------               -------
Total costs and expenses                                    4,242                 3,065
                                                          -------               -------

Loss from operations                                       (2,409)                 (488)

Interest income, net                                           36                     4
Other expense, net                                             (5)                   (1)
                                                          -------               -------
Net loss                                                  $(2,378)              $  (485)
                                                          =======               =======
Net loss per share - basic and diluted                    $ (0.15)              $ (0.04)
                                                          =======               =======

Shares used in computing net
  loss per share - basic and diluted                       16,015                13,456
                                                          =======               =======


                      CONDENSED CONSOLIDATED BALANCE SHEETS
                                 (in thousands)




                                                         March 31,            December 31,
                                                           2005                   2004
                                                          -------               -------
                                                        (unaudited)
                                                                        
ASSETS:
Current assets:
    Cash and cash equivalents                             $ 5,673               $ 7,006
    Other current assets                                    1,444                 2,888
                                                          -------               -------
Total current assets                                        7,117                 9,894

Restricted cash                                               354                   354
Property and equipment, net                                   962                 1,032
Patents and other assets                                    3,447                 3,527
                                                          -------               -------
Total assets                                              $11,880               $14,807
                                                          =======               =======

LIABILITIES AND STOCKHOLDERS' EQUITY:
Current liabilities                                       $ 2,906               $ 3,481
Other liabilities                                             208                   210
Stockholders' equity                                        8,766                11,116
                                                          -------               -------
Total liabilities and
  stockholders' equity                                    $11,880               $14,807
                                                          =======               =======



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