Exhibit 99.1

March 12, 2002 -- Essential Therapeutics Completes Acquisition of Maret
Pharmaceuticals

WALTHAM, Mass., March 12 -- Essential Therapeutics, Inc. (Nasdaq: ETRX)
announced today the completion of the acquisition of Maret Pharmaceuticals, Inc,
in a stock-for-stock exchange that closed yesterday. Maret is a development
stage pharmaceutical company with clinical and pre-clinical programs focused in
hematology, oncology and the prevention of serious infectious diseases. Maret's
programs include a small molecule lead product for restoring blood cell counts
following myeloablative therapies, currently in Phase I clinical trials.
Potential clinical uses for the lead product candidate include the prevention of
thrombocytopenia, anemia and infection in myelosuppressed patients following
chemotherapy or bone marrow transplantation. In addition, Maret's discovery
platform includes a series of preclinical programs targeted at other serious
clinical conditions with significant unmet therapeutic need.

Mark Skaletsky, Chairman and CEO of Essential Therapeutics commented, "With the
addition of Maret Pharmaceuticals, we are rapidly evolving into a clinical-stage
company addressing serious diseases in the therapeutic areas of
hematology/oncology and infectious disease. This is an important step in our
strategic plan to commercialize products for life threatening diseases."

Essential Therapeutics will issue up to 2 million shares of common stock in this
tax-free exchange and the transaction will be accounted for under the purchase
method of accounting. Accordingly, the company expects to incur a non-cash
charge for acquired in-process research and development in the first quarter of
2002.

About Essential Therapeutics

Essential Therapeutics is committed to the discovery and development of
breakthrough biopharmaceutical products for the treatment of life-threatening
diseases. With an emerging pipeline of lead programs and product candidates in
the anti-infective and hematology/ oncology therapy areas, Essential
Therapeutics is dedicated to commercializing novel small molecule products
addressing important unmet therapeutic needs. Additional information on
Essential Therapeutics can be obtained at http://www.essentialtherapeutics.com.

The statements contained in this press release, which are not historical facts,
may be deemed to contain forward-looking statements. Actual results may differ
materially from those expressed or implied in any forward-looking statement as a
result of certain risks and uncertainties. There is no assurance that the
acquisition will result in any of the anticipated benefits therefrom. There is
no assurance that any compounds discovered will successfully proceed through
preclinical development and clinical trials, obtain requisite regulatory
approvals for marketing or result in a commercially useful product. There is no
assurance that Essential Therapeutics will successfully continue existing
corporate collaborations or enter into further collaborations with respect to
any of its internally funded research programs or that current collaborators
will elect to proceed through the various stages of clinical development as
currently anticipated or on the same schedule as we would proceed if we were
conducting such trials independently. For a discussion of other risks and
uncertainties affecting Essential Therapeutics' business, see the Company's
Annual Report on Form 10-K/A for the year ended December 31, 2000, and its
Quarterly Report on Form 10-Q for the quarter ended September 30, 2001. Actual
results and timing of certain events could differ materially from those
indicated in the forward-looking statements as a result of these or other
factors.

Contact:
Essential Therapeutics                   Burns McClellan
Mark Skaletsky                           Lisa Burns (Investors)
President and CEO                        Justin Jackson (Media)
781-647-5554 ext. 206                    212-213-0006