PRAECIS PHARMACEUTICALS INCORPORATED Reports Fourth Quarter and Year End 2005 Financial Results

PRAECIS PHARMACEUTICALS INCORPORATED (NASDAQ: PRCS)
today announced consolidated financial results for the three months
and year ended December 31, 2005.

   Fourth Quarter 2005 Results

   The Company's net loss for the three months ended December 31,
2005 was approximately $1,300,000, or $0.12 per diluted share,
compared to a net loss of approximately $13,422,000, or $1.28 per
diluted share, for the three months ended December 31, 2004. The
decreased net loss for the three months ended December 31, 2005,
compared to the three months ended December 31, 2004, was due
primarily to reduced expenses resulting from the Company's strategic
restructuring announced in May 2005, as well as the recognition of
$4,000,000 in revenues relating to a one-time payment received under a
settlement agreement with a former licensing partner during October
2005. The expense reductions related principally to the voluntary
discontinuation of promotional activities for Plenaxis(R) in the
United States and a reduction in headcount in May 2005. Expenses
incurred during the fourth quarter of 2005 related primarily to the
advancement of the Company's DirectSelect(TM) drug discovery
technology, clinical development of the Company's investigational
compound, PPI-2458, other research, and general and administrative
expenses. During the fourth quarter of 2005, the Company also
recognized a gain of approximately $1,419,000, as well as net cash
proceeds of approximately $18,766,000, associated with the sale of its
corporate headquarters.

   Full Year 2005 Results

   For the year ended December 31, 2005, net loss was approximately
$61,183,000, or $5.83 per diluted share, compared to a net loss of
approximately $57,598,000, or $5.51 per diluted share, for the year
ended December 31, 2004. The net loss for the year ended December 31,
2005 includes approximately $32,173,000 of restructuring and asset
impairment expenses, of which approximately $2,555,000 were severance
costs associated with the discontinuation of promotional activities
for Plenaxis(R) in the United States and the reduction in headcount
referenced above. The Company's balance sheet at December 31, 2005
includes Plenaxis(R)-related inventory and equipment of approximately
$3,608,000. Depending on the outcome of the Company's ongoing effort
to license or sell Plenaxis(R), the Company may record non-cash
write-downs related to these assets. Depending on the timing of that
outcome, which can not be predicted at this time, the 2005 financial
results reported herein could be adjusted in the Company's Annual
Report on Form 10-K. At December 31, 2005, the Company had cash, cash
equivalents and marketable securities of approximately $62,580,000,
compared to approximately $83,349,000 at December 31, 2004. The
Company expects that it should have available resources to allow it to
pursue its current operating plan through approximately the end of
2007, and possibly longer assuming the successful partnering of either
its DirectSelect(TM) drug discovery technology or its PPI-2458
program, or the license or sale of Plenaxis(R) for commercialization
on a worldwide basis.

   All share and per share amounts have been retroactively restated
for all periods presented to reflect a 1-for-5 reverse stock split of
the Company's common stock effected on November 1, 2005.

   Commenting on the past year, Kevin F. McLaughlin, PRAECIS'
President and Chief Executive Officer stated, "2005 was a year of
significant change for the Company. We have entered 2006 as a company
focused on creating value through our proprietary R&D programs, with a
streamlined organization concentrated on advancing our strategic
operating plan. The three major components of that plan include:

   --  Using our DirectSelect(TM) technology to support
        pharmaceutical partnerships in drug discovery and development,
        and to expand our own proprietary development pipeline;

   --  Advancing PPI-2458 through a Phase 1 trial in cancer patients
        and continuing preclinical evaluation of the compound in
        certain inflammatory and autoimmune disorders, including
        rheumatoid arthritis; and

   --  Licensing the commercial rights to Plenaxis(R) or selling the
        product."

   Continuing, Mr. McLaughlin stated, "With respect to our
DirectSelect(TM) technology, we continue to initiate and advance
research collaboration discussions with various major pharmaceutical
companies. Regarding Plenaxis(R), we have engaged Canaccord Adams, an
international investment banking firm with significant expertise in
the life sciences sector, to explore available opportunities for the
licensing or sale of this asset, and the opportunity is currently
being evaluated by a number of interested parties. We look forward to
advancement of these programs and efforts during 2006."

   There will be a conference call to discuss this press release
today beginning at 9:00 a.m. (EST). This call will be broadcast live
over the Internet at www.praecis.com under "Investor Relations." A
telephonic replay of this call will be available beginning at 12:00
Noon (EST), until midnight Friday, February 10, 2006, by calling
888-203-1112 (domestic toll-free) or 719-457-0820, and entering the
passcode 703121. This press release, including the financial results
relating to PRAECIS' fourth quarter and year-ended December 31, 2005,
are also available on PRAECIS' web site under "News Center."

   The Company is planning to report first quarter 2006 results on
May 5, 2006. For information regarding live webcasts and investment
community conference calls related to first quarter 2006 results,
please refer to www.praecis.com approximately one week prior to the
financial reporting release date.

   Upcoming Scientific Conferences and Presentations

   The Company also announced today that it will present at the
following scientific conferences over the next several months:

   DirectSelect(TM)

   --  MedChem Europe 2006 Conference - February 21-22, 2006 -
        Prague, Czech Republic

   --  Drug Discovery Technology Europe 2006 Conference - March
        13-16, 2006 - London, United Kingdom

   --  Cambridge Healthtech Institute's Drug Discovery Chemistry
        Conference 2006 - April 24-26, 2006 - La Jolla, California

   PPI-2458

   --  GTC bio 3rd Cancer Drugs Research and Development Conference -
        February 9-10, 2006 - San Francisco, California

   --  GTC bio Angiogenesis Research and Therapeutics Conference -
        March 9-10, 2006 - San Diego, California

   Additional information regarding specific dates and times for
these presentations will be provided on PRAECIS' website prior to the
occurrence of these various conferences.

   About DirectSelect(TM)

   The Company believes that its DirectSelect(TM) technology will
allow the Company to more rapidly and directly identify orally
available compounds with high affinity and specificity than has
routinely been possible using traditional drug discovery methods. The
Company has expanded its library collection to greater than 5 billion
compounds and is focusing on the creation of novel drug-like molecules
in uncharted chemical space. In addition, a range of new chemical
reactions have been developed that will allow for continued synthesis
of diversified libraries. During the fourth quarter of 2005, as a
further proof-of-concept, three targets - 2 kinase and 1 protease -
were screened to identify hit molecules. In each case, novel advanced
hit molecules were identified. A "hit" is defined as a molecule that
was re-synthesized without accompanying tags used in the library
version of the molecule, confirmed structurally, and shown to inhibit
the biochemical activity of the target. An "advanced hit" represents
the identification of a group or family of related structures that
share a relationship between structure and activity. Several of the
advanced hits are currently being optimized to identify "lead"
molecules through the creation and screening of focused libraries
using DirectSelect(TM). "Lead" molecules are compounds that have
improved potency at inhibiting the target of interest with defined
selectivity for the target. Given the successful internal validation
of the ability of the technology to identify hit molecules, the
Company has initiated activities to screen for new compounds against
therapeutic targets of interest. The continued development and
enhancement of DirectSelect(TM) is currently a key part of the
Company's operating plan, and the Company believes that this
technology may be an important tool for the future of drug discovery
and development.

   About PRAECIS

   PRAECIS PHARMACEUTICALS INCORPORATED is a biopharmaceutical
company focused on the discovery and development of innovative
therapies that either address unmet medical needs or offer
improvements over existing therapies. PRAECIS has a novel MetAP-2
inhibitor, PPI-2458, in clinical development for cancer indications,
including non-Hodgkin's lymphoma and solid tumors, as well as an
innovative drug discovery technology, DirectSelect(TM), which enables
the generation and practical use of ultra-large libraries for the
discovery of orally active compounds for drug development. PRAECIS has
received approval to market Plenaxis(R) in both the United States and
Germany.

   This news release contains forward-looking statements, including
statements regarding the Company's expected cash utilization and
available resources through approximately the end of 2007, the
Company's plans for seeking a partnership relating to, as well as the
internal use of, the Company's DirectSelect(TM) technology, the
continued clinical development and potential partnering of PPI-2458,
the Company's efforts to effect a license or sale of Plenaxis(R) and,
depending on the outcome of that process, the possibility that the
Company's 2005 financial results may be adjusted to reflect non-cash
write-downs of certain Plenaxis(R)-related assets. These statements
are based on the Company's current beliefs and expectations as to
future outcomes and are not guarantees of future events or
performance. These statements are subject to numerous risks,
uncertainties and assumptions that could cause actual events and
results to differ from those anticipated or projected, including, but
not limited to, the Company's ability to manage operating expenses,
unexpected expenditures, the interest of, and financial and other
terms required by, other parties with respect to a possible license or
sale transaction relating to Plenaxis(R), the Company's ability to
continue development of and successfully partner its DirectSelect(TM)
technology and PPI-2458, unexpected results in ongoing and future
clinical or preclinical trials, and the need for additional research
and testing, including as a result of unanticipated determinations by
regulatory authorities, as well as the risks set forth from time to
time in the Company's filings with the Securities and Exchange
Commission, including but not limited to the various risks discussed
in the Company's Quarterly Report on Form 10-Q for the quarter ended
September 30, 2005. The Company undertakes no obligation to update any
forward-looking statement made in this press release to reflect new
information, events or circumstances after the date of this release.

   Plenaxis(R) is a registered trademark of PRAECIS PHARMACEUTICALS
INCORPORATED.
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                 PRAECIS PHARMACEUTICALS INCORPORATED
            Condensed Consolidated Statements of Operations
                 (in thousands, except per share data)
                              (unaudited)


                                Three Months Ended     Year Ended
                                   December 31,       December 31,
                                ------------------ -------------------
                                  2004      2005     2004       2005
                                --------- -------- --------- ---------

Revenues:
    Product sales                   $729     $242    $2,817    $1,679
    Licensing and other
     revenues                         51    4,000       171     5,924
                                --------- -------- --------- ---------
        Total revenues               780    4,242     2,988     7,603

Costs and expenses:
    Cost of goods sold               242      130     1,703     4,019
    Research and development       8,411    5,610    31,455    24,502
    Sales and marketing            3,897        -    18,880     5,988
    General and administrative     1,590    1,538     8,653     6,994
    Restructuring and asset
     impairment                        -        -         -    28,680
                                --------- -------- --------- ---------
        Total costs and
         expenses                 14,140    7,278    60,691    70,183
                                --------- -------- --------- ---------

Operating loss                   (13,360)  (3,036)  (57,703)  (62,580)

Gain on sale of building               -    1,419         -     1,419
Interest (expense) income, net       (62)     317       105       (22)
                                --------- -------- --------- ---------

Net loss                        $(13,422) $(1,300) $(57,598) $(61,183)
                                ========= ======== ========= =========

Basic and diluted net loss per
 share                            $(1.28)  $(0.12)   $(5.51)   $(5.83)
                                ========= ======== ========= =========

Weighted average number of
 basic and diluted shares
 outstanding                      10,476   10,494    10,462    10,490




                 PRAECIS PHARMACEUTICALS INCORPORATED
                 Condensed Consolidated Balance Sheets
                            (in thousands)
                              (unaudited)


                                             December 31, December 31,
                                                 2004         2005
                                             ------------ ------------

Cash and cash equivalents                        $11,178      $57,088
Marketable securities                             72,171        5,492
Accounts receivable and other current assets       2,097        1,080
Net fixed assets                                  64,538        3,559
Inventory and other long-term assets               4,323        2,325
                                             ------------ ------------

     Total assets                               $154,307      $69,544
                                             ============ ============

Current liabilities                               $9,039       $9,579
Long-term liabilities                             33,095        8,802
Total stockholders' equity                       112,173       51,163
                                             ------------ ------------

     Total liabilities and stockholders'
      equity                                    $154,307      $69,544
                                             ============ ============
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