12. The conference call will be available live via the Internet
by accessing Kos' website at www.

affect claims

75 per share, compared to a net loss of $11. This compares
to revenue of $11. In the last quarter of
2004, we successfully initiated clinical trials with R406 for the treatment of
rheumatoid arthritis, and significantly expanded our efforts in oncology
through a broad collaboration agreement with Merck in the field of ubiquitin
ligases.

reduce curing

3 million, or a loss per share of $3.

relaxation tape

For the fourth quarter of 2004, Rigel reported a net loss of $14.8 million,
respectively.12) $(3. (Nasdaq: KOSP), a fully integrated specialty
pharmaceutical company, will announce results for the fourth quarter
and year-ended December 31, 2004, before the market opens on Thursday,
March 3, 2005.

breathing influenza

4 million compared to $46.
"Rigel became a drug development company in 2004 with a portfolio of
product candidates in clinical trials, and additional exciting preclinical
programs expected to enter the clinic by the end of 2005," said James M.
-- The initiation of clinical trials with R406 for the treatment of
rheumatoid arthritis to establish the safety and pharmacokinetics of R406 .m.

relaxation conditions

1 million in the fourth quarter of 2003.0 million in the fourth quarter of 2003.
For the year ended December 31, 2004, Rigel had revenue of $4.
Gower, chairman and chief executive officer of Rigel.

influenza formula

----Kos
Pharmaceuticals, Inc.

respiratory claims

"

Recent Clinical and Business Milestones
In the fourth quarter of 2004 and beginning of 2005, Rigel achieved
several clinical development and business milestones, including:

-- A collaborative research and license agreement with Pfizer for the
development of inhaled products for the treatment of allergic asthma and other
respiratory diseases focusing on Rigel's small molecule compounds that inhibit
Syk kinase, an important regulator of multiple chemical mediators that produce
allergic responses. Any statements contained in this press release that are not
statements of historical fact may be deemed to be forward-looking statements . Rigel does not undertake any
obligation to update forward-looking statements.kospharm.

Respiratory conditions include disorders that affect the lungs.

cold device

5 million and 14.
-- A collaboration agreement with Merck to expand Rigel's research and
development efforts with ubiquitin ligases, a new class of drug target.

claims affect

-- The completion of a Phase I/II trial of R803 for the treatment of HCV
with results that did not meet expectations.

influenza claims

, Inc.rigel.75) $(0.

conditions lungs

The
collaboration will seek to find treatments for cancer and potentially other
diseases, and will allow Rigel to leverage Merck's tremendous resources across
the spectrum of discovery and development activities.com or by calling
719-457 -0820 domestic or international, and entering 5758440 from 2:00
PM ET on March 3, 2005 until 12:00 AM ET on Saturday, March 5, 2005.

trainer reduce

7 million
and a net loss of $56.62 for the same period in 2003.

Kos Pharmaceuticals To Report Fourth Quarter And Year End Results On March 3 2005; Conference Call at 11:00 a.m. ET

ET to discuss the Company's quarterly
results.kospharm.

asthma cold

Rigel reported revenue from collaborations of $1.
As of December 31, 2004, Rigel had cash, cash equivalents and available -
for-sale securities of $71.kospharm.

resistive conditions

9 million, or $0.

This press release contains "forward -looking" statements, including
statements related to Rigel's plans to pursue clinical development of product
candidates and the timing thereof and the potential efficacy of product
candidates .

trainer affect

1 million in the fourth
quarter of 2004, compared to $2.

lungs influenza

, Rigel
Pharmaceuticals, Inc.com)
Rigel's mission is to become a source of novel, small-molecule drugs to
address large, unmet medical needs.80) $(3. is a fully integrated specialty
pharmaceutical company engaged in developing, commercializing ,
manufacturing and marketing proprietary prescription products for the
treatment of chronic diseases .

asthma trainer

Fourth quarter 2004 operating expenses increased due in part to costs related
to preclinical and initial clinical work for R406, a product candidate that
began clinical trials in December 2004 for the treatment of rheumatoid
arthritis, as well as expenses associated with Rigel's Phase I/II trial of
R803 for the treatment of hepatitis C virus (HCV). Cash, cash equivalents and available -for sale securities declined
$173,000 in the fourth quarter of 2004 from the third quarter of 2004 as cash
used for operations was offset by the receipt of an upfront payment from Merck
and cash from the exercise of a warrant previously issued.J. The Company's principal product
development strategy is to reformulate existing pharmaceutical
products with large market potential to improve safety , efficacy, or
patient compliance.

cold tape

0 million in the fourth quarter of 2004,
compared to operating expenses of $14.1 million and a net loss of $41. We have four research and development
programs investigating treatments for asthma/allergy, hepatitis C, rheumatoid
arthritis and oncology. There are a number of
important factors that could cause Rigel's results to differ materially from
those indicated by these forward-looking statements, including risks
associated with the timing and success of clinical trials and the
commercialization of product candidates, as well as other risks detailed from
time to time in Rigel's SEC reports, including its Quarterly Report on Form
10-Q for the quarter ended September 30, 2004.com. Please go to the
website at least fifteen minutes prior to the call to register,
download and install any necessary audio software.

affect trainer

Revenue in the fourth quarter of 2004 reflects the initial revenue from the
Merck + Co.

About Rigel (http://www.62)
Weighted average shares used in
computing net loss per common
share, basic and diluted 19,544 14,796 18,053 11,395

Note A

Stock-based compensation excluded
from:
Research and development $137 $718 $2,000 $924
General and adminstrative 31 159 566 191
$168 $877 $2,566 $1,115

SUMMARY BALANCE SHEET DATA
(in thousands )

December 31, December 31,
2004 2003(1)
(unaudited)
Cash, cash equivalents and
available for sale securities $71,427 $46,500
Total assets 78 ,822 55,524
Stockholder's equity 52,301 39,973

(1) Derived from audited financial statements

claims fee

"In January, we
established an important partnership with Pfizer to develop inhaled products
for the treatment of allergic asthma and COPD based on our pioneering work to
develop allergy treatments that block Syk kinase. Our strategy is to initiate clinical trials with at
least one new product candidate annually and to pursue partnerships with
pharmaceutical and biotechnology companies for late-stage clinical development
and commercialization of those product candidates.

cure breathing

Rigel Announces Fourth Quarter and Year End 2004 Financial Results

Weighted average shares outstanding
for the fourth quarters of 2004 and 2003 were 19.

STATEMENTS OF OPERATIONS
(in thousands, except per share amounts)

Three Months Ended Twelve Months Ended
December 31, December 31,
2004 2003 2004 2003
(unaudited) (unaudited)
Revenues:
Contract revenues from
collaborations $1,100 $2,106 $4,733 $11,055

Operating expenses:
Research and development 12,158 10,423 46,523 40,725
General and administrative 3,676 2,678 12,511 10,042
Stock-based compensation
(see Note A) 168 877 2,566 1,115
Total operating expenses 16,002 13,978 61,600 51,882
Loss from operations (14,902) (11,872 ) (56,867) (40,827)
Loss on sale/disposal of property
and equipment (30) -- (30) (169)
Interest income/(expense), net 206 10 642 (201)
Net loss $(14,726) $(11,862) $(56,255) $ (41,197)
Net loss per common share, basic
and diluted $(0. A replay will also be
available on the website at www.

cure tape

SOUTH SAN FRANCISCO, Calif.
If you would like to receive notices and news on Kos, please visit
the Investor Relations section of the Company website at
www. The Company currently markets Niaspan(R) and
Advicor(R) for the treatment of cholesterol disorders, and Azmacort(R)
for the treatment of asthma.

lungs inspiratory

7
million, or $0.80
per share, in the fourth quarter of 2003. collaboration as well as continued funding from Rigel's
collaboration with Daiichi.5 million at December 31,
2003.

Pharmaceutical Writers/Business Editors

CRANBURY , N. For those who
cannot access the webcast, you can dial into the conference call at
913-981 -4902 confirmation code 5758440.

muscle resistive

(Nasdaq: RIGL) today reported financial results for the
fourth quarter and year ended December 31, 2004.
Total operating expenses were $16.2 million, or a loss per
share of $3.
Words such as "plans," "intends," "expects" and similar expressions are
intended to identify these forward-looking statements.
Following the release, Kos' senior management will host a
conference call at 11:00 a.com
Kos Pharmaceuticals, Inc. Kos is developing additional products and
has proprietary drug delivery technologies in solid-dose and aerosol
metered-dose inhalation administration and is pursuing certain
strategic business development and licensing opportunities .