Rigel To Focus On ITP, DLE And Dry Eye

                    Rigel To Focus On ITP, DLE And Dry Eye

Strategy Provides Multiple Paths to Phase 3/NDA in Next 2-3 Years

PR Newswire

SOUTH SAN FRANCISCO, Calif., Sept. 5, 2013

SOUTH SAN FRANCISCO, Calif., Sept. 5, 2013 /PRNewswire/ --Rigel
Pharmaceuticals, Inc. (Nasdaq: RIGL) today announced its plans to focus the
Company's resources on the completion of three lead clinical programs. These
efforts include commencing a Phase 3 clinical study of fostamatinib, an oral
SYK inhibitor, in Immune Thrombocytopenic Purpura (ITP) pending discussions
with regulatory agencies. Rigel believes that a Phase 3 clinical program would
encompass approximately 150 patients and can be completed in 2015. Rigel's
other two lead programs, R333, a topical dermatological JAK/SYK inhibitor for
discoid lupus erythematosus, and R348, a topical ophthalmic JAK/SYK inhibitor
for dry eye, are presently in Phase 2 studies, with results expected in Q4
2013 and Q2 2014, respectively. Rigel expects to advance one of these two
molecules into a Phase 3 clinical program by 2014/15. The Company will not
continue further development of fostamatinib for the treatment of rheumatoid
arthritis or lymphoma due to insufficient efficacy findings from recent
clinical trials and the competitive landscape for the agent in those
indications.

"Strategically, we have made a decision to concentrate our resources on the
programs that we believe hold the greatest potential for a near term path to
market," said James M. Gower, chairman and chief executive officer of Rigel.
"The size and scope of these clinical programs are such that we can fund and
manage them in-house, thereby maintaining control and flexibility over their
development."

As a consequence of prioritizing projects and looking to conserve the
Company's cash resources, Rigel also announced that it has reduced its
workforce by 18%, resulting in the elimination of 30 positions, mostly from
the drug discovery area. The Company is still assessing the restructuring and
other charges associated with this measure, which are expected to be recorded
predominantly in the third quarter of 2013. As of June 30, 2013, the company
had $251 million in cash and equivalents, which Rigel believes is enough to
maintain its current development priorities into 2016.

Rigel remains committed to its mission to identify and develop novel small
molecule therapeutics and will maintain active programs including: R118, an
oral AMPK activator being developed as a potential treatment for intermittent
claudication (peripheral artery disease).

Immune Thrombocytopenic Purpura (ITP)

Chronic ITP affects approximately 100,000 people, with the majority of these
cases being in women. ITP is a blood disorder in which the immune system
attacks and destroys the body's own blood platelets, which have an important
role in the clotting and healing process. ITP patients can suffer bruising,
bleeding and fatigue as a result of their low blood platelet counts.
Currently marketed therapies aim to raise blood platelet counts, but do not
address the etiology of the disorder. The results of Rigel's Phase 2 study,
published in Blood (volume 113, number 14), showed that fostamatinib may be
effective in treating this rare autoimmune disorder.

Discoid Lupus Erythematosus (DLE)

DLE is a chronic autoimmune disease of the skin, which affects approximately
300,000 Americans - with an estimated 16,000 additional new cases diagnosed in
the US each year. Disc-shaped sores with inflammation, swelling, scaling,
scarring, pigment discoloration, and even hair loss characterize the disease.
The lesions most commonly appear in sun-exposed areas, predominantly on the
face, chest and scalp. Rigel's R333 is a potent, topical JAK and SYK inhibitor
that is designed to interrupt pivotal inflammatory cascade signals with the
potential to prevent or diminish both acute and chronic symptoms. Results from
a Phase 2 clinical study of R333 in DLE are expected in Q4 2013.

Dry Eye

Dry eye disease is an inflammatory disease of the eye that affects more than 5
million Americans. The disease targets the lacrimal (tear producing) glands
of the eye and may be associated with other autoimmune conditions including
Sjögren's syndrome, systemic lupus erythematosus and rheumatoid arthritis.
Rigel has developed a topical ophthalmic (eye drop) formulation of R348, a JAK
and SYK inhibitor, aimed at reducing the inflammation responsible for the
symptoms of this disease. Results of a Phase 2 study of R348 in chronic dry
eye are expected in Q2 2014.

About Rigel (www.rigel.com)

Rigel Pharmaceuticals, Inc.is a clinical-stage drug development company that
discovers and develops novel, small-molecule drugs for the treatment of
inflammatory and autoimmune diseases, as well as muscle disorders. Rigel's
pioneering research focuses on intracellular signaling pathways and related
targets that are critical to disease mechanisms. The company currently has
five product candidates in clinical development: fostamatinib, an oral SYK
inhibitor for ITP; R333, a topical JAK/SYK inhibitor for discoid lupus, and
R348, a topical JAK/SYK inhibitor for dry eye – both in Phase 2 clinical
trials; and two oncology product candidates in Phase 1 development with
partners BerGenBio andDaiichi Sankyo.

This press release contains "forward-looking" statements, including, without
limitation, statements related to development plans, the focus and direction
of Rigel's resources, the timing of planned clinical trials and results,
Rigel's ability to fund and manage its clinical programs in-house, Rigel's
plans with respect to a reduction in force and restructuring charges
associated with those reductions in force, and Rigel's ability to fund and
maintain its current development plans into 2016. Any statements contained in
this press release that are not statements of historical fact may be deemed to
be forward-looking statements. Words such as "planned," "will," "may,"
"expect," and similar expressions are intended to identify these
forward-looking statements. These forward-looking statements are based on
Rigel's current expectations and inherently involve significant risks and
uncertainties. Actual results and the timing of events could differ materially
from those anticipated in such forward looking statements as a result of these
risks and uncertainties, which include, without limitation, the availability
of resources to develop Rigel's product candidates, our need for additional
capital in the future to sufficiently fund our operations and research, the
uncertain timing of completion of and the success of clinical trials, market
competition, risks associated with and Rigel's dependence on Rigel's corporate
partnerships, as well as other risks detailed from time to time in Rigel's
reports filed with theSecurities and Exchange Commission, including its
Quarterly Report on Form10-Q for thequarter ended June 30, 2013. Rigel does
not undertake any obligation to update forward-looking statements and
expressly disclaims any obligation or undertaking to release publicly any
updates or revisions to any forward-looking statements contained herein.

Contact: Raul Rodriguez
Phone: 650.624.1302
Email: invrel@rigel.com

Media Contact: Susan C. Rogers, Alchemy Consulting, Inc.
Phone: 650.430.3777
Email: susan@alchemyemail.com



SOURCE Rigel Pharmaceuticals, Inc.

Website: http://www.rigel.com