Rigel Pharmaceuticals Provides Business

Rigel Pharmaceuticals Provides Business

SOUTH SAN FRANCISCO, Calif., January

13, 2020 /PRNewswire/ -- Rigel Pharmaceuticals, Inc. (Nasdaq:

RIGL) today provided a business update, including preliminary product revenue and total TAVALISSE

(fostamatinib disodium hexahydrate) bottles for the quarter; the European Commision's

(EC) approval of fostamatinib disodium hexahydrate (fostamatinib) for adult patients with chronic immune thrombocytopenia (ITP);

and enrollment progress in its Phase 3 pivotal trial for warm autoimmune hemolytic anemia (AIHA). The company's president

and CEO, Raul Rodriguez, will provide a more detailed company overview during his presentation taking place on Thursday, January

16 at 7:30am PT at the 38th Annual J.P. Morgan Healthcare Conference.

has built a solid foundation for continued growth, anchored by increased revenues from our U.S. commercial business. With European

approval of fostamatinib, we expect to generate revenue from royalty payments beginning in the second half of the year, and importantly,

we will receive a $20 million milestone from our partner, Grifols, S.A.," stated Mr. Rodriguez, Rigel's president and

CEO. "Enrollment of our Phase 3 clinical trial in warm AIHA is accelerating with the ongoing activation of trial sites. This

is an extremely attractive market for Rigel given the lack of an FDA-approved therapy and the synergies with our ITP commercial

business. Additionally, we are making meaningful progress with our novel IRAK 1/4 and RIP1 inhibitor programs and are excited about

their potential value."

While Rigel is still in the process

of determining final results for the fourth quarter of 2019, the company expects to report net product sales of approximately $13.8

million, compared to $7.3 million in the same period of 2018, an increase of 90%.

Contract revenues from collaborations

for the quarter ended December 31, 2019, are expected to be approximately $1.6 million, which consists of a $1.5 million fee earned

pursuant to an amendment in October 2019 of the license and collaboration agreement with Aclaris dated August 27, 2015, as well

as deferred revenue from its collaboration with Grifols related to the performance of certain research and development services.

For the fourth quarter 2019, Rigel expects to report total revenues

of approximately $15.4 million.

The company expects to report cash,

cash equivalents and short-term investments as of December 31, 2019 of approximately $98.0 million, compared to $128.5 million

as of December 31, 2018.

The above information is preliminary,

has not been audited and is subject to change upon completion of the audit of the company's financial statements as of and

for the year ended December 31, 2019.

Growing TAVALISSE in the U.S. Market

During the fourth quarter of 2019,

a total of 1,518 bottles of TAVALISSE were sold in the U.S. of which 1,422 were shipped directly to patients and clinics. The refill

rate at month 4 increased to approximately 54%, reflecting the benefit patients are experiencing as TAVALISSE is used more frequently

in earlier line treatment and physicians become more experienced with its use.

Heading into 2020, Rigel is poised

for further growth with plans to expand its salesforce by six people in key markets. In addition, the company intends to continue

its ongoing data initiatives and leverage recently presented post-hoc data showing a 78% response rate in ITP patients who received

TAVALISSE in second line use.

EC Approval of Fostamatinib and

Rigel today announced that it has received

EC approval of its marketing authorization application (MAA) for fostamatinib for the treatment of chronic immune thrombocytopenia

in adult patients who are refractory to other treatments. With this approval, the company will receive a milestone payment of $20

million based on terms of its collaboration with Grifols, S.A. During the regulatory review process, Grifols began preparing to

launch the product in the major European markets and is now able to begin the regulatory processes for marketing in the individual

countries. The company expects to generate incremental revenue from European sales of fostamatinib in the second half of this year

in the form of royalty payments.

Phase 3 Trial in Warm AIHA

Since the launch of FORWARD (Fostamatinib

Research in Warm Antibody AIHA Disease), Rigel's Phase 3 pivotal trial in warm AIHA, the company has been working with clinics

and regulatory authorities and has established a vast majority of the more than 100 clinical trial sites planned across 22 countries.

With the number of opened sites growing rapidly, over 45 in the last three months, enrollment of the trial has accelerated as planned

with 15 of 20 total patients enrolled in the last two months. The trial remains on track to complete enrollment in mid-2020.

Clinical Development Pipeline

In the fourth quarter of 2019, Rigel

announced results from its Phase 1 clinical trial of R8351, its interleukin-1 receptor-associated kinase 1/4 (IRAK1/4)

inhibitor. This novel molecule is the only asset in clinical development that is a dual inhibitor of IRAK1 and IRAK4 and has been

shown preclinically to block inflammatory cytokine production in response to toll-like receptor (TLR) and the interleukin-1 receptor

(IL-1R) family signaling. The Phase 1 trial established proof-of-mechanism by demonstrating the inhibition of inflammatory cytokine

production in an LPS (lipopolysaccharide) challenge.

In addition, Rigel recently initiated

a Phase 1 trial of its receptor-interacting protein kinase (RIP1) inhibitor, R5521. RIP1 is believed to play a critical

role in necroptosis, a form of regulated cell death implicated in inflammatory and neurodegenerative diseases. Initial data from

Rigel's ongoing Phase 1 suggests R552 has an attractive pharmacokinetic (PK) and safety profile with a half-life of approximately

15 hours. In earlier preclinical studies, the molecule was shown to prevent joint and skin inflammation in a RIP1 kinase-mediated

Both assets target pathways that are

of high interest in the biopharma industry and are widely thought to have significant potential in the treatment of inflammatory

and immune-mediated diseases.

38th Annual J.P. Morgan Webcast

Presentation Details

Rigel's presentation will be

webcast and is scheduled to take place Thursday, January 16 at 7:30am PT. To access the live and subsequently archived webcast,

go to the Investor Relations section of the company's website at www.rigel.com. Please connect to the website several minutes

prior to the start of the live webcast to ensure adequate time for any software download that may be necessary.

In patients with ITP (immune thrombocytopenia),

the immune system attacks and destroys the body's own blood platelets, which play an active role in blood clotting and healing.

Common symptoms of ITP are excessive bruising and bleeding. People suffering with chronic ITP may live with an increased risk of

severe bleeding events that can result in serious medical complications or even death. Current therapies for ITP include steroids,

blood platelet production boosters (TPO-RAs) and splenectomy. However, not all patients respond to existing therapies. As a result,

there remains a significant medical need for additional treatment options for patients with ITP.

Autoimmune hemolytic anemia (AIHA)

is a rare, serious blood disorder in which the immune system produces antibodies that result in the destruction of the body's own

red blood cells. AIHA affects approximately 45,000 adult patients in the U.S. and can be a severe, debilitating disease. To date,

there are no disease-targeted therapies approved for AIHA, despite the unmet medical need that exists for these patients. Warm

antibody AIHA (wAIHA), the most common form of AIHA, is characterized by the presence of antibodies that react with the red blood

cell surface at body temperature.

The investigational candidate, R835,

is an orally available, potent and selective inhibitor of IRAK1 and IRAK4 that has been shown preclinically to block inflammatory

cytokine production in response to toll-like receptor (TLR) and the interleukin-1 receptor (IL-1R) family signaling. TLRs and IL-1Rs

play a critical role in the innate immune response, and dysregulation of these pathways can lead to a variety of inflammatory pathological

conditions. R835 treatment demonstrates amelioration of clinical symptoms in multiple rodent models of inflammatory disease including

psoriasis, arthritis, lupus, multiple sclerosis and gout. The safety and efficacy of R835 has not been established by the FDA or

any healthcare authority.

The investigational candidate, R552,

is an orally available, potent and selective inhibitor of receptor-interacting protein kinase (RIP1). RIP1 is believed to play

a critical role in necroptosis. Necroptosis is a form of regulated cell death where the rupturing of cells leads to the dispersion

of their inner contents, which induces immune responses and enhances inflammation. In preclinical studies, R552 prevented joint

and skin inflammation in a RIP1-mediated murine model of inflammation and tissue damage. The safety and efficacy of R552 has not

been established by the FDA or any healthcare authority.