Rigel Pharmaceuticals : September 2021

Corporate Presentation

S e p t e m b e r 2 0 2 1

Forward-Looking Statement

This presentation contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1955 ("PSLRA") relating to, among other things, the commercial success of TAVALISSE in the U.S. and TAVLESSE in Europe; the three ongoing clinical studies on fostamatinib, including Rigel's Phase 3 clinical trial; any future opportunities to use fostamatinib beyond the treatment of COVID-19; expectations related to the market opportunity for fostamatinib as a COVID-19 therapeutic; Rigel's ability to further develop its clinical stage and early stage product candidates and programs; and Rigel's partnering efforts.

Any statements contained in this presentation that are not statements of historical fact may be deemed to be forward-looking statements and as such are intended to be covered by the safe harbor for "forward-looking statements" provided by the PSLRA. Words such as "potential", "may", "expects", and similar expressions are intended to identify these forward-looking statements. These forward-looking statements are based on Rigel's current expectations and information available to Rigel on the date of this presentation. Actual results and the timing of events could differ materially from those anticipated in such forward looking statements due to a number of factors that involve substantial known and unknown risks and uncertainties, which include, without limitation, risks and uncertainties associated with the commercialization and marketing of TAVALISSE; risks that the FDA, EMA or other regulatory authorities may make adverse decisions regarding fostamatinib; risks that TAVALISSE clinical trials may not be predictive of real-world results or of results in subsequent clinical trials; risks that TAVALISSE may have unintended side effects, adverse reactions or incidents of misuses; the availability of resources to develop Rigel's product candidates; market competition; as well as other risks detailed from time to time in Rigel's reports filed with the Securities and Exchange Commission, including its Annual Report on Form 10-K for the year ended December 31, 2020 and Quarterly Report on Form 10-Q for the quarter ended June 30, 2021. In addition, the COVID-19 pandemic may result in further delays in Rigel's studies, trials and sales, or impact Rigel's ability to obtain supply of TAVALISSE. 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.

2 Please see www.TAVALISSE.com for Important Safety Information and full prescribing information.

Successfully Executing on Key Value Drivers

Grow Global

Sales in ITP

Q2 2021 bottles shipped to patients and clinics increased 12% vs. Q2 2020

Strong persistency rate of 56% maintained

Increasing field force to accelerate our reach among prescribers

Capitalize on wAIHA1 Opportunity

Progressed Phase 3 enrollment to 80 of 90 patients as of August 2, 2021

Advanced clinical program for potential first to market therapeutic for wAIHA

Fast Track designation granted by

FDA

Explore

Fostamatinib in

COVID 19 &

Beyond

Expanded clinical program for the treatment of COVID-19

Enrollment in Rigel-led Phase 3 over half-way point with ~176 pts as of August 12, 2021

Positive results from NHLBI/NIH Phase 2 clinical trial published in

the peer-reviewedjournal, Clinical Infectious Disease

Advance

Pipeline Programs

Advanced development of our IRAK1/4 inhibitor program with positive feedback from FDA on clinical program

Progressed both RIP1 inhibitor programs in collaboration with Lilly

~$2B2

Potential $1B US3

>$2B4

M A R K E T O P P O R T U N I T Y

Substantial

1Investigational compound in this indication and has not been submitted for FDA review. 2Company's internal estimate based on 2018 sales of ITP therapies used for steroid-refractory patients. 3DelveInsight Research

3 "Warm Autoimmune Hemolytic Anemia [wAIHA] - Market Insight, Epidemiology, and Market Forecast". 4Johns Hopkins University COVID-19 Tracker, COVID Tracking Project, IntegriChain 852 and 867 and HHS admissions. Please see slides 39 & 40 for Important Safety Information. Please visit www.TAVALISSE.com for full prescribing information.

Kinase inhibitor indicated for the treatment of thrombocytopenia in adult patients with chronic immune thrombocytopenia (cITP) who have had an insufficient response to a previous treatment.

Select Important Safety Information

Adverse Reactions

• Serious adverse drug reactions in the ITP double-blind studies were febrile neutropenia, diarrhea, pneumonia, and hypertensive crisis, which occurred in 1% of TAVALISSE patients. In addition, severe adverse reactions occurred including dyspnea and hypertension (both 2%), neutropenia, arthralgia, chest pain, diarrhea, dizziness, nephrolithiasis, pain in extremity, toothache, syncope, and hypoxia (all 1%).
• Common adverse reactions (!5% and more common than placebo) from FIT-1 and FIT-2 included: diarrhea, hypertension, nausea, dizziness, ALT and AST increased, respiratory infection, rash, abdominal pain, fatigue, chest pain, and neutropenia.

4 Please see slides 39 & 40 for Important Safety Information. Please visit www.TAVALISSE.com for full prescribing information.

Creating Opportunities to Gain Market Share

81,300 US Adult cITP Patients1

37,000 20,00011,400

Watchful Waiting

Line

2nd Line

6,900

3rd Line

3,500

4th Line

2,500

5L+

~75%

of post- steroid market

44,300 patients actively treated2

• 24,300 patients are 2L or later

Patient switching creates new patient opportunities

• COVID-19presented challenges to clinicians in starting and switching patients last year
• Clinicians anticipate a surge of patients as we return to normal

Sales team leveraging novel MOA, early line data analysis and safety profile in communications

Continuing to publish and collect differentiated evidence

5	1Symphony Health, PatientSource®, 10 years ending September 2019. 2Internal market research conducted in October 2020. Please see slides 39 & 40 for Important Safety Information. Please visit www.TAVALISSE.com
for full prescribing information