Rigel Pharmaceuticals : March 2024

Corporate Presentation

March 2024

1

Forward Looking Statements

This presentation contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1955 ("PSLRA") relating to, among other things, expected commercial and financial results; Rigel's ability to earn and receive milestone payments; expectations related to the potential and market opportunity of REZLIDHIA® (olutasidenib) as therapeutics for relapsed or refractory acute myeloid leukemia (AML) and other conditions; the potential and market opportunity for TAVALISSE® (fostamatinib) as therapeutics for chronic ITP and other conditions; the regulatory approval and commercialization of fostamatinib or olutasidenib in the U.S. and international markets; and Rigel's ability to further develop its clinical stage and early-stage product candidates and Rigel's partnering and collaboration/alliance efforts, including the progress of the Phase 1b clinical trial of R289 for the treatment of lower-risk myeloid dysplastic syndrome (MDS), the advancement of the Phase 2a clinical trial of R552 for the treatment of rheumatoid arthritis, and the development of olutasidenib as a therapy for a broad range of mIDH1+ cancers, including but not limited to AML, MDS, and glioma, and Rigel's partnering efforts and ability to achieve regulatory and commercial milestones and earn and receive milestone payments; and the potential benefits of Rigel's acquisition of U.S. rights to GAVRETO (pralsetinib), including opportunities in NSCLC and DTC, Rigel's ability to leverage its existing commercial infrastructure to market and distribute pralsetinib, Rigel's ability to transition pralsetinib to its distribution network and provide patients with access to pralsetinib, the payment and timing of milestone and royalty payments and Rigel's ability to start recognizing product sales in the third quarter of 2024 and the market opportunity for pralsetinib.

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. Forward-looking statements can be identified by words such as "plan", "potential", "may", "expects", "will" and similar expressions in reference to future periods. Forward-looking statements are neither historical facts nor assurances of future performance. Instead, they are based on Rigel's current beliefs, expectations, and assumptions and hence they inherently involve significant risks, uncertainties and changes in circumstances that are difficult to predict and many of which are outside of Rigel's control. Therefore, you should not rely on any of these forward-looking statements. 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, risks and uncertainties associated with the commercialization and marketing of fostamatinib, olutasidenib or pralsetinib; risks that the FDA, European Medicines Agency, PMDA or other regulatory authorities may make adverse decisions regarding fostamatinib, olutasidenib or pralsetinib; risks that clinical trials may not be predictive of real-world results or of results in subsequent clinical trials; risks that fostamatinib, olutasidenib or pralsetinib may have unintended side effects, adverse reactions or incidents of misuses; the availability of resources to develop, manufacture and commercialize Rigel's product candidates; market competition; and those 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, 2023 and subsequent filings. Any forward-looking statement made by us in this press release is based only on information currently available to us and speaks only as of the date on which it is made. Rigel does not undertake any obligation to update forward-looking statements, whether written or oral, that may be made from time to time, whether as a result of new information, future developments or otherwise, and expressly disclaims any obligation or undertaking to release publicly any updates or revisions to any forward- looking statements contained herein, except as required by law.

Please visit www.TAVALISSE.com for Full Prescribing Information. Please visit www.REZLIDHIA.com for Full Prescribing Information, including Boxed WARNING. Please visit www.GAVRETO.com for Full Prescribing

2 information.

Growing Our Hematology and Oncology Business

In-Licensing and Product Acquisition

• GAVRETO®(pralsetinib) added to existing commercial and medical affairs operations

• New late-stage assets which leverage current capabilities and capacity

Development Programs1

• Evaluate REZLIDHIA in a broad range of IDH1-mutant cancers including AML, MDS and glioma

• R289 IRAK1/4 inhibitor Phase 1b trial in lower-risk MDS

ITP, immune thrombocytopenia; IDH1, isocitrate dehydrogenase-1; mIDH1, mutated IDH1; R/R, relapsed or refractory; AML, acute myeloid leukemia; MDS, myelodysplastic syndrome; IRAK1/4, interleukin

3 receptor-associated kinases 1 and 4. 1. Investigational compounds in these indications and not approved by the FDA. Please see Important Safety Information on slides 50-54. Please visit www.TAVALISSE.com for Full Prescribing Information. Please visit www.REZLIDHIA.com for Full Prescribing Information, including Boxed WARNING. Please visit www.GAVRETO.com for Full Prescribing information.

Acquired U.S. Rights to GAVRETO®

APPROVED IN THE U.S.

GAVRETO is indicated for the treatment of adult patients with metastatic rearranged during transfection (RET)

fusion-positivenon-small cell lung cancer as detected by an FDA-approved test, and adult and pediatric patients 12 years of age and older with advanced or metastatic RET fusion-positive thyroid cancer who require systemic therapy and who are radioactive iodine-refractory (if radioactive iodine is appropriate)*

Please see Important Safety Information on slides 53 & 54

* This indication is approved under accelerated approval based on overall response rate and duration of response. Continued approval

5 for this indication may be contingent upon verification and description of clinical benefit in confirmatory trial(s).

Growing Our Oncology Targeted Therapy Portfolio

6 RET, rearranged during transfection. 1. US Net sales provided by Blueprint Medicines as reported by Genentech, a member of the Roche group.

NSCLC and Treatment of RET fusion-positive Patients

* Multi-Kinase Inhibitors

** Immune Checkpoint Inhibitors(anti PD-1/PD-L1)

NSCLC, non-small cell lung cancer; SCLC, small cell lung cancer; RET, rearranged during transfection. 1. American Cancer Society Key Statistics for Lung Cancer https://www.cancer.org/cancer/types/lung-

7 cancer/about/key-statistics.html2. Kato, S. et al. RET aberrations in diverse cancers: next-generation sequencing of 4,871 patients. Clin Cancer Res. 2017;23(8):1988-1997 doi: 10.1158/1078-0432.CCR-16- 1679 3. Market Research conducted in Q2 2023 with 60 oncologists managing RET fusion-positive patients.

RET-altered Solid Tumors Have Been Underserved Historically1,2,3,4,5

NSCLC, non-small cell lung cancer; RET, rearranged during transfection; ORR, overall response rate.

9 1. Lipson, et al. Nat Med 2012 2. Takeuchi, et al. Nat Med 2012 3. Santoro, et al. J Clin Invest 1992 4. Romei, et al. Oncotarget 2018 5. Gainor JF. et al., BLU-667 ASCO 2019 Presentation

MKIs, Platinum-based Therapies and Immunotherapies are Associated with Suboptimal Response Rates and PFS

Studies Evaluating Kinase Inhibitors in Patients with RET Fusion-positive NSCLC

NOTE: Data is from independent studies, not comparative trials.

Multi-kinase inhibitors: Discontinuation rate 8-24% and rate of AEs grade ≥ 3, 28-92%

MKI, multi-kinase inhibitors; ICI, immune checkpoint inhibitors; PFS, progression-free survival; ORR, overall response rate; NSCLC, non-small cell lung cancer; RET, rearranged during transfection.

1. Drilon A et al. Nat Rev Clin Oncol 15, 151-167 (2018). 2. Lee SH et al. Annals of Oncology. 2017;28(2):292-297.3. Drilon A et al. Lancet Oncology. 2016;17(12):1653- 1660. 4. Hida T et al. Lung Cancer. 2019;138:124-136.

10 5. Horiike A et al. Lung Cancer. 2016;93:43-46. doi:10.1016/j.lungcan.2015.12.011. 6. Mazieres J, Drilon AE, Mhanna L, et al. Efficacy of immune-checkpoint inhibitors (ICI) in non-small cell lung cancer (NSCLC) patients harboring activating molecular alterations (ImmunoTarget).Journal of clinical oncology 7. Gautschi O, et al. Targeting RET in Patients With RET-Rearranged Lung Cancers: Results From the Global, Multicenter RET Registry. J Clin Oncol. 2017;35(13):1403. Epub 2017 Mar 13.