Rigel Reports Second Quarter 2024 Financial Results and Provides Business Update Second quarter total revenue of $36.8 million, which includes TAVALISSE net product sales of $26.4 million, REZLIDHIA net product sales of

SAN FRANCISCO, Calif., August 6, 2024 /PRNewswire/ -- Rigel Pharmaceuticals, Inc. (Nasdaq: RIGL), a commercial

stage biotechnology company focused on hematologic disorders and cancer, today reported financial results for the second quarter ended

June 30, 2024, including sales of TAVALISSE (fostamatinib

disodium hexahydrate) for the treatment of chronic immune thrombocytopenia (ITP); REZLIDHIA (olutasidenib)

for the treatment of relapsed or refractory (R/R) mutated isocitrate dehydrogenase-1 (mIDH1) acute myeloid leukemia (AML); and

GAVRETO (pralsetinib) for the treatment of metastatic rearranged during transfection

(RET) fusion-positive non-small cell lung cancer (NSCLC) and advanced or metastatic thyroid cancer, and recent business progress.

the second quarter, we advanced key strategic initiatives including the successful transfer

of GAVRETO to our commercial portfolio, enabling us to bring this important treatment option

to current and newly prescribed patients without interruption," said Raul Rodriguez, Rigel's president and CEO. "The

addition of GAVRETO, combined with record revenues from TAVALISSE and REZLIDHIA, has allowed

us to approach net income break even. We look to maintain our financial discipline as we expand our commercial reach and advance

our development programs."

Quarter 2024 Business Update

bottle count represents 60-count bottle equivalent

and Development Update

2024 and Year-To-Date Financial Update

quarter ended June 30, 2024, total revenues were $36.8 million, consisting of $26.4 million in TAVALISSE net product sales, $5.2

million in REZLIDHIA net product sales, $1.9 million in GAVRETO net product sales, and $3.4 million in contract revenue from collaborations.

TAVALISSE net product sales grew 24% compared to $21.3 million in the same period of 2023. REZLIDHIA net product sales grew 102% compared

to $2.6 million in the same period of 2023. GAVRETO became commercially available from Rigel on June 27, 2024. Contract revenue

from collaborations consisted of $2.2 million from Kissei Pharmaceutical Co., Ltd. (Kissei) related to delivery of drug supplies,

$1.1 million from Grifols S.A. (Grifols) related to earned royalties, and $0.1 million from Medison Pharma Trading AG (Medison) related

to delivery of drug supplies and earned royalties.

expenses were $36.4 million compared to $32.2 million for the same period of 2023. The increase in costs and expenses was partly due

to higher cost of product sales, driven primarily by higher amortization of intangibles and royalties, increased personnel-related costs,

and increased research and development costs due to the progress of clinical activities, including R289, the company's IRAK

1/4 inhibitor program.

a net loss of $1.0 million, or $0.06 per basic and diluted share, compared to a net loss of $6.6 million, or $0.38 per basic and diluted

share, for the same period of 2023. The basic and diluted share and per share amounts have been restated to reflect the 1-for-10 reverse

stock split effected on June 27, 2024 on a retroactive basis for all periods presented.

For the six months ended June 30,

2024, total revenues were $66.4 million, consisting of $47.5 million in TAVALISSE net product sales, $10.0 million in REZLIDHIA net product

sales, $1.9 million in GAVRETO net product sales, and $6.9 million in contract revenue from collaborations. TAVALISSE net product sales

grew 9% compared to $43.6 million in the same period of 2023. REZLIDHIA net product sales grew 150% compared to $4.0 million in the same

period of 2023. As mentioned above, GAVRETO became commercially available from Rigel on June 27, 2024. Contract revenue from collaborations

consisted of $4.5 million from Kissei related to delivery of drug supplies, $2.2 million from Grifols related to earned royalties, and

$0.2 million from Medison related to delivery of drug supplies and earned royalties.

expenses were $72.9 million compared to $70.9 million for the same period of 2023. The increase in costs and expenses was partly due

to higher cost of product sales, driven primarily by higher amortization of intangibles and royalties, increased personnel-related costs

and higher stock-based compensation expenses mainly from performance awards. These increases were partially offset by decreased research

and development costs due to the timing of clinical trial activities related to R289, the company's IRAK 1/4 inhibitor program,

as well as reduced trial activities related to the completed Phase 3 clinical trials of fostamatinib in patients with COVID-19 and warm

antibody hemolytic anemia (wAIHA).

a net loss of $9.3 million, or $0.53 per basic and diluted share, compared to a net loss of $20.1 million, or $1.16 per basic and diluted

share, for the same period of 2023. As discussed above, the share and per share amounts have been restated to reflect the 1-for-10 reverse

stock split on a retroactive basis for all periods presented.

Cash, cash equivalents

and short-term investments as of June 30, 2024 was $49.1 million, compared to $49.6 million as of March 31, 2024, and $56.9

million as of December 31, 2023.

and Webcast with Slides Today at 4:30pm Eastern Time

live conference call and webcast today at 4:30pm Eastern Time (1:30pm Pacific Time).

can access the live conference call by dialing (877) 407-3088 (domestic) or (201) 389-0927 (international). The conference call will

also be webcast live and can be accessed from the Investor Relations section of the company's website at www.rigel.com.

The webcast will be archived and available for replay after the call via the Rigel website.

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.

Acute myeloid leukemia (AML) is a rapidly progressing cancer of the

blood and bone marrow that affects myeloid cells, which normally develop into various types of mature blood cells. AML occurs primarily

in adults and accounts for about 1 percent of all adult cancers. The American Cancer Society estimates that there will be about 20,800

new cases in the United States, most in adults, in 2024.2

AML affects about half of all patients who, following treatment and remission, experience a return of leukemia cells in the bone marrow.3 Refractory

AML, which affects between 10 and 40 percent of newly diagnosed patients, occurs when a patient fails to achieve remission even after

intensive treatment.4 Quality of life declines for patients with each successive line of treatment for AML, and well-tolerated

treatments in relapsed or refractory disease remain an unmet need.

It is estimated that over 230,000 adults in the U.S. will be diagnosed

with lung cancer in 2024. Lung cancer is the leading cause of cancer death in the U.S, with NSCLC being the most common type accounting

for 80-85% of all lung cancer diagnoses.5 RET fusions are implicated in approximately 1-2% of patients with NSCLC.6

TAVALISSE (fostamatinib disodium hexahydrate) tablets is indicated for the treatment of thrombocytopenia in adult patients with chronic

immune thrombocytopenia (ITP) who have had an insufficient response to a previous treatment.

click here for Important Safety Information and Full Prescribing Information for

REZLIDHIA is indicated for the treatment of adult patients with relapsed or refractory acute myeloid leukemia (AML) with a susceptible

isocitrate dehydrogenase-1 (IDH1) mutation as detected by an FDA-approved test.

click here for Important Safety Information and Full Prescribing Information, including

Boxed WARNING, for REZLIDHIA.

GAVRETO is indicated for the treatment of adult patients with metastatic rearranged during transfection (RET) fusion-positive non-small

cell lung cancer (NSCLC) 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).*

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

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

click here for Important Safety Information and Full Prescribing Information

report side effects of prescription drugs to the FDA, visit www.fda.gov/medwatch or

call 1-800-FDA-1088 (800-332-1088).

REZLIDHIA and GAVRETO are registered trademarks of Rigel Pharmaceuticals, Inc.

Rigel Pharmaceuticals, Inc. (Nasdaq: RIGL) is a biotechnology company dedicated to discovering, developing and providing novel therapies

that significantly improve the lives of patients with hematologic disorders and cancer. Founded in 1996, Rigel is based in South San

Francisco, California. For more information on Rigel, the Company's marketed products and pipeline of potential products, visit www.rigel.com.

This press release contains forward-looking statements relating to, among other things, expected

commercial and financial results, expectations related to the potential and market opportunity of olutasidenib as a therapeutic

for R/R AML and other conditions, the commercialization of fostamatinib for cITP, the commercialization of pralsetinib for the treatment

of non-small cell lung cancer and advanced thyroid cancer, Rigel's ability to further develop its clinical stage product candidates

and Rigel's partnering and collaboration efforts, as well as the progress of the Phase 1b clinical trial of R289 for the treatment

of lower-risk myeloid dysplastic syndrome, olutasidenib's evaluation in acute myeloid leukemia (AML), including in patients

receiving prior venetoclax, and in other hematologic cancers, and including olutasidenib as a maintenance therapy following allogeneic