Rigel Pharmaceuticals, Inc. Announces Inducement Grant under NASDAQ Listing Rule 5635(c)(4)

SOUTH SAN FRANCISCO, Calif., Dec. 8, 2017

Rigel granted stock options to purchase shares of Rigel's common stock to one employee with an exercise price of $4.09 per share, the closing price of Rigel's common stock on December 1, 2017, the first trading date prior to December 4, 2017, the effective date of such grant. The stock options vest as follows: certain of the shares of common stock subject to the award vest over a four year period, with one-fourth of the shares subject to such awards vesting on the first anniversary of the award's vesting commencement date, and the remaining shares vesting in equal monthly installments thereafter, and certain of the shares of common stock subject to the award vest immediately upon achievement of one or more performance conditions.

Rigel is providing this information in accordance with NASDAQ Listing Rule 5635(c)(4).

About Rigel (www.rigel.com)

Rigel Pharmaceuticals, Inc. is a biotechnology company dedicated to discovering, developing and providing novel small molecule drugs that significantly improve the lives of patients with immune and hematological disorders, cancer and rare diseases. Rigel's pioneering research focuses on signaling pathways that are critical to disease mechanisms. The company's current clinical programs include clinical trials of fostamatinib, an oral spleen tyrosine kinase (SYK) inhibitor, in a number of indications. Rigel has submitted, and the FDA has accepted for review, an NDA for fostamatinib in patients with chronic or persistent immune thrombocytopenia (ITP). In addition, Rigel has product candidates in development with partners BerGenBio AS, Daiichi Sankyo and Aclaris Therapeutics.

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