SOUTH SAN FRANCISCO, Calif., June 19, 2017 /PRNewswire/ -- Rigel Pharmaceuticals, Inc. (Nasdaq:RIGL) today announced the U.S. Food and Drug Administration (FDA) has filed its New Drug Application (NDA) for the use of TAVALISSE™ (fostamatinib disodium) in patients with chronic or persistent immune thrombocytopenia (ITP). Rigel expects the action date for the FDA to complete its review will be April 17, 2018, under the Prescription Drug User Fee Act (PDUFA). The FDA previously granted Orphan Drug designation to TAVALISSE™ for the treatment of patients with ITP. 

"The FDA acceptance for filing of our NDA is an exciting milestone for Rigel," said Raul Rodriguez, Rigel's president and chief executive officer. "If approved, we believe TAVALISSE™ will provide a new treatment option for patients with chronic or persistent ITP. We look forward to working closely with the FDA as they review our submission."

The NDA submission is supported by data from the Phase 3 clinical program for fostamatinib in ITP, which was comprised of three studies, two randomized placebo-controlled studies (Studies 047 and 048), and an open-label extension study (Study 049). Together with an initial proof of concept study, the NDA included 163 ITP patients. Across all indications, fostamatinib has been evaluated in over 4,600 subjects.  Data from all studies, including preclinical evaluation and drug manufacturing data, were included in the NDA submission.

About ITP
In patients with ITP, 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 increased risk of severe bleeding events that can result in serious medical complication, or even death.  Currently approved therapies for ITP include steroids, blood platelet production boosters (TPO-RAs) and splenectomy. However, not all patients derive a benefit from existing therapies. As a result, there remains a significant medical need for additional treatment options for patients with ITP.  

About TAVALISSE™ (fostamatinib disodium)
TAVALISSE™ is an oral investigational drug candidate designed to inhibit SYK kinase, a key signaling member in the immune process that leads to platelet destruction in ITP.  Unlike other therapies that modulate the immune system in different ways or stimulate platelet production, fostamatinib may address an underlying autoimmune cause of ITP by impeding platelet destruction.

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 an NDA to the FDA 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.

Forward Looking Statements
This release contains forward-looking statements relating to, among other things, the timing of a response from the FDA to our NDA submission and Rigel's belief that fostamatinib may be an attractive alternative for patients with ITP.  Any statements contained in this press release that are not statements of historical fact may be deemed to be forward-looking statements. Words such as "if," "planned," "will," "may," "expect," and similar expressions are intended to identify these forward-looking statements. These forward-looking statements are based on Rigel's current expectations and inherently involve significant risks and uncertainties. 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, the FDA may interpret Rigel's findings differently, which could result in the FDA not approving any submitted NDA; the availability of resources to develop Rigel's product candidates; Rigel's need for additional capital in the future to sufficiently fund Rigel's operations and research; the uncertain timing of completion of and the success of clinical studies; market competition, risks associated with and Rigel's dependence on Rigel's corporate partnerships; risks related to changes in estimated cash position based on the completion of financial closing procedures and the audit of Rigel's financial statements; as well as other risks detailed from time to time in Rigel's reports filed with the Securities and Exchange Commission, including its Quarterly Report on Form 10-Q for the quarter ended March 31, 2017. 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.

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

Media Contact: Jessica Daitch
Phone: 917.816.6712
Email: jessica.daitch@inventivhealth.com

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SOURCE Rigel Pharmaceuticals, Inc.