• Rigel Pharmaceuticals will present updated Phase 1b R289 results in previously treated lower-risk myelodysplastic syndrome at ASH on December 12, 2026.
• R289 remained generally well tolerated; forthcoming dose-expansion results will provide preliminary efficacy findings, including effects on transfusion dependence.
• Fostamatinib studies scheduled for presentation showed improved platelet counts in immune thrombocytopenia, with no new safety signals in Japanese surveillance.
• Long-term extension findings showed durable hemoglobin responses in warm autoimmune hemolytic anemia, where fostamatinib remains investigational, without new safety signals.

Disclaimer: This news brief was created by Public Technologies (PUBT) using generative artificial intelligence. While PUBT strives to provide accurate and timely information, this AI-generated content is for informational purposes only and should not be interpreted as financial, investment, or legal advice. Rigel Pharmaceuticals Inc. published the original content used to generate this news brief via PR Newswire (Ref. ID: 202611040915PR_NEWS_USPR_____SF88539) on November 04, 2026, and is solely responsible for the information contained therein.