Rigel Announces R289 Granted Orphan Drug Designation by the FDA for MDS

FDA Designations and Development Progress - The US FDA granted Orphan Drug designation to R289 for the treatment of myelodysplastic syndromes (MDS), highlighting the unmet medical need for patients with this rare disorder [1][2] - R289 also received Fast Track designation for the treatment of previously-treated transfusion-dependent lower-risk MDS patients [3] - The ongoing Phase 1b study of R289 is evaluating its safety, tolerability, pharmacokinetics, and preliminary activity in patients with lower-risk MDS who are relapsed or refractory to prior therapies [1] R289 Mechanism and Potential - R289 is a prodrug of R835, a dual inhibitor of IRAK1 and IRAK4, which blocks inflammatory cytokine production in response to TLR and IL-1R signaling [4] - Chronic stimulation of TLR and IL-1R pathways is thought to cause the pro-inflammatory environment in the bone marrow responsible for persistent cytopenias in lower-risk MDS patients [4] - Initial data from the Phase 1b study of R289 in lower-risk MDS patients is encouraging, supporting its potential as a new treatment option [2] Company Overview - Rigel Pharmaceuticals is a biotechnology company focused on discovering, developing, and providing novel therapies for hematologic disorders and cancer [5] - Founded in 1996, Rigel is based in South San Francisco, California, and is listed on the Nasdaq under the ticker RIGL [5]