CAL-263

CAL-263 is a small molecule drug that acts as a selective inhibitor of phosphatidylinositol 3-kinase delta (PI3Kδ). It was initially developed by Calistoga Pharmaceuticals and later by Gilead Sciences. The drug targets the PI3Kδ isoform, which plays a key role in immune cell signaling and inflammatory responses. Its primary indications have included immune system diseases and inflammatory conditions such as asthma, chronic obstructive pulmonary disease (COPD), rheumatoid arthritis, and allergic rhinitis. Clinical development has included Phase 1 studies for allergic rhinitis[1][2][4]. The mechanism of action involves inhibition of PI3Kδ activity, thereby modulating immune cell function and inflammation[1][4].