Anti-tumor activity was observed in CCA and solid tumors across doses and FGFR2 alterations with radiographic tumor reductions in 74 (64%), SD/PR in 83 (72%)...Clinically meaningful disease control and durable responses were observed in pts with FGFR2 f/r CCA....These encouraging dose escalation data confirm the broad therapeutic potential of highly selective FGFR2 targeting with RLY-4008 by demonstrating encouraging initial efficacy across FGFR2-altered solid tumors and genomic alterations, with a differentiated safety profile that avoids FGFR1- and FGFR4-related toxicity.