IDEAYA Biosciences Inc (IDYA.O): IDE849's 17.4-Month 2L mOS and Global Safety Update Further Strengthen Competitive DLL3 ADC Profile

Citi comments on IDYA/Hengrui's updated IDE849 Ph1 data, which further strengthen the competitive DLL3 ADC profile outlined in the prior ESMO note. The newly reported 17.4-month 2L mOS lands at the favorable end of the mid-to-high-teens range implied by the prior 66.4% 12-month landmark OS. Median PFS and cORR in 2L were 6.9 months and 60.8%, in line with prior disclosure; in the broader 2L+ SCLC population, mOS was 14.7 months and cORR 54.5%. Preliminary global trial safety showed 5.0% Gr3+ TRAEs at 2.4 mg/kg across 20 pts vs. 22.2% at 3.5 mg/kg across 18 pts, compared with 33.3% Gr3+ TRAEs at 2.4 mg/kg in Hengrui's more mature dataset;