Investor Presentaiton

DS-7300 ES-SCLC Ph2 study Development update Ph2 dose-finding study for ES-SCLC was initiated in June Ph1/2 study design Dose escalation (Part 1) Advanced/unresectable or metastatic solid tumor (various types of cancer) 0.8 mg /kg 1.6 mg /kg 3.2 mg /kg 4.8 mg /kg Dose expansion (Part 2) [Cohort 1] ESCC [Cohort 2] CRPC [Cohort 3] Squamous NSCLC 6.4 mg /kg ES-SCLC Ph2 study design Daiichi-Sankyo DS-7300 8mg/kg 16.0 mg /kg 12.0 mg /kg ES-SCLC 2L or later randomize 1:1 DS-7300 12mg/kg 8.0 mg /kg Primary endpoint: ORR Secondary endpoint: PFS, DOR, OS, etc ES-SCLC was selected based on Ph1 data N = 80 Extensive stage (ES) means cancer spreads across a wide area and surgical operation and radiation therapy are not applicable No effective treatment and high unmet need for ES-SCLC 2L or later Efficacy and safety of two doses will be evaluated in Ph2 study in patients with ES-SCLC who received at least one prior line of platinum- based chemotherapy Option for addition of 60 patient expansion at RP2D CRPC: castration-resistant prostate cancer, DOR: duration of response, ESCC: esophageal squamous cell carcinoma, NSCLC: non small cell lung cancer, ORR: objective response rate, OS: overall survival, PFS: progression free survival, RP2D: recommended Ph2 dose, SCLC: small cell lung cancer 29 29

View entire presentation