First-in-human Study of DS-1062a for Advanced Solid Tumors (TROPION-PanTumor01)

The dosage strength will change during the study but all participants will receive the same study drug. So the study is not a true 2-arm study, it is a 2-part study. In both parts, participants with pathologically documented unresectable advanced NSCLC and triple negative breast cancer (TNBC) who have been refractory to or relapsed from standard treatment or for which no standard treatment is available, will be enrolled. In Dose Expansion, additional indications (hormone receptor \[HR\]-positive human epidermal growth factor receptor 2 \[HER2\]-negative breast cancer, HR-positive HER2-low breast cancer, HER2-positive breast cancer, small cell lung cancer \[SCLC\], endometrial cancer, pancreatic adenocarcinoma, HER2-negative gastric/gastroesophageal junction \[GEJ\] cancer, esophageal cancer, head and neck squamous cell carcinoma \[HNSCC\], transitional cell carcinoma of the urothelium, colorectal cancer \[CRC\], platinum-resistant ovarian cancer, platinum-sensitive ovarian cancer, cervical cancer, and castration-resistant prostate cancer \[CRPC\]) may be evaluated, if the study treatment demonstrates acceptable safety, tolerability and efficacy in NSCLC participants. After the primary analysis, the main (registered) study will be considered complete, but data will be collected from participants who continue receiving study drug. In the sub-study, the additional indications listed for Dose Expansion (except for head and neck cancer) may be evaluated.