Given the activity of Rova-T observed in studies of SCLC and the prevalence of DLL3 expression in solid tumors described above, this study examined the safety, tolerability, and antitumor activity of Rova-T in patients with DLL3-positive tumors, including NEC/NET, melanoma, MTC, GBM, and other solid tumors. This evidence concerns the gene DLL3 and medullary thyroid gland carcinoma.