A Study to Investigate Safety and Effectiveness of CRN09682 in Participants With SST2-Expressing NENs and Other Solid Tumors

Inclusion Criteria: * Have a histological diagnosis of metastatic or locally advanced inoperable NET, NEC, or other solid tumors that have confirmed radiological progression. * Have one or more measurable disease location per RECIST version 1.1. * Have a tumor that expresses SSR confirmed by SSR imaging. * Have an ECOG performance status of 0, 1, or 2. Exclusion Criteria: * Have tumor progression while undergoing a course of PRRT or within 6 months of completing PRRT. * Have brain metastases unless asymptomatic and stable for at least one month for participants with SCLC or LCLC or at least 3 months for participants with other non-NET solid tumors. * Use of anticancer agents within specified intervals prior to the first dose of study drug. * Had surgery, chemoembolization, or radiofrequency ablation within 90 days prior to first dose of study drug. * Prior participation in any intervention clinical study within 30 days or 5 half-lives (whichever is longer) prior to the first dose of study drug. * Participants with carcinoid syndrome. * Secondary malignancy: participants who have any other malignancy known to be active or treated within 3 years of the start of screening, with the exception of treated cervical intraepithelial neoplasia, superficial (noninvasive) bladder cancer, and non-melanoma skin cancer. * Have prior treatment with MMAE. * Have hypersensitivity or history of anaphylactic reaction to octreotide, other SSAs, and/or MMAE.