A Study to Investigate LYL845 in Adults With Solid Tumors

Inclusion Criteria: * Age ≥ 18 years up to ≤ 75 years at the time of informed consent * Confirmed diagnosis of melanoma, non-small cell lung cancer (NSCLC), or colorectal cancer (CRC) that is metastatic or locally advanced or unresectable and is relapsed and/or refractory (R/R) after standard therapy for each tumor histology * Participants must have received prior systemic treatment for their metastatic disease or locally advanced disease based on tumor type as follows: * Melanoma: participants with disease progression following an immune checkpoint inhibitor (CPI) * NSCLC: participants with disease progression following at least 1 approved systemic therapy, including an immune CPI-containing regimen for appropriate patients or an approved targeted therapy for known molecular abnormalities if applicable to their disease * CRC: participants with disease progression following at least 1 line of therapy, including a fluoropyrimidine with oxaliplatin or irinotecan. Microsatellite instability (MSI) high/mismatch repair deficient (dMMR) CRC participants must have disease progression following systemic therapy with immune CPIs. * Measurable disease including at least 1 lesion that is safely resectable AND a target lesion to measure response and an additional lesion for biopsy * Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1 * Adequate organ and marrow function * Women of childbearing potential must have a negative pregnancy test at screening * All participants must agree to practice highly effective methods of contraception * Fully recovered from toxicity from prior systemic anticancer therapy Exclusion Criteria: * Prior treatment with adoptive cellular therapy * Prior solid organ transplantation * Central nervous system (CNS) involvement of disease that is extensive, symptomatic or untreated, or patients with leptomeningeal disease * Uncontrolled or symptomatic pleural effusion or ascites * Untreated or active systemic infection * Active autoimmune disease requiring treatment or primary immunodeficiency syndrome * Systemic corticosteroids at a dose of \>10 mg of prednisone or equivalent per day * Other primary malignancy within 3 years prior to enrollment * Impaired cardiac function or clinically significant cardiovascular disease * Required chronic anticoagulation, such as warfarin, low molecular weight heparin, or Factor Xa inhibitors * Pregnant or nursing (lactating) women