A Study Assessing KB707 for the Treatment of Advanced Solid Tumor Malignancies Affecting the Lungs

Key Inclusion Criteria: * Age 18 years or older at the time of informed consent * Life expectancy \>12 weeks * Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1 * Have at least one measurable lung lesion per RECIST v1.1 at Screening * Cohorts 1 through 4 only: Histologically confirmed diagnosis of advanced solid tumor malignancy affecting the lungs and the individual has progressed on standard of care therapy, cannot tolerate standard of care therapy, refused standard of care therapy, or has no standard of care therapy. * Cohorts 5, 6, and 7 only: (1) Histologically or cytologically confirmed diagnosis of stage 3 or 4 NSCLC, as per American Joint Committee on Cancer (AJCC) staging system (8th edition) and (2) Subject must meet the following criteria of prior lines of therapy: 1. Subject has previously received no more than one line of prior immune checkpoint inhibitor (ICI) with or without platinum-based chemotherapy, or no more than two prior lines of therapy when given the ICI and platinum-based chemotherapy sequentially as two separate lines. 2. Subjects with an actionable mutation (e.g., EGFR, KRAS, ALK, or ROS1 genomic alteration), are permitted to have received one additional line of approved targeted therapy. Key Exclusion Criteria: * Not fully recovered from prior surgery or radiotherapy, including all radiation-related toxicities * The subject is pregnant, nursing, or plans to become pregnant during study treatment and through three months after the last dose of KB707 * Have known history of positive human immunodeficiency virus (HIV 1/2) * Cohorts 5, 6, and 7 only: 1. Subject has a known additional malignancy that is progressing or requires active treatment 2. Subject has active brain metastases or leptomeningeal metastases 3. Prior anti-PD-1/PD-L1 therapy was intolerable and required discontinuation of treatment 4. Subject has active, known, or suspected autoimmune disease requiring systemic treatment 5. Subject has known acute or chronic hepatitis 6. Subject has active pneumonitis or history of ICI-induced pneumonitis that required steroids