KB707-01 is a Phase 1/2, open-label, multicenter, dose escalation and expansion study. The study will evaluate the safety and tolerability of KB707 in adults with locally advanced or metastatic solid tumors who have progressed on standard of care therapy, cannot tolerate standard of care therapy, refused standard of care therapy, or for whom there is no standard of care therapy as well as the safety, tolerability, preliminary efficacy, and immunologic effect of KB707 administered in combination with Opdualag to subjects with unresectable or metastatic melanoma. Subjects in dose escalation (Cohorts 1 through 3) and dose expansion (Cohort 4) will receive intratumoral injections of KB707 approximately every three weeks. Cohorts 1 through 4 are closed to new enrollment. Dose expansion Cohort 5 and Cohort 6 will evaluate subjects with advanced melanoma. Subjects in Cohort 5 will receive intratumoral injections of KB707 biweekly (q2w), delivered in combination with Opdualag (dosed every q4w per prescribing information). Subjects in Cohort 6 will receive intratumoral injections of KB707 biweekly (q2w), delivered in combination with Keytruda (dosed every q6w per prescribing information). All subjects will be treated until disease progression, death, unacceptable toxicity, symptomatic deterioration, achievement of maximal response, subject choice, Investigator decision to discontinue treatment, or the Sponsor determines to terminate the study.