Study to Evaluate LB-LR1109, Administered Alone for the Treatment of Solid Tumor and in Combination With Atezolizumab for the Treatment of NSCLC

Key Inclusion Criteria:

1. Age ≥18 years old at the time of signing the ICF.
2. (Phase 1a only) Participants must have 1 of the following histologically confirmed advanced or metastatic solid tumors with measurable or non-measurable disease as determined by RECIST v1.1,

   \- NSCLC, HNSCC, RCC, urothelial carcinoma, or malignant melanoma.
3. (Phase 1a only) Participants who have metastatic disease which has progressed during or after approved standard therapies or are intolerant to approved therapies, or for which the participant refuses or is ineligible for standard therapy.
4. Eastern Cooperative Oncology Group Performance Status (ECOG PS) score of 0 or 1.
5. Life expectancy ≥12 weeks.
6. Participants with adequate organ function
7. No potential for childbearing or agree to use adequate contraception
8. Ability to understand the study purpose and procedures and have the willingness to sign a written informed consent document.
9. (Phase 1b only ) Must have histologically confirmed advanced or metastatic NSCLC without actionable genomic alteration that have approved therapies in the location where the participant's live and with measurable disease as determined by RECIST v1.1

Key Exclusion Criteria:

1. Clinically significant cardiac disease or cardiac failure.
2. Untreated or unstable brain or central nervous system (CNS) metastases or Leptomeningeal disease
3. Participants with any concurrent active malignancies
4. Has received prior therapy targeting LILRB or immunoglobulin-like transcript pathway.
5. History of life-threatening toxicity related to prior immune therapy
6. Has not recovered to ≤ Grade 1 or baseline from AEs and/or complications from prior surgical intervention or any anti-cancer treatment before starting study treatment
7. Participants must not have an active, known, or suspected autoimmune disease.
8. Evidence of active infection requiring IV antibiotic treatment ≤7 days prior to initiation of study treatment therapy (does not apply to viral infections that are presumed to be associated with the underlying tumor type required for study entry).
9. Pregnant or lactating or expecting to conceive a child during the study or within 6 months after the last dose of study intervention.
10. Any condition that would, in the Investigator's judgment, interfere with full participation in the study, including administration of study intervention and attending required study visits; pose a significant risk to the participant; or interfere with interpretation of study data.
11. (Phase 1b only) Participants who were previously exposed to atezolizumab