Inclusion Criteria:

          -  Escalation: Histologically or cytologically-confirmed advanced/metastatic or
             non-resectable solid tumors, including sarcoma, that are refractory or intolerant to
             standard therapy, or for which no standard therapy exists that is likely to confer any
             clinical benefit.

          -  Expansion Cohorts: Malignant pleural mesothelioma, gastric adenocarcinoma, colorectal
             adenocarcinoma, pancreatic adenocarcinoma and certain sarcoma subtypes (e.g.,
             chondrosarcoma, Ewing sarcoma) with locally advanced or metastatic, non-resectable
             disease, that are refractory or intolerant to standard therapy, or for which no
             standard therapy exists that is likely to confer any clinical benefit.

          -  Measurable disease as defined by RECISTv1.1 (or modified RECIST for mesothelioma)
             criteria.

          -  Adequate hematologic, coagulation, hepatic and renal function as defined per protocol.

          -  Eastern Cooperative Oncology Group performance status (ECOG PS) of 0 or 1 for Part 1
             and ECOG PS of 0, 1 or 2 for Parts 2 and 3.

        Exclusion Criteria:

          -  Prior treatment with or exposure to DR5 agonists.

          -  Receipt of investigational agents or devices, anticancer therapy and radiotherapy
             (with the exception of palliative localized radiation) within 4 weeks prior to the
             first dose of study drug, and liver-directed therapies (i.e., RFA, TACE/embolization,
             cryotherapy, SBRT) within 12 weeks prior to the first dose of study drug. Exceptions
             per protocol.

          -  Subject has undergone allogeneic hematopoietic stem cell or bone marrow
             transplantation within the last 5 years. Exception: Participants who have had a stem
             cell or bone marrow transplant > 5 years ago are eligible for enrollment, as long as
             there are no symptoms of graft-versus-host disease (GVHD).

          -  Prior or concurrent malignancies. Exception: Subjects with a prior or concurrent
             malignancy whose natural history or treatment does not have the potential to interfere
             with the safety or efficacy assessments of INBRX-109.

          -  Hematologic malignancies.

          -  Known or active primary central nervous system (CNS) tumors, leptomeningeal disease
             and CNS metastases. Exception: Subjects with previously treated, asymptomatic, and
             clinically stable CNS metastases may be allowed study entry if certain criteria apply.

          -  Subjects with chronic liver diseases including but not limited to cirrhosis, NASH,
             alcohol-related liver disease, hemochromatosis, Wilson's disease, alpha-1 antitrypsin
             deficiency, hepatic or biliary autoimmune disorders (i.e., primary biliary
             cholangitis, autoimmune hepatitis).

          -  Acute viral or toxic liver disease within 4 weeks prior to the first dose of study
             drug.

          -  Evidence or history of hepatitis B, hepatitis C, or human immunodeficiency virus (HIV)
             infection.

          -  Clinically significant cardiac condition, including myocardial infarction,
             uncontrolled angina, cerebrovascular accident, or other acute uncontrolled heart
             disease < 3 months; left ventricular ejection fraction (LVEF) < 50%; New York Heart
             Association (NYHA) Class III or IV congestive heart failure; or uncontrolled
             hypertension. Active, hemodynamically significant pulmonary embolism within 3 months
             prior to enrollment on this trial.

          -  Major surgery within 4 weeks prior to enrollment on this trial.

          -  Systemic infection requiring antibiotics within 2 weeks prior to the first dose of
             study drug.

          -  Part 3: Sensitivity or contraindications to carboplatin, cisplatin, pemetrexed,
             fluorouracil, irinotecan, or temozolomide.