Inclusion Criteria:

          -  Ability of the patient or legal guardian to understand the purpose of the study,
             provide signed and dated informed consent from the patient prior to performing any
             protocol-related procedures (including Screening evaluations), and be able and willing
             to comply with the study procedures.

          -  Male or female aged ≥ 18 years.

          -  Advanced solid tumors with evidence of progressive disease as per RECIST no longer
             than 3 months before Informed Consent form (ICF) signature, without any subsequent
             curative intent treatment.

          -  Parts A and B only: Histologically confirmed relapsed/refractory advanced solid tumor,
             progressing after at least one line of treatment for advanced or metastatic disease.

          -  Parts C and D only: Histologically confirmed solid tumors, relapsed post or were
             refractory to at least one line of treatment for advanced disease. BRAF mutant
             melanoma must have progressed to BRAF + MEK inhibitor.

          -  Parts C and D only: Radiologically measurable disease as per RECIST v1.1.

          -  No additional established line of on-label treatment is available or there is a
             contraindication for the indicated labelled therapies as deemed by the Investigator.

          -  Eastern Cooperative Oncology Group (ECOG) Performance Status 0-1.

          -  Adequate pulmonary, cardiovascular, hematological, liver and renal function, per
             Investigator judgment.

          -  All acute toxic effects, of any prior anticancer therapy (e.g., radiotherapy,
             chemotherapy, or surgical procedures) must have resolved to CTCAE v5.0 grade ≤1
             (except alopecia [any grade] or asthenia [up to grade 2 allowed]).

          -  Negative serum pregnancy test within 7 days prior to study treatment in women of
             childbearing potential and women <12 months after menopause.

          -  For women who are not postmenopausal and have not undergone surgical sterilization:
             agreement to remain abstinent or use two adequate highly effective non-hormonal
             methods of contraception, including at least one method with a failure rate of <1 %
             per year, during the treatment period and until 6 months after the last dose of study
             treatment.

          -  For men: agreement to remain abstinent or use contraceptive measures and agreement to
             refrain from donating sperm during the treatment period and for at least 6 months
             after the last dose of study treatment.

          -  Availability and willingness of patients to obtain a baseline and on treatment biopsy
             of the tumor. Available archived biopsies (frozen or formalin fixed) may serve as
             baseline specimens, in patients who have residual tumor masses which can only be
             accessed with significant risk

        Exclusion Criteria:

          -  Symptomatic central nervous system (CNS) metastases. Definitively treated CNS
             metastases (e.g., radiotherapy) stable for at least 6 weeks prior to Day 1 of study
             drug administration are acceptable.

          -  Participants with an active second malignancy. Patients with precancerous lesions,
             concomitant early stages of prostate or breast cancer not requiring active treatment
             (past conditions currently resolved > 3 years prior to Screening are also acceptable),
             and squamous cell carcinoma of the skin not requiring systemic treatment are
             acceptable.

          -  Evidence of significant, uncontrolled concomitant diseases that could affect
             compliance with the protocol or interpretation of results, including uncontrolled
             diabetes mellitus, history of relevant pulmonary disorders, (e.g., severe
             bronchospasm, obstructive pulmonary disease), hyperthyroidism due to thyroiditis and
             known autoimmune diseases or other disease with ongoing fibrosis. Stable vitiligo,
             autoimmune thyroiditis, and preexisting treated type 1 diabetes are acceptable and are
             not exclusion criteria.

          -  Significant cardiovascular/cerebrovascular disease, including myocardial infarction or
             transient ischemic attack (TIA) within 6 months prior to Day 1 of study drug
             administration.

          -  Active or uncontrolled infections requiring systemic antibiotics within one week (7
             days) preceding Day 1 of treatment

          -  Hemoglobin (Hb) <9 g/dL, transfusion of red blood cells allowed to reach threshold
             target.

          -  Neutrophils <1500 /mm3.

          -  Platelets <75000/mm3.

          -  Liver: aspartate aminotransferase (AST) and alanine aminotransferase (ALT) >2.5x upper
             limit of normal (ULN), total bilirubin > 1.5xULN (in documented Gilbert's syndrome >
             3mg/dl) however, if caused by liver metastasis as judged by the Investigator and
             Sponsor AST and ALT >5xULN.

          -  International normalized ratio (INR) >1.5xULN.

          -  Serum creatinine < 1.5 mg/dL or a measured creatinine clearance ≥ 50 mL/min using the
             Cockcroft-Gault formula.

          -  Known replicating human immunodeficiency virus (HIV) or known active (replicative)
             hepatitis B virus or hepatitis C virus infection. Patients with treated
             non-replicative disease are acceptable.

          -  Positivity for coronavirus disease 2019 (COVID-19) by naso-pharyngeal swab test. Known
             serologic conversion is not an exclusion criterion.

          -  Evidence of hepatic cirrhosis with Child-Pugh score C.

          -  Any other diseases, metabolic dysfunction, physical examination finding, or clinical
             laboratory finding > Grade 2 that give reasonable suspicion of a disease or condition
             that would contraindicate the use of an investigational drug.

          -  Major surgery or significant traumatic injury <28 days prior to the first ANV419
             infusion (excluding biopsies) or anticipation of the need for major surgery during
             study treatment.

          -  Severe altered mental status.

          -  Pregnant or breastfeeding women.

          -  Known hypersensitivity to any of the components of ANV419 or its formulation.

          -  Concurrent therapy with any other investigational drug within one month prior to Day 1
             of study drug administration.

          -  Active untreated immune-related endocrinopathies untreatable with replacement. Prior
             immune related toxicities > Grade 3 after treatment with immunostimulatory drugs
             (e.g., colitis, neuropathy) that have not completely resolved.

          -  Chronic treatment with systemic immunosuppressive medications above 10 mg/day
             prednisolone equivalent for any reason