Inclusion Criteria:

          1. Signed, written informed consent.

          2. Age ≥18 years.

          3. Diagnosis of solid cancer that has been completely resected, NED, and eligible for
             observation only as SOC yet remain at risk of relapse per Investigator discretion.
             These include subjects diagnosed with malignant melanoma, non-small cell lung cancer,
             bladder cancer, colorectal cancer, breast cancer, renal cancer, head and neck cancer,
             cervical cancer, and soft tissue sarcoma.

          4. Life expectancy ≥12 months from the time of consent.

          5. Available fresh tissue from surgical excision. If fresh tissue is not available,
             formalin-fixed paraffin-embedded archival tissue may be used. The modality of the
             biopsy (e.g., endobronchial ultrasound, bronchoscopic, computed-tomography-guided
             needle biopsy) is not specified; however, core biopsy and fine needle aspiration are
             acceptable as long as the biopsy can be prepared as a cell block in paraffin-embedded
             tissue.

          6. Eastern Cooperative Oncology Group (ECOG) performance status 0 or 1.

          7. Adequate bone marrow function, as measured from studies of peripheral blood (absolute
             neutrophil count ≥1,500/mm3, absolute lymphocyte count ≥500/mm3, platelet count
             50,000/mm3, hemoglobin >8.0 mg/dL).

          8. Adequate cardiac function (New York Heart Association class ≤II).

          9. Female subjects of childbearing potential must have a negative serum pregnancy test at
             the screening and pretreatment visits, and prior to first dose of study medication.
             Non-childbearing potential (other than by medical reasons) is defined as 1 of the
             following:

               1. ≥45 years of age and amenorrheic for >1 year by self-report.

               2. Amenorrheic for >2 years without a hysterectomy and oophorectomy, and
                  follicle-stimulating hormone value in the postmenopausal range upon screening
                  evaluation.

               3. Status post-hysterectomy, -oophorectomy, or -tubal ligation. If of childbearing
                  potential, female subjects must be willing to use adequate birth control during
                  the study, starting with the screening visit through 120 days after the last dose
                  of study therapy.

             Male subjects with a female partner(s) of childbearing potential must agree to use a
             condom throughout the trial, starting with the screening visit through 120 days after
             the last dose of study therapy. Male subjects with pregnant partners must agree to use
             a condom; no additional method of contraception is required for the pregnant partner.

             Note: Abstinence is acceptable for both female and male subjects if this is the
             subject's established and preferred contraception method.

         10. Subject is willing and able to comply with the requirements of the protocol.

        Exclusion Criteria:

          1. Subjects must not have received anticancer medications or investigational drugs within
             the following intervals before first dose of study drug:

               1. ≤14 days for chemotherapy, targeted small molecule therapy, anticancer hormone
                  therapy, or radiation therapy, with the following exceptions:

                    -  Bisphosphonates and denosumab are permitted.

                    -  Novel imaging agents that have Phase 1 safety data and have not demonstrated
                       therapeutic activity are permitted.

                    -  Physiologic steroid replacement for adrenal insufficiency (e.g., <10 mg
                       prednisone per day) is permitted.

                    -  Prophylactic use of inhaled or topical corticosteroid or short course of
                       intravenous systemic corticosteroid (≤3 days) for radiographic procedures is
                       permitted.

                    -  Use of physiologic corticosteroid replacement therapy must be approved by
                       the medical monitor.

               2. ≤28 days for prior cancer immunotherapy.

               3. ≤28 days for prior monoclonal antibody used for anticancer therapy, with the
                  exception of denosumab.

               4. ≤7 days for immunosuppressive treatment for any reason. Systemic corticosteroids
                  are not allowed except as defined above.

               5. e. ≤28 days before first dose of study drug for all other investigational study
                  drugs or devices.

             Note: Washout is applicable to the screening visit only, and not applicable prior to
             the first dose of study drug. Subjects are not to receive anti-cancer therapies from
             date of consent through the post treatment visit (end of treatment or final safety
             visit).

          2. Diagnosis of clinically significant immunodeficiency (as defined by the principal
             investigator), or actively receiving or potentially needing any form of
             immunosuppressive therapy within 7 days prior to the first dose of study drug until
             the end of the trial.

          3. History or current evidence of any condition, therapy, or laboratory abnormality that
             might confound the results of the trial, interfere with the subject's participation
             for the full duration of the trial, or is not in the best interest of the subject to
             participate, in the opinion of the treating investigator or medical monitor.

          4. Uncontrolled intercurrent illness, including but not limited to uncontrolled
             infection, symptomatic congestive heart failure, unstable angina pectoris,
             uncontrolled cardiac arrhythmia, or social situations that would limit compliance with
             study requirements in the opinion of the treating investigator or medical monitor.

          5. History of intolerance or allergic reactions attributed to compounds of similar
             chemical or biologic composition to AGEN2017 or QS-21 adjuvant.

          6. Women who are pregnant or breastfeeding.