Inclusion Criteria (General Phase 1 and Phase 1b):

          1. Male or female patients aged ≥ 18 years

          2. Histologically or cytologically proven locally advanced or metastatic solid tumors,
             for which no standard therapy exists or standard therapy has failed among the
             following tumor types: melanoma, non-small cell lung cancer, small cell lung cancer,
             head and neck squamous cell, urothelial, gastric, esophageal, cervical,
             hepatocellular, merkel cell, cutaneous squamous cell carcinoma, renal cell,
             endometrial, triple-negative breast, ovarian, and prostate.

          3. ECOG performance status of 0 or 1

          4. Clinical or radiological evidence of disease

          5. Adequate hematological, hepatic and renal function

          6. Resolution of toxic effect(s) of prior anti-cancer therapy to ≤Grade 1 (Patients with
             ≤Grade 2 neuropathy, ≤Grade 2 endocrinopathy or ≤Grade 2 alopecia are exceptions)

          7. Effective contraception for women of child-bearing potential as defined by World
             Health Organization guidelines for 1 "highly effective" method or 2 "effective"
             methods

        Additional Phase 1 Monotherapy and Phase 1b Combination With Nivolumab Expansion Inclusion
        Criteria:

          1. Has one of the following tumor types: melanoma, non-small cell lung cancer, or triple
             negative breast cancer

          2. Agrees to undergo a pre-treatment biopsy and another biopsy while on treatment

        Expansion Inclusion Criteria specific to Melanoma:

          1. Histologically confirmed, unresectable Stage III or Stage IV melanoma, as specified in
             the American Joint Committee on Cancer staging system.

          2. Participants with ocular or uveal melanoma are ineligible.

          3. PD-L1 status must be documented if available.

          4. BRAF (V600) mutation status must be known. Both BRAF-mutated and wild type
             participants are permitted in this cohort.

          5. BRAF-mutated participants must have been treated with approved targeted therapies.

          6. Must have documented progressive or recurrent disease on or after discontinuation of
             anti-PD-(L)1 therapy (administered as monotherapy or as part of a combination) as per
             RECIST 1.1 criteria:

          7. Participants who received anti-PD-(L)1 in the adjuvant setting must have documented
             progressive or recurrent disease on or within 6 months of discontinuation of
             anti-PD-(L)1 therapy (administered as monotherapy or as part of a combination) as per
             RECIST 1.1 criteria.

        Expansion Inclusion Criteria specific to NSCLC:

          1. Histologically confirmed NSCLC meeting stage criteria for stage IIIB, stage IV, or
             recurrent disease.

          2. Participants must have recurrent or progressive disease during or after platinum
             doublet-based chemotherapy or at least two prior lines of systemic therapy for
             advanced or metastatic disease OR Must have recurrent or progressive disease within 6
             months after completing platinum-based chemotherapy for local disease.

          3. Participants must have received and progressed on or after anti-PD-(L)1 therapy, if
             available.

          4. Status for actionable mutations (e.g., EGFR, ALK, ROS1, RET, etc.) must be known (when
             testing is available as per country/region standard of care practices); participants
             with actionable mutations must have received and progressed on, have been intolerant
             to, or not be a candidate for, standard tyrosine kinase inhibitors (as available per
             country/region standard of care practices).

        Expansion Inclusion Criteria specific to TNBC:

          1. Histologically confirmed unresectable, locally advanced or metastatic triple negative
             breast cancer.PD-L1 status, HER2-negative, estrogen receptor-negative, and
             progesterone receptor-negative status must be evaluated by local institutions before
             enrolment per guidelines of the American Society of Clinical Oncology and the College
             of American Pathologists.

          2. Patients must not have received an anti PD-1/PD-L1 for the treatment of the metastatic
             disease, but the administration of an anti PD-1/PD-L1 in the adjuvant setting is
             acceptable.

          3. Patients must have received one line of chemotherapy for the treatment of their
             metastatic disease, and experience progression during or after that line of
             chemotherapy.

          4. Patients must have not received more than one line of chemotherapy for the treatment
             of their unresectable, recurrent or metastatic disease.

        Inclusion Criteria for Phase 2 (General)

          1. Male or female patients aged ≥ 18 years.

          2. ECOG performance status of 0 or 1

          3. Clinical or radiological evidence of measurable disease.

          4. Adequate hematological, hepatic and renal function.

          5. Resolution of toxic effect(s) of prior anti-cancer therapy to ≤Grade 1. (Patients with
             ≤Grade 2 neuropathy, ≤Grade 2 endocrinopathy or ≤Grade 2 alopecia are exceptions.)

          6. Participants must have received and progressed on or after anti-PD-(L)1 therapy.

          7. Effective contraception for women of child-bearing potential as defined by World
             Health Organization guidelines for 1 "highly effective" method or 2 "effective"
             methods

        Additional Inclusion Criteria for Phase 2 (Advanced Melanoma Patients)

          1. Participants who received anti-PD-(L)1 in the advanced/metastatic setting, must have
             documented progressive or recurrent disease on or within 3 months of discontinuation
             of anti-PD-(L)1 therapy

          2. Participants who received anti-PD-(L)1 in the adjuvant setting must have documented
             progressive or recurrent disease on or within 6 months of discontinuation of
             anti-PD-(L)1 therapy

          3. Disease progression was confirmed at least 4 weeks after the initial diagnosis of
             disease progression while receiving an anti PD-1 antibody.

          4. BRAF mutation status must be known and treated with approved targeted therapies.

          5. Received a BRAF inhibitor if the tumor carries a BRAF activating mutation and
             progressed after the last line of treatment.

          6. Participants with ocular or uveal melanoma are ineligible.

          7. Confirmation of radiographic progression on prior anti-PD-(L)1 therapy is required
             with a scan confirming progression at least 4 weeks after the initial progression

        Additional Inclusion Criteria for Phase 2 (Non-small Cell Lung Cancer)

          1. Participants must have recurrent or progressive disease during or after platinum
             doublet-based chemotherapy or at least two prior lines of systemic therapy for
             advanced or metastatic disease OR must have recurrent or progressive disease within 6
             months after completing platinum-based chemotherapy for local disease.

          2. Status for actionable mutations must be known; participants with actionable mutations
             must have received and progressed on, have been intolerant to, or not be a candidate
             for, standard tyrosine kinase inhibitors

        Exclusion Criteria for All Patients (All Phases)

          1. Prior treatment with rhIL2 or any recombinant long acting drug containing an IL2
             moiety.

          2. Concurrent anticancer treatment (with the exception of palliative bone directed
             radiotherapy), immune therapy, or cytokine therapy (except for erythropoietin), major
             surgery (excluding prior diagnostic biopsy), concurrent systemic therapy with steroids
             or other immunosuppressive agents, or use of any investigational drug within 28 days
             before the start of study treatment.

          3. Previous malignant disease other than the current target malignancy within the last 3
             years, with the exception of basal or squamous cell carcinoma of the skin, localized
             prostate cancer or cervical carcinoma in situ.

          4. Rapidly progressive disease.

          5. Any Grade 2 and higher neurological or pulmonary toxicity during a treatment with an
             anti-PD-1 or PD-L1 agent administered as a monotherapy.

          6. Active or history of central nervous system (CNS) metastases unless all of the
             following criteria are met:

               1. CNS lesions are asymptomatic and previously treated.

               2. Patient does not require ongoing steroid treatment daily for replacement for
                  adrenal insufficiency.

               3. Imaging demonstrates stability of disease 28 days from last treatment for CNS
                  metastases.

          7. Receipt of any organ transplantation, autologous or allogeneic stem-cell
             transplantation.

          8. Significant acute or chronic infections, or active or latent hepatitis B or active
             hepatitis C.

          9. Preexisting autoimmune disease needing treatment with systemic immunosuppressive
             agents for more than 28 days within the last 3 years, clinically relevant
             immunodeficiencies, or fever within 7 days of Day 1.

         10. Known severe hypersensitivity reactions to monoclonal antibodies and any history of
             anaphylaxis, or uncontrolled asthma

         11. Serious cardiac illness or medical conditions.

         12. History of life-threatening toxicity related to prior immune therapy except those that
             are unlikely to re-occur with standard countermeasures.