Inclusion Criteria:

          1. ≥18 years of age inclusive, at the time of signing the informed consent

          2. Eastern Cooperative Oncology Group (ECOG) performance status of 0 to 1

          3. Patients with histologically or cytologically confirmed advanced or metastatic
             melanoma (histologically confirmed, unresectable Stage III or IV melanoma),
             mesothelioma or ocular/uveal melanoma

        Exclusion Criteria:

          1. Inability to swallow food or any condition of the upper gastrointestinal tract that
             precludes administration of oral medications

          2. Have prior significant medical history and adverse events (AEs):

               1. History of a prior Grade 3 or 4 immune-related AE (irAE) or any grade ocular irAE
                  from prior immunotherapy

               2. Active autoimmune process (e.g., rheumatoid arthritis, moderate or severe
                  psoriasis, multiple sclerosis, inflammatory bowel disease) (i.e., use of
                  disease-modifying agents, corticosteroids, or immunosuppressive drugs).
                  Replacement therapy (e.g., thyroxine, insulin, or physiologic corticosteroid
                  replacement therapy for adrenal or pituitary insufficiency, etc) is not
                  considered a form of systemic treatment

               3. Known active central nervous system (CNS) metastases and/or carcinomatous
                  meningitis Note: Patients with previously treated brain metastases may
                  participate provided they are stable (without evidence of progression by imaging
                  for at least 4 weeks before the first dose of study treatment and any neurologic
                  symptoms have returned to baseline), have no evidence of new or enlarging brain
                  metastases, and have not required steroids for at least 7 days before study
                  treatment

               4. History or presence of an abnormal electrocardiogram (ECG) that, in the
                  Investigator's opinion, is clinically meaningful. Screening QTc interval > 480
                  milliseconds is excluded (corrected by Fridericia). In the event that a single
                  QTc is > 480 milliseconds, the patient may enrol if the average QTc for the 3
                  ECGs is < 480 milliseconds. For patients with an intraventricular conduction
                  delay (QRS interval > 120 msec), the JTc interval may be used in place of the QTc
                  with Sponsor approval. The JTc must be < 340 milliseconds if JTc is used in place
                  of the QTc. Patients with left bundle branch block are excluded Note: QTc
                  prolongation due to pacemaker may enrol if the JT is normal or with Medical
                  Monitor approval

               5. Evidence of interstitial lung disease or active, non-infectious pneumonitis

               6. Active infection requiring systemic therapy

               7. Known additional malignancy that is progressing or requires active treatment
                  Patients with active malignancy requiring concurrent intervention or previous
                  malignancies (except non-melanoma skin cancers, and the following in situ
                  cancers: bladder, gastric, colon, endometrial, cervical/dysplasia, melanoma or
                  breast) unless a complete remission was achieved at least 2 years prior to study
                  entry and no additional therapy is required during the study period.

               8. Any serious or uncontrolled medical disorder or active infection that, in the
                  opinion of the Investigator, may increase the risk associated with study
                  participation, study drug administration, or would impair the ability of the
                  patient to receive protocol therapy

          3. Treatment with anticancer medications, investigational drugs, surgery and/or radiation
             within the following interval before the first administration of study drug:

               1. < 14 days for chemotherapy, targeted small-molecule therapy, surgical resection
                  of lesions or radiation therapy (prior palliative radiotherapy must have been
                  completed at least 14 days prior to study drug administration). Patients must
                  also not require corticosteroids and must not have had pneumonitis as a result of
                  treatment. A 1-week washout is permitted for palliative radiation to non-CNS
                  disease with Sponsor approval Note: The use of denosumab is permitted

               2. < 14 days for a prior PD-1 pathway-targeted agent

               3. < 28 days for prior monoclonal antibody used for anticancer therapy with the
                  exception of PD-1 pathway-targeted agents

               4. < 28 days or 5 half-lives (whichever is longer) before the first dose for all
                  other investigational study drugs or devices. For investigational agents with
                  long half-lives (e.g., > 5 days), enrolment before the fifth half-life requires
                  Medical Monitor approval