Inclusion Criteria:

          -  Histological diagnosis of locally advanced (primary or recurrent) or metastatic solid
             tumors that are not amenable for treatment with curative intent as follows:

               1. Metastatic pancreatic ductal adenocarcinoma; or

               2. Phase 2 only: Stage IIIb/IV NSCLC or other advanced solid tumors with documented
                  positive KRAS or NRAS mutation as determined using a validated test performed in
                  a CAP/CLIA-certified laboratory (or other comparable local or regional
                  certification).

          -  Have had disease progression during or following at least 1 and not more than 2 prior
             lines of treatment for advanced or metastatic disease.

          -  Patients with NSCLC must have previously received treatment with an anti-PD-1 or
             anti-PD-L1 agent for advanced disease.

          -  Measurable disease as per RECIST v1.1 criteria.

          -  Provision of a baseline tumor sample.

          -  Age ≥18 years (Japanese patients must be ≥20 years old)

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

          -  Adequate bone marrow, renal and liver functions.

          -  Adequate cardiac function.

          -  Informed consent provided.

        Exclusion Criteria:

          -  Prior treatment with avelumab, a PARP inhibitor or MEK inhibitor.

          -  Prior systemic anti-cancer therapy within 2 weeks prior to study enrollment.

          -  Persisting toxicity related to prior therapy.

          -  Current use of immunosuppressive medication.

          -  Known history of immune-mediated colitis, inflammatory bowel disease, pneumonitis,
             pulmonary fibrosis, uveitis or iritis.

          -  Active or prior autoimmune disease that might deteriorate when receiving an
             immunostimulatory agent.

          -  Diagnosis of myelodysplastic syndrome (MDS).

          -  Known symptomatic brain metastases requiring steroids.

          -  Known history of testing positive for HIV or hepatitis.

          -  Clinically significant (ie, active) cardiovascular disease.

          -  History of thromboembolic or cerebrovascular events.

          -  Current or anticipated use of a P-gp inhibitor, inducer, or inhibitor of breast cancer
             resistance protein (BCRP)

          -  Uncontrolled hypertension.

          -  Concurrent neuromuscular disorder that is associated with the potential of elevated
             creatinine kinase.

          -  Known history of Gilbert's syndrome.

          -  History or current evidence of retinal degenerative disease, retinal vein occlusion
             (RVO) or current risk factors for RVO.

          -  Other acute or chronic medical or psychiatric condition.