Key Inclusion Criteria:  Histologically or cytologically confirmed diagnosis of metastatic or locally advanced solid tumors for which no standard therapy exists or standard therapy has failed because of disease progression or unacceptable toxicities. Cohort 1 (colorectal cancer): a) CRC (including microsatellite instability-high [MSI-H] and microsatellite-stable [MSS]) regardless of RAS mutation. b) Disease progression within 3 months after last administration of approved standard therapies. c) Prior cytotoxic chemotherapy for metastatic disease include all the following agents: fluoropyrimidine, oxaliplatin, and irinotecan Adjuvant chemotherapy-based treatments count as prior therapy, as long as relapse had occurred within 6 months of completion of such therapies, prior anti-epidermal growth factor receptor (EGFR) therapy (cetuximab, panitumumab), anti-angiogenic therapy (bevacizumab, aflibercept, ramucirumab), regorafenib, and TAS-102 are allowed. d) No more than 5 prior therapies for metastatic disease. For participants who had disease recurrence within 6 months of completing adjuvant chemotherapy, the adjuvant regimen can be considered as 1 chemotherapy regimen for metastatic disease Cohort 2 (NSCLC): a) NSCLC without known EGFR, anaplastic lymphoma kinase (ALK), and ROS1 genomic tumor aberrations. b) No standard therapy exists or standard therapy has failed. c) No more than 3 prior therapies for metastatic disease  Key Exclusion Criteria:  Primary central nervous system (CNS) tumor (Phase 1), CNS metastasis, and/or carcinomatous meningitis. Participants with prior brain metastases treated at least 4 weeks before the first dose of EU101 that are clinically stable and do not require chronic corticosteroid treatment are allowed Received prior therapy with any anti-CD137 monoclonal antibody (mAb) or agent Major surgery requiring general anesthesia within 3 weeks before first dose of EU101 or still recovering from prior surgery History of allogeneic tissue or organ transplant Human immunodeficiency virus (HIV) infection Active hepatitis B virus or hepatitis C virus infection Current or history of interstitial lung disease, anaphylaxis, uncontrolled asthma, or pneumonitis that has required systemic corticosteroids  Other protocol defined Inclusion/Exclusion criteria may apply