An Open-label Dose Escalation/Expansion Trial to Evaluate the Safety and Anti-tumor Activity of TEV-56278 Alone or in Combination With Pembrolizumab in Participants With Advanced or Metastatic Solid Tumors

The primary objectives of this trial are to: * Characterize the safety and tolerability of TEV-56278 * Determine the Recommended Phase 2 Dose (RP2D) * Evaluate antitumor activity of TEV-56278 * Determine the safety and tolerability of TEV-56278 in combination with pembrolizumab * Determine a RP2D of TEV-56278 in combination with pembrolizumab The secondary objectives of this trial are to: * Characterize the serum pharmacokinetics of TEV-56278 * Evaluate the antitumor activity of TEV-56278 * Determine the safety and tolerability of TEV-56278 * Evaluate other measures of antitumor activity of TEV-56278 * Evaluate anti-tumor activity Participants will be treated up to 12 months with a follow-up period of up to 12 months after last infusion. The total duration of the trial will be up to 25 months for individual participants.

Inclusion Criteria: * Have an established histological diagnosis of selected solid tumor and must have received and progressed on established standard therapies or have been intolerant to such therapy or have been considered by the Investigator as ineligible for approved standard therapy * Have a life expectancy≥12 weeks at the time of the screening * Women of childbearing potential must agree to use highly effective methods of contraception for the course of the trial through 120 days after the last dose of trial medication * Males who are sexually active with women of childbearing potential must agree to use condoms and refrain from donating sperm for the course of the trial through 120 days after the last dose of trial medication NOTE- Additional criteria apply, please contact the investigator for more information Exclusion Criteria: * Has a history of systemic treatment therapy for cancer (including chemotherapy, immunotherapy, radiotherapy, or other investigational drug) or surgery within 4 weeks prior to baseline * Is currently receiving or has received hematopoietic colony-stimulating growth factors within 2 weeks before screening or transfusion support 4 weeks prior to screening * Has a diagnosis of immunodeficiency * Has active known autoimmune disease. * Has a history of or known active brain metastases and/or carcinomatous meningitis and/or leptomeningeal metastasis * Has active or uncontrolled serious infections requiring systemic therapy within 14 days prior to baseline * Has a history of clinically significant cardiovascular or cerebrovascular disease in previous 6 months prior to screening * Has evidence of clinically significant interstitial lung disease or active, noninfectious pneumonitis * Has a seizure disorder requiring therapy (such as steroids or antiepileptics) NOTE- Additional criteria apply, please contact the investigator for more information