A Study of XB628 in Participants With Recurrent Advanced or Metastatic Solid Tumors

Inclusion Criteria: * Eastern Cooperative Oncology Group (ECOG) performance status of 0 to 1. * Minimum life expectancy of ≥ 12 weeks. * Have a recurrent advanced or metastatic solid tumor that is histologically or cytologically confirmed. * Adequate organ and marrow function. * Not amenable to curative treatment with surgery or radiation. * Received at least 1 line of prior systemic anticancer therapy in the recurrent or metastatic setting. * Acceptable alternative therapy was received, refused, intolerable, or no longer effective. * Capable of understanding and complying with the protocol requirements and provide signed informed consent according to the protocol and local requirements. Exclusion Criteria * Primary brain tumors or known active brain metastases. * Major surgery (eg, gastrointestinal surgery, removal or biopsy of brain metastasis) within 4 weeks before the first dose of study treatment. * Received radiation therapy within 1 week before the first dose of study treatment or clinically relevant ongoing complications from prior radiation therapy. * Received prior therapy targeting NK cells (eg, monalizumab). * A woman of childbearing potential has a positive serum pregnancy test within 7 days prior to study treatment.