Study of YH004 (4-1BB Agonist Antibody) in Advanced or Metastatic Malignancy

This is an open-label, non-randomized, two-stage, FIH Phase 1 study, utilizing an accelerated dose escalation followed by a traditional 3 + 3 dose escalation algorithm to identify the MTD and/or RP2D of YH004 as a single agent (monotherapy) and in combination with Toripalimab. The first stage of the study is the dose escalation phase (i.e., Phase 1a). The second stage of the study is the dose expansion phase (i.e., Phase 1b). During the study, dose interruption(s) and/or delay(s) may be implemented based on toxicity. Dose modifications are permitted following protocol guidelines. Intra-patient dose escalations will be allowed for the early dose cohorts (single-patient dose groups) in Phase 1a. Patients will be considered evaluable for safety and tolerability if they receive at least one dose of YH004 or Toripalimab at the specified cohort dose. Patients in all parts of the trial will remain on therapy until confirmed disease progression or for 1 year, whichever occurs first. However, patients who are clinically unstable will discontinue following the initial assessment of disease progression.