A Multiple-dose Study of ASP8374, an Immune Checkpoint Inhibitor, as a Single Agent and in Combination With Pembrolizumab in Subjects With Advanced Solid Tumors

Study Summary

The primary purpose of this study is to evaluate the tolerability and safety profile of ASP8374 when administered as a single agent and in combination with pembrolizumab in participants with locally advanced (unresectable) or metastatic solid tumor malignancies. Also primary purpose is to characterize the pharmacokinetic profile of ASP8374 when administered as a single agent and in combination with pembrolizumab. Last primary purpose of this study is to determine the recommended Phase 2 dose (RP2D) of ASP8374 when administered as a single agent and in combination with pembrolizumab. The secondary purpose of this study is to evaluate the anti-tumor effect (objective response rate \[ORR\], duration of response \[DOR\], persistence of response after discontinuation, and disease control rate \[DCR\]) of ASP8374 when administered as a single agent and in combination with pembrolizumab. NTP: Neutropenia NHAE:Non-haematological AE GBS: Guillain-Barré syndrome"" IRR: Infusion-related reaction AST: Aspartate aminotransferase ALT: Alanine aminotransferase MS/MG: Myasthenia Syndrome/Myasthenia Gravis TRT: Treatment-related Toxicity TCP: Thrombocytopenia

Primary Outcome

DLT was defined as any of the following AE that cannot clearly attribute to a cause other than study drug: Grade (Gr) 4 NTP or Gr ≥ 3 febrile NTP Gr 4 TCP; or Gr 3 TCP accompanied by bleeding that required any transfusion Gr 4 anemia or Gr 3 anemia requiring transfusion Gr ≥ 3 NHAE Gr ≥ 2 pneumonitis Gr ≥ 2 encephalopathy, meningitis, or motor or sensory neuropathy AST or ALT \> 5x upper limit of normal (ULN; Gr ≥ 3) without liver metastases AST or ALT \> 8 x ULN in participants with liver meta

Interventions

• DRUG Pembrolizumab
• DRUG ASP8374