Safety, Tolerability and Pharmacokinetics of a Monoclonal Antibody Specific to B-and T-Lymphocyte Attenuator (BTLA) as Monotherapy and in Combination With an Anti-PD1 Monoclonal Antibody for Injection in Subjects With Advanced Malignancies

The primary objective is to assess the safety and tolerability of TAB004 as monotherapy and in combination with toripalimab in subjects with selected advanced solid malignancies, including lymphoma, and to evaluate the recommended Phase 2 dose. The secondary objectives are to: 1) describe the pharmacokinetic (PK) profile of TAB004 monotherapy and in combination with toripalimab and to describe the PK profile of toripalimab when administered with TAB004, 2) evaluate antitumor activity of TAB004 monotherapy and in combination with toripalimab; and 3) determine the immunogenicity of TAB004 monotherapy and in combination with toripalimab and to determine the immunogenicity of toripalimab when administered with TAB004. The exploratory objectives are to: 1) evaluate pharmacodynamic effects of TAB004 on its target receptor BTLA, as well as effects on the immune system; 2) evaluate biomarkers that may correlate with activity of TAB004 as monotherapy and in combination with toripalimab; 3) evaluate the utility of BTLA ligand, herpesvirus-entry mediator (HVEM), and additional exploratory biomarkers that could aid in selection of appropriate subjects for TAB004 monotherapy and in combination with toripalimab.