The present invention provides methods of treating cancer in a human in need thereof comprising administering to the human: a therapeutically effective amount of a monoclonal antibody that binds to human OX40 comprising: (a) a heavy chain variable region CDR1 comprising the amino acid sequence of SEQ ID NO:1； (b) a heavy chain variable region CDR2 comprising the amino acid sequence of SEQ ID NO:2； (c) a heavy chain variable region CDR3 comprising the amino acid sequence of SEQ ID NO:3； (d) a light chain variable region CDR1 comprising the amino acid sequence of SEQ ID NO:7； (e) a light chain variable region CDR2 comprising the amino acid sequence of SEQ ID NO:8； and (f) a light chain variable region CDR3 comprising the amino acid sequence of SEQ ID NO:9； and a therapeutically effective amount of a monoclonal antibody that binds to human PD- 1 comprising: (a) a heavy chain variable region CDR1 comprising the amino acid sequence of SEQ ID NO:54； (b) a heavy chain variable region CDR2 comprising the amino acid sequence of SEQ ID NO:55； (c) a heavy chain variable region CDR3 comprising the amino acid sequence of SEQ ID NO:56； (d) a light chain variable region CDR1 comprising the amino acid sequence of SEQ ID NO:57； (e) a light chain variable region CDR2 comprising the amino acid sequence of SEQ ID NO:58； and (f) a light chain variable region CDR3 comprising the amino acid sequence of SEQ ID NO:59.
