A humanized antibody molecule capable of binding to human Lymphocyte Activation Gene-3 (LAG-3) with a dissociation constant (K D) of less than 0.2 nM as determined by a Biacore method, comprising: (a) a heavy chain variable region comprising a VHCDR1 amino acid sequence of SEQ ID NO: 4, a VHCDR2 amino acid sequence of SEQ ID NO: 5, and a VHCDR3 amino acid sequence of SEQ ID NO: 3; and a light chain variable region comprising a VLCDR1 amino acid sequence of SEQ ID NO: 13, a VLCDR2 amino acid sequence of SEQ ID NO: 14, and a VLCDR3 amino acid sequence of SEQ ID NO: 15; (b) a VH comprising a VHCDR1 amino acid sequence of SEQ ID NO: 1; a VHCDR2 amino acid sequence of SEQ ID NO: 2; and a VHCDR3 amino acid sequence of SEQ ID NO: 3; and a VL comprising a VLCDR1 amino acid sequence of SEQ ID NO: 10, a VLCDR2 amino acid sequence of SEQ ID NO: 11, and a VLCDR3 amino acid sequence of SEQ ID NO: 12; (c) a VH comprising a VHCDR1 amino acid sequence of SEQ ID NO: 286, a VHCDR2 amino acid sequence of SEQ ID NO: 5, and a VHCDR3 amino acid sequence of SEQ ID NO: 3; and a VL comprising a VLCDR1 amino acid sequence of SEQ ID NO: 13, a VLCDR2 amino acid sequence of SEQ ID NO: 14, and a VLCDR3 amino acid sequence of SEQ ID NO: 15; or (d) a VH comprising a VHCDR1 amino acid sequence of SEQ ID NO: 286; a VHCDR2 amino acid sequence of SEQ ID NO: 2; and a VHCDR3 amino acid sequence of SEQ ID NO: 3; and a VL comprising a VLCDR1 amino acid sequence of SEQ ID NO: 10, a VLCDR2 amino acid sequence of SEQ ID NO: 11, and a VLCDR3 amino acid sequence of SEQ ID NO: 12; wherein the VH comprises four framework regions: a VHFW1 comprising the amino acid sequence of SEQ ID NO: 187, 190, 194 or 196, a VHFW2 comprising the amino acid sequence of SEQ ID NO: 198, 202, 206 or 208, a VHFW3 comprising the amino acid sequence of SEQ ID NO: 210, 212, 217 or 219, and a VHFW4 comprising the amino acid sequence of SEQ ID NO: 221; and the VL comprises four framework regions: a VLFW1 comprising the amino acid sequence of SEQ ID NO: 226, 230, 232, 234, 236 or 238, a VLFW2 comprising the amino acid sequence of SEQ ID NO: 240, 244, 246 or 248, a VLFW3 comprising the amino acid sequence of SEQ ID NO: 252, 255, 259, 261, 265, 267 or 269, and a VLFW4 comprising the amino acid sequence of SEQ ID NO: 271. (a) a heavy chain variable region comprising a VHCDR1 amino acid sequence of SEQ ID NO: 4, a VHCDR2 amino acid sequence of SEQ ID NO: 5, and a VHCDR3 amino acid sequence of SEQ ID NO: 3; and a light chain variable region comprising a VLCDR1 amino acid sequence of SEQ ID NO: 13, a VLCDR2 amino acid sequence of SEQ ID NO: 14, and a VLCDR3 amino acid sequence of SEQ ID NO: 15; (b) a VH comprising a VHCDR1 amino acid sequence of SEQ ID NO: 1; a VHCDR2 amino acid sequence of SEQ ID NO: 2; and a VHCDR3 amino acid sequence of SEQ ID NO: 3; and a VL comprising a VLCDR1 amino acid sequence of SEQ ID NO: 10, a VLCDR2 amino acid sequence of SEQ ID NO: 11, and a VLCDR3 amino acid sequence of SEQ ID NO: 12; (c) a VH comprising a VHCDR1 amino acid sequence of SEQ ID NO: 286, a VHCDR2 amino acid sequence of SEQ ID NO: 5, and a VHCDR3 amino acid sequence of SEQ ID NO: 3; and a VL comprising a VLCDR1 amino acid sequence of SEQ ID NO: 13, a VLCDR2 amino acid sequence of SEQ ID NO: 14, and a VLCDR3 amino acid sequence of SEQ ID NO: 15; or (d) a VH comprising a VHCDR1 amino acid sequence of SEQ ID NO: 286; a VHCDR2 amino acid sequence of SEQ ID NO: 2; and a VHCDR3 amino acid sequence of SEQ ID NO: 3; and a VL comprising a VLCDR1 amino acid sequence of SEQ ID NO: 10, a VLCDR2 amino acid sequence of SEQ ID NO: 11, and a VLCDR3 amino acid sequence of SEQ ID NO: 12;