Patent ID: 8530629

Claim:
An isolated modified OKT3 antibody or antigen binding fragment thereof comprising: a light chain comprising: a light chain Complementary Determining Region (L-CDR)1, a L-CDR2, and a L-CDR3, wherein L-CDR1, L-CDR2 and L-CDR3 are parental OKT3 antibody L-CDR1, L-CDR2 and L-CDR3, respectively; and a heavy chain comprising: a heavy chain Complementary Determining Region (H-CDR)1, a H-CDR2, and a H-CDR3, wherein i) H-CDR1 has the amino acid sequence set forth as SEQ ID NO.: 2, and H-CDR2 and H-CDR3 are parental OKT3 antibody H-CDR2 and H-CDR3, respectively, or ii) H-CDR2 has the amino acid sequence set forth as SEQ ID NO.: 4, and H-CDR1 and H-CDR3 are parental OKT3 antibody H-CDR1 and H-CDR3, respectively, or iii) H-CDR2 has the amino acid sequence set forth as SEQ ID NO.: 5, and H-CDR1 and H-CDR3 are parental OKT3 antibody H-CDR1 and H-CDR3, respectively, or iv) H-CDR3 has the amino acid sequence set forth as SEQ ID NO.: 7, and H-CDR1 and H-CDR2 are parental OKT3 antibody H-CDR1 and H-CDR2, respectively, or v) H-CDR3 has the amino acid sequence set forth as SEQ ID NO.: 8, and H-CDR1 and H-CDR2 are parental OKT3 antibody H-CDR1 and H-CDR2, respectively, and wherein the entire framework region of the modified OKT3 antibody or antigen binding fragment thereof is identical to that of parental OKT3 antibody.