Humanized anti-HLA-DR antibodies
The present invention concerns compositions and methods of use of humanized anti-HLA-DR antibodies. In preferred embodiments, the antibodies induce apoptosis and inhibit proliferation of lymphoma cells without inducing CDC or ADCC. In more preferred embodiments, the humanized anti-HLA-DR antibodies bind to the same epitope of HLA-DR as, or compete for binding to HLA-DR with, a murine L243 antibody. Most preferably, the humanized anti-HLA-DR antibody exhibits a higher affinity for HLA-DR than the parental murine antibody. The humanized HLA-DR antibody is of use for therapy of various diseases such as cancer, autoimmune disease or immune dysregulatory function, and is of particular use for therapy of B cell lymphomas and leukemias. In most preferred embodiments, the humanized anti-HLA-DR antibody is capable of inducing at least partial remission of lymphomas that are resistant to other B cell antibodies, such as rituximab.
1. A method of delivering a therapeutic or diagnostic agent to an HLA-DR positive cell comprising:
a) obtaining an immunoconjugate comprising (i) a humanized anti-HLA-DR antibody or antigen-binding fragment thereof comprising the heavy chain complementarity determining region (CDR) sequences CDR1 (NYGMN, SEQ ID NO: 39), CDR2(WINTYTREPTYADDFKG, SEQ ID NO: 40), and CDR3 (DITAVVPTGFDY, SEQ ID NO: 41) and the light chain CDR sequences CDR1 (RASENIYSNLA, SEQ ID NO: 42), CDR2 (AASNLAD, SEQ ID NO: 43), and CDR3 (QHFWTTPWA, SEQ ID NO: 44), conjugated to (ii) a therapeutic or diagnostic agent; and
b) exposing an HLA-DR positive cell to the immunoconjugate;
wherein the humanized antibody is an IgG4 antibody comprising a Ser241Pro mutation, further comprising light chain murine L243 FR residues R37, K39, V48, F49, and G100and heavy chain murine L243 FR residues F27, K38, K46, A68, and F91.
2. The method of claim 1 , wherein the humanized anti-HLA-DR antibody has a higher affinity for HLA-DR than a murine L243 antibody that comprises the heavy chain CDR sequences CDR1 (NYGMN, SEQ ID NO: 39), CDR2(WINTYTREPTYADDFKG, SEQ ID NO: 40), and CDR3 (DITAVVPTGFDY, SEQ ID NO: 41) and the light chain CDR sequences CDR1 (RASENIYSNLA, SEQ ID NO: 42), CDR2 (AASNLAD, SEQ ID NO: 43), and CDR3 (QHFWTTPWA, SEQ ID NO: 44).
3. The method of claim 1 , wherein the therapeutic agent is selected from the group consisting of a drug, a toxin, an enzyme, a radionuclide, an immunomodulator, a cytokine, a hormone, a antibody or fragment thereof, an anti-angiogenic agent, a cytotoxic agent, a pro-apoptosis agent, and a photodynamic agent.
4. The method of claim 3 , wherein the toxin is selected from the group consisting of ricin, abrin, alpha toxin, saporin, ribonuclease (RNase), DNase I, Staphylococcal enterotoxin-A, pokeweed antiviral protein, gelonin, diphtheria toxin, Pseudomonas exotoxin and Pseudomonas endotoxin.
5. The method of claim 3 , wherein the radionuclide is selected from the group consisting of 18 F, 32 P, 33 P, 45 Ti, 47 Sc, 52 Fe, 59 Fe, 62 Cu, 64 Cu, 67 Cu, 67 Ga, 68 Ga, 75 Se, 77 As, 86 Y, 89 Sr, 89 Zr, 90 Y, 94 Tc, 94m Tc, 99 Mo, 99m Tc, 105 Pd, 105 Rh, 111 Ag, 111 In, 123 I, 124 I, 125 I, 131 I, 142 Pr, 143 Pr, 149 Pm, 153 Sm, 154-158 Gd, 161 Tb, 166 Dy, 166 Ho, 169 r, 175 Lu, 177 Lu, 186 Re, 188 Re, 189 Re, 194 Ir, 198 Au, 199 Au, 211 At, 211 Pb, 212 Bi, 212 Pb, 213 Bi, 223 Ra, 225 Ac, and an alpha-emitting radionuclide.
6. The method of claim 1 , wherein the diagnostic agent is selected from the group consisting of a radionuclide, a radiological contrast agent, a paramagnetic ion, a metal, a fluorescent label, an ultrasound contrast agent and a photoactive agent.
7. The method of claim 6 , wherein the diagnostic agent is a radionuclide selected from the group consisting of 18 F, 52 Fe, 62 Cu, 64 Cu, 67 Cu, 67 Ga, 68 Ga, 86 Y, 89 Zr, 94 Tc, 94m Tc, 99m Tc, 111 In, 123 I, 124 I, 125 I, and 131 I.