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Affinity Maturation of Monoclonal Antibody 1E11 by Targeted Randomization in CDR3 Regions Optimizes Therapeutic Antibody Targeting of HER2-Positive Gastric Cancer.

Ko BK, Choi S, Cui LG, Lee YH, Hwang IS, Kim KT, Shim H, Lee JS - PLoS ONE (2015)

Bottom Line: Milder selection pressure favored the selection of more diverse clones, whereas higher selection stringency resulted in the convergence of the panning output to a smaller number of clones with improved affinity.Clone 1A12 inhibited tumor growth of NCI-N87 xenograft model with similar efficacy to trastuzumab alone, and the combination treatment of 1A12 and trastuzumab completely removed the established tumors.These results suggest that humanized and affinity matured monoclonal antibody 1A12 is a highly optimized molecule for future therapeutic development against HER2-positive tumors.

View Article: PubMed Central - PubMed

Affiliation: Therapeutic antibody research center, AbClon Inc., Seoul, Korea.

ABSTRACT
Anti-HER2 murine monoclonal antibody 1E11 has strong and synergistic anti-tumor activity in HER2-overexpressing gastric cancer cells when used in combination with trastuzumab. We presently optimized this antibody for human therapeutics. First, the complementarity determining regions (CDRs) of the murine antibody were grafted onto human germline immunoglobulin variable genes. No difference in affinity and biological activity was observed between chimeric 1E11 (ch1E11) and humanized 1E11 (hz1E11). Next, affinity maturation of hz1E11 was performed by the randomization of CDR-L3 and H3 residues followed by stringent biopanning selection. Milder selection pressure favored the selection of more diverse clones, whereas higher selection stringency resulted in the convergence of the panning output to a smaller number of clones with improved affinity. Clone 1A12 had four amino acid substitutions in CDR-L3, and showed a 10-fold increase in affinity compared to the parental clone and increased potency in an in vitro anti-proliferative activity assay with HER2-overepxressing gastric cancer cells. Clone 1A12 inhibited tumor growth of NCI-N87 xenograft model with similar efficacy to trastuzumab alone, and the combination treatment of 1A12 and trastuzumab completely removed the established tumors. These results suggest that humanized and affinity matured monoclonal antibody 1A12 is a highly optimized molecule for future therapeutic development against HER2-positive tumors.

No MeSH data available.


Related in: MedlinePlus

Affinity-matured hz1E11 clones shows antitumor activity in HER2-overexpressing gastric cancer models.NCI-N87 cells (A) and OE-19 cells (B) were treated with antibodies for 4 days in the complete growth media. The cell viability was measured in duplicates (mean ± SD) using WST-1 reagent. The 100% viability was defined as the viability of the antibody-untreated wells. C, NCI-N87 (n = 5 mice/group) cells were inoculated into mice and antibody treatments started when tumor volumes reached approximately 200 mm3. Mice received a dose of 20 mg/kg for single agent treatment and 10 mg/kg of each antibody for combination treatment. Administration days are indicated by arrows. Tumor volume (mm3) was expressed as the mean ± SD. For clarity, only positive error bars are shown.
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pone.0134600.g005: Affinity-matured hz1E11 clones shows antitumor activity in HER2-overexpressing gastric cancer models.NCI-N87 cells (A) and OE-19 cells (B) were treated with antibodies for 4 days in the complete growth media. The cell viability was measured in duplicates (mean ± SD) using WST-1 reagent. The 100% viability was defined as the viability of the antibody-untreated wells. C, NCI-N87 (n = 5 mice/group) cells were inoculated into mice and antibody treatments started when tumor volumes reached approximately 200 mm3. Mice received a dose of 20 mg/kg for single agent treatment and 10 mg/kg of each antibody for combination treatment. Administration days are indicated by arrows. Tumor volume (mm3) was expressed as the mean ± SD. For clarity, only positive error bars are shown.

Mentions: Both 1A12 and 1F11 antibodies showed slightly increased anti-proliferative activities as a single agent compared to hz1E11 on NCI-N87 and OE-19 gastric cancer cell lines that overexpress HER2 (Fig 5A and 5B), whereas in combination with trastuzumab, their anti-proliferative activities was superior to that trastuzumab alone and equivalent to hz1E11 plus trastuzumab. The anti-proliferative activity of 1A12 and 1F11 was confirmed in vivo in NCI-N87 xenograft model. Superior antitumor activity was evident in combination with trastuzumab to that of each agent alone in both xenograft models (Fig 5C).


Affinity Maturation of Monoclonal Antibody 1E11 by Targeted Randomization in CDR3 Regions Optimizes Therapeutic Antibody Targeting of HER2-Positive Gastric Cancer.

Ko BK, Choi S, Cui LG, Lee YH, Hwang IS, Kim KT, Shim H, Lee JS - PLoS ONE (2015)

Affinity-matured hz1E11 clones shows antitumor activity in HER2-overexpressing gastric cancer models.NCI-N87 cells (A) and OE-19 cells (B) were treated with antibodies for 4 days in the complete growth media. The cell viability was measured in duplicates (mean ± SD) using WST-1 reagent. The 100% viability was defined as the viability of the antibody-untreated wells. C, NCI-N87 (n = 5 mice/group) cells were inoculated into mice and antibody treatments started when tumor volumes reached approximately 200 mm3. Mice received a dose of 20 mg/kg for single agent treatment and 10 mg/kg of each antibody for combination treatment. Administration days are indicated by arrows. Tumor volume (mm3) was expressed as the mean ± SD. For clarity, only positive error bars are shown.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4520604&req=5

pone.0134600.g005: Affinity-matured hz1E11 clones shows antitumor activity in HER2-overexpressing gastric cancer models.NCI-N87 cells (A) and OE-19 cells (B) were treated with antibodies for 4 days in the complete growth media. The cell viability was measured in duplicates (mean ± SD) using WST-1 reagent. The 100% viability was defined as the viability of the antibody-untreated wells. C, NCI-N87 (n = 5 mice/group) cells were inoculated into mice and antibody treatments started when tumor volumes reached approximately 200 mm3. Mice received a dose of 20 mg/kg for single agent treatment and 10 mg/kg of each antibody for combination treatment. Administration days are indicated by arrows. Tumor volume (mm3) was expressed as the mean ± SD. For clarity, only positive error bars are shown.
Mentions: Both 1A12 and 1F11 antibodies showed slightly increased anti-proliferative activities as a single agent compared to hz1E11 on NCI-N87 and OE-19 gastric cancer cell lines that overexpress HER2 (Fig 5A and 5B), whereas in combination with trastuzumab, their anti-proliferative activities was superior to that trastuzumab alone and equivalent to hz1E11 plus trastuzumab. The anti-proliferative activity of 1A12 and 1F11 was confirmed in vivo in NCI-N87 xenograft model. Superior antitumor activity was evident in combination with trastuzumab to that of each agent alone in both xenograft models (Fig 5C).

Bottom Line: Milder selection pressure favored the selection of more diverse clones, whereas higher selection stringency resulted in the convergence of the panning output to a smaller number of clones with improved affinity.Clone 1A12 inhibited tumor growth of NCI-N87 xenograft model with similar efficacy to trastuzumab alone, and the combination treatment of 1A12 and trastuzumab completely removed the established tumors.These results suggest that humanized and affinity matured monoclonal antibody 1A12 is a highly optimized molecule for future therapeutic development against HER2-positive tumors.

View Article: PubMed Central - PubMed

Affiliation: Therapeutic antibody research center, AbClon Inc., Seoul, Korea.

ABSTRACT
Anti-HER2 murine monoclonal antibody 1E11 has strong and synergistic anti-tumor activity in HER2-overexpressing gastric cancer cells when used in combination with trastuzumab. We presently optimized this antibody for human therapeutics. First, the complementarity determining regions (CDRs) of the murine antibody were grafted onto human germline immunoglobulin variable genes. No difference in affinity and biological activity was observed between chimeric 1E11 (ch1E11) and humanized 1E11 (hz1E11). Next, affinity maturation of hz1E11 was performed by the randomization of CDR-L3 and H3 residues followed by stringent biopanning selection. Milder selection pressure favored the selection of more diverse clones, whereas higher selection stringency resulted in the convergence of the panning output to a smaller number of clones with improved affinity. Clone 1A12 had four amino acid substitutions in CDR-L3, and showed a 10-fold increase in affinity compared to the parental clone and increased potency in an in vitro anti-proliferative activity assay with HER2-overepxressing gastric cancer cells. Clone 1A12 inhibited tumor growth of NCI-N87 xenograft model with similar efficacy to trastuzumab alone, and the combination treatment of 1A12 and trastuzumab completely removed the established tumors. These results suggest that humanized and affinity matured monoclonal antibody 1A12 is a highly optimized molecule for future therapeutic development against HER2-positive tumors.

No MeSH data available.


Related in: MedlinePlus