Limits...
Cergutuzumab amunaleukin (CEA-IL2v), a CEA-targeted IL-2 variant-based immunocytokine for combination cancer immunotherapy: Overcoming limitations of aldesleukin and conventional IL-2-based immunocytokines

View Article: PubMed Central - PubMed

ABSTRACT

We developed cergutuzumab amunaleukin (CEA-IL2v, RG7813), a novel monomeric CEA-targeted immunocytokine, that comprises a single IL-2 variant (IL2v) moiety with abolished CD25 binding, fused to the C-terminus of a high affinity, bivalent carcinoembryonic antigen (CEA)-specific antibody devoid of Fc-mediated effector functions. Its molecular design aims to (i) avoid preferential activation of regulatory T-cells vs. immune effector cells by removing CD25 binding; (ii) increase the therapeutic index of IL-2 therapy by (a) preferential retention at the tumor by having a lower dissociation rate from CEA-expressing cancer cells vs. IL-2R-expressing cells, (b) avoiding any FcγR-binding and Fc effector functions and (c) reduced binding to endothelial cells expressing CD25; and (iii) improve the pharmacokinetics, and thus convenience of administration, of IL-2. The crystal structure of the IL2v-IL-2Rβγ complex was determined and CEA-IL2v activity was assessed using human immune effector cells. Tumor targeting was investigated in tumor-bearing mice using 89Zr-labeled CEA-IL2v. Efficacy studies were performed in (a) syngeneic mouse models as monotherapy and combined with anti-PD-L1, and in (b) xenograft mouse models in combination with ADCC-mediating antibodies. CEA-IL2v binds to CEA with pM avidity but not to CD25, and consequently did not preferentially activate Tregs. In vivo, CEA-IL2v demonstrated superior pharmacokinetics and tumor targeting compared with a wild-type IL-2-based CEA immunocytokine (CEA-IL2wt). CEA-IL2v strongly expanded NK and CD8+ T cells, skewing the CD8+:CD4+ ratio toward CD8+ T cells both in the periphery and in the tumor, and mediated single agent efficacy in syngeneic MC38-CEA and PancO2-CEA models. Combination with trastuzumab, cetuximab and imgatuzumab, all of human IgG1 isotype, resulted in superior efficacy compared with the monotherapies alone. Combined with anti-PD-L1, CEA-IL2v mediated superior efficacy over the respective monotherapies, and over the combination with an untargeted control immunocytokine. These preclinical data support the ongoing clinical investigation of the cergutuzumab amunaleukin immunocytokine with abolished CD25 binding for the treatment of CEA-positive solid tumors in combination with PD-L1 checkpoint blockade and ADCC competent antibodies.

No MeSH data available.


Related in: MedlinePlus

Immuno-pharmacodynamics in tumor-free and tumor-bearing C57BL/6 mice: (A) Peripheral T and NK cell expansion by CEA-IL2v. Shown are lymphocytes in blood 7 d after a single i.v. dose of CEA-IL2v. (B) Increase in the numbers of circulating (per μL blood) and intratumoral (per g tissue) CD8+ T cells, γδ T cells and NK cells in LLC1-CEA syngeneic tumor model 5 d after injection of 0.5 or 2 mg/kg muCEA-IL2v as determined by flow cytometry (upper panels). A skewing of the T cell compartment in favor of CD8+ T cells as shown by the ratio of CD8+ T to total CD4+ T and Treg in the blood and tumors of LLC1-CEA tumor-bearing mice (lower panels). (C) Increase of CD3 T cells in LLC1-CEA syngeneic tumor model 5 d after injection of 1.0 mg/kg CEA-IL2v as determined by immunohistochemistry.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC5384349&req=5

f0004: Immuno-pharmacodynamics in tumor-free and tumor-bearing C57BL/6 mice: (A) Peripheral T and NK cell expansion by CEA-IL2v. Shown are lymphocytes in blood 7 d after a single i.v. dose of CEA-IL2v. (B) Increase in the numbers of circulating (per μL blood) and intratumoral (per g tissue) CD8+ T cells, γδ T cells and NK cells in LLC1-CEA syngeneic tumor model 5 d after injection of 0.5 or 2 mg/kg muCEA-IL2v as determined by flow cytometry (upper panels). A skewing of the T cell compartment in favor of CD8+ T cells as shown by the ratio of CD8+ T to total CD4+ T and Treg in the blood and tumors of LLC1-CEA tumor-bearing mice (lower panels). (C) Increase of CD3 T cells in LLC1-CEA syngeneic tumor model 5 d after injection of 1.0 mg/kg CEA-IL2v as determined by immunohistochemistry.

Mentions: In tumor-free mice, a strong expansion of peripheral CD8+ T and NK cells after treatment with 0.5 and 2 mg/kg CEA-IL2v was observed (Fig. 4A). A more detailed analysis using different doses of CEA-IL2v showed that after an initial and rapid drop in cell numbers, putatively a re-distribution phenomenon, CD8+, γδ T cells and NKp46+ NK cells underwent a strong expansion in the blood that peaked around days 4 to 7, and returned to baseline levels ca. 2 weeks post treatment (Fig. S6A). The increase in cell numbers was accompanied by a corresponding increase in the expression of the proliferation marker Ki67 (Fig. S6B). As total CD4+ T cell numbers did not significantly change, the preferential expansion of the CD8+ T cells skewed the T cell compartment in favor of this subset (Fig. S6B). These data are in line with experiments using IL-2-antibody complexes that no longer interact with CD25 and caused a strong preferential expansion of CD8+ T-memory over CD4+ T cells.41Figure 4.


Cergutuzumab amunaleukin (CEA-IL2v), a CEA-targeted IL-2 variant-based immunocytokine for combination cancer immunotherapy: Overcoming limitations of aldesleukin and conventional IL-2-based immunocytokines
Immuno-pharmacodynamics in tumor-free and tumor-bearing C57BL/6 mice: (A) Peripheral T and NK cell expansion by CEA-IL2v. Shown are lymphocytes in blood 7 d after a single i.v. dose of CEA-IL2v. (B) Increase in the numbers of circulating (per μL blood) and intratumoral (per g tissue) CD8+ T cells, γδ T cells and NK cells in LLC1-CEA syngeneic tumor model 5 d after injection of 0.5 or 2 mg/kg muCEA-IL2v as determined by flow cytometry (upper panels). A skewing of the T cell compartment in favor of CD8+ T cells as shown by the ratio of CD8+ T to total CD4+ T and Treg in the blood and tumors of LLC1-CEA tumor-bearing mice (lower panels). (C) Increase of CD3 T cells in LLC1-CEA syngeneic tumor model 5 d after injection of 1.0 mg/kg CEA-IL2v as determined by immunohistochemistry.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC5384349&req=5

f0004: Immuno-pharmacodynamics in tumor-free and tumor-bearing C57BL/6 mice: (A) Peripheral T and NK cell expansion by CEA-IL2v. Shown are lymphocytes in blood 7 d after a single i.v. dose of CEA-IL2v. (B) Increase in the numbers of circulating (per μL blood) and intratumoral (per g tissue) CD8+ T cells, γδ T cells and NK cells in LLC1-CEA syngeneic tumor model 5 d after injection of 0.5 or 2 mg/kg muCEA-IL2v as determined by flow cytometry (upper panels). A skewing of the T cell compartment in favor of CD8+ T cells as shown by the ratio of CD8+ T to total CD4+ T and Treg in the blood and tumors of LLC1-CEA tumor-bearing mice (lower panels). (C) Increase of CD3 T cells in LLC1-CEA syngeneic tumor model 5 d after injection of 1.0 mg/kg CEA-IL2v as determined by immunohistochemistry.
Mentions: In tumor-free mice, a strong expansion of peripheral CD8+ T and NK cells after treatment with 0.5 and 2 mg/kg CEA-IL2v was observed (Fig. 4A). A more detailed analysis using different doses of CEA-IL2v showed that after an initial and rapid drop in cell numbers, putatively a re-distribution phenomenon, CD8+, γδ T cells and NKp46+ NK cells underwent a strong expansion in the blood that peaked around days 4 to 7, and returned to baseline levels ca. 2 weeks post treatment (Fig. S6A). The increase in cell numbers was accompanied by a corresponding increase in the expression of the proliferation marker Ki67 (Fig. S6B). As total CD4+ T cell numbers did not significantly change, the preferential expansion of the CD8+ T cells skewed the T cell compartment in favor of this subset (Fig. S6B). These data are in line with experiments using IL-2-antibody complexes that no longer interact with CD25 and caused a strong preferential expansion of CD8+ T-memory over CD4+ T cells.41Figure 4.

View Article: PubMed Central - PubMed

ABSTRACT

We developed cergutuzumab amunaleukin (CEA-IL2v, RG7813), a novel monomeric CEA-targeted immunocytokine, that comprises a single IL-2 variant (IL2v) moiety with abolished CD25 binding, fused to the C-terminus of a high affinity, bivalent carcinoembryonic antigen (CEA)-specific antibody devoid of Fc-mediated effector functions. Its molecular design aims to (i) avoid preferential activation of regulatory T-cells vs. immune effector cells by removing CD25 binding; (ii) increase the therapeutic index of IL-2 therapy by (a) preferential retention at the tumor by having a lower dissociation rate from CEA-expressing cancer cells vs. IL-2R-expressing cells, (b) avoiding any FcγR-binding and Fc effector functions and (c) reduced binding to endothelial cells expressing CD25; and (iii) improve the pharmacokinetics, and thus convenience of administration, of IL-2. The crystal structure of the IL2v-IL-2Rβγ complex was determined and CEA-IL2v activity was assessed using human immune effector cells. Tumor targeting was investigated in tumor-bearing mice using 89Zr-labeled CEA-IL2v. Efficacy studies were performed in (a) syngeneic mouse models as monotherapy and combined with anti-PD-L1, and in (b) xenograft mouse models in combination with ADCC-mediating antibodies. CEA-IL2v binds to CEA with pM avidity but not to CD25, and consequently did not preferentially activate Tregs. In vivo, CEA-IL2v demonstrated superior pharmacokinetics and tumor targeting compared with a wild-type IL-2-based CEA immunocytokine (CEA-IL2wt). CEA-IL2v strongly expanded NK and CD8+ T cells, skewing the CD8+:CD4+ ratio toward CD8+ T cells both in the periphery and in the tumor, and mediated single agent efficacy in syngeneic MC38-CEA and PancO2-CEA models. Combination with trastuzumab, cetuximab and imgatuzumab, all of human IgG1 isotype, resulted in superior efficacy compared with the monotherapies alone. Combined with anti-PD-L1, CEA-IL2v mediated superior efficacy over the respective monotherapies, and over the combination with an untargeted control immunocytokine. These preclinical data support the ongoing clinical investigation of the cergutuzumab amunaleukin immunocytokine with abolished CD25 binding for the treatment of CEA-positive solid tumors in combination with PD-L1 checkpoint blockade and ADCC competent antibodies.

No MeSH data available.


Related in: MedlinePlus