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Dll4 blockade potentiates the anti-tumor effects of VEGF inhibition in renal cell carcinoma patient-derived xenografts.

Miles KM, Seshadri M, Ciamporcero E, Adelaiye R, Gillard B, Sotomayor P, Attwood K, Shen L, Conroy D, Kuhnert F, Lalani AS, Thurston G, Pili R - PLoS ONE (2014)

Bottom Line: Single agent treatment with REGN1035 resulted in significant tumor growth inhibition (36-62%) that was equivalent to or exceeded the single agent anti-tumor activity of the VEGF pathway inhibitors sunitinib (38-54%) and ziv-aflibercept (46%).Importantly, combination treatments with REGN1035 plus VEGF inhibitors resulted in enhanced anti-tumor effects (72-80% growth inhibition), including some tumor regression.Overall, these findings demonstrate the potent anti-tumor activity of Dll4 blockade in RCC patient-derived tumors and a combination benefit for the simultaneous targeting of the Dll4 and VEGF signaling pathways, highlighting the therapeutic potential of this treatment modality in RCC.

View Article: PubMed Central - PubMed

Affiliation: Genitourinary Program, Roswell Park Cancer Institute, Buffalo, New York, United States of America.

ABSTRACT

Background: The Notch ligand Delta-like 4 (Dll4) is highly expressed in vascular endothelium and has been shown to play a pivotal role in regulating tumor angiogenesis. Blockade of the Dll4-Notch pathway in preclinical cancer models has been associated with non-productive angiogenesis and reduced tumor growth. Given the cross-talk between the vascular endothelial growth factor (VEGF) and Delta-Notch pathways in tumor angiogenesis, we examined the activity of a function-blocking Dll4 antibody, REGN1035, alone and in combination with anti-VEGF therapy in renal cell carcinoma (RCC).

Methods and results: Severe combined immunodeficiency (SCID) mice bearing patient-derived clear cell RCC xenografts were treated with REGN1035 and in combination with the multi-targeted tyrosine kinase inhibitor sunitinib or the VEGF blocker ziv-aflibercept. Immunohistochemical and immunofluorescent analyses were carried out, as well as magnetic resonance imaging (MRI) examinations pre and 24 hours and 2 weeks post treatment. Single agent treatment with REGN1035 resulted in significant tumor growth inhibition (36-62%) that was equivalent to or exceeded the single agent anti-tumor activity of the VEGF pathway inhibitors sunitinib (38-54%) and ziv-aflibercept (46%). Importantly, combination treatments with REGN1035 plus VEGF inhibitors resulted in enhanced anti-tumor effects (72-80% growth inhibition), including some tumor regression. Magnetic resonance imaging showed a marked decrease in tumor perfusion in all treatment groups. Interestingly, anti-tumor efficacy of the combination of REGN1035 and ziv-aflibercept was also observed in a sunitinib resistant ccRCC model.

Conclusions: Overall, these findings demonstrate the potent anti-tumor activity of Dll4 blockade in RCC patient-derived tumors and a combination benefit for the simultaneous targeting of the Dll4 and VEGF signaling pathways, highlighting the therapeutic potential of this treatment modality in RCC.

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Effect of combined Dll4 blockade on RP-R-01 tumor and stromal cells.Mice were treated with vehicle, human Dll4-specific antibody REGN421 (10 mg/kg, 5x/wk, s.q.), mouse Dll4-specific antibody REGN1035 (5 mg/kg, 1x/wk, s.q.) or combination. (A) Tumor growth curve of treatment groups. Each line represents the average tumor volume (mm3) of each treatment group ± S.E. (B) Average end point tumor weights. *p<0.05, as compared to vehicle group; combination compared to single agents (REGN421, p = 0.160; REGN1035, p = 0.691) using adjusted t-test analysis.
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pone-0112371-g007: Effect of combined Dll4 blockade on RP-R-01 tumor and stromal cells.Mice were treated with vehicle, human Dll4-specific antibody REGN421 (10 mg/kg, 5x/wk, s.q.), mouse Dll4-specific antibody REGN1035 (5 mg/kg, 1x/wk, s.q.) or combination. (A) Tumor growth curve of treatment groups. Each line represents the average tumor volume (mm3) of each treatment group ± S.E. (B) Average end point tumor weights. *p<0.05, as compared to vehicle group; combination compared to single agents (REGN421, p = 0.160; REGN1035, p = 0.691) using adjusted t-test analysis.

Mentions: Species-specific Taqman RNA gene expression analysis was performed to determine the levels of Dll4 expression in the RP-R-01 model and to gain a better understanding of the anti-tumor mechanism of anti-Dll4 therapy. Mouse Dll4 was robustly expressed in the stroma of RP-R-01 tumors, consistent with the function of Dll4 as a critical regulator of tumor angiogenesis, whereas the levels of tumor-cell expressed Dll4 (human) were very low, at the limit of detection (Fig. S4). To determine the relative contributions of blocking stromal (mouse) Dll4 vs. Dll4 expressed by tumor cells (human) to the overall anti-tumor activity, we treated RP-R-01 tumor-bearing SCID mice with the human Dll4-specific monoclonal antibody REGN421 (enoticumab), the mouse Dll4-specific antibody REGN1035, or the combination. As shown in Figures 7A and 7B, treatment with human Dll4-specific REGN421 showed only marginal anti-tumor efficacy, with no significant differences observed from the vehicle treated group. The mouse Dll4-specific REGN1035 treatment, on the other hand, resulted in significant RP-R-01 tumor growth inhibition (67%, p<0.01), consistent with results shown in Figure 1. Combination treatment of anti-human and anti-mouse Dll4 antibodies did not result in enhanced anti-tumor effects compared to single agent administration of REGN1035. These results demonstrate that the anti-tumor activity of Dll4 blockade in the RP-R-01 RCC model is entirely dependent on targeting Dll4 in the tumor stroma as opposed to tumor cell-expressed Dll4, and furthermore highlights the lack of tumor growth-promoting autocrine Dll4-Notch tumor cell signaling in this model.


Dll4 blockade potentiates the anti-tumor effects of VEGF inhibition in renal cell carcinoma patient-derived xenografts.

Miles KM, Seshadri M, Ciamporcero E, Adelaiye R, Gillard B, Sotomayor P, Attwood K, Shen L, Conroy D, Kuhnert F, Lalani AS, Thurston G, Pili R - PLoS ONE (2014)

Effect of combined Dll4 blockade on RP-R-01 tumor and stromal cells.Mice were treated with vehicle, human Dll4-specific antibody REGN421 (10 mg/kg, 5x/wk, s.q.), mouse Dll4-specific antibody REGN1035 (5 mg/kg, 1x/wk, s.q.) or combination. (A) Tumor growth curve of treatment groups. Each line represents the average tumor volume (mm3) of each treatment group ± S.E. (B) Average end point tumor weights. *p<0.05, as compared to vehicle group; combination compared to single agents (REGN421, p = 0.160; REGN1035, p = 0.691) using adjusted t-test analysis.
© Copyright Policy
Related In: Results  -  Collection

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Show All Figures
getmorefigures.php?uid=PMC4231048&req=5

pone-0112371-g007: Effect of combined Dll4 blockade on RP-R-01 tumor and stromal cells.Mice were treated with vehicle, human Dll4-specific antibody REGN421 (10 mg/kg, 5x/wk, s.q.), mouse Dll4-specific antibody REGN1035 (5 mg/kg, 1x/wk, s.q.) or combination. (A) Tumor growth curve of treatment groups. Each line represents the average tumor volume (mm3) of each treatment group ± S.E. (B) Average end point tumor weights. *p<0.05, as compared to vehicle group; combination compared to single agents (REGN421, p = 0.160; REGN1035, p = 0.691) using adjusted t-test analysis.
Mentions: Species-specific Taqman RNA gene expression analysis was performed to determine the levels of Dll4 expression in the RP-R-01 model and to gain a better understanding of the anti-tumor mechanism of anti-Dll4 therapy. Mouse Dll4 was robustly expressed in the stroma of RP-R-01 tumors, consistent with the function of Dll4 as a critical regulator of tumor angiogenesis, whereas the levels of tumor-cell expressed Dll4 (human) were very low, at the limit of detection (Fig. S4). To determine the relative contributions of blocking stromal (mouse) Dll4 vs. Dll4 expressed by tumor cells (human) to the overall anti-tumor activity, we treated RP-R-01 tumor-bearing SCID mice with the human Dll4-specific monoclonal antibody REGN421 (enoticumab), the mouse Dll4-specific antibody REGN1035, or the combination. As shown in Figures 7A and 7B, treatment with human Dll4-specific REGN421 showed only marginal anti-tumor efficacy, with no significant differences observed from the vehicle treated group. The mouse Dll4-specific REGN1035 treatment, on the other hand, resulted in significant RP-R-01 tumor growth inhibition (67%, p<0.01), consistent with results shown in Figure 1. Combination treatment of anti-human and anti-mouse Dll4 antibodies did not result in enhanced anti-tumor effects compared to single agent administration of REGN1035. These results demonstrate that the anti-tumor activity of Dll4 blockade in the RP-R-01 RCC model is entirely dependent on targeting Dll4 in the tumor stroma as opposed to tumor cell-expressed Dll4, and furthermore highlights the lack of tumor growth-promoting autocrine Dll4-Notch tumor cell signaling in this model.

Bottom Line: Single agent treatment with REGN1035 resulted in significant tumor growth inhibition (36-62%) that was equivalent to or exceeded the single agent anti-tumor activity of the VEGF pathway inhibitors sunitinib (38-54%) and ziv-aflibercept (46%).Importantly, combination treatments with REGN1035 plus VEGF inhibitors resulted in enhanced anti-tumor effects (72-80% growth inhibition), including some tumor regression.Overall, these findings demonstrate the potent anti-tumor activity of Dll4 blockade in RCC patient-derived tumors and a combination benefit for the simultaneous targeting of the Dll4 and VEGF signaling pathways, highlighting the therapeutic potential of this treatment modality in RCC.

View Article: PubMed Central - PubMed

Affiliation: Genitourinary Program, Roswell Park Cancer Institute, Buffalo, New York, United States of America.

ABSTRACT

Background: The Notch ligand Delta-like 4 (Dll4) is highly expressed in vascular endothelium and has been shown to play a pivotal role in regulating tumor angiogenesis. Blockade of the Dll4-Notch pathway in preclinical cancer models has been associated with non-productive angiogenesis and reduced tumor growth. Given the cross-talk between the vascular endothelial growth factor (VEGF) and Delta-Notch pathways in tumor angiogenesis, we examined the activity of a function-blocking Dll4 antibody, REGN1035, alone and in combination with anti-VEGF therapy in renal cell carcinoma (RCC).

Methods and results: Severe combined immunodeficiency (SCID) mice bearing patient-derived clear cell RCC xenografts were treated with REGN1035 and in combination with the multi-targeted tyrosine kinase inhibitor sunitinib or the VEGF blocker ziv-aflibercept. Immunohistochemical and immunofluorescent analyses were carried out, as well as magnetic resonance imaging (MRI) examinations pre and 24 hours and 2 weeks post treatment. Single agent treatment with REGN1035 resulted in significant tumor growth inhibition (36-62%) that was equivalent to or exceeded the single agent anti-tumor activity of the VEGF pathway inhibitors sunitinib (38-54%) and ziv-aflibercept (46%). Importantly, combination treatments with REGN1035 plus VEGF inhibitors resulted in enhanced anti-tumor effects (72-80% growth inhibition), including some tumor regression. Magnetic resonance imaging showed a marked decrease in tumor perfusion in all treatment groups. Interestingly, anti-tumor efficacy of the combination of REGN1035 and ziv-aflibercept was also observed in a sunitinib resistant ccRCC model.

Conclusions: Overall, these findings demonstrate the potent anti-tumor activity of Dll4 blockade in RCC patient-derived tumors and a combination benefit for the simultaneous targeting of the Dll4 and VEGF signaling pathways, highlighting the therapeutic potential of this treatment modality in RCC.

Show MeSH
Related in: MedlinePlus