- Email: [email protected]
Targeting Mutant KRAS for Immunogenic Cell Death Induction
Please cite this article in press as: Galluzzi, Targeting Mutant KRAS for Immunogenic Cell Death Induction, Trends in Pharmacological Sciences (2019), https://doi.org/10.1016/j.tips.2019.11.004
Trends in Pharmacological Sciences
Spotlight
Targeting Mutant KRAS for Immunogenic Cell Death Induction Lorenzo Galluzzi1,2,3,4,5,* Although somatic KRAS mutations are common in human tumors, no inhibitor of mutant KRAS was clinically available until recently. Canon and colleagues describe the ability of a clinically available KRASG12C inhibitor to drive immunogenic cancer cell death, thus constituting a promising combinatorial partner for immune checkpoint blockers.
KRAS proto-oncogene, GTPase (KRAS), physiologically operates as a transducer of mitogenic signals downstream of tyrosine kinase receptors by alternating between an active (GTP-bound) and an inactive (GDP-bound) state [1]. Among various signal transduction cascades, active KRAS drives mitogen-activated protein kinase (MAPK) signaling, de facto supporting cell survival and proliferation [1] (Figure 1). Somatic KRAS mutations that prevent the binding of GTPase-activating proteins, and hence lock KRAS in its active state, are common across a variety of human neoplasms [2]. In a fraction of cases, such KRAS mutations (e.g., the G12C substitution) are associated with so-called ‘oncogene addiction’ (i.e., a strict dependence of cancer cells on oncogenic alterations for survival) [3], which raised considerable interest in mutant KRAS as a potential therapeutic target. Until recently, however, only inhibitors of signal transducers that operate downstream of KRAS, such as B-Raf proto-oncogene, serine/threonine kinase (BRAF) and mitogen-activated protein kinase kinase 7 (MAPKK7, best known as MEK) have (successfully)
entered clinical development [4,5]. Conversely, small molecule inhibitors of mutant KRAS available until recently, such as the KRASG12C-selective agent ARS-1620 [3], were incompatible with clinical application (largely due to suboptimal potency as a consequence of limited target occupancy) [6]. Now, Canon and colleagues report on the first covalent inhibitor of KRASG12C amenable to clinical development, as they demonstrate the immunostimulatory effects of mutant KRAS blockage [7]. Upon identifying a series of novel acrylamide-based molecules that bind to a previously unexploited groove in KRASG12C that confers enhanced potency and selectivity, Canon and colleagues harnessed intensive screening and structure-based design to discover AMG 510 as a KRASG12C-targeting agent with improved target occupancy [7]. Accordingly, AMG 510 exhibited approximately tenfold potency as compared with ARS-1620 in a nucleotide-exchange assay with recombinant GDP-bound KRASG12C, and it was exquisitely specific for KRASG12C over wild type KRAS [7]. These superior pharmacological features supported the expedited initiation of a Phase I–II clinical trial, testing the safety, tolerability, pharmacokinetic, and efficacy of AMG 510 in patients with solid tumors bearing KRASG12C (Clinical Trial Number: NCT03600883). Alongside, Canon and collaborators embarked upon the preclinical characterization of AMG 510 in human and mouse tumors. AMG510 mediated robust antiproliferative effects against multiple human and mouse KRASG12Cexpressing cell lines, but not against cancer cells expressing wild type KRAS, KRASG12D, or KRASG12V, in vitro [7]. Along similar lines, AMG 510 efficiently reduced the growth of pancre-
atic MIA PaCa-2 T2 xenografts, pulmonary NCI-H358 xenografts, and colorectal patient-derived xenografts (all of which expressed KRASG12C), as it limited the phosphorylation of the KRAS signal transducer mitogen-activated protein kinase 1 (MAPK1, best known as ERK) in the tumor tissue (a marker of target engagement), starting from a dose of 3–10 mg/kg (depending on model). However, no disease clearance was observed in xenograft experiments. Conversely, the antineoplastic effects of AMG 510 against mouse colorectal carcinoma CT26 tumors engineered to express KRASG12C (instead of KRASG12D) established in immunocompetent syngeneic animals (manifesting at doses of 100–200 mg/kg) was associated with disease clearance in a fraction of animals (2/10 at the 100 mg/kg dose, 8/10 at the 200 mg/kg dose). These findings corroborated the potency and specificity of AMG 510 as they pointed to a potential involvement of the immune system in the activity of the drug. AMG 510 also performed well in combination with conventional chemotherapeutics and targeted anticancer agents that are commonly employed in the management of cancers bearing alterations in KRAS signaling, including the DNA-damaging drug carboplatin (which is commonly used in patients with lung tumors, a large fraction of which is characterized by KRAS mutations), as well as MEK inhibitors (which are approved by regulatory agencies for the treatment of melanomas, nonsmall cell lung carcinomas, and anaplastic thyroid carcinomas with BRAF mutations). In particular, AMG 510 effects were at least additive (if not synergistic) to the effects of carboplatin and the experimental MEK inhibitor PD0325901 against NCI-H358 xenografts growing in immunocompromised mice [7]. Moreover, administration of AMG
Trends in Pharmacological Sciences, -- 2019, Vol. --, No. --
1
Please cite this article in press as: Galluzzi, Targeting Mutant KRAS for Immunogenic Cell Death Induction, Trends in Pharmacological Sciences (2019), https://doi.org/10.1016/j.tips.2019.11.004
Trends in Pharmacological Sciences
Figure 1. Principles of KRAS Signaling. (A) Normally, KRAS cycles between an active (GTP-bound) and an inactive (GDP-bound) state, thanks to the activity of GDP-exchange factors (GEFs) and GTPase-activating proteins (GAPs), which ensure physiological signal transduction downstream of growth factor receptors. (B) Mutant variants of KRAS, including KRAS G12C, lose the ability to bind GAPs and hence are locked in an active state, de facto mediating potent oncogenic effects. Abbreviation: Pi, Inorganic phosphate.
510 to immunocompetent mice bearing syngeneic CT26 lesions was associated with improved tumor infiltration by immune effector cells, such as dendritic cells and proliferating CD8+ cytotoxic T lymphocytes, and hence could be successfully combined with immune checkpoint blockers (ICBs) specific for programmed cell death 1 (PDCD1, best known as PD-1), with a disease eradication rate of 90% in the AMG 510 + PD-1 blocker group (as compared with 10% in the AMG 510 group, and 20% in the PD1 blocker group) [7]. These findings suggest that AMG 510 causes a form of cell death culminating with the elicitation of anticancer immune responses that can be boosted by immune checkpoint blockage [8,9]. Finally, Canon and collaborators reported promising preliminary findings on the clinical activity of AMG 510. Specifically, they presented data on two patients with metastatic lung cancer receiving 180 mg and 360 mg AMG 510 in the context of a dose-escalation Phase I–II clinical study (Clinical Trial Number: NCT03600883), who exhibited extraordinary radiographic responses 6 weeks after initiation of 2
treatment, with decreases in tumor burden at different disease sites ranging from approximately –30% to complete eradication (–100%), in the absence of major toxicity [7]. Although preliminary, these findings support the clinical applicability of AMG 510.
preparation. The L.G. laboratory is supported by a Breakthrough Level 2 grant from the US Department of Defense (DoD), Breast Cancer Research Program (BRCP) (#BC180476P1), a startup grant from the Department of Radiation Oncology at Weill Cornell Medicine (New York, USA), industrial collaborations with Lytix (Oslo, Norway) and Phosplatin (New York, USA), and donations from Phosplatin (New York, USA), the Luke Heller TECPR2 Foundation (Boston, USA), and Sotio a.s. (Prague, Czech Republic).
Disclaimer Statement L.G. provides remunerated consulting to OmniSEQ (Buffalo, NY, USA), Astra Zeneca (Gaithersburg, MD, USA), Inzen (New York, NY, USA), Boehringer Ingelheim (Vienna, Austria), and the Luke Heller TECPR2 Foundation (Boston, MA, USA), and he is a member of the Scientific Advisory Committee of OmniSEQ (Buffalo, NY, USA). 1Department
In summary, AMG 510 stands out as the first KRASG12C inhibitor amenable to clinical development that combines targeted anticancer activity (reflecting the dependency of multiple malignant, but not normal, cell types on constitutive KRAS signaling for survival or proliferation) and immunogenic cell death induction (reflecting the activation of a cell death modality that is compatible with the initiation of anticancer immunity) [10]. As such, AMG 510 may represent a perfect combinatorial partner for ICB-based immunotherapy and clinical trials testing such combinations in patients with KRASG12C-expressing tumors are urgently awaited.
Acknowledgments I thank Ilio Vitale and Gwenola Manic (Italian Institute for Genomic Medicine, Candiolo, Italy) for help with figure
Trends in Pharmacological Sciences, -- 2019, Vol. --, No. --
of Radiation Oncology, Weill Cornell Medical College, New York, NY, USA
2Sandra
and Edward Meyer Cancer Center, New York, NY, USA
3Caryl
and Israel Englander Institute for Precision Medicine, New York, NY, USA
4Department
of Dermatology, Yale School of Medicine, New Haven, CT, USA
5Universite ´
de Paris, Paris, France
*Correspondence: [email protected] https://doi.org/10.1016/j.tips.2019.11.004 ª 2019 Elsevier Ltd. All rights reserved.
References 1. Simanshu, D.K. et al. (2017) RAS proteins and their regulators in human disease. Cell 170, 17–33 2. AACR Project GENIE Consortium (2017) AACR Project GENIE: powering precision medicine through an international consortium. Cancer Discov. 7, 818–831 3. Janes, M.R. et al. (2018) Targeting KRAS mutant cancers with a covalent G12Cspecific inhibitor. Cell 172, 578–589 4. Chapman, P.B. et al. (2011) Improved survival with vemurafenib in melanoma with BRAF
Please cite this article in press as: Galluzzi, Targeting Mutant KRAS for Immunogenic Cell Death Induction, Trends in Pharmacological Sciences (2019), https://doi.org/10.1016/j.tips.2019.11.004
Trends in Pharmacological Sciences
V600Emutation. N. Engl. J. Med. 364, 2507– 2516 5. Flaherty, K.T. et al. (2012) Improved survival with MEK inhibition in BRAFmutated melanoma. N. Engl. J. Med. 367, 107–114 6. Molina-Arcas, M. et al. (2019) Development of combination therapies to maximize the
impact of KRAS-G12C inhibitors in lung cancer. Sci. Transl. Med 11, eaaw7999 7. Canon, J. et al. (2019) The clinical KRAS(G12C) inhibitor AMG 510 drives anti-tumour immunity. Nature 575, 217–223 8. Humeau, J. et al. (2019) Gold standard assessment of immunogenic cell death in
oncological mouse models. Methods Mol. Biol. 1884, 297–315 9. Galluzzi, L. et al. (2018) Linking cellular stress responses to systemic homeostasis. Nat. Rev. Mol. Cell Biol. 19, 731–745 10. Galluzzi, L. et al. (2018) The hallmarks of successful anticancer immunotherapy. Sci. Transl. Med. 10, eaat7807
Trends in Pharmacological Sciences, -- 2019, Vol. --, No. --
3
Trends in Pharmacological Sciences
Spotlight
Targeting Mutant KRAS for Immunogenic Cell Death Induction Lorenzo Galluzzi1,2,3,4,5,* Although somatic KRAS mutations are common in human tumors, no inhibitor of mutant KRAS was clinically available until recently. Canon and colleagues describe the ability of a clinically available KRASG12C inhibitor to drive immunogenic cancer cell death, thus constituting a promising combinatorial partner for immune checkpoint blockers.
KRAS proto-oncogene, GTPase (KRAS), physiologically operates as a transducer of mitogenic signals downstream of tyrosine kinase receptors by alternating between an active (GTP-bound) and an inactive (GDP-bound) state [1]. Among various signal transduction cascades, active KRAS drives mitogen-activated protein kinase (MAPK) signaling, de facto supporting cell survival and proliferation [1] (Figure 1). Somatic KRAS mutations that prevent the binding of GTPase-activating proteins, and hence lock KRAS in its active state, are common across a variety of human neoplasms [2]. In a fraction of cases, such KRAS mutations (e.g., the G12C substitution) are associated with so-called ‘oncogene addiction’ (i.e., a strict dependence of cancer cells on oncogenic alterations for survival) [3], which raised considerable interest in mutant KRAS as a potential therapeutic target. Until recently, however, only inhibitors of signal transducers that operate downstream of KRAS, such as B-Raf proto-oncogene, serine/threonine kinase (BRAF) and mitogen-activated protein kinase kinase 7 (MAPKK7, best known as MEK) have (successfully)
entered clinical development [4,5]. Conversely, small molecule inhibitors of mutant KRAS available until recently, such as the KRASG12C-selective agent ARS-1620 [3], were incompatible with clinical application (largely due to suboptimal potency as a consequence of limited target occupancy) [6]. Now, Canon and colleagues report on the first covalent inhibitor of KRASG12C amenable to clinical development, as they demonstrate the immunostimulatory effects of mutant KRAS blockage [7]. Upon identifying a series of novel acrylamide-based molecules that bind to a previously unexploited groove in KRASG12C that confers enhanced potency and selectivity, Canon and colleagues harnessed intensive screening and structure-based design to discover AMG 510 as a KRASG12C-targeting agent with improved target occupancy [7]. Accordingly, AMG 510 exhibited approximately tenfold potency as compared with ARS-1620 in a nucleotide-exchange assay with recombinant GDP-bound KRASG12C, and it was exquisitely specific for KRASG12C over wild type KRAS [7]. These superior pharmacological features supported the expedited initiation of a Phase I–II clinical trial, testing the safety, tolerability, pharmacokinetic, and efficacy of AMG 510 in patients with solid tumors bearing KRASG12C (Clinical Trial Number: NCT03600883). Alongside, Canon and collaborators embarked upon the preclinical characterization of AMG 510 in human and mouse tumors. AMG510 mediated robust antiproliferative effects against multiple human and mouse KRASG12Cexpressing cell lines, but not against cancer cells expressing wild type KRAS, KRASG12D, or KRASG12V, in vitro [7]. Along similar lines, AMG 510 efficiently reduced the growth of pancre-
atic MIA PaCa-2 T2 xenografts, pulmonary NCI-H358 xenografts, and colorectal patient-derived xenografts (all of which expressed KRASG12C), as it limited the phosphorylation of the KRAS signal transducer mitogen-activated protein kinase 1 (MAPK1, best known as ERK) in the tumor tissue (a marker of target engagement), starting from a dose of 3–10 mg/kg (depending on model). However, no disease clearance was observed in xenograft experiments. Conversely, the antineoplastic effects of AMG 510 against mouse colorectal carcinoma CT26 tumors engineered to express KRASG12C (instead of KRASG12D) established in immunocompetent syngeneic animals (manifesting at doses of 100–200 mg/kg) was associated with disease clearance in a fraction of animals (2/10 at the 100 mg/kg dose, 8/10 at the 200 mg/kg dose). These findings corroborated the potency and specificity of AMG 510 as they pointed to a potential involvement of the immune system in the activity of the drug. AMG 510 also performed well in combination with conventional chemotherapeutics and targeted anticancer agents that are commonly employed in the management of cancers bearing alterations in KRAS signaling, including the DNA-damaging drug carboplatin (which is commonly used in patients with lung tumors, a large fraction of which is characterized by KRAS mutations), as well as MEK inhibitors (which are approved by regulatory agencies for the treatment of melanomas, nonsmall cell lung carcinomas, and anaplastic thyroid carcinomas with BRAF mutations). In particular, AMG 510 effects were at least additive (if not synergistic) to the effects of carboplatin and the experimental MEK inhibitor PD0325901 against NCI-H358 xenografts growing in immunocompromised mice [7]. Moreover, administration of AMG
Trends in Pharmacological Sciences, -- 2019, Vol. --, No. --
1
Please cite this article in press as: Galluzzi, Targeting Mutant KRAS for Immunogenic Cell Death Induction, Trends in Pharmacological Sciences (2019), https://doi.org/10.1016/j.tips.2019.11.004
Trends in Pharmacological Sciences
Figure 1. Principles of KRAS Signaling. (A) Normally, KRAS cycles between an active (GTP-bound) and an inactive (GDP-bound) state, thanks to the activity of GDP-exchange factors (GEFs) and GTPase-activating proteins (GAPs), which ensure physiological signal transduction downstream of growth factor receptors. (B) Mutant variants of KRAS, including KRAS G12C, lose the ability to bind GAPs and hence are locked in an active state, de facto mediating potent oncogenic effects. Abbreviation: Pi, Inorganic phosphate.
510 to immunocompetent mice bearing syngeneic CT26 lesions was associated with improved tumor infiltration by immune effector cells, such as dendritic cells and proliferating CD8+ cytotoxic T lymphocytes, and hence could be successfully combined with immune checkpoint blockers (ICBs) specific for programmed cell death 1 (PDCD1, best known as PD-1), with a disease eradication rate of 90% in the AMG 510 + PD-1 blocker group (as compared with 10% in the AMG 510 group, and 20% in the PD1 blocker group) [7]. These findings suggest that AMG 510 causes a form of cell death culminating with the elicitation of anticancer immune responses that can be boosted by immune checkpoint blockage [8,9]. Finally, Canon and collaborators reported promising preliminary findings on the clinical activity of AMG 510. Specifically, they presented data on two patients with metastatic lung cancer receiving 180 mg and 360 mg AMG 510 in the context of a dose-escalation Phase I–II clinical study (Clinical Trial Number: NCT03600883), who exhibited extraordinary radiographic responses 6 weeks after initiation of 2
treatment, with decreases in tumor burden at different disease sites ranging from approximately –30% to complete eradication (–100%), in the absence of major toxicity [7]. Although preliminary, these findings support the clinical applicability of AMG 510.
preparation. The L.G. laboratory is supported by a Breakthrough Level 2 grant from the US Department of Defense (DoD), Breast Cancer Research Program (BRCP) (#BC180476P1), a startup grant from the Department of Radiation Oncology at Weill Cornell Medicine (New York, USA), industrial collaborations with Lytix (Oslo, Norway) and Phosplatin (New York, USA), and donations from Phosplatin (New York, USA), the Luke Heller TECPR2 Foundation (Boston, USA), and Sotio a.s. (Prague, Czech Republic).
Disclaimer Statement L.G. provides remunerated consulting to OmniSEQ (Buffalo, NY, USA), Astra Zeneca (Gaithersburg, MD, USA), Inzen (New York, NY, USA), Boehringer Ingelheim (Vienna, Austria), and the Luke Heller TECPR2 Foundation (Boston, MA, USA), and he is a member of the Scientific Advisory Committee of OmniSEQ (Buffalo, NY, USA). 1Department
In summary, AMG 510 stands out as the first KRASG12C inhibitor amenable to clinical development that combines targeted anticancer activity (reflecting the dependency of multiple malignant, but not normal, cell types on constitutive KRAS signaling for survival or proliferation) and immunogenic cell death induction (reflecting the activation of a cell death modality that is compatible with the initiation of anticancer immunity) [10]. As such, AMG 510 may represent a perfect combinatorial partner for ICB-based immunotherapy and clinical trials testing such combinations in patients with KRASG12C-expressing tumors are urgently awaited.
Acknowledgments I thank Ilio Vitale and Gwenola Manic (Italian Institute for Genomic Medicine, Candiolo, Italy) for help with figure
Trends in Pharmacological Sciences, -- 2019, Vol. --, No. --
of Radiation Oncology, Weill Cornell Medical College, New York, NY, USA
2Sandra
and Edward Meyer Cancer Center, New York, NY, USA
3Caryl
and Israel Englander Institute for Precision Medicine, New York, NY, USA
4Department
of Dermatology, Yale School of Medicine, New Haven, CT, USA
5Universite ´
de Paris, Paris, France
*Correspondence: [email protected] https://doi.org/10.1016/j.tips.2019.11.004 ª 2019 Elsevier Ltd. All rights reserved.
References 1. Simanshu, D.K. et al. (2017) RAS proteins and their regulators in human disease. Cell 170, 17–33 2. AACR Project GENIE Consortium (2017) AACR Project GENIE: powering precision medicine through an international consortium. Cancer Discov. 7, 818–831 3. Janes, M.R. et al. (2018) Targeting KRAS mutant cancers with a covalent G12Cspecific inhibitor. Cell 172, 578–589 4. Chapman, P.B. et al. (2011) Improved survival with vemurafenib in melanoma with BRAF
Please cite this article in press as: Galluzzi, Targeting Mutant KRAS for Immunogenic Cell Death Induction, Trends in Pharmacological Sciences (2019), https://doi.org/10.1016/j.tips.2019.11.004
Trends in Pharmacological Sciences
V600Emutation. N. Engl. J. Med. 364, 2507– 2516 5. Flaherty, K.T. et al. (2012) Improved survival with MEK inhibition in BRAFmutated melanoma. N. Engl. J. Med. 367, 107–114 6. Molina-Arcas, M. et al. (2019) Development of combination therapies to maximize the
impact of KRAS-G12C inhibitors in lung cancer. Sci. Transl. Med 11, eaaw7999 7. Canon, J. et al. (2019) The clinical KRAS(G12C) inhibitor AMG 510 drives anti-tumour immunity. Nature 575, 217–223 8. Humeau, J. et al. (2019) Gold standard assessment of immunogenic cell death in
oncological mouse models. Methods Mol. Biol. 1884, 297–315 9. Galluzzi, L. et al. (2018) Linking cellular stress responses to systemic homeostasis. Nat. Rev. Mol. Cell Biol. 19, 731–745 10. Galluzzi, L. et al. (2018) The hallmarks of successful anticancer immunotherapy. Sci. Transl. Med. 10, eaat7807
Trends in Pharmacological Sciences, -- 2019, Vol. --, No. --
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