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Squicciarini T, Villani R, Apollonio B, Fucci L, Zambetti M, Rossini M, Pinto R, Tommasi S, De Roma I, Strippoli S, Guida M. Case report: Is severe toxicity the price to pay for high sensitivity to checkpoint inhibitors immunotherapy in desmoplastic melanoma? Front Immunol 2024; 15:1369531. [PMID: 38799429 PMCID: PMC11117064 DOI: 10.3389/fimmu.2024.1369531] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2024] [Accepted: 04/23/2024] [Indexed: 05/29/2024] Open
Abstract
Background Desmoplastic melanoma (DM) is a rare subtype of melanoma characterized by high immunogenicity which makes it particularly suitable for immune checkpoint inhibitors (ICIs) treatment. Case presentation We report the case of a 53-year-old man with metastatic DM successfully treated with the combination of anti-CTLA-4 and anti-PD-1 antibodies, who developed serious immune-related adverse events (irAEs). The primary tumor was characterized by absent PD-L1 expression and no-brisk lymphocytes infiltration. NGS showed absence of BRAF mutation, a high tumor mutational burden, and an UV-induced DNA damage signature. Metastatic lesions regressed rapidly after few cycles of ICIs until complete response, however the patient developed serious irAEs including hypothyroidism, adrenal deficiency, and acute interstitial nephritis which led to the definitive suspension of treatment. Currently, the patient has normal renal functionality and no disease relapse after 26 months from starting immunotherapy, and after 9 months from its definitive suspension. Conclusion Efficacy and toxicity are two sides of the same coin of high sensitivity to ICIs in DM. For this reason, these patients should be closely monitored during ICIs therapy to promptly identify serious side effects and to correctly manage them.
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Affiliation(s)
- Teresa Squicciarini
- Rare Tumors and Melanoma Unit, IRCCS Istituto Tumori Giovanni Paolo II, Bari, Italy
| | - Rossella Villani
- Rare Tumors and Melanoma Unit, IRCCS Istituto Tumori Giovanni Paolo II, Bari, Italy
| | - Benedetta Apollonio
- Rare Tumors and Melanoma Unit, IRCCS Istituto Tumori Giovanni Paolo II, Bari, Italy
| | - Livia Fucci
- Pathology Unit, IRCCS Istituto Tumori Giovanni Paolo II, Bari, Italy
| | - Milena Zambetti
- Pathology Unit, IRCCS Istituto Tumori Giovanni Paolo II, Bari, Italy
| | - Michele Rossini
- Nephrology, Dialysis and Transplantation, Department of Precision and Regenerative Medicine and Ionian Area, University of Bari, Bari, Italy
| | - Rosamaria Pinto
- Molecular Diagnostics and Pharmacogenetics Unit, IRCCS Istituto Tumouri “Giovanni Paolo II”, Bari, Italy
| | - Stefania Tommasi
- Molecular Diagnostics and Pharmacogenetics Unit, IRCCS Istituto Tumouri “Giovanni Paolo II”, Bari, Italy
| | - Ileana De Roma
- Rare Tumors and Melanoma Unit, IRCCS Istituto Tumori Giovanni Paolo II, Bari, Italy
| | - Sabino Strippoli
- Rare Tumors and Melanoma Unit, IRCCS Istituto Tumori Giovanni Paolo II, Bari, Italy
| | - Michele Guida
- Rare Tumors and Melanoma Unit, IRCCS Istituto Tumori Giovanni Paolo II, Bari, Italy
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Fetter T, Fietz S, Bertlich M, Braegelmann C, de Vos-Hillebrand L, Wenzel J, Heine A, Landsberg J, Jansen P. Severe autoimmune hemolytic anemia following immunotherapy with checkpoint inhibitors in two patients with metastatic melanoma: a case report. Front Immunol 2024; 15:1342845. [PMID: 38571955 PMCID: PMC10987708 DOI: 10.3389/fimmu.2024.1342845] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Accepted: 02/27/2024] [Indexed: 04/05/2024] Open
Abstract
Introduction Over the past decade, immune checkpoint inhibitors such as antibodies against cytotoxicity T-lymphocyte-associated protein 4 (CTLA-4) and programmed cell death protein 1 (PD-1) have become an important armamentarium against a broad spectrum of malignancies. However, these specific inhibitors can cause adverse autoimmune reactions by impairing self-tolerance. Hematologic side effects of immune checkpoint inhibitors, including autoimmune hemolytic anemia (AIHA), are rare but can be life-threatening. Case report Herein, we report two patients on immune checkpoint inhibitors for metastatic melanoma who developed AIHA with symptoms of dyspnea and fatigue. In the first patient, symptoms alleviated after discontinuation of combined anti CTLA-4 and anti-PD-1 therapy, initiation of corticosteroids and application of a single red blood cell transfusion. Due to subsequent progress of melanoma, combinational anti-PD-1 and tyrosine kinase inhibitor therapy was initiated based on multidisciplinary tumor board decision. After two months, she again developed the described hematological and clinical signs of AIHA leading to cessation of anti-PD-1 therapy and initiation of corticosteroids, which again resulted in an alleviation of her symptoms. Due to further progression, the patient received dacarbazine for several months before she decided to stop any therapy other than palliative supportive care. In the second patient, discontinuation of anti-PD-1 therapy and initiation of corticosteroids entailed a complete alleviation of his symptoms. After refusing chemotherapy due to subsequent melanoma progression, he received radiotherapy of bone metastases and is currently enrolled in a clinical trial. The patient did not develop AIHA ever since. Conclusion Hematologic immune-related adverse events due to treatment with immune checkpoint inhibitors are rare but can have life-threatening consequences. If dyspnea and other clinical symptoms are present, AIHA should be considered as a potential cause and treated promptly in a multidisciplinary setting. An expanded comprehension of risk factors and pathogenesis of AIHA is needed to identify high-risk patients beforehand, leading to more effective predictive and reactive treatment approaches.
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Affiliation(s)
- Tanja Fetter
- Center of Dermatooncology and Phlebology, University Hospital Bonn, Bonn, Germany
| | - Simon Fietz
- Center of Dermatooncology and Phlebology, University Hospital Bonn, Bonn, Germany
| | - Maya Bertlich
- Center of Dermatooncology and Phlebology, University Hospital Bonn, Bonn, Germany
| | | | | | - Joerg Wenzel
- Center of Dermatooncology and Phlebology, University Hospital Bonn, Bonn, Germany
| | - Annkristin Heine
- Department of Oncology, Hematology and Rheumatology, University Hospital Bonn, Bonn, Germany
| | - Jennifer Landsberg
- Center of Dermatooncology and Phlebology, University Hospital Bonn, Bonn, Germany
| | - Philipp Jansen
- Center of Dermatooncology and Phlebology, University Hospital Bonn, Bonn, Germany
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Kleef R, Nagy R, Baierl A, Bacher V, Bojar H, McKee DL, Moss R, Thoennissen NH, Szász M, Bakacs T. Low-dose ipilimumab plus nivolumab combined with IL-2 and hyperthermia in cancer patients with advanced disease: exploratory findings of a case series of 131 stage IV cancers - a retrospective study of a single institution. Cancer Immunol Immunother 2020; 70:1393-1403. [PMID: 33151369 PMCID: PMC8053148 DOI: 10.1007/s00262-020-02751-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2020] [Accepted: 10/14/2020] [Indexed: 02/07/2023]
Abstract
The 3-year overall survival (OS) rate of patients with previously treated or untreated stage III or IV melanoma has by now reached 63% using ipilimumab and nivolumab therapy. However, immune-related adverse events (irAEs) of grade 3 or 4 occurred in 59% of patients leading to discontinuation of therapy in 24.5% of patients and one death. Therapy with checkpoint inhibitors could be safer and more effective in combination with hyperthermia and fever inducing therapies. We conducted a retrospective analysis to test the safety and efficacy of a new combination immune therapy in 131 unselected stage IV solid cancer patients with 23 different histological types of cancer who exhausted all conventional treatments. Treatment consisted of locoregional- and whole-body hyperthermia, individually dose adapted interleukin 2 (IL-2) combined with low-dose ipilimumab (0.3 mg/kg) plus nivolumab (0.5 mg/kg). The objective response rate (ORR) was 31.3%, progression-free survival (PFS) was 10 months, survival probabilities at 6 months was 86.7% (95% CI, 81.0–92.8%), at 9 months was 73.5% (95% CI, 66.2–81.7%), at 12 months was 66.5% (95% CI, 58.6–75.4%), while at 24 months survival was 36.6% (95% CI:28.2%; 47.3%). irAEs of World Health Organization (WHO) Toxicity Scale grade 1, 2, 3, and 4 were observed in 23.66%, 16.03%, 6.11%, and 2.29% of patients, respectively. Our results suggest that the irAEs profile of the combined treatment is safer than that of the established protocols without compromising efficacy.
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Affiliation(s)
- R Kleef
- Immunology and Integrative Oncology, Auhofstraße 1, 1130, Vienna, Austria
| | - R Nagy
- Immunology and Integrative Oncology, Auhofstraße 1, 1130, Vienna, Austria
| | - A Baierl
- Department of Statistic and Operations Research, University of Vienna, Oskar-Morgenstern-Platz 1, 1090, Vienna, Austria
| | - V Bacher
- Immunology and Integrative Oncology, Auhofstraße 1, 1130, Vienna, Austria
| | - H Bojar
- NextGen Oncology, Dusseldorf, Germany
| | - D L McKee
- Integrative Cancer Consulting, Aptos, CA, USA
| | - R Moss
- Moss Reports, 104 Main Street, Unit 1422, Blue Hill, ME, 04614-1422, USA
| | - N H Thoennissen
- Oncology Center at Lenbachplatz, Ottostr. 3, 80333, Munich, Germany
| | - M Szász
- Cancer Centre, Semmelweis University, 1083, Budapest, Hungary
| | - T Bakacs
- PRET Therapeutics Ltd, 1124, Budapest, Hungary.
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Bakacs T, Moss RW, Kleef R, Szasz MA, Anderson CC. Exploiting autoimmunity unleashed by low-dose immune checkpoint blockade to treat advanced cancer. Scand J Immunol 2019; 90:e12821. [PMID: 31589347 DOI: 10.1111/sji.12821] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Revised: 07/31/2019] [Accepted: 08/26/2019] [Indexed: 12/15/2022]
Abstract
As a result of the cancer immunotherapy revolution, more than 2000 immuno-oncology agents are currently being tested or are in use to improve responses. Not unexpectedly, the 2018 Nobel Prize in Physiology or Medicine was awarded to James P. Allison and Tasuku Honjo for their development of cancer therapy by the blockade of co-inhibitory signals. Unfortunately, manipulation of the co-inhibitory receptors has also resulted in a safety issue: widespread iatrogenic immune-related adverse events (irAEs). Autoimmunity is emerging as the nemesis of immunotherapy. Originally, it was assumed that CTLA-4 blockade selectively targets T cells relevant to the antitumour immune response. However, an uncontrolled pan T cell activation was induced compromising tolerance to healthy self-tissues. The irAEs are very similar to that of a chronic graft-versus-host-disease (GVHD) reaction following allogeneic bone marrow transplantation (BMT). We hypothesized that ipilimumab induced a graft-versus-malignancy (GVM) effect, which eradicated metastatic melanoma in a minority of patients, but also involved an auto-GVHD reaction that resulted in widespread autoimmunity in the majority. Therefore, we argued for a profound theoretical point against the consensus of experts. The task is not to desperately put the genie back in the bottle by immune-suppressive treatments, but instead to harness the autoimmune forces. In this way, the same goal could be achieved by an antibody as by the adoptive transfer of alloreactive donor lymphocytes, but without severe GVHD. The proof-of-principle of a low-dose-combination immune checkpoint therapy, consisting only of approved drugs and treatments, was demonstrated in 111 stage IV cancer patients.
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Affiliation(s)
| | | | - Ralf Kleef
- Immunology & Integrative Oncology, Kleef Hyperthermie, Vienna, Austria
| | | | - Colin C Anderson
- Departments of Surgery and Medical Microbiology & Immunology, Alberta Diabetes Institute, Alberta Transplant Institute, University of Alberta, Edmonton, Alberta, Canada
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5
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Kerepesi C, Bakács T, Szabados T. MiStImm: an agent-based simulation tool to study the self-nonself discrimination of the adaptive immune response. Theor Biol Med Model 2019; 16:9. [PMID: 31046789 PMCID: PMC6498635 DOI: 10.1186/s12976-019-0105-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2019] [Accepted: 04/12/2019] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND There is an increasing need for complex computational models to perform in silico experiments as an adjunct to in vitro and in vivo experiments in immunology. We introduce Microscopic Stochastic Immune System Simulator (MiStImm), an agent-based simulation tool, that is designed to study the self-nonself discrimination of the adaptive immune system. MiStImm can simulate some components of the humoral adaptive immune response, including T cells, B cells, antibodies, danger signals, interleukins, self cells, foreign antigens, and the interactions among them. The simulation starts after conception and progresses step by step (in time) driven by random simulation events. We also have provided tools to visualize and analyze the output of the simulation program. RESULTS As the first application of MiStImm, we simulated two different immune models, and then we compared performances of them in the mean of self-nonself discrimination. The first model is a so-called conventional immune model, and the second model is based on our earlier T-cell model, called "one-signal model", which is developed to resolve three important paradoxes of immunology. Our new T-cell model postulates that a dynamic steady state coupled system is formed through low-affinity complementary TCR-MHC interactions between T cells and host cells. The new model implies that a significant fraction of the naive polyclonal T cells is recruited into the first line of defense against an infection. Simulation experiments using MiStImm have shown that the computational realization of the new model shows real patterns. For example, the new model develops immune memory and it does not develop autoimmune reaction despite the hypothesized, enhanced TCR-MHC interaction between T cells and self cells. Simulations also demonstrated that our new model gives better results to overcome a critical primary infection answering the paradox "how can a tiny fraction of human genome effectively compete with a vastly larger pool of mutating pathogen DNA?" CONCLUSION The outcomes of our in silico experiments, presented here, are supported by numerous clinical trial observations from the field of immunotherapy. We hope that our results will encourage investigations to make in vitro and in vivo experiments clarifying questions about self-nonself discrimination of the adaptive immune system. We also hope that MiStImm or some concept in it will be useful to other researchers who want to implement or compare other immune models.
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Affiliation(s)
- Csaba Kerepesi
- Institute for Computer Science and Control, Hungarian Academy of Sciences, Kende u 13-17, Budapest, 1111, Hungary.
| | - Tibor Bakács
- Alfréd Rényi Institute of Mathematics, Hungarian Academy of Sciences, Reáltanoda u 13-15, Budapest, 1053, Hungary
| | - Tamás Szabados
- Department of Stochastics, Budapest University of Technology and Economics, Müegyetem rkp 3, Budapest, 1521, Hungary
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Sitkovsky MV, Hatfield S, Abbott R, Belikoff B, Lukashev D, Ohta A. Hostile, hypoxia-A2-adenosinergic tumor biology as the next barrier to overcome for tumor immunologists. Cancer Immunol Res 2015; 2:598-605. [PMID: 24990240 DOI: 10.1158/2326-6066.cir-14-0075] [Citation(s) in RCA: 168] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Hypoxia-driven, A2A adenosine receptor (A2AR)-mediated (hypoxia-A2-adenosinergic), T-cell-autonomous immunosuppression was first recognized as critical and nonredundant in protecting normal tissues from inflammatory damage and autoimmunity. However, this immunosuppressive mechanism can be highjacked by bacteria and tumors to provide misguided protection for pathogens and cancerous tissues. Inhibitors of the hypoxia-A2-adenosinergic pathway represent a conceptually novel type of immunologic coadjuvants that could be combined with cancer vaccines, adoptive cell transfer, and/or blockade of negative immunologic regulators to further prolong patient survival and to minimize treatment-related side effects. In support of this approach are preclinical studies and findings that some human cancers are resistant to chemotherapies and immunotherapies due to the tumor-generated extracellular adenosine and A2AR on antitumor T and natural killer (NK) cells. Among the coadjuvants are (i) antagonists of A2AR, (ii) extracellular adenosine-degrading drugs, (iii) inhibitors of adenosine generation by CD39/CD73 ectoenzymes, and (iv) inhibitors of hypoxia-HIF-1α signaling. Combining these coadjuvants with CTLA-4 and/or PD-1 blockade is expected to have additive or even synergistic effects of targeting two different antitumor protective mechanisms. It is expected that even after multicombinatorial blockade of negative immunologic regulators, the antitumor T and NK cells would still be vulnerable to inhibition by hypoxia and A2AR. Yet to be tested is the potential capacity of coadjuvants to minimize the side effects of CTLA-4 and/or PD-1 blockade by decreasing the dose of blocking antibodies or by eliminating the need for dual blockade.
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Affiliation(s)
- Michail V Sitkovsky
- Authors' Affiliation: New England Inflammation and Tissue Protection Institute, Northeastern University, Boston, Massachusetts
| | - Stephen Hatfield
- Authors' Affiliation: New England Inflammation and Tissue Protection Institute, Northeastern University, Boston, Massachusetts
| | - Robert Abbott
- Authors' Affiliation: New England Inflammation and Tissue Protection Institute, Northeastern University, Boston, Massachusetts
| | - Bryan Belikoff
- Authors' Affiliation: New England Inflammation and Tissue Protection Institute, Northeastern University, Boston, Massachusetts
| | - Dmitriy Lukashev
- Authors' Affiliation: New England Inflammation and Tissue Protection Institute, Northeastern University, Boston, Massachusetts
| | - Akio Ohta
- Authors' Affiliation: New England Inflammation and Tissue Protection Institute, Northeastern University, Boston, Massachusetts
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7
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Lesokhin AM, Callahan MK, Postow MA, Wolchok JD. On being less tolerant: Enhanced cancer immunosurveillance enabled by targeting checkpoints and agonists of T cell activation. Sci Transl Med 2015; 7:280sr1. [DOI: 10.1126/scitranslmed.3010274] [Citation(s) in RCA: 123] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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Bakacs T, Mehrishi JN. Anti-CTLA-4 therapy may have mechanisms similar to those occurring in inherited human CTLA4 haploinsufficiency. Immunobiology 2014; 220:624-5. [PMID: 25638260 DOI: 10.1016/j.imbio.2014.11.019] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2014] [Accepted: 11/29/2014] [Indexed: 01/16/2023]
Abstract
The inhibitory anti-CTLA-4 antibody, ipilimumab, dramatically improved survival in a subgroup of metastatic melanoma patients. The majority, however, suffered autoimmune-related adverse events (irAEs), sometimes pathognomonic of acute graft-versus-host-disease (GVHD). This implies that the CTLA-4 blockade is not tumor specific. We make a risky but testable prediction: anti-CTLA-4 therapy may have mechanism similar to that occurring in inherited human CTLA-4 haploinsufficiency. If so, a therapeutic paradigm shift is required. The task is not desperately trying to put the genie back in the bottle by immune-suppressive treatments, but harnessing the immense forces liberated by the anti-CTLA-4 antibody blockade by pretargeting or dose adjustment.
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Affiliation(s)
- Tibor Bakacs
- Department of Probability, Alfred Renyi Institute of Mathematics, Hungarian Academy of Sciences, Realtanoda utca 13-15, H-1053 Budapest, Hungary.
| | - Jitendra N Mehrishi
- The Cambridge Blood, Umbilical Cord Blood Stem Cells for Cell Therapy (Adults/Children), Cultivated RBC Research Initiative (Independent of and separate from the University of Cambridge), Macfarlane Cl. 13, Impington, Cambridge CB24 9LZ, United Kingdom.
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9
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Antonia SJ, Larkin J, Ascierto PA. Immuno-oncology Combinations: A Review of Clinical Experience and Future Prospects. Clin Cancer Res 2014; 20:6258-68. [DOI: 10.1158/1078-0432.ccr-14-1457] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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10
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Slavin S, Moss RW, Bakacs T. Control of minimal residual cancer by low dose ipilimumab activating autologous anti-tumor immunity. Pharmacol Res 2013; 79:9-12. [PMID: 24200897 DOI: 10.1016/j.phrs.2013.10.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/24/2013] [Accepted: 10/24/2013] [Indexed: 10/26/2022]
Abstract
In this perspective article, we address the controversy regarding the safety-efficacy issue in ipilimumab trials. While the CTLA-4 blockade interrupted T-cell pathways responsible for immune down-regulation and mediated regression of established malignant tumors in a minority of patients, this has to be weighed against the immune related adverse events (irAEs) suffered by the majority. Based on two groundbreaking but neglected proof-of-principle papers that demonstrated augmented graft-vs.-malignancy (GVM) effect that reversed the relapse of malignancy without worsening the graft-vs.-host disease (GVHD) by a CTLA-4 blockade, here we suggest a therapeutic paradigm shift, which may help break the impasse and resolve this timely issue in oncology.
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Affiliation(s)
- Shimon Slavin
- International Center for Cell Therapy and Cancer Immunotherapy (CTCI), 14 Weizman St., Tel Aviv 64238, Israel.
| | - Ralph W Moss
- Cancer Decisions, PO Box 1076, Lemont, PA 16851, United States.
| | - Tibor Bakacs
- Department of Probability, Alfred Renyi Institute of Mathematics, Hungarian Academy of Sciences, Realtanoda utca 13-15, H-1053 Budapest, Hungary.
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Bakacs T, Mehrishi JN, Szabó M, Moss RW. Interesting possibilities to improve the safety and efficacy of ipilimumab (Yervoy). Pharmacol Res 2012; 66:192-7. [PMID: 22503629 DOI: 10.1016/j.phrs.2012.03.015] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/07/2012] [Revised: 03/28/2012] [Accepted: 03/28/2012] [Indexed: 10/28/2022]
Abstract
As predicted, an anti-CTLA-4 mAb (ipilimumab) on binding to T lymphocytes breaks down immune-tolerance. Thereby, it was hoped, tumor-specific-T cells would be freed for a sustained attack on cancer cells. Data on ipilimumab treatment in 1498 patients with advanced melanoma (in 14 phase I-III trials) has shown immune-related adverse events (irAEs) in 64.2% of the patients consistent with tolerance breakdown. However, there is no evidence that the antitumor effects via a CTLA-4 blockade are attributable to T cells specifically targeting tumor cells. In fact, several trials indicate a possible correlation between grade 3 and 4 irAEs with clinical efficacy of ipilimumab; tumor regression may be associated with autoimmunity development. Therefore, we suggest a new treatment paradigm. The non-tumor specific pan-lymphocytic activation should be exploited by a 'pretargeting' approach proven successful in radioimmunodetection and radioimmunotherapy. First, an anti-tumor mAb conjugated with streptavidin (StAv) should be administered to be followed by the delivery of biotin-labeled anti-CTLA-4 mAb. This schedule has the virtue of endowing T cells with the ability to travel to tumor sites without prematurely succumbing to apoptosis, while streptavidin's ultra-high affinity for biotin (K(D), 10⁻¹⁵ M) ensures capturing all T cells binding biotin labeled anti-CTLA-4. Using the law of mass action, we calculated that following administration of ipilimumab at >1 mg/L concentration (∼5 mg per patient ∼70 kgbw), the immense forces of the immune system liberated by the anti-CTLA-4 antibody blockade would then be focused with laser sharp accuracy on tumor cells without collateral damage to normal host cells.
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Affiliation(s)
- Tibor Bakacs
- Department of Probability, Alfred Renyi Institute of Mathematics, Hungarian Academy of Sciences, Realtanoda Utca 13-15, H-1053 Budapest, Hungary
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