14 results on '"Theocharopoulos C"'
Search Results
2. Antibody-drug conjugates: Functional principles and applications in oncology and beyond
- Author
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Theocharopoulos, C. Lialios, P.-P. Samarkos, M. Gogas, H. Ziogas, D.C.
- Abstract
In the era of precision medicine, antibody-based therapeutics are rapidly enriched with emerging advances and new proof-of-concept formats. In this context, antibody-drug conjugates (ADCs) have evolved to merge the high selectivity and specificity of monoclonal antibodies (mAbs) with the cytotoxic potency of attached payloads. So far, ten ADCs have been approved by FDA for oncological indications and many others are currently being tested in clinical and preclinical level. This paper summarizes the essential components of ADCs, from their functional principles and structure up to their limitations and resistance mechanisms, focusing on all latest bioengineering breakthroughs such as bispecific mAbs, dual-drug platforms as well as novel linkers and conjugation chemistries. In continuation of our recent review on anticancer implication of ADC’s technology, further insights regarding their potential usage outside of the oncological spectrum are also presented. Better understanding of immunoconjugates could maximize their efficacy and optimize their safety, extending their use in everyday clinical practice. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.
- Published
- 2021
3. An overview of antibody–drug conjugates in oncological practice
- Author
-
Theocharopoulos, C. Lialios, P.-P. Gogas, H. Ziogas, D.C.
- Subjects
body regions - Abstract
Antibody–drug conjugates (ADCs) are designed to manipulate the toxic efficacy of specific chemotherapeutic compounds, employing the high affinity of antibody-mediated delivery so as to drive them selectively to target cancer cells. These immunoconjugates encompass the general tendency towards precision medicine and avert the systemic toxicities of conventional chemotherapy, accomplishing an improved therapeutic index. Cumulative experience acquired from first-generation ADCs offers new perspectives to these promising therapeutic modalities for various hematological and solid cancers and propels their clinical development in a faster-than-ever pace, as indicated by the approval of four novel ADCs during the last year. This paper aims to provide an up-to-date overview of the eight ADCs approved by the US Food and Drug Administration and their current indications in oncological practice. Starting from their bio-pharmaceutical background, we track their clinical evolution, with an emphasis on the pivotal trials that led to their commercial release. Late-stage studies examining these eight ADCs in other-than-approved settings as well as the investigation of potential new candidates are also reviewed. In the close future, more data are expected to expand ADCs’ oncological utility and to further reshape their role in cancer therapeutics. © The Author(s), 2020.
- Published
- 2020
4. Rodents, lagomorphs and insectivores, from the middle Miocene hominoid locality of Çandir (Turkey)
- Author
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de Bruijn H., van den Hoek Ostende L., Kristkoiz-Boon E., Rummel M., Theocharopoulos C., Ünay E., and de Bruijn, H., Utrecht University, Faculty of Earth Sciences, Budapestlaan 4, Utrecht, Netherlands -- van den Hoek Ostende, L., National Natuurhistorisch Museum, P.O. Box 9517, Leiden, RA 2300, Netherlands -- Kristkoiz-Boon, E., Rotwandstrasse 33, Starnberg 82319, Germany -- Rummel, M., Römerstrasse 17, Weissenburg 91781, Germany -- Theocharopoulos, C., National University of Athens, Dept. of Earth Sciences, Athens, Panepistimiopolis 15784, Greece -- Ünay, E., Cümhüriyet University, Faculty of Geology, Sivas 58140, Turkey
- Subjects
Middle Miocene ,Turkey ,parasitic diseases ,Mammalia ,Rodentia ,Insectivora ,Lagomorpha - Abstract
The small mammals from Çandir Loc. 2 are described. The rodents are represented by six families with thirteen species, the lagomorphs by one family with two species and the insectivores by four families with four species. The diverse rodent association with species that are endemic for the eastern Mediterranean area as well as species that are known from south western and central Europe does not allow an unequivocal correlation to the MN scale because the ranges of some of the latter do not overlap in the reference faunas. It is suggested that the traditional correlation of the Çandir fauna with MN6 has to be re-evaluated on the basis of the entire mammal content.
- Published
- 2003
5. Deep Learning for Image Analysis in the Diagnosis and Management of Esophageal Cancer.
- Author
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Theocharopoulos C, Davakis S, Ziogas DC, Theocharopoulos A, Foteinou D, Mylonakis A, Katsaros I, Gogas H, and Charalabopoulos A
- Abstract
Esophageal cancer has a dismal prognosis and necessitates a multimodal and multidisciplinary approach from diagnosis to treatment. High-definition white-light endoscopy and histopathological confirmation remain the gold standard for the definitive diagnosis of premalignant and malignant lesions. Artificial intelligence using deep learning (DL) methods for image analysis constitutes a promising adjunct for the clinical endoscopist that could effectively decrease BE overdiagnosis and unnecessary surveillance, while also assisting in the timely detection of dysplastic BE and esophageal cancer. A plethora of studies published during the last five years have consistently reported highly accurate DL algorithms with comparable or superior performance compared to endoscopists. Recent efforts aim to expand DL utilization into further aspects of esophageal neoplasia management including histologic diagnosis, segmentation of gross tumor volume, pretreatment prediction and post-treatment evaluation of patient response to systemic therapy and operative guidance during minimally invasive esophagectomy. Our manuscript serves as an introduction to the growing literature of DL applications for image analysis in the management of esophageal neoplasia, concisely presenting all currently published studies. We also aim to guide the clinician across basic functional principles, evaluation metrics and limitations of DL for image recognition to facilitate the comprehension and critical evaluation of the presented studies.
- Published
- 2024
- Full Text
- View/download PDF
6. Antibody-drug conjugates for hepato-pancreato-biliary malignancies: "Magic bullets" to the rescue?
- Author
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Theocharopoulos C, Ziogas IA, Douligeris CC, Efstathiou A, Kolorizos E, Ziogas DC, and Kontis E
- Subjects
- Humans, Antineoplastic Agents, Immunological therapeutic use, Immunoconjugates therapeutic use, Biliary Tract Neoplasms drug therapy, Pancreatic Neoplasms drug therapy, Liver Neoplasms drug therapy
- Abstract
Hepato-Pancreato-Biliary (HPB) malignancies constitute a highly aggressive group of cancers that have a dismal prognosis. Patients not amenable to curative intent surgical resection are managed with systemic chemotherapy which, however, confers little survival benefit. Antibody-Drug Conjugates (ADCs) are tripartite compounds that merge the intricate selectivity and specificity of monoclonal antibodies with the cytodestructive potency of attached supertoxic payloads. In view of the unmet need for drugs that will enhance the survival rates of HPB cancer patients, the assessment of ADCs for treating HPB malignancies has become the focus of extensive clinical and preclinical investigation, showing encouraging preliminary results. In the current review, we offer a comprehensive overview of the growing body of evidence on ADC approaches tested for HPB malignancies. Starting from a concise discussion of the functional principles of ADCs, we summarize here all available data from preclinical and clinical studies evaluating ADCs in HPB cancers., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)
- Published
- 2024
- Full Text
- View/download PDF
7. New Emerging Targets in Cancer Immunotherapy: The Role of B7-H3.
- Author
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Koumprentziotis IA, Theocharopoulos C, Foteinou D, Angeli E, Anastasopoulou A, Gogas H, and Ziogas DC
- Abstract
Immune checkpoints (ICs) are molecules implicated in the fine-tuning of immune response via co-inhibitory or co-stimulatory signals, and serve to secure minimized host damage. Targeting ICs with various therapeutic modalities, including checkpoint inhibitors/monoclonal antibodies (mAbs), antibody-drug conjugates (ADCs), and CAR-T cells has produced remarkable results, especially in immunogenic tumors, setting a paradigm shift in cancer therapeutics through the incorporation of these IC-targeted treatments. However, the large proportion of subjects who experience primary or secondary resistance to available IC-targeted options necessitates further advancements that render immunotherapy beneficial for a larger patient pool with longer duration of response. B7-H3 (B7 Homolog 3 Protein, CD276) is a member of the B7 family of IC proteins that exerts pleiotropic immunomodulatory effects both in physiologic and pathologic contexts. Mounting evidence has demonstrated an aberrant expression of B7-H3 in various solid malignancies, including tumors less sensitive to current immunotherapeutic options, and has associated its expression with advanced disease, worse patient survival and impaired response to IC-based regimens. Anti-B7-H3 agents, including novel mAbs, bispecific antibodies, ADCs, CAR-T cells, and radioimmunotherapy agents, have exhibited encouraging antitumor activity in preclinical models and have recently entered clinical testing for several cancer types. In the present review, we concisely present the functional implications of B7-H3 and discuss the latest evidence regarding its prognostic significance and therapeutic potential in solid malignancies, with emphasis on anti-B7-H3 modalities that are currently evaluated in clinical trial settings. Better understanding of B7-H3 intricate interactions in the tumor microenvironment will expand the oncological utility of anti-B7-H3 agents and further shape their role in cancer therapeutics.
- Published
- 2024
- Full Text
- View/download PDF
8. Polymorphisms in CLEC5A and CLEC7A genes modify risk for inflammatory bowel disease.
- Author
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Legaki E, Koutouratsas T, Theocharopoulos C, Lagkada V, and Gazouli M
- Abstract
Background: Inflammatory bowel disease (IBD) seems to arise from an interplay between genetic and environmental factors. CLEC5A and CLEC7A genes code for 2 members of the C-type lectin receptor superfamily, which participate in the immune response against various pathogens, mediating inflammatory signaling. CLEC5A polymorphisms have been linked to the risk of Crohn's disease (CD), whereas CLEC7A has been implicated in fungal dysbiosis, chemically induced colitis in mice and undertreated ulcerative colitis (UC) in humans. This study aimed to explore how specific CLEC5A and CLEC7A polymorphisms contribute to the development of CD and UC., Methods: One hundred twelve CD patients, 94 UC patients and 164 sex- and age- matched healthy individuals were genotyped for the single nucleotide polymorphisms rs2078178 and rs16910631 of the CLEC7A gene, and rs1285933 of the CLEC5A gene., Results: The CLEC7A rs2078178 AA genotype was more frequent in UC patients compared to healthy individuals, The CLEC7A rs16910631 CT genotype was significantly associated with UC risk compared to healthy individuals, while there was no statistical correlation with CD. The CLEC5A rs1285933 GA genotype was found to be protective against UC and CD, and the AA genotype against CD. Carriers of the rs1285933 A allele appeared to have reduced susceptibility to CD, implying that the presence of the A allele could be protective against CD development., Conclusions: This is the first study to correlate the CLEC5A rs1285933 polymorphism with the risk for UC. The rs2078178 AA genotype and the CLEC7A rs16910631 CT could be promising biomarkers for UC susceptibility., Competing Interests: Conflict of Interest: None, (Copyright: © Hellenic Society of Gastroenterology.)
- Published
- 2024
- Full Text
- View/download PDF
9. Digging into the NGS Information from a Large-Scale South European Population with Metastatic/Unresectable Pancreatic Ductal Adenocarcinoma: A Real-World Genomic Depiction.
- Author
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Ziogas DC, Papadopoulou E, Gogas H, Sakellariou S, Felekouras E, Theocharopoulos C, Stefanou DT, Theochari M, Boukovinas I, Matthaios D, Koumarianou A, Zairi E, Liontos M, Koutsoukos K, Metaxa-Mariatou V, Kapetsis G, Meintani A, Tsaousis GN, and Nasioulas G
- Abstract
Despite ongoing oncological advances, pancreatic ductal adenocarcinoma (PDAC) continues to have an extremely poor prognosis with limited targeted and immunotherapeutic options. Its genomic background has not been fully characterized yet in large-scale populations all over the world. Methods: Replicating a recent study from China, we collected tissue samples from consecutive Greek patients with pathologically-confirmed metastatic/unresectable PDAC and retrospectively investigated their genomic landscape using next generation sequencing (NGS). Findings: From a cohort of 409 patients, NGS analysis was successfully achieved in 400 cases (56.50% males, median age: 61.8 years). Consistent with a previous study, KRAS was the most frequently mutated gene in 81.50% of tested samples, followed by TP53 (50.75%), CDKN2 (8%), and SMAD4 (7.50%). BRCA1/2 variants with on-label indications were detected in 2%, and 87.50% carried a variant associated with off-label treatment ( KRAS , ERBB2 , STK11 , or HRR-genes), while 3.5% of the alterations had unknown/preliminary-studied actionability ( TP53/CDKN2A ). Most of HRR-alterations were in intermediate- and low-risk genes ( CHEK2 , RAD50 , RAD51 , ATM , FANCA , FANCL , FANCC , BAP1 ), with controversial actionability: 8% harbored a somatic non- BRCA1/2 alteration, 6 cases had a high-risk alteration ( PALB2 , RAD51C ), and one co-presented a PALB2/BRCA2 alteration. Elevated LOH was associated with HRR-mutated status and TP53 mutations while lowered LOH was associated with KRAS alterations. Including TMB/MSI data, the potential benefit from an NGS-oriented treatment was increased from 1.91% to 13.74% (high-MSI: 0.3%, TMB > 10 muts/MB: 12.78%). TMB was slightly increased in females (4.75 vs. 4.46 muts/MB) and in individuals with age > 60 (4.77 vs. 4.40 muts/MB). About 28.41% showed PD-L1 > 1% either in tumor or immune cells, 15.75% expressed PD-L1 ≥ 10%, and only 1.18% had PD-L1 ≥ 50%. This is the largest depiction of real-world genomic characteristics of European patients with PDAC, which offers some useful clinical and research insights.
- Published
- 2023
- Full Text
- View/download PDF
10. Beyond CTLA-4 and PD-1 Inhibition: Novel Immune Checkpoint Molecules for Melanoma Treatment.
- Author
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Ziogas DC, Theocharopoulos C, Lialios PP, Foteinou D, Koumprentziotis IA, Xynos G, and Gogas H
- Abstract
More than ten years after the approval of ipilimumab, immune checkpoint inhibitors (ICIs) against PD-1 and CTLA-4 have been established as the most effective treatment for locally advanced or metastatic melanoma, achieving durable responses either as monotherapies or in combinatorial regimens. However, a considerable proportion of patients do not respond or experience early relapse, due to multiple parameters that contribute to melanoma resistance. The expression of other immune checkpoints beyond the PD-1 and CTLA-4 molecules remains a major mechanism of immune evasion. The recent approval of anti-LAG-3 ICI, relatlimab, in combination with nivolumab for metastatic disease, has capitalized on the extensive research in the field and has highlighted the potential for further improvement of melanoma prognosis by synergistically blocking additional immune targets with new ICI-doublets, antibody-drug conjugates, or other novel modalities. Herein, we provide a comprehensive overview of presently published immune checkpoint molecules, including LAG-3, TIGIT, TIM-3, VISTA, IDO1/IDO2/TDO, CD27/CD70, CD39/73, HVEM/BTLA/CD160 and B7-H3. Beginning from their immunomodulatory properties as co-inhibitory or co-stimulatory receptors, we present all therapeutic modalities targeting these molecules that have been tested in melanoma treatment either in preclinical or clinical settings. Better understanding of the checkpoint-mediated crosstalk between melanoma and immune effector cells is essential for generating more effective strategies with augmented immune response.
- Published
- 2023
- Full Text
- View/download PDF
11. Mechanisms of resistance to immune checkpoint inhibitors in melanoma: What we have to overcome?
- Author
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Ziogas DC, Theocharopoulos C, Koutouratsas T, Haanen J, and Gogas H
- Subjects
- Humans, Ipilimumab therapeutic use, Immune Checkpoint Inhibitors therapeutic use, Immunotherapy, Nivolumab pharmacology, Nivolumab therapeutic use, Melanoma pathology
- Abstract
Marching into the second decade after the approval of ipilimumab, it is clear that immune checkpoint inhibitors (ICIs) have dramatically improved the prognosis of melanoma. Although the current edge is already high, with a 4-year OS% of 77.9% for adjuvant nivolumab and a 6.5-year OS% of 49% for nivolumab/ipilimumab combination in the metastatic setting, a high proportion of patients with advanced melanoma have no benefit from immunotherapy, or experience an early disease relapse/progression in the first few months of treatment, surviving much less. Reasonably, the primary and acquired resistance to ICIs has entered into the focus of clinical research with positive (e.g., nivolumab and relatlimab combination) and negative feedbacks (e.g., nivolumab with pegylated-IL2, pembrolizumab with T-VEC, nivolumab with epacadostat, and combinatorial triplets of BRAF/MEK inhibitors with immunotherapy). Many intrinsic (intracellular or intra-tumoral) but also extrinsic (systematic) events are considered to be involved in the development of this resistance to ICIs: i) melanoma cell immunogenicity (e.g., tumor mutational burden, antigen-processing machinery and immunogenic cell death, neoantigen affinity and heterogeneity, genomic instability, melanoma dedifferentiation and phenotypic plasticity), ii) immune cell trafficking, T-cell priming, and cell death evasion, iii) melanoma neovascularization, cellular TME components(e.g., T
regs , CAFs) and extracellular matrix modulation, iv) metabolic antagonism in the TME(highly glycolytic status, upregulated CD39/CD73/adenosine pathway, iDO-dependent tryptophan catabolism), v) T-cell exhaustion and negative immune checkpoints, and vi) gut microbiota. In the present overview, we discuss how these parameters compromise the efficacy of ICIs, with an emphasis on the lessons learned by the latest melanoma studies; and in parallel, we describe the main ongoing approaches to overcome the resistance to immunotherapy. Summarizing this information will improve the understanding of how these complicated dynamics contribute to immune escape and will help to develop more effective strategies on how anti-tumor immunity can surpass existing barriers of ICI-refractory melanoma., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier Ltd. All rights reserved.)- Published
- 2023
- Full Text
- View/download PDF
12. Neuromuscular Complications of Targeted Anticancer Agents: Can Tyrosine Kinase Inhibitors Induce Myasthenia Gravis? Getting Answers From a Case Report up to a Systematic Review.
- Author
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Ziogas DC, Mandellos D, Theocharopoulos C, Lialios PP, Bouros S, Ascierto PA, and Gogas H
- Abstract
More than 40 tyrosine kinase inhibitors (TKIs) have received hematological or oncological indications over the past 20 years, following the approval of imatinib, and many others are currently being tested in clinical and preclinical level. Beyond their common toxicities, no certain agent from this large class of molecularly targeted therapies was strongly associated with "off-target" impairment of neuromuscular transmission, and although myasthenia gravis (MG) is a well-characterized autoimmune disorder, only few sporadic events proven by serologically detected causative autoantibodies and/or by positive electrophysiological tests are reported in the literature. Herein, we present the first case of anti-MUSK (+) MG in a woman with metastatic BRAF-mutant melanoma after long-term treatment with dabrafenib (BRAF inhibitor) and trametinib (MEK inhibitor). Triggered by this report, a systematic literature review was conducted, summarizing all other cancer cases that developed MG, after exposure to any type of targeted agent and regardless of the underlying malignancy. All available data on the clinical diagnosis, the potential of administered TKIs to induce a seropositive myasthenic syndrome, the immune and non-immune-mediated pathogenesis of postsynaptic damage, and the challenging management of this neuromuscular toxicity were collected and discussed. In the presented case, MG was confirmed by both autoantibodies and nerve-conduction tests, while its reactivation after TKIs rechallenge supports a more than coincidental association. The following review identified 12 cancer cases with TKI-related MG in six case reports and one case series. In most of them, the myasthenia diagnosis was challenging, since the clinical symptomatology of fatigable weakness was not corroborating with consistent laboratory and electrophysiological findings. In fact, anti-AchR titers were positive in five and anti-MuSK only in the abovementioned individual. The symptomatology corresponded to TKI discontinuation and standard treatment with pyridostigmine and prednisolone; intravenous immunoglobulin was added only in three, and two required mechanical ventilation. In an era where TKIs will be prescribed more frequently for various malignancies, even in combinations with immune-checkpoint inhibitors, this report synthesizes their risk for neuromuscular complications and increases the clinicians' awareness in order to extend the on-treatment and overall survival of TKI-treated cancer patients., Competing Interests: HG has received grants and personal fees from Roche, BMS, MSD, and Novartis and personal fees from Amgen and Pierre Fabre, outside the submitted work. PA has a consultant/advisory role for BMS, Roche-Genentech, MSD, Array, Novartis, Merck Serono, Pierre Fabre, Incyte, NewLink Genetics, Genmab, Medimmune, AstraZeneca, Syndax, SunPharma, Sanofi, Idera, Ultimovacs, Sandoz, Immunocore, 4SC, Alkermes, Italfarmaco, Nektar, Boehringer-Ingelheim, Eisai, Regeneron, Daiichi Sankyo, Pfizer, Oncosec, Nouscom, Takis, Lunaphore, and Seagen, and he has also received research funds from BMS, Roche, Array, and Sanofi and travel support from MSD, outside the submitted work. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Ziogas, Mandellos, Theocharopoulos, Lialios, Bouros, Ascierto and Gogas.)
- Published
- 2021
- Full Text
- View/download PDF
13. Antibody-Drug Conjugates: Functional Principles and Applications in Oncology and Beyond.
- Author
-
Theocharopoulos C, Lialios PP, Samarkos M, Gogas H, and Ziogas DC
- Abstract
In the era of precision medicine, antibody-based therapeutics are rapidly enriched with emerging advances and new proof-of-concept formats. In this context, antibody-drug conjugates (ADCs) have evolved to merge the high selectivity and specificity of monoclonal antibodies (mAbs) with the cytotoxic potency of attached payloads. So far, ten ADCs have been approved by FDA for oncological indications and many others are currently being tested in clinical and preclinical level. This paper summarizes the essential components of ADCs, from their functional principles and structure up to their limitations and resistance mechanisms, focusing on all latest bioengineering breakthroughs such as bispecific mAbs, dual-drug platforms as well as novel linkers and conjugation chemistries. In continuation of our recent review on anticancer implication of ADC's technology, further insights regarding their potential usage outside of the oncological spectrum are also presented. Better understanding of immunoconjugates could maximize their efficacy and optimize their safety, extending their use in everyday clinical practice.
- Published
- 2021
- Full Text
- View/download PDF
14. An overview of antibody-drug conjugates in oncological practice.
- Author
-
Theocharopoulos C, Lialios PP, Gogas H, and Ziogas DC
- Abstract
Antibody-drug conjugates (ADCs) are designed to manipulate the toxic efficacy of specific chemotherapeutic compounds, employing the high affinity of antibody-mediated delivery so as to drive them selectively to target cancer cells. These immunoconjugates encompass the general tendency towards precision medicine and avert the systemic toxicities of conventional chemotherapy, accomplishing an improved therapeutic index. Cumulative experience acquired from first-generation ADCs offers new perspectives to these promising therapeutic modalities for various hematological and solid cancers and propels their clinical development in a faster-than-ever pace, as indicated by the approval of four novel ADCs during the last year. This paper aims to provide an up-to-date overview of the eight ADCs approved by the US Food and Drug Administration and their current indications in oncological practice. Starting from their bio-pharmaceutical background, we track their clinical evolution, with an emphasis on the pivotal trials that led to their commercial release. Late-stage studies examining these eight ADCs in other-than-approved settings as well as the investigation of potential new candidates are also reviewed. In the close future, more data are expected to expand ADCs' oncological utility and to further reshape their role in cancer therapeutics., Competing Interests: Conflict of interest statement: HG has received grants and personal fees by Roche, BMS, MSD, Novartis and personal fees by Amgen and Pierre Fabre, outside the submitted work. All other authors declare no conflict of interest., (© The Author(s), 2020.)
- Published
- 2020
- Full Text
- View/download PDF
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