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Robles O. Regulatory Submission Characteristics and Recalls of Medical Devices Receiving 510(k) Clearance. JAMA 2023; 329:1609. [PMID: 37159040 DOI: 10.1001/jama.2023.4089] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Affiliation(s)
- Omar Robles
- Mossavar-Rahmani Center for Business and Government, John F. Kennedy School of Government at Harvard University, Cambridge, Massachusetts
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2
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Jackson JJ, Shibuya GM, Ravishankar B, Adusumilli L, Bradford D, Brockstedt DG, Bucher C, Bui M, Cho C, Colas C, Cutler G, Dukes A, Han X, Hu DX, Jacobson S, Kassner PD, Katibah GE, Ko MYM, Kolhatkar U, Leger PR, Ma A, Marshall L, Maung J, Ng AA, Okano A, Pookot D, Poon D, Ramana C, Reilly MK, Robles O, Schwarz JB, Shakhmin AA, Shunatona HP, Sreenivasan R, Tivitmahaisoon P, Xu M, Zaw T, Wustrow DJ, Zibinsky M. Potent GCN2 Inhibitor Capable of Reversing MDSC-Driven T Cell Suppression Demonstrates In Vivo Efficacy as a Single Agent and in Combination with Anti-Angiogenesis Therapy. J Med Chem 2022; 65:12895-12924. [PMID: 36127295 DOI: 10.1021/acs.jmedchem.2c00736] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
General control nonderepressible 2 (GCN2) protein kinase is a cellular stress sensor within the tumor microenvironment (TME), whose signaling cascade has been proposed to contribute to immune escape in tumors. Herein, we report the discovery of cell-potent GCN2 inhibitors with excellent selectivity against its closely related Integrated Stress Response (ISR) family members heme-regulated inhibitor kinase (HRI), protein kinase R (PKR), and (PKR)-like endoplasmic reticulum kinase (PERK), as well as good kinome-wide selectivity and favorable PK. In mice, compound 39 engages GCN2 at levels ≥80% with an oral dose of 15 mg/kg BID. We also demonstrate the ability of compound 39 to alleviate MDSC-related T cell suppression and restore T cell proliferation, similar to the effect seen in MDSCs from GCN2 knockout mice. In the LL2 syngeneic mouse model, compound 39 demonstrates significant tumor growth inhibition (TGI) as a single agent. Furthermore, TGI mediated by anti-VEGFR was enhanced by treatment with compound 39 demonstrating the complementarity of these two mechanisms.
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Affiliation(s)
- Jeffrey J Jackson
- RAPT Therapeutics, 561 Eccles Avenue, South San Francisco, California94080, United States
| | - Grant M Shibuya
- RAPT Therapeutics, 561 Eccles Avenue, South San Francisco, California94080, United States
| | - Buvana Ravishankar
- RAPT Therapeutics, 561 Eccles Avenue, South San Francisco, California94080, United States
| | - Lavanya Adusumilli
- RAPT Therapeutics, 561 Eccles Avenue, South San Francisco, California94080, United States
| | - Delia Bradford
- RAPT Therapeutics, 561 Eccles Avenue, South San Francisco, California94080, United States
| | - Dirk G Brockstedt
- RAPT Therapeutics, 561 Eccles Avenue, South San Francisco, California94080, United States
| | - Cyril Bucher
- RAPT Therapeutics, 561 Eccles Avenue, South San Francisco, California94080, United States
| | - Minna Bui
- RAPT Therapeutics, 561 Eccles Avenue, South San Francisco, California94080, United States
| | - Cynthia Cho
- RAPT Therapeutics, 561 Eccles Avenue, South San Francisco, California94080, United States
| | - Christoph Colas
- RAPT Therapeutics, 561 Eccles Avenue, South San Francisco, California94080, United States
| | - Gene Cutler
- RAPT Therapeutics, 561 Eccles Avenue, South San Francisco, California94080, United States
| | - Adrian Dukes
- RAPT Therapeutics, 561 Eccles Avenue, South San Francisco, California94080, United States
| | - Xinping Han
- RAPT Therapeutics, 561 Eccles Avenue, South San Francisco, California94080, United States
| | - Dennis X Hu
- RAPT Therapeutics, 561 Eccles Avenue, South San Francisco, California94080, United States
| | - Scott Jacobson
- RAPT Therapeutics, 561 Eccles Avenue, South San Francisco, California94080, United States
| | - Paul D Kassner
- RAPT Therapeutics, 561 Eccles Avenue, South San Francisco, California94080, United States
| | - George E Katibah
- RAPT Therapeutics, 561 Eccles Avenue, South San Francisco, California94080, United States
| | - Michelle Yoo Min Ko
- RAPT Therapeutics, 561 Eccles Avenue, South San Francisco, California94080, United States
| | - Urvi Kolhatkar
- RAPT Therapeutics, 561 Eccles Avenue, South San Francisco, California94080, United States
| | - Paul R Leger
- RAPT Therapeutics, 561 Eccles Avenue, South San Francisco, California94080, United States
| | - Anqi Ma
- RAPT Therapeutics, 561 Eccles Avenue, South San Francisco, California94080, United States
| | - Lisa Marshall
- RAPT Therapeutics, 561 Eccles Avenue, South San Francisco, California94080, United States
| | - Jack Maung
- RAPT Therapeutics, 561 Eccles Avenue, South San Francisco, California94080, United States
| | - Andrew A Ng
- RAPT Therapeutics, 561 Eccles Avenue, South San Francisco, California94080, United States
| | - Akinori Okano
- RAPT Therapeutics, 561 Eccles Avenue, South San Francisco, California94080, United States
| | - Deepa Pookot
- RAPT Therapeutics, 561 Eccles Avenue, South San Francisco, California94080, United States
| | - Daniel Poon
- RAPT Therapeutics, 561 Eccles Avenue, South San Francisco, California94080, United States
| | - Chandru Ramana
- RAPT Therapeutics, 561 Eccles Avenue, South San Francisco, California94080, United States
| | - Maureen K Reilly
- RAPT Therapeutics, 561 Eccles Avenue, South San Francisco, California94080, United States
| | - Omar Robles
- RAPT Therapeutics, 561 Eccles Avenue, South San Francisco, California94080, United States
| | - Jacob B Schwarz
- RAPT Therapeutics, 561 Eccles Avenue, South San Francisco, California94080, United States
| | - Anton A Shakhmin
- RAPT Therapeutics, 561 Eccles Avenue, South San Francisco, California94080, United States
| | - Hunter P Shunatona
- RAPT Therapeutics, 561 Eccles Avenue, South San Francisco, California94080, United States
| | - Raashi Sreenivasan
- RAPT Therapeutics, 561 Eccles Avenue, South San Francisco, California94080, United States
| | | | - Mengshu Xu
- RAPT Therapeutics, 561 Eccles Avenue, South San Francisco, California94080, United States
| | - Thant Zaw
- RAPT Therapeutics, 561 Eccles Avenue, South San Francisco, California94080, United States
| | - David J Wustrow
- RAPT Therapeutics, 561 Eccles Avenue, South San Francisco, California94080, United States
| | - Mikhail Zibinsky
- RAPT Therapeutics, 561 Eccles Avenue, South San Francisco, California94080, United States
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Jorapur A, Marshall LA, Jacobson S, Xu M, Marubayashi S, Zibinsky M, Hu DX, Robles O, Jackson JJ, Baloche V, Busson P, Wustrow D, Brockstedt DG, Talay O, Kassner PD, Cutler G. EBV+ tumors exploit tumor cell-intrinsic and -extrinsic mechanisms to produce regulatory T cell-recruiting chemokines CCL17 and CCL22. PLoS Pathog 2022; 18:e1010200. [PMID: 35025968 PMCID: PMC8791514 DOI: 10.1371/journal.ppat.1010200] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Revised: 01/26/2022] [Accepted: 12/13/2021] [Indexed: 12/15/2022] Open
Abstract
The Epstein-Barr Virus (EBV) is involved in the etiology of multiple hematologic and epithelial human cancers. EBV+ tumors employ multiple immune escape mechanisms, including the recruitment of immunosuppressive regulatory T cells (Treg). Here, we show some EBV+ tumor cells express high levels of the chemokines CCL17 and CCL22 both in vitro and in vivo and that this expression mirrors the expression levels of expression of the EBV LMP1 gene in vitro. Patient samples from lymphoblastic (Hodgkin lymphoma) and epithelial (nasopharyngeal carcinoma; NPC) EBV+ tumors revealed CCL17 and CCL22 expression of both tumor cell-intrinsic and -extrinsic origin, depending on tumor type. NPCs grown as mouse xenografts likewise showed both mechanisms of chemokine production. Single cell RNA-sequencing revealed in vivo tumor cell-intrinsic CCL17 and CCL22 expression combined with expression from infiltrating classical resident and migratory dendritic cells in a CT26 colon cancer mouse tumor engineered to express LMP1. These data suggest that EBV-driven tumors employ dual mechanisms for CCL17 and CCL22 production. Importantly, both in vitro and in vivo Treg migration was effectively blocked by a novel, small molecule antagonist of CCR4, CCR4-351. Antagonism of the CCR4 receptor may thus be an effective means of activating the immune response against a wide spectrum of EBV+ tumors.
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Affiliation(s)
- Aparna Jorapur
- Discovery Biology, RAPT Therapeutics, Inc., South San Francisco, California, United States of America
| | - Lisa A. Marshall
- Quantitative Biology, RAPT Therapeutics, Inc., South San Francisco, California, United States of America
| | - Scott Jacobson
- Discovery Biology, RAPT Therapeutics, Inc., South San Francisco, California, United States of America
| | - Mengshu Xu
- Computational Biology, RAPT Therapeutics, Inc., South San Francisco, California, United States of America
| | - Sachie Marubayashi
- Discovery Biology, RAPT Therapeutics, Inc., South San Francisco, California, United States of America
| | - Mikhail Zibinsky
- Drug Discovery, RAPT Therapeutics, Inc., South San Francisco, California, United States of America
| | - Dennis X. Hu
- Drug Discovery, RAPT Therapeutics, Inc., South San Francisco, California, United States of America
| | - Omar Robles
- Drug Discovery, RAPT Therapeutics, Inc., South San Francisco, California, United States of America
| | - Jeffrey J. Jackson
- Drug Discovery, RAPT Therapeutics, Inc., South San Francisco, California, United States of America
| | - Valentin Baloche
- CNRS-UMR 8126, Gustave Roussy and Paris-Sud/Paris-Saclay University, Villejuif, France
| | - Pierre Busson
- CNRS-UMR 8126, Gustave Roussy and Paris-Sud/Paris-Saclay University, Villejuif, France
| | - David Wustrow
- Drug Discovery, RAPT Therapeutics, Inc., South San Francisco, California, United States of America
| | - Dirk G. Brockstedt
- Discovery Biology, RAPT Therapeutics, Inc., South San Francisco, California, United States of America
| | - Oezcan Talay
- Discovery Biology, RAPT Therapeutics, Inc., South San Francisco, California, United States of America
| | - Paul D. Kassner
- Quantitative Biology, RAPT Therapeutics, Inc., South San Francisco, California, United States of America
| | - Gene Cutler
- Computational Biology, RAPT Therapeutics, Inc., South San Francisco, California, United States of America
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4
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Marshall LA, Marubayashi S, Jorapur A, Jacobson S, Zibinsky M, Robles O, Hu DX, Jackson JJ, Pookot D, Sanchez J, Brovarney M, Wadsworth A, Chian D, Wustrow D, Kassner PD, Cutler G, Wong B, Brockstedt DG, Talay O. Tumors establish resistance to immunotherapy by regulating T reg recruitment via CCR4. J Immunother Cancer 2021; 8:jitc-2020-000764. [PMID: 33243932 PMCID: PMC7692993 DOI: 10.1136/jitc-2020-000764] [Citation(s) in RCA: 47] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/25/2020] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND Checkpoint inhibitors (CPIs) such as anti-PD(L)-1 and anti-CTLA-4 antibodies have resulted in unprecedented rates of antitumor responses and extension of survival of patients with a variety of cancers. But some patients fail to respond or initially respond but later relapse as they develop resistance to immune therapy. One of the tumor-extrinsic mechanisms for resistance to immune therapy is the accumulation of regulatory T cells (Treg) in tumors. In preclinical and clinical studies, it has been suggested that tumor trafficking of Treg is mediated by CC chemokine receptor 4 (CCR4). Over 90% of human Treg express CCR4 and migrate toward CCL17 and CCL22, two major CCR4 ligands that are either high at baseline or upregulated in tumors on CPI treatment. Hence, CCR4 antagonism has the potential to be an effective antitumor treatment by reducing the accumulation of Treg into the tumor microenvironment (TME). METHODS We developed in vitro and in vivo models to assess Treg migration and antitumor efficacy using a potent and selective CCR4 antagonist, CCR4-351. We used two separate tumor models, Pan02 and CT26 mouse tumors, that have high and low CCR4 ligand expression, respectively. Tumor growth inhibition as well as the frequency of tumor-infiltrating Treg and effector T cells was assessed following the treatment with CCR4 antagonist alone or in combination with CPI. RESULTS Using a selective and highly potent, novel small molecule inhibitor of CCR4, we demonstrate that migration of CCR4+ Treg into the tumor drives tumor progression and resistance to CPI treatment. In tumor models with high baseline levels of CCR4 ligands, blockade of CCR4 reduced the number of Treg and enhanced antitumor immune activity. Notably, in tumor models with low baseline level of CCR4 ligands, treatment with immune CPIs resulted in significant increases of CCR4 ligands and Treg numbers. Inhibition of CCR4 reduced Treg frequency and potentiated the antitumor effects of CPIs. CONCLUSION Taken together, we demonstrate that CCR4-dependent Treg recruitment into the tumor is an important tumor-extrinsic mechanism for immune resistance. Blockade of CCR4 led to reduced frequency of Treg and resulted in increased antitumor activity, supporting the clinical development of CCR4 inhibitors in combination with CPI for the treatment of cancer. STATEMENT OF SIGNIFICANCE CPI upregulates CCL17 and CCL22 expression in tumors and increases Treg migration into the TME. Pharmacological antagonism of the CCR4 receptor effectively inhibits Treg recruitment and results in enhanced antitumor efficacy either as single agent in CCR4 ligandhigh tumors or in combination with CPIs in CCR4 ligandlow tumors.
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Affiliation(s)
| | | | | | | | | | - Omar Robles
- RAPT Therapeutics, South San Francisco, California, USA
| | | | | | - Deepa Pookot
- RAPT Therapeutics, South San Francisco, California, USA
| | | | | | | | - David Chian
- Lyell Immunopharma, South San Francisco, California, USA
| | - David Wustrow
- RAPT Therapeutics, South San Francisco, California, USA
| | | | - Gene Cutler
- RAPT Therapeutics, South San Francisco, California, USA
| | - Brian Wong
- RAPT Therapeutics, South San Francisco, California, USA
| | | | - Oezcan Talay
- RAPT Therapeutics, South San Francisco, California, USA
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5
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Marshall L, Ravishankar B, Kolhatkar U, Xu M, Adusumilli L, Pookot D, Zaw T, Ramana C, Sreenivasan R, Zibinsky M, Jackson J, Shibuya G, Leger P, Robles O, Ma A, Ng A, Shakhmin A, Guagua J, Jacobson S, Wong S, Bradford D, McGaha TL, Ciudad MT, Talmadge JE, Britton HC, Katibah G, Cutler G, Wustrow D, Kassner PD, Brockstedt DG. Abstract 3153: Targeting the stress response kinase GCN2 to restore immunity in the tumor microenvironment. Cancer Res 2021. [DOI: 10.1158/1538-7445.am2021-3153] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Recent advances in cancer metabolism suggest that targeting amino acid metabolism represents a promising strategy for the development of novel therapeutic agents. Tumor, stromal and myeloid-derived suppressor cells (MDSC) within the tumor microenvironment (TME) create a nutrient-poor environment that inhibit immune function and support tumor growth. GCN2 (general control nonderepressible 2), a stress response kinase, plays a key role in maintaining cellular homeostasis under a wide range of stressors. Phosphorylation of GCN2 (pGCN2) in response to stress leads to inhibition of global protein synthesis and subsequently leads to 1) T cell anergy and apoptosis, 2) enhanced MDSC-dependent immune suppression and 3) tumor cell survival. Collectively, these roles suggest that GCN2 inhibition could have both a direct anticancer and an immune-activating effect. Treating nutrient-deprived T cells in vitro with a RAPT GCN2 inhibitor (RPT-GCN2i) rescued CD4+ and CD8+ T cell proliferation and effector functions. The RPT-GCN2i also reversed T cell suppression mediated by MDSCs derived from healthy donors or cancer patients. Using syngeneic mouse tumor models, we demonstrated that translational induction of activating transcription factor 4 (ATF4) is a strong marker of GCN2 pathway activation in vivo. Oral administration of an RPT-GCN2i exhibited notable drug-target occupancy and potently inhibited GCN2 kinase and ATF4 in the TME. RPT-GCN2i as a single agent and in combination with checkpoint blockade or angiogenesis inhibitor (anti-VEGFR) led to delays in tumor growth rate in various syngeneic tumor models. In addition, GCN2 inhibition redirected MDSC within the TME from a suppressive to inflammatory phenotype through downregulation of Arg1 and iNOS. Our results show that inhibition of GCN2 is an attractive approach for enhancing antitumor immune response and therefore GCN2 is a promising therapeutic target for the treatment of cancer.
Citation Format: Lisa Marshall, Buvana Ravishankar, Urvi Kolhatkar, Mengshu Xu, Lavanya Adusumilli, Deepa Pookot, Thant Zaw, Chandru Ramana, Raashi Sreenivasan, Mikhail Zibinsky, Jeffrey Jackson, Grant Shibuya, Paul Leger, Omar Robles, Anqi Ma, Andrew Ng, Anton Shakhmin, Justy Guagua, Scott Jacobson, Steve Wong, Delia Bradford, Tracy L. McGaha, M Teresa Ciudad, James E. Talmadge, Holly C. Britton, George Katibah, Gene Cutler, David Wustrow, Paul D. Kassner, Dirk G. Brockstedt. Targeting the stress response kinase GCN2 to restore immunity in the tumor microenvironment [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 3153.
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Affiliation(s)
| | | | | | - Mengshu Xu
- 1RAPT Therapeutics, South San Francisco, CA
| | | | | | - Thant Zaw
- 1RAPT Therapeutics, South San Francisco, CA
| | | | | | | | | | | | - Paul Leger
- 1RAPT Therapeutics, South San Francisco, CA
| | | | - Anqi Ma
- 1RAPT Therapeutics, South San Francisco, CA
| | - Andrew Ng
- 1RAPT Therapeutics, South San Francisco, CA
| | | | | | | | - Steve Wong
- 1RAPT Therapeutics, South San Francisco, CA
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Katibah G, Ohol Y, Bucher C, Adusumilli L, Kaveri D, Robles O, Sun M, Cho C, Milestone H, Ames R, Jacobson S, Nebalasca D, Gomez- Guagua J, Sanchez J, Grandcolas M, Wong S, Brovarney M, Ramana C, Zaw T, Nguyen L, Tivitmahaisoon P, Ng A, Ma A, Gomez B, Ko M, Leger P, Jackson J, Shibuya G, Shakhmin A, Bradford D, Xu M, Zibinsky M, Poon D, Wustrow D, Kassner P, Brockstedt D. Abstract 1646: Development of small-molecule HPK1 inhibitors to unleash tumor-specific T cell responses. Cancer Res 2021. [DOI: 10.1158/1538-7445.am2021-1646] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Hematopoietic progenitor kinase 1 (HPK1) is an intracellular protein kinase that negatively regulates T cell signaling and proliferation. Upon T cell receptor (TCR) activation, active HPK1 phosphorylates the adaptor protein SLP76 in the TCR complex, recruiting the negative regulator 14-3-3 and targeting components of the TCR signaling complex for degradation. HPK1 thus limits the TCR signaling important for mounting an effective immune response against tumor cells. We are employing structure-guided drug design to develop potent small-molecule inhibitors of HPK1. Our compounds potently inhibit HPK1 in biochemical assays, reduce levels of phosphorylated SLP76 and concomitantly increase IL-2 production by Jurkat T cells. Importantly, our HPK1 inhibitors enhance cytokine production by human and mouse primary T cells above that observed with TCR activation alone. Treatment of mice with orally available HPK1 inhibitors results in increased activation of antigen-specific CD8+ T cells in vivo and decreased tumor growth as single agent and in combination with clinically relevant checkpoint inhibitor antibodies. Our work confirms the importance of HPK1 for T cell function and supports HPK1 as a promising next generation immuno-oncology target.
Citation Format: George Katibah, Yamini Ohol, Cyril Bucher, Lavanya Adusumilli, Deepika Kaveri, Omar Robles, Michael Sun, Cynthia Cho, Heather Milestone, Rachel Ames, Scott Jacobson, Dan Nebalasca, Justy Gomez- Guagua, Jerick Sanchez, Molly Grandcolas, Steve Wong, Martin Brovarney, Chandru Ramana, Thant Zaw, Lan Nguyen, Parcharee Tivitmahaisoon, Andrew Ng, Anqi Ma, Blanca Gomez, Michelle Ko, Paul Leger, Jeffrey Jackson, Grant Shibuya, Anton Shakhmin, Delia Bradford, Mengshu Xu, Mikhail Zibinsky, Daniel Poon, David Wustrow, Paul Kassner, Dirk Brockstedt. Development of small-molecule HPK1 inhibitors to unleash tumor-specific T cell responses [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 1646.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | - Steve Wong
- RAPT Therapeutics, South San Francisco, CA
| | | | | | - Thant Zaw
- RAPT Therapeutics, South San Francisco, CA
| | - Lan Nguyen
- RAPT Therapeutics, South San Francisco, CA
| | | | - Andrew Ng
- RAPT Therapeutics, South San Francisco, CA
| | - Anqi Ma
- RAPT Therapeutics, South San Francisco, CA
| | | | | | - Paul Leger
- RAPT Therapeutics, South San Francisco, CA
| | | | | | | | | | - Mengshu Xu
- RAPT Therapeutics, South San Francisco, CA
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7
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Robles O, Jackson JJ, Marshall L, Talay O, Chian D, Cutler G, Diokno R, Hu DX, Jacobson S, Karbarz E, Kassner PD, Ketcham JM, McKinnell J, Meleza C, Reilly MK, Riegler E, Shunatona HP, Wadsworth A, Younai A, Brockstedt DG, Wustrow DJ, Zibinsky M. Novel Piperidinyl-Azetidines as Potent and Selective CCR4 Antagonists Elicit Antitumor Response as a Single Agent and in Combination with Checkpoint Inhibitors. J Med Chem 2020; 63:8584-8607. [PMID: 32667798 DOI: 10.1021/acs.jmedchem.0c00988] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The C-C chemokine receptor 4 (CCR4) is broadly expressed on regulatory T cells (Treg) as well as other circulating and tissue-resident T cells. Treg can be recruited to the tumor microenvironment (TME) through the C-C chemokines CCL17 and CCL22. Treg accumulation in the TME has been shown to dampen the antitumor immune response and is thought to be an important driver in tumor immune evasion. Preclinical and clinical data suggest that reducing the Treg population in the TME can potentiate the antitumor immune response of checkpoint inhibitors. We have developed small-molecule antagonists of CCR4, featuring a novel piperidinyl-azetidine motif, that inhibit the recruitment of Treg into the TME and elicit antitumor responses as a single agent or in combination with an immune checkpoint blockade. The discovery of these potent, selective, and orally bioavailable CCR4 antagonists, and their activity in in vitro and in vivo models, is described herein.
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Affiliation(s)
- Omar Robles
- RAPT Therapeutics, 561 Eccles Avenue, South San Francisco, California 94080, United States
| | - Jeffrey J Jackson
- RAPT Therapeutics, 561 Eccles Avenue, South San Francisco, California 94080, United States
| | - Lisa Marshall
- RAPT Therapeutics, 561 Eccles Avenue, South San Francisco, California 94080, United States
| | - Oezcan Talay
- RAPT Therapeutics, 561 Eccles Avenue, South San Francisco, California 94080, United States
| | - David Chian
- RAPT Therapeutics, 561 Eccles Avenue, South San Francisco, California 94080, United States
| | - Gene Cutler
- RAPT Therapeutics, 561 Eccles Avenue, South San Francisco, California 94080, United States
| | - Raymond Diokno
- RAPT Therapeutics, 561 Eccles Avenue, South San Francisco, California 94080, United States
| | - Dennis X Hu
- RAPT Therapeutics, 561 Eccles Avenue, South San Francisco, California 94080, United States
| | - Scott Jacobson
- RAPT Therapeutics, 561 Eccles Avenue, South San Francisco, California 94080, United States
| | - Emily Karbarz
- RAPT Therapeutics, 561 Eccles Avenue, South San Francisco, California 94080, United States
| | - Paul D Kassner
- RAPT Therapeutics, 561 Eccles Avenue, South San Francisco, California 94080, United States
| | - John M Ketcham
- RAPT Therapeutics, 561 Eccles Avenue, South San Francisco, California 94080, United States
| | - Jenny McKinnell
- RAPT Therapeutics, 561 Eccles Avenue, South San Francisco, California 94080, United States
| | - Cesar Meleza
- RAPT Therapeutics, 561 Eccles Avenue, South San Francisco, California 94080, United States
| | - Maureen K Reilly
- RAPT Therapeutics, 561 Eccles Avenue, South San Francisco, California 94080, United States
| | - Erin Riegler
- RAPT Therapeutics, 561 Eccles Avenue, South San Francisco, California 94080, United States
| | - Hunter P Shunatona
- RAPT Therapeutics, 561 Eccles Avenue, South San Francisco, California 94080, United States
| | - Angela Wadsworth
- RAPT Therapeutics, 561 Eccles Avenue, South San Francisco, California 94080, United States
| | - Ashkaan Younai
- RAPT Therapeutics, 561 Eccles Avenue, South San Francisco, California 94080, United States
| | - Dirk G Brockstedt
- RAPT Therapeutics, 561 Eccles Avenue, South San Francisco, California 94080, United States
| | - David J Wustrow
- RAPT Therapeutics, 561 Eccles Avenue, South San Francisco, California 94080, United States
| | - Mikhail Zibinsky
- RAPT Therapeutics, 561 Eccles Avenue, South San Francisco, California 94080, United States
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8
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Chen R, Zhu M, Chaudhari RR, Robles O, Chen Y, Skillern W, Qin Q, Wierda W, Zhang S, Hull KG, Romo D, Plunkett W. Abstract 1854: Novel pateamine analogs to target the translation initiation factor eIF4A in chronic lymphocytic leukemia. Cancer Res 2019. [DOI: 10.1158/1538-7445.am2019-1854] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
The viability of chronic lymphocytic leukemia (CLL) is critically dependent upon staving off death by apoptosis, a hallmark of CLL pathophysiology. The overexpression of the Bcl-2 family proteins likely play a major role in the apoptosis blockade in CLL, and has been an effective target of CLL therapy. The recognition that Mcl-1, a major component of the anti-apoptotic response, is intrinsically short-lived and must be continually resynthesized suggested a novel therapeutic approach. Pateamine A (PatA), a macrolide marine natural product, inhibits cap-dependent translation by binding to the initiation factor eIF4A. We have previously reported the first total synthesis of PatA. Mechanistic studies suggested that binding of eIF4A to PatA caused the stalling of initiation complexes on mRNA, halting the translation initiation process. In this study, we demonstrated that a synthetic derivative of PatA, des-methyl des-amino PatA (DMDAPatA), blocked mRNA translation, reduced Mcl-1 protein and initiated apoptosis in CLL cells. This action was synergistic with the Bcl-2 antagonist ABT-199, by a mechanism to inhibit the two parallel arms of apoptosis control in CLL. However, avid binding to human plasma proteins limited DMDAPatA potency, precluding further development. To address this, we synthesized a new series of 27 PatA analogs with modifications on various regions of PatA, and screened their toxicity against the primary CLL cells. Any modifications on the side chain, or the rigid binding domain of the PatA macrolide ring led to complete loss of activity. Rather, introduction of an amino group at either the C2 or C3 positions of the flexible region of the macrocycle retained the activity and reduced plasma protein binding, likely through a lowered lipophilicity. We identified three new leads with potent inhibition of proteins synthesis and strong CLL cytotoxicity. They also exhibited greater selectivity towards CLL cells over normal lymphocytes comparing to the parental compound PatA. To gain structural insights into the interaction of the PatA analogs with eIF4A, a homology model of the human eIF4A1 was generated using the closed conformation of the eIF4A3 structure (PDB ID: 2HYI) as a template. The predicted PatA binding site is located at the interface of the N-terminal domain and the C-terminal domain, in between the RNA and ATP binding sites. In silico docking analysis of the PatA analogs to eIF4A correlated with their structure-activity relationships and suggested that these compounds may act by stabilizing the closed conformation of eIF4A. Thus, these novel PatA analogs hold promise for application to cancers within the appropriate biological context, such as CLL.
Citation Format: Rong Chen, Mingzhao Zhu, Rajan R. Chaudhari, Omar Robles, Yuling Chen, Wesley Skillern, Qun Qin, William Wierda, Shuxing Zhang, Kenneth G. Hull, Daniel Romo, William Plunkett. Novel pateamine analogs to target the translation initiation factor eIF4A in chronic lymphocytic leukemia [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 1854.
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Affiliation(s)
- Rong Chen
- 1UT MD Anderson Cancer Ctr., Houston, TX
| | | | | | | | | | | | - Qun Qin
- 1UT MD Anderson Cancer Ctr., Houston, TX
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Jackson JJ, Ketcham JM, Younai A, Abraham B, Biannic B, Beck HP, Bui MHT, Chian D, Cutler G, Diokno R, Hu DX, Jacobson S, Karbarz E, Kassner PD, Marshall L, McKinnell J, Meleza C, Okal A, Pookot D, Reilly MK, Robles O, Shunatona HP, Talay O, Walker JR, Wadsworth A, Wustrow DJ, Zibinsky M. Discovery of a Potent and Selective CCR4 Antagonist That Inhibits Treg Trafficking into the Tumor Microenvironment. J Med Chem 2019; 62:6190-6213. [DOI: 10.1021/acs.jmedchem.9b00506] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Jeffrey J. Jackson
- RAPT Therapeutics, 561 Eccles Avenue, South San Francisco, California 94080, United States
| | - John M. Ketcham
- RAPT Therapeutics, 561 Eccles Avenue, South San Francisco, California 94080, United States
| | - Ashkaan Younai
- RAPT Therapeutics, 561 Eccles Avenue, South San Francisco, California 94080, United States
| | - Betty Abraham
- RAPT Therapeutics, 561 Eccles Avenue, South San Francisco, California 94080, United States
| | - Berenger Biannic
- RAPT Therapeutics, 561 Eccles Avenue, South San Francisco, California 94080, United States
| | - Hilary P. Beck
- RAPT Therapeutics, 561 Eccles Avenue, South San Francisco, California 94080, United States
| | - Minna H. T. Bui
- RAPT Therapeutics, 561 Eccles Avenue, South San Francisco, California 94080, United States
| | - David Chian
- RAPT Therapeutics, 561 Eccles Avenue, South San Francisco, California 94080, United States
| | - Gene Cutler
- RAPT Therapeutics, 561 Eccles Avenue, South San Francisco, California 94080, United States
| | - Raymond Diokno
- RAPT Therapeutics, 561 Eccles Avenue, South San Francisco, California 94080, United States
| | - Dennis X. Hu
- RAPT Therapeutics, 561 Eccles Avenue, South San Francisco, California 94080, United States
| | - Scott Jacobson
- RAPT Therapeutics, 561 Eccles Avenue, South San Francisco, California 94080, United States
| | - Emily Karbarz
- RAPT Therapeutics, 561 Eccles Avenue, South San Francisco, California 94080, United States
| | - Paul D. Kassner
- RAPT Therapeutics, 561 Eccles Avenue, South San Francisco, California 94080, United States
| | - Lisa Marshall
- RAPT Therapeutics, 561 Eccles Avenue, South San Francisco, California 94080, United States
| | - Jenny McKinnell
- RAPT Therapeutics, 561 Eccles Avenue, South San Francisco, California 94080, United States
| | - Cesar Meleza
- RAPT Therapeutics, 561 Eccles Avenue, South San Francisco, California 94080, United States
| | - Abood Okal
- RAPT Therapeutics, 561 Eccles Avenue, South San Francisco, California 94080, United States
| | - Deepa Pookot
- RAPT Therapeutics, 561 Eccles Avenue, South San Francisco, California 94080, United States
| | - Maureen K. Reilly
- RAPT Therapeutics, 561 Eccles Avenue, South San Francisco, California 94080, United States
| | - Omar Robles
- RAPT Therapeutics, 561 Eccles Avenue, South San Francisco, California 94080, United States
| | - Hunter P. Shunatona
- RAPT Therapeutics, 561 Eccles Avenue, South San Francisco, California 94080, United States
| | - Oezcan Talay
- RAPT Therapeutics, 561 Eccles Avenue, South San Francisco, California 94080, United States
| | - James R. Walker
- RAPT Therapeutics, 561 Eccles Avenue, South San Francisco, California 94080, United States
| | - Angela Wadsworth
- RAPT Therapeutics, 561 Eccles Avenue, South San Francisco, California 94080, United States
| | - David J. Wustrow
- RAPT Therapeutics, 561 Eccles Avenue, South San Francisco, California 94080, United States
| | - Mikhail Zibinsky
- RAPT Therapeutics, 561 Eccles Avenue, South San Francisco, California 94080, United States
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Jorapur A, Marshall L, Bradford D, Brovarney M, Chian D, Wadsworth A, Sanchez J, Jacobson S, Karbarz E, Robles O, Younai A, Ketcham J, Ng A, Tivitmahaisoon P, Pookot D, Marubayashi S, Kozon N, Colas C, Okal A, Cutler G, Wustrow D, Schwarz J, Talay O, Brockstedt D, Wong B. FLX193: A Potent, Selective CCR4 Antagonist for Allergic Disorders. The Journal of Immunology 2019. [DOI: 10.4049/jimmunol.202.supp.119.5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Abstract
Type 2 helper T cells (Th2)cells have been shown to express CCR4 receptor, and play a critical role in driving the pathogenesis of asthma and atopic dermatitis. FLX193 is a best-in-class, highly-potent and selective small molecule CCR4 antagonist under investigation for the treatment of allergic disorders. FLX193 blocked migration of CCR4+ Th2 cells (human and mouse) towards CCL17 and CCL22 in an in vitro chemotaxis assay. FLX193 is well-tolerated in animals at efficacious doses. In an Ovalbumin (OVA)-induced asthma model, FLX193 significantly reduced lymphocyte and eosinophil counts in the Bronchoalveolar lavage (BAL) fluid and showed a reduction of the effector Th2-relevant cytokines IL-5 and IL-13. FLX193 treatment also reduced the levels of CCL17 and CCL22 in the BAL fluid, indicating an overall reduction of inflammation. In addition, we used an atopic dermatitis mouse model to demonstrate that treatment with FLX193 decreased CCR4+ T-cell mediated inflammation. Hence, FLX193 shows promise in the treatment of atopic dermatitis.
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Chen R, Zhu M, Chaudhari RR, Robles O, Chen Y, Skillern W, Qin Q, Wierda WG, Zhang S, Hull KG, Romo D, Plunkett W. Creating novel translation inhibitors to target pro-survival proteins in chronic lymphocytic leukemia. Leukemia 2019; 33:1663-1674. [DOI: 10.1038/s41375-018-0364-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2018] [Revised: 10/30/2018] [Accepted: 12/03/2018] [Indexed: 12/20/2022]
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Talay O, Marshall L, Meleza C, Reilly MK, Robles O, Zibisky M, Okal A, Seitz L, McKinnell J, Jacobson S, Riegler E, Karbaz E, Chian D, Wadsworth A, Kassner P, Wustrow D, Fridman JS. Abstract 4600: Potent and selective C-C chemokine receptor (CCR4) antagonists potentiate anti-tumor immune responses by inhibiting regulatory T cells (Treg). Cancer Res 2017. [DOI: 10.1158/1538-7445.am2017-4600] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Naturally suppressive CD4+ Foxp3+ Treg are essential for immune tolerance. Although Treg-mediated suppression of effector cells is important to control inflammation and prevent autoimmune diseases, the presence of Treg in the tumor microenvironment (TME) has been shown to dampen anti-tumor immune responses. Human Treg express CCR4, the receptor for the chemokines CCL17 and CCL22. These chemokines are produced by tumor cells, tumor-associated macrophages and dendritic cells, as well as by effector T cells (Teff). Preclinical and clinical data supports a role for CCR4-mediated recruitment and accumulation of Treg in the TME which can be associated with poor prognosis. Further, recent longitudinal studies in patients receiving IO agents demonstrate an influx of Treg in responding patients which may dampen optimal anti-tumor responses. Therefore, CCR4 is an ideal target to selectively block Treg recruitment into the TME.
We have developed structurally unique series of small molecule antagonists of CCR4. These antagonists have cellular potencies in multiple assays (e.g. chemotaxis of primary human Treg in 100% serum) in the low double-digit nM range. Representative compounds are selective against other chemokine receptors, GPCRs and ion channels, including the hERG channel, and lack inhibition of common human CYP450 enzymes. Moreover, compounds have excellent in vitro and in vivo ADME properties, consistent with convenient oral dosing. In preclinical syngeneic tumor models, these CCR4 antagonists block Treg migration and support expansion of activated Teff. In contrast to the non-selective approach of depleting anti-CCR4 antibodies, our compounds reduce Treg in the tumor, but not in peripheral tissues such as blood, spleen or skin. In preclinical efficacy studies, CCR4 antagonists potentiate the anti-tumor effects of various checkpoint inhibitors and immune stimulators such as anti-PD-L1 and anti-CD137 antibodies. We observe enhanced tumor growth inhibition and increased tumor regressions when these agents are combined with CCR4 antagonists, without any gross toxicity. Further characterization of these CCR4 antagonists and their anti-tumor effects will be described.
Citation Format: Oezcan Talay, Lisa Marshall, Cesar Meleza, Maureen K. Reilly, Omar Robles, Mikhail Zibisky, Abood Okal, Lisa Seitz, Jenny McKinnell, Scott Jacobson, Erin Riegler, Emily Karbaz, David Chian, Angela Wadsworth, Paul Kassner, David Wustrow, Jordan S. Fridman. Potent and selective C-C chemokine receptor (CCR4) antagonists potentiate anti-tumor immune responses by inhibiting regulatory T cells (Treg) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 4600. doi:10.1158/1538-7445.AM2017-4600
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Zhu M, Harshbarger WD, Robles O, Krysiak J, Hull KG, Cho SW, Richardson RD, Yang Y, Garcia A, Spiegelman L, Ramirez B, Wilson CT, Yau JA, Moore JT, Walker CB, Sacchettini JC, Liu WR, Sieber SA, Smith JW, Romo D. A strategy for dual inhibition of the proteasome and fatty acid synthase with belactosin C-orlistat hybrids. Bioorg Med Chem 2017; 25:2901-2916. [PMID: 28236510 PMCID: PMC5522751 DOI: 10.1016/j.bmc.2017.01.020] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2016] [Accepted: 01/13/2017] [Indexed: 11/21/2022]
Abstract
The proteasome, a validated cellular target for cancer, is central for maintaining cellular homeostasis, while fatty acid synthase (FAS), a novel target for numerous cancers, is responsible for palmitic acid biosynthesis. Perturbation of either enzymatic machine results in decreased proliferation and ultimately cellular apoptosis. Based on structural similarities, we hypothesized that hybrid molecules of belactosin C, a known proteasome inhibitor, and orlistat, a known inhibitor of the thioesterase domain of FAS, could inhibit both enzymes. Herein, we describe proof-of-principle studies leading to the design, synthesis and enzymatic activity of several novel, β-lactone-based, dual inhibitors of these two enzymes. Validation of dual enzyme targeting through activity-based proteome profiling with an alkyne probe modeled after the most potent inhibitor, and preliminary serum stability studies of selected derivatives are also described. These results provide proof of concept for dual targeting of the proteasome and fatty acid synthase-thioesterase (FAS-TE) enabling a new approach for the development of drug-candidates with potential to overcome resistance.
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Affiliation(s)
- Mingzhao Zhu
- Department of Chemistry & Biochemistry and CPRIT Synthesis and Drug-Lead Discovery Laboratory, Baylor University, Waco, TX 76706, USA
| | - Wayne D Harshbarger
- Department of Biochemistry & Biophysics, Texas A&M University, College Station, TX 77840, USA
| | - Omar Robles
- Department of Chemistry, Texas A&M University, College Station, TX 77842, USA
| | - Joanna Krysiak
- Department of Chemistry, Technische Universität München, Lichtenbergstr. 4, 85747 Garching, Germany
| | - Kenneth G Hull
- Department of Chemistry & Biochemistry and CPRIT Synthesis and Drug-Lead Discovery Laboratory, Baylor University, Waco, TX 76706, USA
| | - Sung Wook Cho
- Department of Chemistry, Texas A&M University, College Station, TX 77842, USA
| | | | - Yanyan Yang
- Department of Chemistry, Texas A&M University, College Station, TX 77842, USA
| | - Andres Garcia
- Department of Chemistry, Texas A&M University, College Station, TX 77842, USA
| | - Lindsey Spiegelman
- Department of Chemistry, Texas A&M University, College Station, TX 77842, USA
| | - Bianca Ramirez
- Department of Chemistry, Texas A&M University, College Station, TX 77842, USA
| | | | - Ju Anne Yau
- Department of Chemistry, Texas A&M University, College Station, TX 77842, USA
| | - James T Moore
- Department of Chemistry, Texas A&M University, College Station, TX 77842, USA
| | - Caitlen B Walker
- Department of Chemistry, Texas A&M University, College Station, TX 77842, USA
| | - James C Sacchettini
- Department of Biochemistry & Biophysics, Texas A&M University, College Station, TX 77840, USA
| | - Wenshe R Liu
- Department of Chemistry, Texas A&M University, College Station, TX 77842, USA
| | - Stephan A Sieber
- Department of Chemistry, Technische Universität München, Lichtenbergstr. 4, 85747 Garching, Germany
| | - Jeffrey W Smith
- Sanford Burnham Medical Research Institute, La Jolla, CA, USA
| | - Daniel Romo
- Department of Chemistry & Biochemistry and CPRIT Synthesis and Drug-Lead Discovery Laboratory, Baylor University, Waco, TX 76706, USA.
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Abstract
Even though syphilis can be prevented effectively and treated inexpensively, it has remained a global public health problem. Untreated congenital syphilis results in neonatal death, stillbirth, preterm birth, or congenital deformities. Many developing countries have recently instituted syphilis prevention programs in antenatal care, but there has not been a systematic study of the effects of such programs. This paper is the first to study antenatal testing laws initiated in the U.S. in 1938-1947 which mandated physicians and other persons permitted by law to attend to a pregnant woman to test her for syphilis. We use the variation in the timing of state antenatal testing laws to estimate the laws' effect on neonatal mortality rates and deaths due to preterm birth. Using 1931-1947 Vital Statistics data, we find that these laws decreased neonatal mortality rates of nonwhites by 3.15 per 1000 live births (a 8.6% reduction) while having no discernible impact on whites. The laws contributed to an 18% narrowing of the white-nonwhite neonatal mortality gap by 1947. Using 1950 U.S. Census data, we find that mandatory antenatal testing led to a 7% increase in the cohort size of nonwhite poor, which is consistent with the neonatal mortality results. We find universal antenatal testing to be very cost-effective, with an estimated $7600 cost (in 2013 dollars) per life-year saved.
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Affiliation(s)
- Winnie Fung
- Department of Business and Economics, Wheaton College, 501 College Avenue, Wheaton, IL 60187, United States.
| | - Omar Robles
- U.S. Bureau of Labor Statistics, 2 Massachusetts Avenue, NE, Washington, DC 20212, United States.
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Robles O, Bruce J, Atkinson HG, Buscher D, Scriven K, Kim Bart K, French S. Statement and Action Agenda from the Girls in Emergencies
Collaborative. Ann Glob Health 2015; 81:331-2. [DOI: 10.1016/j.aogh.2015.08.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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Abstract
Bioactive natural products and derivatives remain an enduring starting point for the discovery of new cellular targets for disease intervention and lead compounds for the development of new therapeutic agents. The former goal is accomplished through the synthesis of bioactive cellular probes from natural products, enabling insights into the mechanism of action of these natural products by classical affinity chromatography or more recent proteome profiling methods. However, the direct and selective modification of native natural products for these purposes remains a challenge due to the structural complexity and the wide functional group diversity found in these natural substances. The lack of selective synthetic methods available to directly manipulate unprotected complex small molecules, in particular to perform structure-activity relationship studies and prepare appropriate cellular probes, has recently begun to be addressed, benefitting from the broader emerging area of chemoselective synthetic methodology. Thus, new reagents, catalysts and reaction processes are enabling both chemo- and site-selective modifications of complex, native natural products. In this review, we describe selected recent examples of these functionalization strategies in this emerging area.
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Affiliation(s)
- Omar Robles
- Department of Chemistry, Texas A&M University, College Station, Texas 77842-3012, USA.
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Ranieri B, Robles O, Romo D. Correction to “Concise Synthesis of the Isothiourea Organocatalysts Homobenzotetramisole and Derivatives”. J Org Chem 2013. [DOI: 10.1021/jo4015485] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Affiliation(s)
- Beatrice Ranieri
- Department of Chemistry, Texas A&M University, P.O. Box 30012, College Station, Texas 77842-3012, United States
| | - Omar Robles
- Department of Chemistry, Texas A&M University, P.O. Box 30012, College Station, Texas 77842-3012, United States
| | - Daniel Romo
- Department of Chemistry, Texas A&M University, P.O. Box 30012, College Station, Texas 77842-3012, United States
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Robles O, Serna-Saldívar SO, Gutiérrez-Uribe JA, Romo D. Cyclopropanations of olefin-containing natural products for simultaneous arming and structure activity studies. Org Lett 2012; 14:1394-7. [PMID: 22360738 DOI: 10.1021/ol300105q] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Cyclopropanations of alkene-containing natural products that proceed under mild conditions are reported for simultaneous arming and structure-activity relationship studies. An alkynyl diazo ester under Rh(II) catalysis is employed for cyclopropanations of electron-rich olefins while an alkynyl sulfonium ylide is used for electron-poor olefins. This approach enables simultaneous natural product derivatization for SAR studies and arming (i.e., via alkyne attachment) for subsequent conjugation with reporter tags (e.g., biotin, fluorophores, photoaffinity labels) for mechanism of action studies including cellular target identification and proteome profiling experiments.
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Affiliation(s)
- Omar Robles
- Department of Chemistry, Texas A&M University, P.O. Box 30012, College Station, Texas 77842-3012, United States
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Pajares S, González C, Robles O, Casado P, Gómez A, Cuenca C, Ramiro M, Hita L, Villar E, Fernandez R. 185 DUAL-TASK PROGRAM TRAINING IN PATIENTS WITH ACQUIRED BRAIN INJURY. Parkinsonism Relat Disord 2010. [DOI: 10.1016/s1353-8020(10)70186-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Robles O, McDonald FE. Convergent Synthesis of Fostriecin via Selective Alkene Couplings and Regioselective Asymmetric Dihydroxylation. Org Lett 2009; 11:5498-501. [DOI: 10.1021/ol902365n] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Omar Robles
- Department of Chemistry, Emory University, Atlanta, Georgia 30322
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Desco M, Sanchez-González J, Robles O, Navas J, Reig S, Franco C, de Villoria JG, García-Barreno P, Arango C. fMRI study of math-gifted adolescents and controls while performing the Raven Progressive Matrices task. Neuroimage 2009. [DOI: 10.1016/s1053-8119(09)71002-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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Crespo-Leiro MG, Robles O, Paniagua MJ, Marzoa R, Naya C, Flores X, Suárez F, Gómez M, Grille Z, Cuenca JJ, Castro-Beiras A, Arnal F. Reversal of cardiac cirrhosis following orthotopic heart transplantation. Am J Transplant 2008; 8:1336-9. [PMID: 18444927 DOI: 10.1111/j.1600-6143.2008.02227.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Irreversible hepatic cirrhosis greatly increases the risks attending heart transplantation (HT), and is accordingly considered to be an absolute contraindication for HT unless combined heart and liver transplantation can be performed. It is now recognized that hepatic cirrhosis can undergo regression if the source of insult is removed, but no cases of post-HT regression of cirrhosis of cardiac origin have hitherto been reported. Here we report a case of cardiac cirrhosis that underwent complete regression following orthotopic HT, and we discuss the implications of this case.
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Affiliation(s)
- M G Crespo-Leiro
- Heart Failure and Heart Transplantation Unit, Complejo Hospitalario Universitario Juan Canalejo, La Coruña, Spain.
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Affiliation(s)
- Omar Robles
- Department of Chemistry, Emory University, Atlanta, Georgia 30322
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25
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Fernández-Torres R, Almagro M, del Pozo J, Robles O, Martínez-González C, Mazaira M, Fonseca E. [Lichenoid drug eruption induced by olanzapine]. Actas Dermosifiliogr 2008; 99:221-224. [PMID: 18358199] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/26/2023] Open
Abstract
Lichenoid drug eruptions can mimic idiopathic lichen planus and other dermatoses. The list of drugs that can cause them is long and growing steadily. Although cutaneous side effects of antipsychotics are rare, various cutaneous manifestations have been reported in association with olanzapine. We present the case of a patient who developed an atypical lichenoid eruption due to olanzapine. A review of the literature in Medline from 1951 to 2007 and in the Indice Médico Español (Spanish Medical Index) revealed no previous cases of lichenoid eruptions associated with the use of this drug.
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Fernández-Torres R, Almagro M, del Pozo J, Robles O, Martínez-González C, Mazaira M, Fonseca E. Lichenoid Drug Eruption Induced by Olanzapine. Actas Dermo-Sifiliográficas (English Edition) 2008. [DOI: 10.1016/s1578-2190(08)70236-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
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Zabala A, Bombin I, Rapado M, Andres P, Gonzalez C, Mayoral M, Robles O, Rodriguez J, de la Serna E, Arango C. Neuropsychological functioning in early-onset first-episode psychosis: lack of differences among diagnostic subgroups. Eur Psychiatry 2007. [DOI: 10.1016/j.eurpsy.2007.01.467] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
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Favela J, Natsu H, Pérez C, Robles O, Morán AL, Romero R, Martínez-Enríquez AM, Decouchant D. Empirical Evaluation of Collaborative Support for Distributed Pair Programming. Groupware: Design, Implementation, and Use 2004. [DOI: 10.1007/978-3-540-30112-7_18] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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Robles O. [Development of human resources]. Rev Med Chil 1998; 126:26-33. [PMID: 9838278] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
The purposes, objectives and strategies of WHO for the development of human resources are described and commented. The implication of this programme were emphasized in relation to the strategy of primary health care. The mediate and longterm plans are analyzed, underlining the fellowship activities and the training of academic personnel.
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Gutierrez O, Nawrath J, Bravo I, Cariola N, Freile B, Janzana J, Budinic M, Mikacic P, Muñoz E, Dekovic J, Bejarano J, Robles O. [Administration in the National Health Service. Problems and recommendations]. Rev Med Chil 1970; 98:124-32. [PMID: 5455809] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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