1
|
Thornton P, Reader V, Digby Z, Smolak P, Lindsay N, Harrison D, Clarke N, Watt AP. Reversal of High Fat Diet-Induced Obesity, Systemic Inflammation, and Astrogliosis by the NLRP3 Inflammasome Inhibitors NT-0249 and NT-0796. J Pharmacol Exp Ther 2024; 388:813-826. [PMID: 38336379 DOI: 10.1124/jpet.123.002013] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2023] [Revised: 12/14/2023] [Accepted: 01/02/2024] [Indexed: 02/12/2024] Open
Abstract
Systemic and cerebral inflammatory responses are implicated in the pathogenesis of obesity and associated metabolic impairment. While the NOD-, LRR-, and pyrin domain-containing protein 3 (NLRP3) inflammasome has been linked to obesity-associated inflammation, whether it contributes to the development or maintenance of obesity is unknown. We provide support for a direct role of saturated fatty acids, such as palmitic acid, as NLRP3 activating stimuli in obese states. To investigate whether NLRP3 activation contributes to the pathogenesis of diet-induced obesity (DIO) in mice, we tested two different clinical-stage NLRP3 inflammasome inhibitors. We demonstrate a contributory role of this key inflammasome to established obesity and associated systemic and cerebral inflammation. By comparing their effects to calorie restriction, we aimed to identify specific NLRP3-sensitive mechanisms contributing to obesity-induced inflammation (as opposed to be those regulated by weight loss per se). In addition, a direct comparison of an NLRP3 inhibitor to a glucagon like peptide-1 receptor agonist, semaglutide (Wegovy), in the DIO model allowed an appreciation of the relative efficacy of these two therapeutic strategies on obesity, its associated systemic inflammatory response, and cerebral gliosis. We show that two structurally distinct, NLRP3 inhibitors, NT-0249 and NT-0796, reverse obesity in the DIO mouse model and that brain exposure appears necessary for efficacy. In support of this, we show that DIO-driven hypothalamic glial fibrillary acidic protein expression is blocked by dosing with NT-0249/NT-0796. While matching weight loss driven by semaglutide or calorie restriction, remarkably, NLRP3 inhibition provided enhanced improvements in disease-relevant biomarkers of acute phase response, cardiovascular inflammation, and lipid metabolism. SIGNIFICANCE STATEMENT: Obesity is a global health concern that predisposes individuals to chronic disease such as diabetes and cardiovascular disease at least in part by promoting systemic inflammation. We report that in mice fed a high-fat, obesogenic diet, obesity is reversed by either of two inhibitors of the intracellular inflammatory mediator NLRP3. Furthermore, NLRP3 inhibition reduces both hypothalamic gliosis and circulating biomarkers of cardiovascular disease risk beyond what can be achieved by either the glucagon like peptide-1 agonist semaglutide or calorie restriction alone.
Collapse
Affiliation(s)
- Peter Thornton
- NodThera, Cambridge, United Kingdom (P.T., V.R., Z.D., N.L., D.H., N.C., A.P.W.) and Seattle, Washington (P.S.)
| | - Valérie Reader
- NodThera, Cambridge, United Kingdom (P.T., V.R., Z.D., N.L., D.H., N.C., A.P.W.) and Seattle, Washington (P.S.)
| | - Zsofia Digby
- NodThera, Cambridge, United Kingdom (P.T., V.R., Z.D., N.L., D.H., N.C., A.P.W.) and Seattle, Washington (P.S.)
| | - Pamela Smolak
- NodThera, Cambridge, United Kingdom (P.T., V.R., Z.D., N.L., D.H., N.C., A.P.W.) and Seattle, Washington (P.S.)
| | - Nicola Lindsay
- NodThera, Cambridge, United Kingdom (P.T., V.R., Z.D., N.L., D.H., N.C., A.P.W.) and Seattle, Washington (P.S.)
| | - David Harrison
- NodThera, Cambridge, United Kingdom (P.T., V.R., Z.D., N.L., D.H., N.C., A.P.W.) and Seattle, Washington (P.S.)
| | - Nick Clarke
- NodThera, Cambridge, United Kingdom (P.T., V.R., Z.D., N.L., D.H., N.C., A.P.W.) and Seattle, Washington (P.S.)
| | - Alan P Watt
- NodThera, Cambridge, United Kingdom (P.T., V.R., Z.D., N.L., D.H., N.C., A.P.W.) and Seattle, Washington (P.S.)
| |
Collapse
|
2
|
McCoull W, Boyd S, Brown MR, Coen M, Collingwood O, Davies NL, Doherty A, Fairley G, Goldberg K, Hardaker E, He G, Hennessy EJ, Hopcroft P, Hodgson G, Jackson A, Jiang X, Karmokar A, Lainé AL, Lindsay N, Mao Y, Markandu R, McMurray L, McLean N, Mooney L, Musgrove H, Nissink JWM, Pflug A, Reddy VP, Rawlins PB, Rivers E, Schimpl M, Smith GF, Tentarelli S, Travers J, Troup RI, Walton J, Wang C, Wilkinson S, Williamson B, Winter-Holt J, Yang D, Zheng Y, Zhu Q, Smith PD. Optimization of an Imidazo[1,2- a]pyridine Series to Afford Highly Selective Type I1/2 Dual Mer/Axl Kinase Inhibitors with In Vivo Efficacy. J Med Chem 2021; 64:13524-13539. [PMID: 34478292 DOI: 10.1021/acs.jmedchem.1c00920] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Inhibition of Mer and Axl kinases has been implicated as a potential way to improve the efficacy of current immuno-oncology therapeutics by restoring the innate immune response in the tumor microenvironment. Highly selective dual Mer/Axl kinase inhibitors are required to validate this hypothesis. Starting from hits from a DNA-encoded library screen, we optimized an imidazo[1,2-a]pyridine series using structure-based compound design to improve potency and reduce lipophilicity, resulting in a highly selective in vivo probe compound 32. We demonstrated dose-dependent in vivo efficacy and target engagement in Mer- and Axl-dependent efficacy models using two structurally differentiated and selective dual Mer/Axl inhibitors. Additionally, in vivo efficacy was observed in a preclinical MC38 immuno-oncology model in combination with anti-PD1 antibodies and ionizing radiation.
Collapse
Affiliation(s)
| | - Scott Boyd
- Oncology R&D, AstraZeneca, Cambridge CB4 0WG, U.K
| | - Martin R Brown
- Discovery Sciences, R&D, AstraZeneca, Cambridge CB4 0WG, U.K
| | - Muireann Coen
- Clinical Pharmacology & Safety Sciences, BioPharmaceuticals R&D, AstraZeneca, Cambridge CB4 0WG, U.K
| | | | | | - Ann Doherty
- Clinical Pharmacology & Safety Sciences, BioPharmaceuticals R&D, AstraZeneca, Cambridge CB4 0WG, U.K
| | - Gary Fairley
- Oncology R&D, AstraZeneca, Cambridge CB4 0WG, U.K
| | | | | | - Guang He
- Pharmaron Beijing Co., Ltd., 6 Taihe Road BDA, Beijing 100176, P. R. China
| | - Edward J Hennessy
- Oncology R&D, AstraZeneca, Gatehouse Park, Waltham, Massachusetts 02451, United States
| | - Philip Hopcroft
- Discovery Sciences, R&D, AstraZeneca, Cambridge CB4 0WG, U.K
| | - George Hodgson
- Discovery Sciences, R&D, AstraZeneca, Cambridge CB4 0WG, U.K
| | - Anne Jackson
- Discovery Sciences, R&D, AstraZeneca, Cambridge CB4 0WG, U.K
| | - Xiefeng Jiang
- Pharmaron Beijing Co., Ltd., 6 Taihe Road BDA, Beijing 100176, P. R. China
| | - Ankur Karmokar
- Oncology R&D, AstraZeneca, Mereside, Alderley Park, Macclesfield SK10 4TG, U.K
| | - Anne-Laure Lainé
- Pharmaceutical Sciences, BioPharmaceuticals R&D, AstraZeneca, Cambridge CB4 0WG, U.K
| | | | - Yumeng Mao
- Oncology R&D, AstraZeneca, Cambridge CB4 0WG, U.K
| | | | | | | | - Lorraine Mooney
- Oncology R&D, AstraZeneca, Mereside, Alderley Park, Macclesfield SK10 4TG, U.K
| | - Helen Musgrove
- Oncology R&D, AstraZeneca, Mereside, Alderley Park, Macclesfield SK10 4TG, U.K
| | | | - Alexander Pflug
- Discovery Sciences, R&D, AstraZeneca, Cambridge CB4 0WG, U.K
| | - Venkatesh Pilla Reddy
- Clinical Pharmacology & Safety Sciences, BioPharmaceuticals R&D, AstraZeneca, Cambridge CB4 0WG, U.K
| | | | - Emma Rivers
- Discovery Sciences, R&D, AstraZeneca, Cambridge CB4 0WG, U.K
| | | | - Graham F Smith
- Clinical Pharmacology & Safety Sciences, BioPharmaceuticals R&D, AstraZeneca, Cambridge CB4 0WG, U.K
| | - Sharon Tentarelli
- Oncology R&D, AstraZeneca, Gatehouse Park, Waltham, Massachusetts 02451, United States
| | - Jon Travers
- Oncology R&D, AstraZeneca, Cambridge CB4 0WG, U.K
| | | | | | - Cheng Wang
- Pharmaron Beijing Co., Ltd., 6 Taihe Road BDA, Beijing 100176, P. R. China
| | | | | | | | - Dejian Yang
- Pharmaron Beijing Co., Ltd., 6 Taihe Road BDA, Beijing 100176, P. R. China
| | - Yuting Zheng
- Pharmaron Beijing Co., Ltd., 6 Taihe Road BDA, Beijing 100176, P. R. China
| | - Qianxiu Zhu
- Pharmaron Beijing Co., Ltd., 6 Taihe Road BDA, Beijing 100176, P. R. China
| | - Paul D Smith
- Oncology R&D, AstraZeneca, Cambridge CB4 0WG, U.K
| |
Collapse
|
3
|
Baldwin DS, Dang M, Farquharson L, Fitzpatrick N, Lindsay N, Quirk A, Rhodes E, Shah P, Williams R, Crawford MJ. Quality of English inpatient mental health services for people with anxiety or depressive disorders: Findings and recommendations from the core audit of the National Clinical Audit of Anxiety and Depression. Compr Psychiatry 2021; 104:152212. [PMID: 33160123 DOI: 10.1016/j.comppsych.2020.152212] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Revised: 09/04/2020] [Accepted: 09/17/2020] [Indexed: 10/23/2022] Open
Abstract
BACKGROUND Clinical audit is a sustained cyclical quality improvement process seeking to improve patient care and outcomes by evaluating services against explicit standards and implementing necessary changes. National audits aim to improve population-level clinical care by identifying unwarranted variations and making recommendations for clinicians, managers and service commissioners. The National Clinical Audit of Anxiety and Depression aimed to improve clinical care for people admitted to English hospitals for treatment of anxiety and depression, to provide comparative data on quality of care, and to support local quality improvement initiatives by identifying and sharing examples of best practice. PROCEDURES Thirteen standards were developed based on NICE guidelines, literature review and feedback from a steering committee and reference group of service users and carers. All providers of NHS inpatient mental health services in England were asked to submit details of between 20 and 100 eligible service users/patients admitted between April 2017 and September 2018. To ascertain data reliability, participating services re-audited 5 sets of case-notes with a second auditor, and the coordinating team checked 10 randomly-selected sets of case-notes from 3 services, also selected at random. The reference group and steering committee identified key findings and developed a series of recommendations, which were discussed in regional quality improvement workshops and on-line webinars. FINDINGS Data from 3795 case notes were analysed. A sizeable proportion of records indicated that at least one important aspect of initial assessment was not documented. Many service users/patients who could have benefited from an intervention targeted at optimising physical health did not receive it. Only a minority (39%) were referred for psychological therapy. Use of outcome measures varied considerably but no single outcome measure was being used routinely. Most individuals had a care plan recorded in the notes, but a review date was documented in only two-thirds, and almost half of individuals had not received a copy. CONCLUSIONS There was considerable variation between English mental health services across many variables, and much scope for improvement. Clinicians should ensure that care plans are developed collaboratively with service users/patients and identified carers should be provided with information about support services. Health services should investigate the reasons for low referral rates for psychological therapies. Clinicians should ensure all service users have jointly developed crisis plans in place at discharge. Service managers should agree outcome measures to evaluate the treatment provided and clinicians should use these measures at initial assessment and review appointments. The implementation of such changes provides an opportunity for collaborative research into mental health service delivery and quality.
Collapse
Affiliation(s)
- D S Baldwin
- NCAAD Clinical Lead, Royal College of Psychiatrists, United Kingdom; Psychiatry, Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, United Kingdom; University Department of Psychiatry and Mental Health, University of Cape Town, Cate Town, South Africa.
| | - M Dang
- NCAAD Programme Manager, Royal College of Psychiatrists, United Kingdom
| | - L Farquharson
- Clinical Advisor to the Spotlight Audits, Royal College of Psychiatrists, United Kingdom; Clinical Psychology, University of East London, United Kingdom
| | - N Fitzpatrick
- NCAAD Project Officer, Royal College of Psychiatrists, United Kingdom
| | - N Lindsay
- NCAAD Project Officer, Royal College of Psychiatrists, United Kingdom
| | - A Quirk
- CCQI Head of Clinical Audit and Research, Royal College of Psychiatrists, United Kingdom
| | - E Rhodes
- NCAAD Deputy Programme Manager, Royal College of Psychiatrists, United Kingdom
| | - P Shah
- NCAAD Service User Advisor, Royal College of Psychiatrists, United Kingdom
| | - R Williams
- CCQI Clinical Fellow, Royal College of Psychiatrists, United Kingdom; Department of Brain Sciences, Imperial College London, United Kingdom
| | - M J Crawford
- College Centre for Quality Improvement, Royal College of Psychiatrists, United Kingdom; Mental Health Research, Faculty of Medicine, Imperial College London, United Kingdom
| |
Collapse
|
4
|
Flemington V, Davies EJ, Robinson D, Sandin LC, Delpuech O, Zhang P, Hanson L, Farrington P, Bell S, Falenta K, Gibbons FD, Lindsay N, Smith A, Wilson J, Roberts K, Tonge M, Hopcroft P, Willis SE, Roudier MP, Rooney C, Coker EA, Jaaks P, Garnett MJ, Fawell SE, Jones CD, Ward RA, Simpson I, Cosulich SC, Pease JE, Smith PD. AZD0364 Is a Potent and Selective ERK1/2 Inhibitor That Enhances Antitumor Activity in KRAS-Mutant Tumor Models when Combined with the MEK Inhibitor, Selumetinib. Mol Cancer Ther 2020; 20:238-249. [PMID: 33273059 DOI: 10.1158/1535-7163.mct-20-0002] [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] [Received: 01/07/2020] [Revised: 07/13/2020] [Accepted: 11/06/2020] [Indexed: 11/16/2022]
Abstract
The RAS-regulated RAF-MEK1/2-ERK1/2 (RAS/MAPK) signaling pathway is a major driver in oncogenesis and is frequently dysregulated in human cancers, primarily by mutations in BRAF or RAS genes. The clinical benefit of inhibitors of this pathway as single agents has only been realized in BRAF-mutant melanoma, with limited effect of single-agent pathway inhibitors in KRAS-mutant tumors. Combined inhibition of multiple nodes within this pathway, such as MEK1/2 and ERK1/2, may be necessary to effectively suppress pathway signaling in KRAS-mutant tumors and achieve meaningful clinical benefit. Here, we report the discovery and characterization of AZD0364, a novel, reversible, ATP-competitive ERK1/2 inhibitor with high potency and kinase selectivity. In vitro, AZD0364 treatment resulted in inhibition of proximal and distal biomarkers and reduced proliferation in sensitive BRAF-mutant and KRAS-mutant cell lines. In multiple in vivo xenograft models, AZD0364 showed dose- and time-dependent modulation of ERK1/2-dependent signaling biomarkers resulting in tumor regression in sensitive BRAF- and KRAS-mutant xenografts. We demonstrate that AZD0364 in combination with the MEK1/2 inhibitor, selumetinib (AZD6244 and ARRY142886), enhances efficacy in KRAS-mutant preclinical models that are moderately sensitive or resistant to MEK1/2 inhibition. This combination results in deeper and more durable suppression of the RAS/MAPK signaling pathway that is not achievable with single-agent treatment. The AZD0364 and selumetinib combination also results in significant tumor regressions in multiple KRAS-mutant xenograft models. The combination of ERK1/2 and MEK1/2 inhibition thereby represents a viable clinical approach to target KRAS-mutant tumors.
Collapse
Affiliation(s)
- Vikki Flemington
- Bioscience, Oncology R&D, AstraZeneca, Cambridge, England, United Kingdom.
| | - Emma J Davies
- Bioscience, Oncology R&D, AstraZeneca, Cambridge, England, United Kingdom
| | - David Robinson
- Bioscience, Oncology R&D, AstraZeneca, Cambridge, England, United Kingdom
| | - Linda C Sandin
- Bioscience, Oncology R&D, AstraZeneca, Cambridge, England, United Kingdom
| | - Oona Delpuech
- Bioscience, Oncology R&D, AstraZeneca, Cambridge, England, United Kingdom
| | - Pei Zhang
- Bioscience, Oncology R&D, AstraZeneca, Cambridge, England, United Kingdom
| | - Lyndsey Hanson
- Bioscience, Oncology R&D, AstraZeneca, Cambridge, England, United Kingdom
| | - Paul Farrington
- Bioscience, Oncology R&D, AstraZeneca, Cambridge, England, United Kingdom
| | - Sigourney Bell
- Bioscience, Oncology R&D, AstraZeneca, Cambridge, England, United Kingdom
| | - Katarzyna Falenta
- Bioscience, Oncology R&D, AstraZeneca, Cambridge, England, United Kingdom
| | - Francis D Gibbons
- DMPK, Oncology, Oncology R&D, AstraZeneca, Cambridge, England, United Kingdom and Waltham, Massachusetts
| | - Nicola Lindsay
- DMPK, Oncology, Oncology R&D, AstraZeneca, Cambridge, England, United Kingdom and Waltham, Massachusetts
| | - Aaron Smith
- DMPK, Oncology, Oncology R&D, AstraZeneca, Cambridge, England, United Kingdom and Waltham, Massachusetts
| | - Joanne Wilson
- DMPK, Oncology, Oncology R&D, AstraZeneca, Cambridge, England, United Kingdom and Waltham, Massachusetts
| | - Karen Roberts
- Discovery Science, BioPharmaceuticals R&D, AstraZeneca, Cambridge, England, United Kingdom
| | - Michael Tonge
- Discovery Science, BioPharmaceuticals R&D, AstraZeneca, Cambridge, England, United Kingdom
| | - Philip Hopcroft
- Discovery Science, BioPharmaceuticals R&D, AstraZeneca, Cambridge, England, United Kingdom
| | - Sophie E Willis
- Translational Medicine, Oncology R&D, AstraZeneca, Cambridge, England, United Kingdom
| | - Martine P Roudier
- Translational Medicine, Oncology R&D, AstraZeneca, Cambridge, England, United Kingdom
| | - Claire Rooney
- Translational Medicine, Oncology R&D, AstraZeneca, Cambridge, England, United Kingdom
| | | | - Patricia Jaaks
- Wellcome Sanger Institute, Cambridge, England, United Kingdom
| | | | | | | | - Richard A Ward
- Medicinal Chemistry, Oncology R&D, AstraZeneca, Cambridge, England, United Kingdom
| | | | | | | | - Paul D Smith
- Bioscience, Oncology R&D, AstraZeneca, Cambridge, England, United Kingdom
| |
Collapse
|
5
|
Ward RA, Anderton MJ, Bethel P, Breed J, Cook C, Davies EJ, Dobson A, Dong Z, Fairley G, Farrington P, Feron L, Flemington V, Gibbons FD, Graham MA, Greenwood R, Hanson L, Hopcroft P, Howells R, Hudson J, James M, Jones CD, Jones CR, Li Y, Lamont S, Lewis R, Lindsay N, McCabe J, McGuire T, Rawlins P, Roberts K, Sandin L, Simpson I, Swallow S, Tang J, Tomkinson G, Tonge M, Wang Z, Zhai B. Discovery of a Potent and Selective Oral Inhibitor of ERK1/2 (AZD0364) That Is Efficacious in Both Monotherapy and Combination Therapy in Models of Nonsmall Cell Lung Cancer (NSCLC). J Med Chem 2019; 62:11004-11018. [DOI: 10.1021/acs.jmedchem.9b01295] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Affiliation(s)
- Richard A. Ward
- Oncology and Discovery Sciences R&D, AstraZeneca, Darwin Building and Hodgkin Building, c/o Darwin Building, 310 Cambridge Science Park, Milton Rd, Cambridge CB4 0WG, U.K
| | - Mark J. Anderton
- Oncology and Discovery Sciences R&D, AstraZeneca, Darwin Building and Hodgkin Building, c/o Darwin Building, 310 Cambridge Science Park, Milton Rd, Cambridge CB4 0WG, U.K
| | - Paul Bethel
- Chemical Development, Pharmaceutical Technology & Development, AstraZeneca, Macclesfield Campus, Macclesfield SK10 2NA, U.K
| | - Jason Breed
- Oncology and Discovery Sciences R&D, AstraZeneca, Darwin Building and Hodgkin Building, c/o Darwin Building, 310 Cambridge Science Park, Milton Rd, Cambridge CB4 0WG, U.K
| | - Calum Cook
- Oncology and Discovery Sciences R&D, AstraZeneca, Darwin Building and Hodgkin Building, c/o Darwin Building, 310 Cambridge Science Park, Milton Rd, Cambridge CB4 0WG, U.K
| | - Emma J. Davies
- Oncology and Discovery Sciences R&D, AstraZeneca, Darwin Building and Hodgkin Building, c/o Darwin Building, 310 Cambridge Science Park, Milton Rd, Cambridge CB4 0WG, U.K
| | - Andrew Dobson
- Chemical Development, Pharmaceutical Technology & Development, AstraZeneca, Macclesfield Campus, Macclesfield SK10 2NA, U.K
| | - Zhiqiang Dong
- Pharmaron Beijing Co., Ltd., 6 Taihe Road BDA, Beijing 100176, P.R. China
| | - Gary Fairley
- Oncology and Discovery Sciences R&D, AstraZeneca, Darwin Building and Hodgkin Building, c/o Darwin Building, 310 Cambridge Science Park, Milton Rd, Cambridge CB4 0WG, U.K
| | - Paul Farrington
- Bioscience, Oncology R&D, AstraZeneca, Alderley Park, Macclesfield SK10 4TG, U.K
| | - Lyman Feron
- Oncology and Discovery Sciences R&D, AstraZeneca, Darwin Building and Hodgkin Building, c/o Darwin Building, 310 Cambridge Science Park, Milton Rd, Cambridge CB4 0WG, U.K
| | - Vikki Flemington
- Oncology and Discovery Sciences R&D, AstraZeneca, Darwin Building and Hodgkin Building, c/o Darwin Building, 310 Cambridge Science Park, Milton Rd, Cambridge CB4 0WG, U.K
| | - Francis D. Gibbons
- DMPK, Oncology R&D, AstraZeneca, Waltham, Massachusetts 02451, United States
| | - Mark A. Graham
- Chemical Development, Pharmaceutical Technology & Development, AstraZeneca, Macclesfield Campus, Macclesfield SK10 2NA, U.K
| | - Ryan Greenwood
- Oncology and Discovery Sciences R&D, AstraZeneca, Darwin Building and Hodgkin Building, c/o Darwin Building, 310 Cambridge Science Park, Milton Rd, Cambridge CB4 0WG, U.K
| | - Lyndsey Hanson
- Bioscience, Oncology R&D, AstraZeneca, Alderley Park, Macclesfield SK10 4TG, U.K
| | - Philip Hopcroft
- Oncology and Discovery Sciences R&D, AstraZeneca, Darwin Building and Hodgkin Building, c/o Darwin Building, 310 Cambridge Science Park, Milton Rd, Cambridge CB4 0WG, U.K
| | - Rachel Howells
- Oncology and Discovery Sciences R&D, AstraZeneca, Darwin Building and Hodgkin Building, c/o Darwin Building, 310 Cambridge Science Park, Milton Rd, Cambridge CB4 0WG, U.K
| | | | | | | | | | - Yongchao Li
- Pharmaron Beijing Co., Ltd., 6 Taihe Road BDA, Beijing 100176, P.R. China
| | - Scott Lamont
- Oncology and Discovery Sciences R&D, AstraZeneca, Darwin Building and Hodgkin Building, c/o Darwin Building, 310 Cambridge Science Park, Milton Rd, Cambridge CB4 0WG, U.K
| | - Richard Lewis
- Medicinal Chemistry, Respiratory, Inflammation and Autoimmune (RIA), BioPharmaceuticals R&D, AstraZeneca, Gothenburg 431 50, Sweden
| | - Nicola Lindsay
- Oncology and Discovery Sciences R&D, AstraZeneca, Darwin Building and Hodgkin Building, c/o Darwin Building, 310 Cambridge Science Park, Milton Rd, Cambridge CB4 0WG, U.K
| | - James McCabe
- Chemical Development, Pharmaceutical Technology & Development, AstraZeneca, Macclesfield Campus, Macclesfield SK10 2NA, U.K
| | - Thomas McGuire
- Oncology and Discovery Sciences R&D, AstraZeneca, Darwin Building and Hodgkin Building, c/o Darwin Building, 310 Cambridge Science Park, Milton Rd, Cambridge CB4 0WG, U.K
| | - Philip Rawlins
- Oncology and Discovery Sciences R&D, AstraZeneca, Darwin Building and Hodgkin Building, c/o Darwin Building, 310 Cambridge Science Park, Milton Rd, Cambridge CB4 0WG, U.K
| | - Karen Roberts
- Oncology and Discovery Sciences R&D, AstraZeneca, Darwin Building and Hodgkin Building, c/o Darwin Building, 310 Cambridge Science Park, Milton Rd, Cambridge CB4 0WG, U.K
| | | | | | - Steve Swallow
- Chemical Development, Pharmaceutical Technology & Development, AstraZeneca, Macclesfield Campus, Macclesfield SK10 2NA, U.K
| | - Jia Tang
- Pharmaron Beijing Co., Ltd., 6 Taihe Road BDA, Beijing 100176, P.R. China
| | - Gary Tomkinson
- Chemical Development, Pharmaceutical Technology & Development, AstraZeneca, Macclesfield Campus, Macclesfield SK10 2NA, U.K
| | - Michael Tonge
- Oncology and Discovery Sciences R&D, AstraZeneca, Darwin Building and Hodgkin Building, c/o Darwin Building, 310 Cambridge Science Park, Milton Rd, Cambridge CB4 0WG, U.K
| | - Zhenhua Wang
- Pharmaron Beijing Co., Ltd., 6 Taihe Road BDA, Beijing 100176, P.R. China
| | - Baochang Zhai
- Pharmaron Beijing Co., Ltd., 6 Taihe Road BDA, Beijing 100176, P.R. China
| |
Collapse
|
6
|
Gibbons FD, Sandin L, Hanson L, Whiteley R, Farrington P, Lindsay N, Davies E, Pease JE, Flemington V. Abstract 4913: A PK/PD model quantitatively describes inhibition and down-regulation of p90RSK by ERK inhibitor AZD0364. Cancer Res 2018. [DOI: 10.1158/1538-7445.am2018-4913] [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
ERK1/2 is a key protein in the MAPK pathway, regulating phenotypes such as proliferation and migration. Upstream mutations (e.g., KRAS mutations in non-small-cell lung (NSCLC)) can cause the pathway to become constitutively activated, driving tumor growth. AZD0364 is a potent, selective inhibitor of ERK's kinase activity against its cytosolic substrate p90RSK. It is currently in preclinical development, where it has shown dose-dependent, anti-tumor activity in xenograft models of KRAS-mutant NSCLC, including Calu-6 (where it shows regression) and A549. Treatment with AZD0364 demonstrates rapid and near-complete inhibition of phospho-p90RSK. In addition, prolonged inhibition with AZD0364 causes a gradual downregulation of p90RSK protein over time, without any corresponding change in p90RSK mRNA. Here we present a pharmacokinetic/pharmacodynamic (PK/PD) model that links AZD0364 concentration to inhibition of ERK activity through both a direct inhibition of phospho-p90RSK and an indirect down-regulation of total-p90RSK protein. Anti-proliferative and pro-apoptotic effects on efficacy are linked to changes in p90RSK. The model leads to two key implications (i) repeated dosing will cause apparent potency to improve over time, since the pool of available substrate (i.e., p90RSK) is itself being reduced and (ii) recovery of signaling to baseline will depend not on washout of the inhibitor but on protein synthesis rates. Protein half-lives appear quite different between tumor models of KRAS-mutant NSCLC, with A549 (~20h) significantly slower than Calu-6 (~4h). The model provides a conceptual framework on which to link the timescale of PD changes with those seen in efficacy. Taken together, this means that while a new PD steady-state is achieved in Calu-6 in a few days, it also recovers quickly, necessitating constant cover (daily dosing) to drive regression. On the other hand, while A549 is more robust to inhibition, and slower to reach steady-state inhibition (~2 weeks), it is also slower to recover, so that intermittent schedules can achieve efficacy similar to those achievable with daily dosing.
Citation Format: Francis D. Gibbons, Linda Sandin, Lyndsey Hanson, Rebecca Whiteley, Paul Farrington, Nicola Lindsay, Emma Davies, J Elizabeth Pease, Vikki Flemington. A PK/PD model quantitatively describes inhibition and down-regulation of p90RSK by ERK inhibitor AZD0364 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4913.
Collapse
|
7
|
Simpson I, Anderton MJ, Andrews DM, Breed J, Davies E, Debreczeni JE, Flemington V, Gibbons FD, Graham MA, Hopcroft P, Howard T, Hudson J, Jones CD, Jones C, Lindsay N, Pease JE, Rawlins P, Roberts K, Swallow S, St-Gallay S, Tonge ME, Ward RA. Abstract 1647: Discovery of AZD0364, a potent and selective oral inhibitor of ERK1/2 that is efficacious in both monotherapy and combination therapy in models of NSCLC. Cancer Res 2018. [DOI: 10.1158/1538-7445.am2018-1647] [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 RAS/MAPK pathway is a major driver in oncogenesis and is dysregulated in approximately 30% of human cancers, primarily by mutations in BRAF or RAS genes. The extracellular-signal-regulated kinases (ERK1 and ERK2) serve as key central nodes within this pathway. The feasibility of targeting the RAS/MAPK pathway has been demonstrated by the initial clinical responses observed to BRAF and MEK inhibitors in BRAF V600E/K metastatic melanoma, however resistance frequently develops by reactivation of the pathway. Direct targeting of ERK1/2, may provide another therapeutic option in tumours with mutations in BRAF or RAS genes. Importantly, ERK1/2 inhibition may have clinical utility in overcoming acquired resistance to RAF and MEK inhibitors where RAS/MAPK pathway reactivation has occurred, such as relapsed BRAF V600E/K melanoma. Starting from our published work,1 we will describe for the first time, a scaffold hopping approach leading to the identification of AZD0364, a pre-clinical ERK1/2 inhibitor candidate drug. Driven by conformational modelling and structure-based design, and by utilising novel sulfamidate ring opening chemistry, a high lipophilicity efficiency core was identified. Structure based, multi-parameter based optimisation of this improved core ultimately led to AZD0364. AZD0364 exhibits high cellular potency against a direct downstream substrate on the MAPK pathway (e.g. inhibition of phospho-p90RSK1 in BRAFV600E mutant A375 cells, IC50 = 6 nM). The molecule is a highly selective kinase inhibitor (10/329 kinases tested are inhibited at >50% at a 1 µM) and has long residence time on the protein (as determined by SPR on human unphosphorylated-ERK2: pKd = 10; t1/2 = 277 mins). The good in vitro potency and selectivity is complemented by excellent physico-chemical properties (maximum absorbable dose estimated to be >4 g) and good oral pharmacokinetics across species, leading to a low predicted dose to man. In xenograft models, AZD0364 inhibits phospho-p90RSK1 in tumors in a dose-dependent manner. AZD0364 induces regressions in the KRAS mutant NSCLC Calu 6 xenograft model. AZD0364 can also be combined safely and effectively with the MEK1/2 inhibitor selumetinib in KRAS mutant NSCLC xenograft models. 1Richard A. Ward et. al. Structure-Guided Discovery of Potent and Selective Inhibitors of ERK1/2 from a Modestly Active and Promiscuous Chemical Start Point, J. Med. Chem. 2017, 60, 3438−3450.
Citation Format: Iain Simpson, Mark J. Anderton, David M. Andrews, Jason Breed, Emma Davies, Judit E. Debreczeni, Vikki Flemington, Francis D. Gibbons, Mark A. Graham, Philip Hopcroft, Tina Howard, Julian Hudson, Clifford D. Jones, Christopher Jones, Nicola Lindsay, J Elizabeth Pease, Philip Rawlins, Karen Roberts, Steve Swallow, Steve St-Gallay, Michael E. Tonge, Richard A. Ward. Discovery of AZD0364, a potent and selective oral inhibitor of ERK1/2 that is efficacious in both monotherapy and combination therapy in models of NSCLC [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 1647.
Collapse
|
8
|
Flemington V, Simpson I, Davies E, Robinson D, Lindsay N, Hanson L, Hopcroft P, Tonge M, Roberts K, Ward R. Abstract B156: Discovery and characterization of AZ6197, a potent and selective ERK1/2 inhibitor. Mol Cancer Ther 2018. [DOI: 10.1158/1535-7163.targ-17-b156] [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 RAS/MAPK pathway is a major driver in oncogenesis and is dysregulated in approximately 30% of human cancers, primarily by mutations in BRAF or RAS genes. The extracellular-signal-regulated kinases (ERK1 and ERK2) serve as key central nodes within this pathway. The feasibility of targeting the RAS/MAPK pathway has been demonstrated by the initial positive clinical responses observed to BRAF and MEK inhibitors in BRAF V600E/K metastatic melanoma; however, resistance frequently develops by reactivation of the RAS/MAPK pathway. Direct targeting of ERK1/2 may provide another therapeutic option in tumors with mutations in BRAF or RAS genes and, importantly, may overcome acquired resistance to RAF and MEK inhibitors where RAS/MAPK pathway reactivation has occurred, such as relapsed BRAF V600E/K melanoma. Here we describe the discovery and characterization of compound 35 (Ward et al., J Med Chem 2017 27;60), also known as AZ6197. AZ6197 is a highly potent and selective inhibitor of ERK1 and ERK2, with IC50 of <1nM in biochemical assays. AZ6197 reduces cellular phospho-p90RSK1 levels in BRAF and RAS mutant cancer cell lines and inhibits proliferation of cancer cell lines exhibiting dysregulation of RAS/MAPK pathway signaling, including cell lines with mutations in BRAF, NRAS, or KRAS. AZ6197 is also active in multiple BRAF- and MEK- inhibitor resistant A375 melanoma cell lines, which have acquired a range of mutations that reactivate the RAS/MAPK pathway. In tumor xenograft models, AZ6197 reduces the pharmacodynamic (PD) biomarkers phospho-p90RSK1 and phospho-FRA1 in tumors in line with compound exposure levels, and induces significant tumor regression in the KRAS mutant NSCLC Calu 6 xenograft model. AZ6197 can be combined safely and effectively with the MEK1/2 inhibitor selumetinib in KRAS mutant NSCLC xenograft models, and this simultaneous targeting of MEK and ERK leads to synergistic tumor regressions being observed in multiple xenografts. In summary, AZ6197 is a potent and selective ERK1/2 inhibitor with activity in cell lines and tumor xenograft models with RAS/MAPK pathway activation. AZ6197 also has significant activity in BRAF mutant melanoma cell lines in which resistance to RAF and MEK inhibitors is due to the acquisition of NRAS and MEK1 mutations. Combination treatment of AZ6197 and the MEK1/2 inhibitor selumetinib drives synergistic tumor regression in multiple KRAS mutant xenograft models.
Citation Format: Vikki Flemington, Iain Simpson, Emma Davies, David Robinson, Nicola Lindsay, Lyndsey Hanson, Philip Hopcroft, Michael Tonge, Karen Roberts, Richard Ward. Discovery and characterization of AZ6197, a potent and selective ERK1/2 inhibitor [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2017 Oct 26-30; Philadelphia, PA. Philadelphia (PA): AACR; Mol Cancer Ther 2018;17(1 Suppl):Abstract nr B156.
Collapse
|
9
|
Ward RA, Bethel P, Cook C, Davies E, Debreczeni JE, Fairley G, Feron L, Flemington V, Graham MA, Greenwood R, Griffin N, Hanson L, Hopcroft P, Howard TD, Hudson J, James M, Jones CD, Jones CR, Lamont S, Lewis R, Lindsay N, Roberts K, Simpson I, St-Gallay S, Swallow S, Tang J, Tonge M, Wang Z, Zhai B. Structure-Guided Discovery of Potent and Selective Inhibitors of ERK1/2 from a Modestly Active and Promiscuous Chemical Start Point. J Med Chem 2017; 60:3438-3450. [PMID: 28376306 DOI: 10.1021/acs.jmedchem.7b00267] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
There are a number of small-molecule inhibitors targeting the RAS/RAF/MEK/ERK signaling pathway that have either been approved or are in clinical development for oncology across a range of disease indications. The inhibition of ERK1/2 is of significant current interest, as cell lines with acquired resistance to BRAF and MEK inhibitors have been shown to maintain sensitivity to ERK1/2 inhibition in preclinical models. This article reports on our recent work to identify novel, potent, and selective reversible ERK1/2 inhibitors from a low-molecular-weight, modestly active, and highly promiscuous chemical start point, compound 4. To guide and inform the evolution of this series, inhibitor binding mode information from X-ray crystal structures was critical in the rapid exploration of this template to compound 35, which was active when tested in in vivo antitumor efficacy experiments.
Collapse
Affiliation(s)
- Richard A Ward
- IMED Oncology and Discovery Sciences, AstraZeneca , Darwin Building, and AstraZeneca, Hodgkin Building, c/o Darwin Building, 310 Cambridge Science Park, Milton Road, Cambridge CB4 0WG, U.K
| | - Paul Bethel
- AstraZeneca , Charter Way, Macclesfield, SK10 2NA, U.K
| | - Calum Cook
- IMED Oncology and Discovery Sciences, AstraZeneca , Darwin Building, and AstraZeneca, Hodgkin Building, c/o Darwin Building, 310 Cambridge Science Park, Milton Road, Cambridge CB4 0WG, U.K
| | - Emma Davies
- IMED Oncology and Discovery Sciences, AstraZeneca , Darwin Building, and AstraZeneca, Hodgkin Building, c/o Darwin Building, 310 Cambridge Science Park, Milton Road, Cambridge CB4 0WG, U.K
| | - Judit E Debreczeni
- IMED Oncology and Discovery Sciences, AstraZeneca , Darwin Building, and AstraZeneca, Hodgkin Building, c/o Darwin Building, 310 Cambridge Science Park, Milton Road, Cambridge CB4 0WG, U.K
| | - Gary Fairley
- IMED Oncology and Discovery Sciences, AstraZeneca , Darwin Building, and AstraZeneca, Hodgkin Building, c/o Darwin Building, 310 Cambridge Science Park, Milton Road, Cambridge CB4 0WG, U.K
| | - Lyman Feron
- IMED Oncology and Discovery Sciences, AstraZeneca , Darwin Building, and AstraZeneca, Hodgkin Building, c/o Darwin Building, 310 Cambridge Science Park, Milton Road, Cambridge CB4 0WG, U.K
| | - Vikki Flemington
- IMED Oncology and Discovery Sciences, AstraZeneca , Darwin Building, and AstraZeneca, Hodgkin Building, c/o Darwin Building, 310 Cambridge Science Park, Milton Road, Cambridge CB4 0WG, U.K
| | - Mark A Graham
- AstraZeneca , Charter Way, Macclesfield, SK10 2NA, U.K
| | - Ryan Greenwood
- IMED Oncology and Discovery Sciences, AstraZeneca , Darwin Building, and AstraZeneca, Hodgkin Building, c/o Darwin Building, 310 Cambridge Science Park, Milton Road, Cambridge CB4 0WG, U.K
| | | | | | - Philip Hopcroft
- IMED Oncology and Discovery Sciences, AstraZeneca , Darwin Building, and AstraZeneca, Hodgkin Building, c/o Darwin Building, 310 Cambridge Science Park, Milton Road, Cambridge CB4 0WG, U.K
| | - Tina D Howard
- AstraZeneca , Alderley Park, Macclesfield SK10 4TG, U.K
| | - Julian Hudson
- AstraZeneca , Alderley Park, Macclesfield SK10 4TG, U.K
| | - Michael James
- AstraZeneca , Alderley Park, Macclesfield SK10 4TG, U.K
| | | | | | - Scott Lamont
- IMED Oncology and Discovery Sciences, AstraZeneca , Darwin Building, and AstraZeneca, Hodgkin Building, c/o Darwin Building, 310 Cambridge Science Park, Milton Road, Cambridge CB4 0WG, U.K
| | - Richard Lewis
- AstraZeneca , Charter Way, Macclesfield, SK10 2NA, U.K
| | - Nicola Lindsay
- IMED Oncology and Discovery Sciences, AstraZeneca , Darwin Building, and AstraZeneca, Hodgkin Building, c/o Darwin Building, 310 Cambridge Science Park, Milton Road, Cambridge CB4 0WG, U.K
| | - Karen Roberts
- IMED Oncology and Discovery Sciences, AstraZeneca , Darwin Building, and AstraZeneca, Hodgkin Building, c/o Darwin Building, 310 Cambridge Science Park, Milton Road, Cambridge CB4 0WG, U.K
| | - Iain Simpson
- IMED Oncology and Discovery Sciences, AstraZeneca , Darwin Building, and AstraZeneca, Hodgkin Building, c/o Darwin Building, 310 Cambridge Science Park, Milton Road, Cambridge CB4 0WG, U.K
| | | | - Steve Swallow
- AstraZeneca , Charter Way, Macclesfield, SK10 2NA, U.K
| | - Jia Tang
- Pharmaron Beijing Co., Ltd. , 6 Taihe Road BDA, Beijing, 100176, P.R. China
| | - Michael Tonge
- IMED Oncology and Discovery Sciences, AstraZeneca , Darwin Building, and AstraZeneca, Hodgkin Building, c/o Darwin Building, 310 Cambridge Science Park, Milton Road, Cambridge CB4 0WG, U.K
| | - Zhenhua Wang
- Pharmaron Beijing Co., Ltd. , 6 Taihe Road BDA, Beijing, 100176, P.R. China
| | - Baochang Zhai
- Pharmaron Beijing Co., Ltd. , 6 Taihe Road BDA, Beijing, 100176, P.R. China
| |
Collapse
|
10
|
|
11
|
Somers GI, Lindsay N, Lowdon BM, Jones AE, Freathy C, Ho S, Woodrooffe AJM, Bayliss MK, Manchee GR. A Comparison of the Expression and Metabolizing Activities of Phase I and II Enzymes in Freshly Isolated Human Lung Parenchymal Cells and Cryopreserved Human Hepatocytes. Drug Metab Dispos 2007; 35:1797-805. [PMID: 17627976 DOI: 10.1124/dmd.107.015966] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The pulmonary and hepatic expression and catalytic activities of phase I and II drug-metabolizing enzymes were compared using human lung and liver tissue, and lung parenchymal cells (LPCs) and cryopreserved hepatocytes. Cytochrome P450 gene expression was generally lower in lung than in liver and CYP3A4 expression in lung was negligible. Esterase gene expression was similar in lung and liver. Expression of all sulfotransferase isoforms in lung was similar to or higher than that in liver. Lung tissue expressed low levels of UGT. However, the expression of UGT2A1 in lung was higher than that in liver. There was a range of catalytic activities in LPCs, including cytochrome P450, esterase, and sulfation pathways. Phase I activities were generally less than 10% of those determined in hepatocytes. Rates of ester hydrolysis and sulfation in LPCs were similar to those in hepatocytes. When measurable, glucuronidation in LPCs was present at very low levels, reflecting the gene expression data. The metabolism of salbutamol, formoterol, and budesonide was also investigated. Production of salbutamol-4-O-sulfate and budesonide oleate was observed in LPCs from at least two of three donor preparations studied. Formoterol sulfate and low levels of formoterol glucuronide were detected in one of three donors. In general, drug-metabolizing capability of LPCs is low compared with liver, although some evidence for substantial sulfation and deesterification capacity was observed. Therefore, these data support the use of this cell-based system for the investigation of key routes of xenobiotic metabolism in human lung parenchyma.
Collapse
Affiliation(s)
- G I Somers
- Drug Metabolism and Pharmacokinetics, Respiratory and Inflammation Centre of Excellence for Drug Discovery, GlaxoSmithKline, Stevenage, UK.
| | | | | | | | | | | | | | | | | |
Collapse
|
12
|
|
13
|
Abstract
A peptide Tyr.Arg.Asp.Leu.Lys.Leu corresponding to the carboxy-terminal six amino acids of small-t antigen predicted from the DNA sequence of SV40 was synthesised, coupled to bovine serum albumin and to ovalbumin and used to raise antibody in rabbits. The sera obtained immunoprecipitated [125I]peptide. It also recognised SV40 small-t that was synthesised in vitro from SV40 mRNA or extracted from SV40 infected monkey cells. The immunoprecipitation of small-t was inhibited by added peptide. To demonstrate that the determinant was present at the carboxy-terminal end of the molecule, truncated versions of small-t coded for by 0.54-0.59 deletion mutants were tested. dl 890 small-t, which contains an in-phase deletion removing nine amino acids but leaving the carboxy-terminal sequences intact, was recognised by the antipeptide serum. By contrast dl 885 small-t, which has an out-of-phase deletion leading to an altered carboxy terminus coded in an alternative reading frame, was not recognised. The data confirm the location and specificity of the determinant recognised on small-t by the antipeptide serum.
Collapse
|
14
|
Abstract
A 53-year-old male with a long-standing idiopathic pure red cell aplasia, refractory to testosterone cypionate, fluoxymesterone, and corticosteroid, was successfully treated with oxymetholone. Blood count, bone marrow, reticuloendothelial bone marrow scan, and ferrokinetic studies showed a marked increase of erythropoiesis in response to oxymetholone. The patient became hematologically normal within 12 weeks and has required no further transfusions. This observation suggests possible difference of mechanisms in the action of various androgenic drugs. It also suggests that failure of response to one androgenic agent does not necessarily mean the other androgenic agents will not be effective in cases of refractory idiopathic pure red cell aplasia.
Collapse
|
15
|
Gourgoutis GD, Das G, Lindsay N. Splenic uptake of 99m technetium sulphur colloid as an index of portal hypertension. Am J Gastroenterol 1972; 57:435-42. [PMID: 5030550] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
|