151
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Ratni H, Ebeling M, Baird J, Bendels S, Bylund J, Chen KS, Denk N, Feng Z, Green L, Guerard M, Jablonski P, Jacobsen B, Khwaja O, Kletzl H, Ko CP, Kustermann S, Marquet A, Metzger F, Mueller B, Naryshkin NA, Paushkin SV, Pinard E, Poirier A, Reutlinger M, Weetall M, Zeller A, Zhao X, Mueller L. Discovery of Risdiplam, a Selective Survival of Motor Neuron-2 ( SMN2) Gene Splicing Modifier for the Treatment of Spinal Muscular Atrophy (SMA). J Med Chem 2018; 61:6501-6517. [PMID: 30044619 DOI: 10.1021/acs.jmedchem.8b00741] [Citation(s) in RCA: 282] [Impact Index Per Article: 47.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
SMA is an inherited disease that leads to loss of motor function and ambulation and a reduced life expectancy. We have been working to develop orally administrated, systemically distributed small molecules to increase levels of functional SMN protein. Compound 2 was the first SMN2 splicing modifier tested in clinical trials in healthy volunteers and SMA patients. It was safe and well tolerated and increased SMN protein levels up to 2-fold in patients. Nevertheless, its development was stopped as a precautionary measure because retinal toxicity was observed in cynomolgus monkeys after chronic daily oral dosing (39 weeks) at exposures in excess of those investigated in patients. Herein, we describe the discovery of 1 (risdiplam, RG7916, RO7034067) that focused on thorough pharmacology, DMPK and safety characterization and optimization. This compound is undergoing pivotal clinical trials and is a promising medicine for the treatment of patients in all ages and stages with SMA.
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Affiliation(s)
- Hasane Ratni
- F. Hoffmann-La Roche Ltd., pRED, Pharma Research & Early Development , Roche Innovation Center Basel , Grenzacherstrasse 124 , 4070 Basel , Switzerland
| | - Martin Ebeling
- F. Hoffmann-La Roche Ltd., pRED, Pharma Research & Early Development , Roche Innovation Center Basel , Grenzacherstrasse 124 , 4070 Basel , Switzerland
| | - John Baird
- PTC Therapeutics, Inc. , 100 Corporate Court , South Plainfield , New Jersey 07080 , United States
| | - Stefanie Bendels
- F. Hoffmann-La Roche Ltd., pRED, Pharma Research & Early Development , Roche Innovation Center Basel , Grenzacherstrasse 124 , 4070 Basel , Switzerland
| | - Johan Bylund
- F. Hoffmann-La Roche Ltd., pRED, Pharma Research & Early Development , Roche Innovation Center Basel , Grenzacherstrasse 124 , 4070 Basel , Switzerland
| | - Karen S Chen
- SMA Foundation , 888 Seventh Avenue, Suite 400 , New York , New York 10019 , United States
| | - Nora Denk
- F. Hoffmann-La Roche Ltd., pRED, Pharma Research & Early Development , Roche Innovation Center Basel , Grenzacherstrasse 124 , 4070 Basel , Switzerland
| | - Zhihua Feng
- Section of Neurobiology, Department of Biological Sciences , University of Southern California , Los Angeles , California 90089 , United States
| | - Luke Green
- F. Hoffmann-La Roche Ltd., pRED, Pharma Research & Early Development , Roche Innovation Center Basel , Grenzacherstrasse 124 , 4070 Basel , Switzerland
| | - Melanie Guerard
- F. Hoffmann-La Roche Ltd., pRED, Pharma Research & Early Development , Roche Innovation Center Basel , Grenzacherstrasse 124 , 4070 Basel , Switzerland
| | - Philippe Jablonski
- F. Hoffmann-La Roche Ltd., pRED, Pharma Research & Early Development , Roche Innovation Center Basel , Grenzacherstrasse 124 , 4070 Basel , Switzerland
| | - Bjoern Jacobsen
- F. Hoffmann-La Roche Ltd., pRED, Pharma Research & Early Development , Roche Innovation Center Basel , Grenzacherstrasse 124 , 4070 Basel , Switzerland
| | - Omar Khwaja
- F. Hoffmann-La Roche Ltd., pRED, Pharma Research & Early Development , Roche Innovation Center Basel , Grenzacherstrasse 124 , 4070 Basel , Switzerland
| | - Heidemarie Kletzl
- F. Hoffmann-La Roche Ltd., pRED, Pharma Research & Early Development , Roche Innovation Center Basel , Grenzacherstrasse 124 , 4070 Basel , Switzerland
| | - Chien-Ping Ko
- Section of Neurobiology, Department of Biological Sciences , University of Southern California , Los Angeles , California 90089 , United States
| | - Stefan Kustermann
- F. Hoffmann-La Roche Ltd., pRED, Pharma Research & Early Development , Roche Innovation Center Basel , Grenzacherstrasse 124 , 4070 Basel , Switzerland
| | - Anne Marquet
- F. Hoffmann-La Roche Ltd., pRED, Pharma Research & Early Development , Roche Innovation Center Basel , Grenzacherstrasse 124 , 4070 Basel , Switzerland
| | - Friedrich Metzger
- F. Hoffmann-La Roche Ltd., pRED, Pharma Research & Early Development , Roche Innovation Center Basel , Grenzacherstrasse 124 , 4070 Basel , Switzerland
| | - Barbara Mueller
- F. Hoffmann-La Roche Ltd., pRED, Pharma Research & Early Development , Roche Innovation Center Basel , Grenzacherstrasse 124 , 4070 Basel , Switzerland
| | - Nikolai A Naryshkin
- PTC Therapeutics, Inc. , 100 Corporate Court , South Plainfield , New Jersey 07080 , United States
| | - Sergey V Paushkin
- SMA Foundation , 888 Seventh Avenue, Suite 400 , New York , New York 10019 , United States
| | - Emmanuel Pinard
- F. Hoffmann-La Roche Ltd., pRED, Pharma Research & Early Development , Roche Innovation Center Basel , Grenzacherstrasse 124 , 4070 Basel , Switzerland
| | - Agnès Poirier
- F. Hoffmann-La Roche Ltd., pRED, Pharma Research & Early Development , Roche Innovation Center Basel , Grenzacherstrasse 124 , 4070 Basel , Switzerland
| | - Michael Reutlinger
- F. Hoffmann-La Roche Ltd., pRED, Pharma Research & Early Development , Roche Innovation Center Basel , Grenzacherstrasse 124 , 4070 Basel , Switzerland
| | - Marla Weetall
- PTC Therapeutics, Inc. , 100 Corporate Court , South Plainfield , New Jersey 07080 , United States
| | - Andreas Zeller
- F. Hoffmann-La Roche Ltd., pRED, Pharma Research & Early Development , Roche Innovation Center Basel , Grenzacherstrasse 124 , 4070 Basel , Switzerland
| | - Xin Zhao
- PTC Therapeutics, Inc. , 100 Corporate Court , South Plainfield , New Jersey 07080 , United States
| | - Lutz Mueller
- F. Hoffmann-La Roche Ltd., pRED, Pharma Research & Early Development , Roche Innovation Center Basel , Grenzacherstrasse 124 , 4070 Basel , Switzerland
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152
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Van Alstyne M, Simon CM, Sardi SP, Shihabuddin LS, Mentis GZ, Pellizzoni L. Dysregulation of Mdm2 and Mdm4 alternative splicing underlies motor neuron death in spinal muscular atrophy. Genes Dev 2018; 32:1045-1059. [PMID: 30012555 PMCID: PMC6075148 DOI: 10.1101/gad.316059.118] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Accepted: 05/24/2018] [Indexed: 12/01/2022]
Abstract
Van Alstyne et al. show that loss of SMN-dependent regulation of Mdm2 and Mdm4 alternative splicing underlies p53-mediated death of motor neurons in SMA, establishing a causal link between snRNP dysfunction and neurodegeneration. Ubiquitous deficiency in the survival motor neuron (SMN) protein causes death of motor neurons—a hallmark of the neurodegenerative disease spinal muscular atrophy (SMA)—through poorly understood mechanisms. Here, we show that the function of SMN in the assembly of spliceosomal small nuclear ribonucleoproteins (snRNPs) regulates alternative splicing of Mdm2 and Mdm4, two nonredundant repressors of p53. Decreased inclusion of critical Mdm2 and Mdm4 exons is most prominent in SMA motor neurons and correlates with both snRNP reduction and p53 activation in vivo. Importantly, increased skipping of Mdm2 and Mdm4 exons regulated by SMN is necessary and sufficient to synergistically elicit robust p53 activation in wild-type mice. Conversely, restoration of full-length Mdm2 and Mdm4 suppresses p53 induction and motor neuron degeneration in SMA mice. These findings reveal that loss of SMN-dependent regulation of Mdm2 and Mdm4 alternative splicing underlies p53-mediated death of motor neurons in SMA, establishing a causal link between snRNP dysfunction and neurodegeneration.
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Affiliation(s)
- Meaghan Van Alstyne
- Center for Motor Neuron Biology and Disease, Columbia University, New York, New York 10032, USA.,Department of Pathology and Cell Biology, Columbia University, New York, New York 10032, USA
| | - Christian M Simon
- Center for Motor Neuron Biology and Disease, Columbia University, New York, New York 10032, USA.,Department of Pathology and Cell Biology, Columbia University, New York, New York 10032, USA
| | - S Pablo Sardi
- Neuroscience Therapeutic Area, Sanofi, Framingham, Massachusetts 01701, USA
| | | | - George Z Mentis
- Center for Motor Neuron Biology and Disease, Columbia University, New York, New York 10032, USA.,Department of Pathology and Cell Biology, Columbia University, New York, New York 10032, USA.,Department of Neurology, Columbia University, New York, New York 10032, USA
| | - Livio Pellizzoni
- Center for Motor Neuron Biology and Disease, Columbia University, New York, New York 10032, USA.,Department of Pathology and Cell Biology, Columbia University, New York, New York 10032, USA
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153
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Sumner CJ, Crawford TO. Two breakthrough gene-targeted treatments for spinal muscular atrophy: challenges remain. J Clin Invest 2018; 128:3219-3227. [PMID: 29985170 DOI: 10.1172/jci121658] [Citation(s) in RCA: 67] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The motor neuron disease spinal muscular atrophy (SMA) is caused by recessive, loss-of-function mutations of the survival motor neuron 1 gene (SMN1). Alone, such mutations are embryonically lethal, but SMA patients retain a paralog gene, SMN2, that undergoes alternative pre-mRNA splicing, producing low levels of SMN protein. By mechanisms that are not well understood, reduced expression of the ubiquitously expressed SMN protein causes an early-onset motor neuron disease that often results in infantile or childhood mortality. Recently, striking clinical improvements have resulted from two novel treatment strategies to increase SMN protein by (a) modulating the splicing of existing SMN2 pre-mRNAs using antisense oligonucleotides, and (b) transducing motor neurons with self-complementary adeno-associated virus 9 (scAAV9) expressing exogenous SMN1 cDNA. We review the recently published clinical trial results and discuss the differing administration, tissue targeting, and potential toxicities of these two therapies. We also focus on the challenges that remain, emphasizing the many clinical and biologic questions that remain open. Answers to these questions will enable further optimization of these remarkable SMA treatments as well as provide insights that may well be useful in application of these therapeutic platforms to other diseases.
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Affiliation(s)
| | - Thomas O Crawford
- Department of Neurology.,Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
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