1. Academic Validation
  2. Discovery of Small Molecule Splicing Modulators of Survival Motor Neuron-2 (SMN2) for the Treatment of Spinal Muscular Atrophy (SMA)

Discovery of Small Molecule Splicing Modulators of Survival Motor Neuron-2 (SMN2) for the Treatment of Spinal Muscular Atrophy (SMA)

  • J Med Chem. 2018 Dec 27;61(24):11021-11036. doi: 10.1021/acs.jmedchem.8b01291.
Atwood K Cheung 1 Brian Hurley 1 Ryan Kerrigan 1 Lei Shu 1 Donovan N Chin 1 Yiping Shen 1 Gary O'Brien 1 Moo Je Sung 1 Ying Hou 1 Jake Axford 1 Emma Cody 1 Robert Sun 1 Aleem Fazal 1 Cary Fridrich 1 Carina C Sanchez 1 Ronald C Tomlinson 1 Monish Jain 1 Lin Deng 1 Keith Hoffmaster 1 Cheng Song 1 Mailin Van Hoosear 1 Youngah Shin 1 Rebecca Servais 1 Christopher Towler 2 Marc Hild 1 Daniel Curtis 1 William F Dietrich 1 Lawrence G Hamann 1 Karin Briner 1 Karen S Chen 3 Dione Kobayashi 3 Rajeev Sivasankaran 1 Natalie A Dales 1
Affiliations

Affiliations

  • 1 Novartis Institutes for BioMedical Research , 250 Massachusetts Avenue , Cambridge , Massachusetts 02139 , United States.
  • 2 Novartis Pharmaceuticals , 250 Massachusetts Avenue , Cambridge , Massachusetts 02139 , United States.
  • 3 SMA Foundation , 888 Seventh Avenue, Suite 400 , New York , New York 10019 , United States.
Abstract

Spinal muscular atrophy (SMA), a rare neuromuscular disorder, is the leading genetic cause of death in infants and toddlers. SMA is caused by the deletion or a loss of function mutation of the survival motor neuron 1 (SMN1) gene. In humans, a second closely related gene SMN2 exists; however it codes for a less stable SMN protein. In recent years, significant progress has been made toward disease modifying treatments for SMA by modulating SMN2 pre-mRNA splicing. Herein, we describe the discovery of LMI070/branaplam, a small molecule that stabilizes the interaction between the spliceosome and SMN2 pre-mRNA. Branaplam (1) originated from a high-throughput phenotypic screening hit, pyridazine 2, and evolved via multiparameter lead optimization. In a severe mouse SMA model, branaplam treatment increased full-length SMN RNA and protein levels, and extended survival. Currently, branaplam is in clinical studies for SMA.

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