NCALD Antisense Oligonucleotide Therapy in Addition to Nusinersen further Ameliorates Spinal Muscular Atrophy in Mice

  • Am J Hum Genet. 2019 Jul 3;105(1):221-230. doi: 10.1016/j.ajhg.2019.05.008.
Laura Torres-Benito  1 ,  Svenja Schneider  1 ,  Roman Rombo  1 ,  Karen K Ling  2 ,  Vanessa Grysko  1 ,  Aaradhita Upadhyay  1 ,  Natalia L Kononenko  3 ,  Frank Rigo  2 ,  C Frank Bennett  2 ,  Brunhilde Wirth  4
Affiliations
  • 1. Institute of Human Genetics, University of Cologne, 50931 Cologne, Germany; Center for Molecular Medicine Cologne, University of Cologne, 50931 Cologne, Germany.
  • 2. Ionis Pharmaceuticals, Carlsbad, CA 92008, USA.
  • 3. Excellence Cluster on Cellular Stress Responses in Aging Associated Diseases (CECAD), University of Cologne, 50931 Cologne, Germany.
  • 4. Institute of Human Genetics, University of Cologne, 50931 Cologne, Germany; Center for Molecular Medicine Cologne, University of Cologne, 50931 Cologne, Germany; Institute for Genetics, University of Cologne, 50674 Cologne, Germany; Center for Rare Diseases, University Hospital of Cologne, 50931 Cologne, Germany. Electronic address: [email protected].
PMID: 31230718 DOI: 10.1016/j.ajhg.2019.05.008
Abstract

Spinal muscular atrophy (SMA) is a neuromuscular disease causing the most frequent genetic childhood lethality. Recently, nusinersen, an antisense oligonucleotide (ASO) that corrects SMN2 splicing and thereby increases full-length SMN protein, has been approved by the FDA and EMA for SMA therapy. However, the administration of nusinersen in severe and/or post-symptomatic SMA-affected individuals is insufficient to counteract the disease. Therefore, additional SMN-independent therapies are needed to support the function of motoneurons and neuromuscular junctions. We recently identified asymptomatic SMN1-deleted individuals who were protected against SMA by reduced expression of neurocalcin delta (NCALD). NCALD reduction is proven to be a protective modifier of SMA across species, including worm, zebrafish, and mice. Here, we identified Ncald-ASO3-out of 450 developed Ncald ASOs-as the most efficient and non-toxic ASO for the CNS, by applying a stepwise screening strategy in cortical neurons and adult and neonatal mice. In a randomized-blinded preclinical study, a single subcutaneous low-dose SMN-ASO and a single intracerebroventricular Ncald-ASO3 or control-ASO injection were presymptomatically administered in a severe SMA mouse model. NCALD reduction of >70% persisted for about 1 month. While low-dose SMN-ASO rescues multiorgan impairment, additional NCALD reduction significantly ameliorated SMA pathology including electrophysiological and histological properties of neuromuscular junctions and muscle at P21 and motoric deficits at 3 months. The present study shows the additional benefit of a combinatorial SMN-dependent and SMN-independent ASO-based therapy for SMA. This work illustrates how a modifying gene, identified in some asymptomatic individuals, helps to develop a therapy for all SMA-affected individuals.

Keywords
ASO therapy; NCALD; SMA; SMN1; SMN2; modifier gene; motor neuron disorder; neuromuscular disorder; neuromuscular junction; spinal muscular atrophy.
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