Muscle Protection

Lower motor neurons of the spinal cord are the main cell type affected by SMA. When the lower motor neurons deteriorate, they no longer efficiently contact their target muscles, ultimately leading to loss of voluntary muscle contraction, which causes muscle wasting, or atrophy, due to inactivity.

The goal of muscle protection is to protect the muscles from atrophy, increase muscle mass, and perhaps even restore some muscle function. Similar to neuroprotection, this strategy does not address the underlying genetics of SMA, rather, the aim is to slow or stop the progression of the disease. It could be used in combination with approaches designed to increase SMN protein levels.

It is thought that these approaches may be more appropriate for milder types of SMA. They may include:

  • Small molecules that enhance the ability of muscles to contract

Tirasemtiv is being studied in clinical trials for people with Motor Neurone Disease (MND) by Cytokinetics. The effects of Tirasemtiv on leg and respiratory muscle function are being examined and whether it may reduce fatigue and improve muscle strength during exercise. As motor neurons are affected in both MND and SMA, the possibilities are also being investigated for SMA.

  • Muscle mass regulators that may improve muscle strength

A number of compounds that are able to increase muscle mass have been identified in the laboratory. Some of these drugs are currently being tested in SMA model mice. Updates on these drugs will be provided when studies are published.
 

2021

Apitegromab Receives Fast Track Designation in the US

Scholar Rock Announces Results from TOPAZ Phase 2 Trial in SMA Types 2 and 3
 

2020

Scholar Rock Announces Encouraging Interim Data from the TOPAZ Phase 2 Trial of SRK-015

Catalyst Pharmaceuticals Completes Enrolment for a Study of Amifampridine Phosphate in Ambulatory Patients who have SMA Type 3

Scholar Rock Reports Delays in Interim Trial Results Due to COVID-19

SCHOLAR ROCK SUMMARISES PROGRESS TO DATE WITH SRK-015
 

2019

SCHOLAR ROCK REPORTS PRELIMINARY PHARMACOKINETIC AND PHARMACODYNAMIC DATA FROM TOPAZ PHASE 2 TRIAL OF SRK-015 FOR THE TREATMENT OF SMA

POSITIVE INTERIM RESULTS FROM PHASE I TRIAL ANNOUNCED BY SCHOLAR ROCK
 

2018

SCHOLAR ROCK ANNOUNCE SRK-015 ORPHAN DRUG DESIGNATION NEWS AND PUBLISH PRE-CLINICAL DATA

Cytokinetics Release CK-2127107 Phase II Clinical Trial Data

FIRST COHORT DOSING COMPLETED IN SRK-015 PHASE 1 CLINICAL TRIAL

Scholar Rock Experimental Drug for SMA Granted Orphan Drug Status
 

2017

CYTOKINETICS DRUG AWARDED ORPHAN DRUG DESIGNATION IN THE US

CYTOKINETICS INITIATES SECOND COHORT IN PHASE 2 TRIAL OF CK-2127107

 

2016

CYTOKINETICS INITIATES PHASE II TRIAL OF POTENTIAL SMA DRUG