Success in trials for neurodegenerative diseases Huntington’s and Spinal Muscular Atrophy (SMA) might also provide a new trajectory for possible cures in other similar diseases, such as Amyotrophic Lateral Sclerosis (ALS), for which we’re yet to find solid cures or prevention mechanisms.
Huntington’s Disease is an inherited progressive disorder, which usually develops in middle age. The characteristics of Huntington’s are the gradual deterioration and death of brain cells which harshly affect cognitive and behavioural capacities. There’s no cure for the disease. SMA is a disease that causes weakness and progressive wasting of muscles as a result of the loss of motor neurons in the spinal cord and brainstem.
Only in June 2017 was the first drug, Nusinersen, approved to cure SMA. This new experimental class of drugs has been used in two separate trials for both Huntington’s and SMA sufferers with success. Babies on the Nusinersen trial displayed signs of regained strength and stability in the four years spent administered on the drug. This has prompted optimism for treatment of other disorders with a similar pathology.
The novel drugs used are antisense oligonucleotides which intercept genetic flaws at their source; these can be synthetically engineered in the lab. In the Huntington’s trial, these work by shutting down the switches that govern whether the flaw is turned on or off in an individual, stopping the instructions for the genetic defect from being translated into proteins. The mechanism for the SMA version of the drug has a slightly different trajectory in that it engenders the formation of proteins where these have been lost, but the inherent nature of the antisense oligonucleotide drugs remain the same.
Despite the promise of the results, this form of drug cannot simply be swallowed or injected, but requires careful machinery to ensure it intercepts the correct place in an individual. As such, this could be very costly to produce, especially on a large scale, which brings into question the economic and ethical implications of administering such a drug, still in its infancy. Regardless, the discovery has at least uncovered a new possible route for alleviating the long-sustained hardships associated with the treatment and prevention of these disorders.
To read the formal press release about the treatment trials, click here.