Recent regulator approvals and exciting new preclinical data has refocused attention on a treatment approach for genetic conditions that has travelled a long and winding road towards clinical use.
Antisense oligonucleotides represent a method of altering protein levels at the post transcriptional level – it basically stops certain RNAs from being translated into protein.
And recently, a new clinical trial has been registered which will explore the use of this treatment approach in people with Parkinson’s.
In today’s post, we will look at what antisense oligonucleotides are, how they work, what research has been conducted in the context of Parkinson’s, and some of the limitations of this approach that still exist.
Spinal muscular atrophy (or SMA) is a genetic disorder that results in the degeneration of motor neurons in the spinal cord. This leads to progressive weakening and atrophy of muscules, ultimately leaving sufferers paralysed. It is caused by loss-of-function mutations in the survival motor neuron 1 (SMN1) gene.
It is a terrible condition that starts in very young children and has an incidence approaching 1:10,000 live births.
Luckily, novel therapies are being developed to deal with this condition, and in 2016, the US FDA approved a new treatment – following rather dramatic clinical trial results – called Nusinersen. This new therapy has caused a great deal of excitement as it basically halted the progression of SMA in many cases.
And a recent long term report highlights some of these very impressive results:
Title: Nusinersen in later-onset spinal muscular atrophy: Long-term results from the phase 1/2 studies.
Authors: Darras BT, Chiriboga CA, Iannaccone ST, Swoboda KJ, Montes J, Mignon L, Xia S, Bennett CF, Bishop KM, Shefner JM, Green AM, Sun P, Bhan I, Gheuens S, Schneider E, Farwell W, De Vivo DC; ISIS-396443-CS2/ISIS-396443-CS12 Study Groups.
Journal: Neurology. 2019 May 21;92(21):e2492-e2506.
PMID: 31019106 (This report is OPEN ACCESS if you would like to read it)
Most importantly, Nusinersen is having real impact on the children who are affected by this condition:
Interesting, but what exactly is Nusinersen?
It is an antisense oligonucleotide.
What are antisense oligonucleotides?
At the end of each year, it is a useful practise to review the triumphs (and failures) of the past 12 months. It is an exercise of putting everything into perspective.
2017 has been an incredible year for Parkinson’s research.
And while I appreciate that statements like that will not bring much comfort to those living with the condition, it is still important to consider and appreciate what has been achieved over the last 12 months.
In this post, we will try to provide a summary of the Parkinson’s-related research that has taken place in 2017 (Be warned: this is a VERY long post!)
The number of research reports and clinical trial studies per year since 1817
As everyone in the Parkinson’s community is aware, in 2017 we were observing the 200th anniversary of the first description of the condition by James Parkinson (1817). But what a lot of people fail to appreciate is how little research was actually done on the condition during the first 180 years of that period.
The graphs above highlight the number of Parkinson’s-related research reports published (top graph) and the number of clinical study reports published (bottom graph) during each of the last 200 years (according to the online research search engine Pubmed – as determined by searching for the term “Parkinson’s“).
PLEASE NOTE, however, that of the approximately 97,000 “Parkinson’s“-related research reports published during the last 200 years, just under 74,000 of them have been published in the last 20 years.
That means that 3/4 of all the published research on Parkinson’s has been conducted in just the last 2 decades.
And a huge chunk of that (almost 10% – 7321 publications) has been done in 2017 only.
So what happened in 2017? Continue reading