Oligonucleotide therapies represent one of the most promising advances in precision medicine today. These small, synthetic strands of nucleotides; like antisense oligonucleotides (ASOs) and small interfering RNAs (siRNAs); work by directly targeting the genetic instructions within our cells to modify or silence disease-causing genes.
Already, oligonucleotide-based drugs have gained approval for conditions such as spinal muscular atrophy (SMA), transforming outcomes for patients who previously had few options. Beyond SMA, over 30 oligonucleotide therapeutics are currently in clinical trials targeting a wide range of diseases, including various cancers, neurological disorders, and rare genetic diseases. (Source: The Times of India)
Where Are Oligonucleotides Found and Why Are They Important?
Oligonucleotides are short strands of nucleotides, the building blocks of DNA and RNA, typically consisting of 15 to 30 bases. In nature, oligonucleotides are fragments of nucleic acids involved in key cellular processes like DNA replication, transcription, and gene regulation.
In therapeutic applications, synthetic oligonucleotides are designed to bind selectively to specific RNA or DNA sequences inside cells. This specificity allows them to:
- Modulate gene expression by blocking or altering the way genes are read
- Correct faulty RNA splicing, which is a common cause of many genetic diseases
- Silence harmful mutant genes that produce toxic proteins
Their small size and precise targeting make oligonucleotides uniquely suited to intervene directly at the genetic level, which traditional small-molecule drugs or biologics cannot easily achieve.
This precision is why oligonucleotide therapies are game-changers in treating genetic disorders like SMA; they don’t just treat symptoms but correct the underlying genetic errors that cause disease.
Unlike traditional drugs that often target symptoms or proteins downstream, oligonucleotides act upstream at the genetic level.
The SMA Success Story: A New Era of Hope
Spinal muscular atrophy (SMA) is a genetic disorder characterised by the loss of motor neurons, leading to muscle wasting and severe physical disability. Before oligonucleotide therapies, SMA was often fatal in infancy or early childhood, with very limited treatment options.
Genomic analysis identified mutations in the SMN1 gene as the cause of spinal muscular atrophy and revealed the closely related SMN2 gene as a potential backup. Researchers discovered that a single nucleotide change in SMN2 causes exon 7 skipping, leading to insufficient functional protein. This insight enabled the design of nusinersen, an antisense oligonucleotide that corrects SMN2 splicing to restore SMN protein levels.
This breakthrough:
- Improves muscle strength and motor function
- Slows or halts disease progression
- Extends survival rates significantly
For many patients, especially when treated early, this means gaining critical milestones such as sitting, walking, and even breathing independently; transforming what was once a devastating diagnosis into a manageable condition.
“We’ve shown that splice-switching oligonucleotides can restore functional protein; even in severe genetic disorders like Duchenne muscular dystrophy,”
says Dr. Steve Wilton, whose pioneering work contributed to the development of several FDA-approved therapies.
Why Zetta Genomics Is Excited
At Zetta Genomics, our mission is to accelerate genomic innovation and translate it into actionable healthcare solutions. Oligonucleotide therapies perfectly embody this mission by transforming genetic knowledge into precise treatments.
We are actively exploring ways to:
- Integrate and leverage genomic data to uncover new therapeutic opportunities
- Support development pipelines for next-generation oligonucleotide drugs
- Enable clinicians and researchers with insights that unlock these therapies’ full potential
As the genetic frontier expands, oligonucleotides are a powerful tool in our arsenal; delivering hope for patients worldwide.
Want to read more:
Dr. Steve Wilton https://www.perroninstitute.org/research/research-groups/steve-wilton/
- FDA page on Spinraza (nusinersen) approval and information:
https://pmc.ncbi.nlm.nih.gov/articles/PMC5382937 - Review article on oligonucleotide therapies (Nature Reviews Drug Discovery):
https://www.nature.com/articles/nrd.2017.162
Foundational Research & Mechanistic Insights
Hua et al. – Enhancement of SMN2 exon 7 inclusion by ASOs targeting the exon
- Hua Y, Vickers TA, Baker BF, et al. Enhancement of SMN2 exon 7 inclusion by antisense oligonucleotides targeting the exon. PLoS Biology. 2007.
https://pubmed.ncbi.nlm.nih.gov/31093018/
Singh et al. – Identification of ISS‑N1
- Singh RN, et al. (2006). Study defining ISS‑N1 as a critical intronic splicing silencer in SMN2 intron 7.
- Mapped and validated ISS‑N1 as a powerful therapeutic target; targeting it reverses exon 7 exclusion in SMN2 https://pmc.ncbi.nlm.nih.gov/articles/PMC4356243/
Li (2020) – Review on nusinersen as a therapeutic agent
- Qing Li. Nusinersen as a Therapeutic Agent for Spinal Muscular Atrophy. Yonsei Medical Journal. 2020.
- Covers mechanism of action, cellular uptake, blood-brain barrier crossing, pharmacokinetics, and early clinical trials of nusinersen https://pmc.ncbi.nlm.nih.gov/articles/PMC7105407/
