Alan Cohen
MD, Chief Medical Officer, Arcturus Therapeutics
New mRNA technologies are in development that have the potential to make a major impact on the lives of children and adults with two rare life-limiting genetic conditions.
During the Covid-19 pandemic, a spotlight was shone on an exciting medical advance: messenger RNA (mRNA) technology, which was credited with speeding up vaccine development.
The world’s first self-amplifying mRNA Covid vaccine to gain approval was developed by Arcturus Therapeutics, which has been working on RNA technology for over 13 years. Currently, the company is in the clinical development stage of evaluating mRNA medicines to treat patients with two rare, life-limiting conditions.
This is transformative for rare diseases because
mRNA technologies address the underlying genetic cause
Explaining cystic fibrosis and ornithine transcarbamylase deficiency
The first is cystic fibrosis (CF), a chronic, progressive genetic disease affecting over 100,000 people worldwide1 that primarily damages the lungs and digestive system, resulting in malnutrition and poor growth and development in children and young adults. Arcturus is currently developing mRNA therapy, which aims to produce proteins directly in the lungs to thin mucus and prevent infections.
The second is ornithine transcarbamylase (OTC) deficiency, a rare metabolic condition affecting over 10,000 people worldwide.2 This occurs when mutations in the OTC gene result in a missing or malfunctioning enzyme, causing a build-up of ammonia in the blood, which is highly toxic to the brain and nervous system. The company is developing an mRNA medicine that turns the patient’s own liver cells into “factories” that produce the missing OTC enzyme and allow the body to detoxify ammonia naturally.
Giving the body ‘instructions’ to produce disease-preventing proteins
The advantage mRNA medicines have over current therapies is that they use synthetic mRNA to provide cells with the ‘instructions’ to produce the proteins needed to prevent or treat a disease.
“This is transformative for rare diseases because mRNA technologies address the underlying genetic cause, rather than just managing its symptoms,” explains Alan Cohen, MD, Chief Medical Officer at Arcturus Therapeutics. “Since approximately 80% of all rare diseases are genetic and many involve a single missing or defective protein, mRNA offers a unique ‘blueprint’ solution.”
Nevertheless, developing mRNA medicines for rare diseases can take around 10 years. “However, patients with CF lung disease and adults with OTC deficiency currently enrolling in our Phase 2 studies could gain access to an active drug many years before both therapies would be approved by the regulatory agencies and widely available,” says Dr Cohen. “This is an opportunity to make meaningful inroads to improve the overall survival and quality of life for those burdened by rare diseases.”
[1] Guo, J. et al. Worldwide rates of diagnosis and effective treatment for cystic fibrosis. 2022. https://doi.org/10.1016/j.jcf.2022.01.009.
[2] NORD. Ornithine Transcarbamylase Deficiency. 2025. tinyurl.com/4knh2xkd.
