The world’s only experimental vaccine for coeliac disease entered its Phase 2 trial in Melbourne this week and will be soon enrolling participants across the country.
Known as Nexvax2, the vaccine is the only therapy currently being trialled to modulate the immune response seen in coeliac disease, one of the most prevalent autoimmune diseases in the world.
Coeliac disease is a condition likely caused by genetic and environmental factors that initiate an abnormal immune system response to the gluten protein, found in wheat, rye, barley, and oats.
The Phase 1 trial of Nexvax2 was completed in early September and involved 14 participants, half of whom were injected with the vaccine twice a week. The vaccine was shown to be safe and well-tolerated at its highest doses.
The Phase 2 trial will expand to 150 participants across the US, Australia and New Zealand and observe whether the treatment is effective long-term, and if coeliac disease sufferers can inject themselves with the vaccines at home.
Dr Jason Tye-Din, the lead researcher and head of ceoliac research at the Walter and Eliza Hall Institute, told BuzzFeed News that the ultimate aim would be for patients to routinely inject themselves at home with the vaccine, as do diabetics with insulin.
Tye-Din says it is unclear whether this would be a lifelong requirement or a process that would only require a few years of injections.
“The hope would be that after a series of injections to retrain the immune system, they would be treated and that would be it.”
The body’s T cells (cells that play a central role in mediating immune response) mount an attack response against the protein in coeliacs, as they do not recognise it as food.
The immune reaction causes inflammation and damage to the gastrointestinal tract by flattening the tiny, finger-like nodes on the surface, a process known as villous atrophy.
Chronic gut inflammation, anaemia, gastrointestinal cancer, abnormal liver function, arthritis, Multiple Sclerosis, epilepsy and infertility are some of the conditions in a wide range associated with long-term damage caused by coeliac disease.
“The goal of Nexvax2 is to switch off this abnormal response and really restore the immune system to a normal situation, which is tolerance of gluten in the diet,” said Tye-Din.
Around 1 in 70 Australians are thought to be coeliacs, and it’s estimated that around 80% of this population live undiagnosed.
The only current treatment is a lifelong diet that stops all gluten exposure and is followed strictly.
The prevalence rate of coeliac disease is also on the rise in Western societies and is estimated to be four times that in the 1950s.
“This is really mirroring a trend in a range of allergies and autoimmune diseases; it seems to be on the rise particularly in Western communities and there’s a lot of theories about why this could be the case … no-one really knows,” said Tye-Din.
Speculated environmental causes of coeliac disease are the changing gut biome in Western civilisation, the omnipresence of gluten in processed foods, and changes in the way wheat is grown and processed.
Phase 2 of the NexVax2 vaccine will run for approximately one year and Tye-Din is optimistic that this trial could see a successful reprogramming of the immune system response so that coeliacs can tolerate gluten.