Platypus venom and chubby mice – the keys to an Australian Ozempic?
The remarkable story of Platypep
University of Adelaide researcher Alanah Bradey shared updates of the Platypep research project on Thursday when she delivered a ‘lunch and learn’ session at AusHealth’s head office in Adelaide.
The Platypep project, funded by AusHealth since 2016, has taken another important step towards creating an Australian-made version of Ozempic, the Type 2 diabetes drug that found fame (and fortune) as a means of weight loss.
Alanah’s presentation amounted to a series of ‘who knew?!’ moments that had the audience shaking their heads…
The story of weight-loss drugs begins with a peptide called GLP-1, which is found in the human body. However, researchers found a version of the peptide – a ‘GLP-1 receptor agonist’ – in a large American lizard called a Gila monster.
The lizard’s GLP-1ra was proven to be effective at stimulating insulin production in humans and eventuated in the first drug of its type, a daily-injection medication called Exenatide in 2005.
Meanwhile, a Danish-made drug called Ozempic was being developed, specifically a longer-acting GLP-1 that required only one injection a week. It enjoyed both notoriety and explosive sales after its launch in 2010, championed as an appetite suppressant and a highly effective aid to weight loss.
Today, however, it’s not all up-side. Weight loss drugs using GLP-1s are expensive and not without side effects – in some instances threatening serious compromise to pancreatic function.
Which brings us to the platypus.
Like the Gila monster, the platypus and its monotreme cousin the echidna, both have venom in their biology – and this venom also contains a version of GLP-1. Platypuses are especially interesting: they have spurs on their hind legs which they use in mating season, fighting with a rival male to inject him with venom. The vanquished suitor is shot up with GLP-1, which causes a huge spike of insulin production and knocks him unconscious owing to a crash in his blood sugar levels.
In 2021, Professor Glenn King at the University of Queensland collaborated with AusHealth to look at the bioactivity of both monotremes’ GLP-1s and design 23 new synthetic GLP-1 peptides. the following year, the University of Adelaide team was charged with testing all 23 ‘platy-peptides’ for their efficacy in stimulating insulin production and suppressing appetite.
Six peptides were found to be the most potent and taken to the next phase of the research – which commences this month.
The three-month in vivo trial sees mice fattened with a special diet before being injected with the peptides. They will be monitored for glucose levels, reductions in food intake, lowering of body mass and tested for other markers, including cholesterol.
The team are hoping to isolate a candidate that can be used to create a drug with greater efficacy and fewer side effects and also be administered by methods more friendly than injection.
According to Alanah, “It’s estimated that by 2030 there’ll be more than 1 billion people who are obese, so the commercial potential of a project like this is massive. GLP-1s are also being researched for their potential in other diseases like cardiovascular disease, Alzheimer’s and polycystic ovary syndrome.
“The potential is enormous.”
For more information, visit AusHealth Ventures