By Liam Mannix
Hundreds of thousands of doses of a new drug to treat a major disease are being handed out to patients this week after a small, independent team of Australian scientists won a rare approval – upending the normal drug development pathway.
The success of their audacious strategy paves the way for charities and not-for-profits to bring drugs to market for diseases that are neglected by big pharmaceutical companies because the people needing the medication are too poor.
Amanda Handley, Brett Carter and Dr George Rugarabamu with Professor Mark Sullivan (front), managing director of Medicines Development for Global Health.Credit: Wayne Taylor
The new drug – moxidectin – treats river blindness, a disease caused by a parasitic worm that affects about 20 million people, many living in extreme poverty in sub-Saharan Africa.
Last week, doctors started administering hundreds of thousands of doses in Ghana. An Australian trial for scabies, a neglected disease that affects up to a third of children in remote Aboriginal communities, concluded in 2022, with research still ongoing.
Getting a new drug approved by the powerful US Food and Drug Administration is so expensive and difficult – typically costing about $2.4 billion and taking more than 10 years – that Australian companies, including pharma giant CSL, have only achieved it about a dozen times.
The team behind moxidectin – not-for-profit pharma company Medicines Development for Global Health (MDGH) – did it in five years for about $20 million, with a team of just 10 people working out of a nondescript Melbourne office.
An illustration of the parasitic worm that causes river blindness.Credit: Getty Images/Science Photo Library RF
“This is as hard as anything in the world,” said Professor Tony Kelleher, director of the Kirby Institute and a veteran of several drug-development efforts.
“Moxidectin has a chance of making a large impact.”
Neglected diseases, which include river blindness, dengue and scabies, affect nearly two billion people every year and kill an estimated 200,000.
Many of these people are among the poorest in the world, which means they are unattractive customers for pharmaceutical companies.
Moxidectin treats river blindness, a disease caused by a parasitic worm.Credit: Medicines Development for Global Health
“The entire global health arena is a perfect example of prejudice. These are poor people we don’t know. So who really cares about them?” says Professor Mark Sullivan, a former top executive at Gilead and GSK (GlaxoSmithKline).
When Sullivan left big pharma in 2005 to found MDGH, his theory centred on the US FDA’s Priority Review Voucher Program.
Since 2007, the regulator has offered vouchers to anyone who can get a drug approved for a neglected disease. They entitle the holder to a “priority review”, shaving months off a new drug’s approval time.
Those vouchers are worth as much as $560 million to pharma companies. But anyone can claim them – theoretically.
MDGH’s high-risk plan was to get investors to gamble that a small team of scientists working as a not-for-profit could get a drug for a neglected disease approved by the FDA.
If the approval came through, the voucher could be sold – returning profit to investors, with enough money left over to pay for the drug to be distributed.
“If you try to prospectively rationalise the approach, it does not make any sense,” says Sullivan.
“A lot of people said, early on, ‘How could that possibly work?’”
Sullivan’s first employee, a former senior scientist with biotech company Bavarian Nordic, Amanda Handley, thought the idea was crazy – but it had the potential to make a huge difference to the lives of some of the world’s most disadvantaged. “I would love to do that,” she said.
Next, they needed a drug.
In the 1980s, a now-defunct company developed moxidectin as an animal dewormer.
It’s widely used in agriculture and not approved for use in humans – but looked promising enough for the World Health Organisation to trial the drug against river blindness in 2000. But the WHO ran out of money before they could analyse the results.
When MDGH did the analysis, they discovered it worked “mindbogglingly well”, said George Rugarabamu, the company’s principal for corporate development. The published trial indicates the drug is 86 per cent more effective than current treatments.
In 2018, MDGH won approval for moxidectin from the FDA and became the first not-for-profit to receive a review voucher – which they sold to Novo Nordisk, the makers of Ozempic.
River blindness is caused by the microscopic parasitic worm Onchocerca volvulus, which is spread by the bite of a blackfly that breeds in river rapids. It jumps from fly to human, burrowing under the skin and eventually producing millions of juvenile worms.
The juveniles live close to the surface of the skin, causing lumps and rashes. If they enter the eye, they can cause permanent blindness.
The worms can survive inside the body by excreting an immune-masking agent. Moxidectin paralyses the worm, stopping it from releasing the masker, and the immune system then attacks and kills the parasite.
Last week, the Ghana Health Service started distributing more than 250,000 doses to affected communities.
“I did a lot of crying, actually” said Handley.
“To have that impact on someone’s life, to give them a drug that means they probably won’t go blind, is just amazing, absolutely amazing.”
The Examine newsletter explains and analyses science with a rigorous focus on the evidence. Sign up to get it each week.