Positive developments in the search for a HD treatment

Fri December, 18th 2020

Researchers are making significant progress in the hunt for ways to treat or prevent HD with an increasing number of clinical trials planned to test promising new drugs.

That was the message from a group of leading international researchers who spoke at the Huntington’s Victoria Community Conference this month.

Professor Tony Hannan from the Florey Institute in Melbourne, who has been doing HD research for 25 years, said community members could take comfort from the progress being made.

“This is the most hopeful time in the history of Huntington’s research, all these clinical trials and the knowledge of the disease is just growing and growing,” Professor Hannan said.

“All of these technologies that have been developed, even outside the Huntington’s field, are coming to bear on the disease.”

Professor Ed Wild said the biggest advance in recent years had been the successful clinical trial in 2017 of a drug aimed at lowering the levels of the mutant huntingtin protein that causes the damage to the brain people with HD experience.

“That changed the playing field really and there are now multiple huntingtin lowering trials already happening and there are at least half a dozen more that are expected to start up in the next two to three years,” said Professor Wild who is associate director of the University College London’s Huntington’s Disease Centre.

“We have gene therapies that are happening now and those probably wouldn’t have happened now or would have taken longer to start if we hadn’t had that result in 2017 showing we can give this drug to lower the protein and bigger doses give bigger reductions in protein.”

The huntingtin-lowering drug is now being tested by pharmaceutical giant Roche in a phase 3 clinical trial at sites across the world, including in Melbourne. A phase 3 trial is the final step before approval can be sought to be make a drug publicly available.

The biggest question researchers are looking to answer in the Roche trial is whether reductions in the mutant protein translate to a slowing of the progression of the disease in the participating group who are in the early symptomatic phase.

Results from that trial are expected in 2022. Professor Wild said the drug being tested was also likely to be used in a clinical trial with people who have the HD gene but are not yet displaying any symptoms.

“The same drug in theory should be able to delay or prevent the onset of the disease in people who have the mutation but don’t have any signs or symptoms of the disease,” he said.

“That will definitely require a separate trial.”

Dr Paul Zeun, who is also from University College London, told the conference that another important discovery in recent years had been the discovery of markers in the body that could be used to measure the success of treatments aimed at delaying or preventing the onset of the disease.

 Higher levels of one important biomarker, the Neurofilament light protein, can be detected in the spinal fluid of HD gene carriers as early as 24 years before the onset of the disease it was discovered in a landmark study Dr Zeun worked on.

“The more we know about Huntington’s disease, how the disease works, how it progresses, new and improved biomarkers, all those things increase the likelihood of finding successful treatments,” he said.

Professor Russell Snell from the University of Auckland spoke to the conference about the collaborative efforts that led to some of the most important HD research breakthroughs, including the discovery of the gene in 1993.

He said there was both collaboration and competition in the HD research field now with everybody chasing the same goal.

“There is an incredibly motivated research group around the world, working and absolutely dedicated to find a treatment as quickly as possible,” he said.

“Nobody is giving up until this darn thing is sorted you can be sure of that.”