SEATTLE – , which was the change in the summated motor unit index (MUNIX) from baseline to week 36.
The drug, CNM-Au8, is being developed by Clene, and would represent a novel mechanism of action. “This is a brand-new approach. We used it complementary with riluzole and it was well tolerated, so I see this as an add-on therapy. I think if we can show some more positivity and longer-term results, it’s going to be a game changer for ALS,” Matthew Kiernan, MBBS, PhD, said in an interview. Dr. Kiernan presented the results at the 2022 annual meeting of the American Academy of Neurology.
Jim Kling/MDedge News
Dr. Matthew Kiernan
Riluzole (Rilutek), which received Food and Drug Administration approval in 1995, inhibits glutamate release to counter excitotoxicity, which is believed to play a role in ALS, Huntington’s disease, ischemia, and other acute and chronic neurodegenerative diseases. The other FDA-approved agent for ALS is the neuroprotective agent and free-radical scavenger edaravone (Radicava), approved in 2017.
CNM-Au8 is made up of catalytically active gold nanocrystals that cross the blood-brain barrier, but lacks the toxicity associated with other synthetic gold compounds, according to the company. The formulation is also being investigated for the treatment of Parkinson’s disease and multiple sclerosis. Basic research has shown that it stabilizes mitochondria and reduces accumulation of the TDP-43 protein, which is linked to spread of ALS through the brain, Dr. Kiernan said during his presentation.
The treatment is well tolerated. “Normally in an ALS trial, we see about a 25% dropout rate. There were no dropouts on the active compound in the clinical trial. There are less deaths, so improved survival,” said Dr. Kiernan, the Bushell chair of neurology at the University of Sydney and codirector of the Brain and Mind Center in Sydney.
Good safety signal
The fact that the trial missed its primary endpoint isn’t too concerning, according to Nicholas Johnson, MD, who comoderated the session where the study was presented. “ALS clinical trials are incredibly difficult to conduct, especially a phase 2 learning-phase clinical trial. At this phase, I’m much more buoyed by the fact that they have a good safety signal, and that they’re willing to move forward to that phase 3 clinical trial,” Dr. Johnson said in an interview. He is vice chair of research at Virginia Commonwealth University, Richmond.
A phase 3 clinical trial is in development in the United States and Europe. The drug also is included as part of the HEALEY ALS Platform Trial, which is testing multiple ALS therapies simultaneously. “The results from that should be available by the second half of this year and it will also inform us as to what the approach should be,” said Dr. Kiernan.
Dr. Johnson also was enthusiastic. “I’m excited to see the results in terms of the primary endpoints for that next phase 3 clinical trial,” he said.