Amyotrophic lateral sclerosis (ALS) is a fatal and debilitating disease diagnosis, with an average life expectancy of two to five years. But an international team of researchers has figured out a treatment that extends lifespan by nearly two years — the longest and most successful drug therapy to date. Their study, published in the journal Neurology, gives hope to the 20,000 Americans reportedly living with ALS today.

"We are shocked at how well this treatment can stop the progression of ALS," said the study's lead author Joseph Beckman, a professor of biochemistry and biophysics at the College of Science at Oregon State University, in a press release. Beckman and his team of researchers respectively from Oregon State University, University of Melbourne, University of Texas Southwestern, University of Central Florida, and the Pasteur Institute of Montevideo worked to extend lifespan longer than any other treatment currently available on the market. ALS is the result of deteriorating motor neurons in the spinal cord, a deterioration that's been linked to mutations in both copper and an enzyme called SOD1.

According to the National Institute of Neurological Disorders and Stroke, ALS attacks the nerve cells in charge of voluntary muscle movement and destroys motor neurons. Disease onset may be subtle, but it soon leads to muscle weakness in the arms and legs, slurred speech, difficulty swallowing or chewing, respiratory or heart failure, and eventually death.

"The damage from ALS is happening primarily in the spinal cord and that's also one of the most difficult places in the body to absorb copper," Beckman said of the first trials. "Copper itself is necessary but can be toxic, so its levels are tightly controlled in the body. The therapy we're working toward delivers copper selectively into the cells in the spinal cord that actually need it. Otherwise, the compound keeps copper inert."

In 1993, scientists discovered ALS patients had mutations in a gene that produces SOD1. Knowing this, researchers tested a compound called Copper — ATSM, which helps deliver copper to damaged cells. When SOD1 is broken down in the body, it "unfolds" and becomes toxic, leading to the death of motor neurons. Because copper stabilizes SOD1, it's able to stop it from unfolding. Before these trials, the most effective drug was only able to extend lifespan by about a month.

Although they have only tested it out in mice so far, they’re confident the treatment can be replicated in humans and prove to be just as successful.

"We have a solid understanding of why the treatment works in the mice, and we predict it should work in both familial and possibly sporadic human patients," Beckman said. "But we won't know until we try. We want people to understand that we are moving to human trials as quickly as we can."

Source: Beckman J, Williams JR, and Trias E, et al. Copper delivery to the CNS by CuATSM effectively treats motor neuron disease in SODG93A mice co-expressing the copper-chaperone-for-SOD. Neurology of Disease. 2016.