Amyotrophic lateral sclerosis (ALS) has returned to global headlines in recent days after Grey's Anatomy star Eric Dane revealed he’d been diagnosed with the neurodegenerative disease. The news comes as a new Israeli-developed drug, PrimeC, has drawn attention for its potential to slow the progression of ALS.
Developed by biotech startup NeuroSense Therapeutics, PrimeC was recently named the most promising experimental treatment by the ALS Association in the U.S. The drug is being tested in a clinical trial led by Prof. Vivian Drory at Tel Aviv’s Sourasky Medical Center, the largest of three sites participating in the study and the only one in Israel.
“This is a relatively early-stage study but it’s already significant given how few Israeli companies make it this far in ALS drug development,” said Prof. Drory, a senior neurologist and former head of the neuromuscular disease unit at the hospital. “There are almost no effective treatments for ALS today, so even initial positive results are important.”
Although the trial is only at phase 2 and includes a small group of patients, the results have been encouraging: PrimeC slowed the rate of disease progression — a key achievement given how rapidly ALS typically advances. “That alone is meaningful,” Drory said. “Still, larger studies are needed to confirm the findings.”
A fatal disease with no cure
ALS is a fatal neurodegenerative disease that attacks motor neurons in the brain and spinal cord, leading to progressive muscle paralysis. As these neurons die, communication between the nervous system and muscles breaks down. Over time, patients lose the ability to walk, speak and eventually breathe on their own — though cognitive abilities are usually preserved.
The exact cause remains unclear, though research points to a mix of genetic, environmental and inflammatory factors. Early symptoms include weakness in the limbs, such as trouble walking, writing or buttoning a shirt.
As the disease progresses, patients develop difficulty swallowing and speaking, lose weight and eventually experience respiratory failure — the leading cause of death in ALS.
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Despite years of research, no cure exists. Current treatments only aim to slow deterioration and improve quality of life. According to Drory, only a few companies worldwide — including a small number in Israel — are actively working on ALS drug development.
Alon Ben-Noon, founder and CEO of NeuroSense, said his team has spent eight years trying to develop effective therapies. “ALS is a cruel disease that strikes suddenly and upends lives,” he said. “We believe PrimeC offers hope — not just to slow the decline but to give patients more time and moments of optimism.”
Prof. Vivian DroryPhoto: CourtesyClinical results show slower decline
PrimeC combines two drugs under a proprietary patent. In a phase 2b trial, patients who took the drug for six months experienced a roughly 30% slower disease progression compared to those who were given a placebo.
Globally, over 200,000 people are estimated to live with ALS, including about 30,000 in the U.S. and Canada. The U.S. diagnoses around 5,000 new cases each year (about 150 in Israel). By 2040, the global number is expected to rise by 20%. The disease is most commonly diagnosed between ages 40 and 70 but can appear earlier or later. Most patients die within two to five years of diagnosis.
The trial lasted 18 months, with the first six months conducted as a double-blind, placebo-controlled study. During that period, some patients received PrimeC while others received a placebo. In the following year, all participants were given the drug.
The study focused on the ALS Functional Rating Scale-Revised (ALSFRS-R), a standard metric for tracking motor function in ALS patients, including their ability to walk, eat and speak. This score is closely linked to patients' quality of life.
The trial enrolled 68 patients from Israel, Canada and Italy. All received PrimeC or placebo tablets twice daily for six months, followed by an open-label extension in which everyone took PrimeC for an additional 12 months.
Patients who began with PrimeC showed a greater than 30% slower decline in ALSFRS-R scores after 18 months compared to those who started on placebo. “The long-term results are encouraging and show how PrimeC slowed disease progression in a measurable way,” said Drory. “This highlights its potential and the urgent need for innovative ALS treatments.”
Alon Ben-NoonPhoto: PRNext step: Phase 3 trials
Drory stressed that while the findings are promising, PrimeC is not a breakthrough cure. “This isn’t a life-saving drug yet — but it is a meaningful step,” she said. “There’s real hope but we still need larger clinical trials to validate the results.”
The drug has been granted “orphan drug” status by both the U.S. Food and Drug Administration (FDA) and the European Medicines Agency (EMA), a designation for treatments targeting rare, life-threatening diseases.
“It’s exciting to see this kind of progress come from an Israeli company,” said Drory. “But we have to stay realistic. The road to a true treatment is still long.”