Neurosense, Health Canada discuss approval path for PrimeC

Neurosense Therapeutics said it recently held a “constructive” meeting with Health Canada to discuss potential regulatory pathways for PrimeC, its experimental oral therapy for amyotrophic lateral sclerosis (ALS).

The meeting focused on the company’s proposed new drug submission (NDS) strategy and the clinical, biomarker, and long-term outcomes data supporting a potential application for PrimeC, Neurosense said in a U.S. Securities and Exchange Commission filing.

Neurosense presented additional data requested by Health Canada to support a future NDS filing, which the company is seeking to advance through Canada’s Notice of Compliance with Conditions pathway, a mechanism designed to facilitate earlier access to promising therapies addressing serious unmet medical needs. The company said it expects to receive an official response from the agency in the third quarter of this year.

ALS is caused by the progressive loss of motor neurons, the nerve cells responsible for controlling muscle movement. As these cells die, patients experience worsening muscle weakness and increasing difficulty in doing activities such as walking, speaking, swallowing, and breathing. While approved ALS therapies can help slow disease progression and manage ALS symptoms, there remains a need for more effective treatments.

PrimeC is an extended-release tablet that contains a fixed combination of ciprofloxacin, an antibiotic, and celecoxib, an anti-inflammatory medication, both of which are already approved for other indications. The treatment is expected to slow disease progression by targeting inflammation and other biological pathways thought to drive ALS.

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Trial data promising

Neurosense aims to seek accelerated approval of PrimeC in Canada based on findings from the Phase 2b PARADIGM trial (NCT05357950), which enrolled 68 adults with ALS. Participants were randomly assigned to receive daily PrimeC or a placebo for six months, in addition to standard ALS treatments. After completing the main trial, patients could enter a one-year, open-label extension in which all received PrimeC.

Results from the placebo-controlled portion of the study showed that patients given PrimeC tended to experience slower disease progression, as measured with the ALS Functional Rating Scale-Revised (ALSFRS-R), than those on a placebo, but the difference was not statistically significant.

In subgroup analyses, however, researchers found that participants who adhered closely to the study protocol experienced a significant, 37.4% reduction in disease progression compared with placebo.

Long-term data spanning the main trial and the extension continued to support the superiority of PrimeC over a placebo. For example, patients who received PrimeC for a full year had a 43% higher survival rate than those who started on a placebo and switched to PrimeC after six months.

After 18 months of follow-up, the estimated median survival for those continuously on PrimeC was 36.3 months, while those initially assigned to a placebo lived for a median of 21.4 months. This represented a 65% reduction in the risk of death.

Neurosense is also preparing to launch the Phase 3 PARAGON study to support a regulatory application to the U.S. Food and Drug Administration (FDA) and, if conditional approval is ultimately granted, potentially full approval in Canada.

The FDA, after providing positive feedback on the trial’s design, cleared Neurosense to initiate PARAGON late last year. The study expects to enroll about 300 ALS patients across the U.S. and Europe. Participants will receive PrimeC or a placebo for one year, after which all will receive PrimeC in an open-label extension.