Neurosense finalizing protocol for Phase 3 trial of PrimeC for ALS
With FDA clearance, trial can start recruiting about 300 patients in mid-2025
Neurosense Therapeutics is working on finishing touches for the protocol of a Phase 3 study testing PrimeC, an oral treatment the company is developing for amyotrophic lateral sclerosis (ALS), and plans to submit the protocol for approval to the U.S. Food and Drug Administration (FDA) in the first half of 2025.
In a type C meeting to discuss the clinical development of PrimeC, the FDA gave positive feedback on the pivotal trial’s design, which could mean it aligns with regulatory standards and can produce the data that will form the basis for a marketing application.
With this step, the company remains on track to start recruiting about 300 patients for the Phase 3 study in mid-2025. The plan is to randomly assign two patients to PrimeC for every one patient on a placebo. After 12 months, patients have the option to enter a 12-month open-label extension where they can switch to PrimeC, or continue to receive it.
“The feedback from the FDA regarding our clinical strategy for the planned pivotal Phase 3 study and the plan for submission of an eventual marketing application, represents a significant milestone in our drug development program,” Alon Ben-Noon, CEO of Neurosense, said in a company press release.
PrimeC designed to slow ALS progression
PrimeC is an extended-release oral tablet that contains a fixed dose of two medications already approved by the FDA: the antibiotic ciprofloxacin and celecoxib, which is used to reduce inflammation. It is expected to slow disease progression by targeting inflammation and other key mechanisms that lead to neurodegeneration in ALS.
In PARADIGM (NCT05357950), a completed Phase 2b study, PrimeC was tested against a placebo, both taken as two tablets by mouth twice daily for six months, in 68 adults diagnosed with ALS. Patients then had the option to enter an open-label extension where all received PrimeC for up to an additional 12 months.
Consistent with earlier data, the 18-month readout showed that, compared with patients who were initially assigned to a placebo before switching to PrimeC, disease progression was slowed by 33% in those who received PrimeC from the start. There was also an increase of 58% in the survival rate.
Because both ciprofloxacin and celecoxib are marketed in the U.S., the company is planning on an eventual 505(b)(2) marketing application, pending positive Phase 3 data. This approval pathway can help to avoid unnecessary duplication of studies already performed on previously approved medications.
The positive feedback on the new protocol “validates the progress we’ve made and reinforces our commitment to advancing a potential therapeutic option for people living with ALS, whose need for innovative treatments is urgent. This step brings us closer to delivering a much-needed solution to the ALS community,” Ben-Noon said.
Meanwhile, Neurosense is seeking early marketing approval in Canada based mainly on findings from PARADIGM. Should the Canadian agency agree to clear PrimeC based on that early data, the upcoming Phase 3 trial will be used as a confirmatory study to potentially gain full approval in the country.
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