Background
PrimeC is a combination therapy composed of two FDA approved drugs: ciprofloxacin and celecoxib. PrimeC is reported to act by regulating several biological mechanisms associated with motor neuron degeneration in ALS such as inflammation and iron accumulation (Salomon-Zimri et al, 2025).
PrimeC has shown promising data in preclinical models of ALS. Data from Justin Ichida’s lab at University of Southern California (USC) showed that PrimeC was able to increase cell survival rate in patient derived neurons in a dish. Additionally, PrimeC treated zebrafish carrying ALS-causing gene mutations, showed improvement in their swimming abilities compared to their untreated peers (Goldsthein et al., 2020).
NeuroSense launched two phase 1 and one phase 2a clinical trials at single centers in the US and Israel to test the safety and tolerability of PrimeC in humans. Data showed that PrimeC was safe and well tolerated after 12 months (Salomon-Zimri et al., 2023)
Trial Design & Results
In 2022 NeuroSense started a Phase 2b, double-blind clinical trial (PARADIGM) in 68 subjects with ALS. The trial was randomized at a 2:1 ratio to receive PrimeC or placebo for 6 months followed by a 12-month open label extension period;
- The drug or placebo were administered orally twice a day. Subjects were evaluated every 2 months for safety, tolerability, and various efficacy measurements as secondary outcomes.
- This was a multicenter and international study that took place in Italy, Canada and Israel .
- Analysis of ALSFRS-R data showed that at the 6-month timepoint, particiapnts treated with PrimeC had a higher score although this did not reach significance.Data from the Opel Label Extension (OLE) showed increased ALSFRS scores and survival for participants who had been taking PrimeC from the start of the trial compared to those who had started on placebo.
- The data from the PARDIGM trial has now been published with the conclusion “PrimeC was safe and well tolerated over 18 months. Although not powered for efficacy, functional and biomarker findings support a confirmatory trial.”
- Through 2024 NeuroSense met with different regulatory agencies and is now planning a larger phase 3 clinical trial to evaluate Prime C efficacy.
Summary
These clinical studies demonstrate safety and tolerability of PrimeC in people with ALS. The secondary functional measures potentially suggest clinical benefit; however, the trial was underpowered for efficacy measures so further trials are necessary for assessing PrimeC efficacy. We look forward to the results of the planned phase 3 clinical trial that should allow better understanding of the therapeutic potential of PrimeC.
International Alliance of ALS/MND Associations
April 2026
Disclaimer: Consult with a healthcare professional to determine if you could potentially participate in a PrimeC clinical trial. Always disclose your medical history, including any drugs, natural supplements, or herbal medicines currently being used.
The original language of communication is English and any translation cannot be guaranteed for accuracy of messaging.