Extended-Release Ciprofloxacin + Celecoxib Associated with Prolonged Survival in Phase 2b ALS Trial Extension

Treatment with PrimeC (ciprofloxacin and celecoxib extended release; NeuroSense Therapeutics, Cambridge, MA) was associated with prolonged overall survival in people with amyotrophic lateral sclerosis (ALS), according to results from extended follow-up from the PARADIGM phase 2b clinical trial (NCT05357950). People with ALS who received PrimeC continuously during both the double-blind and open-label phases of the study had a longer estimated median survival than those initially assigned to placebo.

PARADIGM was a randomized, double-blind, placebo-controlled phase 2b study that enrolled 68 participants with ALS. Participants were randomized 2:1 to receive PrimeC or placebo during a 6-month double-blind period, followed by an open-label extension in which placebo-assigned individuals crossed over to active treatment. PrimeC is an extended-release oral fixed-dose combination of ciprofloxacin and celecoxib intended to target multiple ALS-related pathways. Previously reported results from the trial included statistically significant slowing of disease progression and favorable safety and tolerability; the current results focus on long-term survival.

Key findings reported from the study include the following:

• Median overall survival was 36.3 months among those treated continuously with PrimeC vs 21.4 months among those initially assigned to placebo who later crossed over to PrimeC, an estimated difference of 14.9 months (approximately 70%).
• Kaplan–Meier survival curves demonstrated sustained separation between groups over follow-up, with a statistically significant log-rank test (P=.0218).
• In a Cox proportional hazards model adjusted for baseline risk factors, PrimeC treatment was associated with a 65% reduction in risk of death compared with placebo (hazard ratio [HR], 0.35; 95% CI, 0.17 to 0.71; P=.0037).

Source: NeuroSense Therapeutics. NeuroSense announces statistically significant 65% reduction in risk of death and greater than 14-month median survival benefit with PrimeC in ALS. PR Newswire. Published 18 February, 2026. Accessed 20 February, 2026. https://prnmedia.prnewswire.com/news-releases/neurosense-announces-statistically-significant-65-reduction-in-risk-of-death-and-greater-than-14-month-median-survival-benefit-with-primec-in-als-302691462.html