Two Generic Drugs That Cost $1 a Day Just Showed the Biggest Survival Benefit in ALS History

Twenty dollars. That is the cost per additional month of survival if you calculate the pharmacoeconomics of NeuroSense Therapeutics' Phase 2b PARADIGM trial results using generic component pricing. For context, riluzole, the 31-year-old standard of care in amyotrophic lateral sclerosis, runs about $3,200 per month of additional survival. Tofersen, the antisense oligonucleotide approved in 2023 for the 2 percent of ALS patients with SOD1 mutations, costs $425,560 in year one and has not yet demonstrated a survival benefit in a randomized controlled trial.

PrimeC, NeuroSense's lead candidate, is not a novel molecule but a fixed-dose extended-release combination of celecoxib (the arthritis drug sold as Celebrex) and ciprofloxacin (the antibiotic your doctor prescribes for UTIs), two generics that together cost roughly 55 cents a day at any pharmacy.

On June 30, NeuroSense announced that PARADIGM hit its primary endpoint: a statistically significant reduction in TDP-43 levels compared to placebo (p=0.0421 at Day 180, p<0.001 at Day 540), making it the first randomized, placebo-controlled trial to demonstrate a treatment-associated reduction in this protein in living ALS patients. TDP-43 misfolding is present in over 97 percent of ALS cases and is widely recognized as a central driver of disease progression.

What PARADIGM Actually Showed

PARADIGM enrolled 68 patients across four ALS referral centers in Canada, Italy, and Israel, randomizing them to PrimeC or placebo for six months before transitioning everyone to PrimeC for another 12 months in a blinded open-label extension, with most patients in both arms also taking riluzole. Previously reported secondary outcomes include a 36.5 percent slowing of functional decline on the ALSFRS-R scale at 12 months (p=0.008), 32.8 percent at 18 months (p=0.007), and a median survival benefit of approximately 15 months with a hazard ratio of 0.35 (p=0.004).

A hazard ratio of 0.35 means patients on PrimeC had roughly 65 percent lower risk of death at any given point during the study, and for a disease that kills most people within two to five years of diagnosis, 15 additional months is not incremental.

The Cost-per-Survival-Month Calculation

No published analysis has compared the cost per month of additional survival across the full landscape of ALS therapies. We ran the numbers using publicly available drug pricing, clinical trial survival data, and standard treatment durations.

Drug	Annual Cost	Survival Benefit	Cost / Survival Month	Status
Riluzole (generic)	$5,360	~2.5 months	~$3,216	FDA-approved (1995)
Edaravone (Radicava)	$171,000	Not demonstrated	N/A	FDA-approved (2017)
Relyvrio (AMX0035)	$158,000	Phase 3 failed	Withdrawn	Pulled April 2024
Tofersen (Qalsody)	$397,000 avg	Not confirmed in RCT	N/A	Accelerated approval, SOD1 only
PrimeC (generic cost)	~$200	~15 months (Phase 2b)	~$20	Phase 2b complete

Methodology: for riluzole, we use the CADTH generic price of $5,360 per year and a Cochrane-estimated survival benefit of 2 to 3 months, assuming 18 months of average treatment, yielding $8,040 divided by 2.5 months or $3,216 per additional month alive. For PrimeC generic components, Drugs.com and GoodRx show celecoxib 200mg at roughly $95 per year and ciprofloxacin 500mg at roughly $99 per year, totaling about $200 annually, which over 18 months of treatment is $300 total for 15 months of additional survival, or $20 per month.

Even if NeuroSense prices branded PrimeC at the ICER cost-effectiveness threshold previously calculated for ALS drugs ($9,100 to $30,700 per year), the cost per survival month would land between $910 and $3,070, roughly equivalent to generic riluzole while delivering six times more survival months.

Why This Might Not Matter: Relyvrio's Ghost

Anyone paying attention to ALS drug development knows where this story could end. In September 2022, the FDA approved Relyvrio, another combination of two existing compounds (sodium phenylbutyrate and taurursodiol), based on a Phase 2 trial of 137 patients. Amylyx priced it at $158,000 per year despite ICER recommending $9,100 to $30,700. Eighteen months later, the Phase 3 PHOENIX trial enrolled 664 patients across 65 sites, and Relyvrio did not beat placebo on any primary or secondary endpoint. Amylyx pulled it from the market on April 4, 2024, cut 70 percent of its workforce, and left thousands of patients who had been paying for an ineffective drug with nothing.

PrimeC faces the same Phase 2-to-3 valley, and the comparison stings: Relyvrio's CENTAUR Phase 2 enrolled 137 patients while PrimeC's PARADIGM enrolled 68, meaning a trial half the size of one that failed to replicate.

What PrimeC Has That Relyvrio Didn't

Three things differentiate PrimeC's dataset, though none guarantees a different outcome. First, PrimeC demonstrated target engagement against TDP-43, the specific protein implicated in 97 percent of ALS cases, whereas Relyvrio targeted the more diffuse pathways of endoplasmic reticulum stress and mitochondrial dysfunction, which are harder to measure and validate. Reducing TDP-43 levels in a blinded trial does not prove clinical benefit, but it does suggest the drug is reaching the biology it claims to change.

Second, PrimeC showed a survival signal with a hazard ratio of 0.35 (p=0.004), among the strongest ever reported in an ALS trial, while Relyvrio's Phase 2 produced only a weaker, non-significant survival trend, and survival is considerably harder to fake with a placebo effect than functional rating scales are. Third, PrimeC slowed ALSFRS-R decline by 36.5 percent at 12 months compared to Relyvrio's approximately 23 percent, and bigger effects are more likely to survive replication in larger trials, though ALS drug development is littered with Phase 2 effects that shrank or vanished entirely.

Limitations

Several caveats constrain these data. PARADIGM enrolled only 68 patients, a sample size that amplifies random variation. Part of the survival analysis draws from a single large study site in Israel, and single-site survival data in ALS has historically been unreliable due to differences in patient selection and care standards. TDP-43 remains a surrogate biomarker that the FDA has not accepted as a registrational endpoint, so Phase 3 will still need functional improvement on ALSFRS-R. Our cost calculation uses generic component pricing, but NeuroSense's proprietary extended-release formulation will cost substantially more. And NeuroSense's market capitalization of $25 million, with NRSN at $0.72 per share, suggests institutional investors are pricing in substantial Phase 3 risk.

Practical Takeaways

For ALS patients and families: PrimeC's Phase 3 PARAGON trial will enroll approximately 300 participants, primarily in the United States, with enrollment information posted to ClinicalTrials.gov. Both celecoxib and ciprofloxacin are FDA-approved generics that individual physicians can prescribe off-label, though whether separate generics replicate the pharmacokinetics of PrimeC's extended-release formulation is unknown, and long-term ciprofloxacin carries real risks including tendon rupture and neuropathy.

For policymakers: PrimeC exposes a structural absurdity in which two of the cheapest drugs in the pharmacopeia require hundreds of millions in clinical development and regulatory costs, with the resulting branded product priced orders of magnitude above generic component cost, even when the disease it targets kills 5,000 Americans per year.

The Bottom Line

PrimeC is simultaneously the most cost-effective and the most uncertain ALS therapy candidate in modern history. At generic prices, it costs $20 per additional month of survival. At any plausible branded price, it would still beat every FDA-approved ALS drug on cost-effectiveness by a wide margin. But 68 patients is 68 patients, and Relyvrio proved that ALS Phase 2 data can evaporate completely in Phase 3. The 300-patient PARAGON trial will determine whether PrimeC's numbers hold. Until then, the most remarkable finding from PARADIGM may not be the survival curve or the TDP-43 signal. It may be that two of the most thoroughly understood drugs on the planet, both off-patent for decades, might work against a disease that has resisted every purpose-built molecule thrown at it.

Sources

1. NeuroSense Therapeutics (June 30, 2026). NeuroSense Achieves Primary Endpoint in Phase 2b ALS Study with Statistically Significant Reduction of TDP-43. prnewswire.com
2. CADTH Common Drug Review (2018). Pharmacoeconomic Review Report: Edaravone (Radicava). Cost Comparison Table for ALS. ncbi.nlm.nih.gov
3. CDA-AMC (2025). Tofersen (Qalsody) Reimbursement Review. $425,560 year-one cost. ncbi.nlm.nih.gov
4. Pharmacy Times (April 4, 2024). Amylyx Voluntarily Discontinues ALS Treatment Relyvrio Following Phase 3 Trial Results. pharmacytimes.com
5. Drugs.com. Celecoxib Prices. Generic 200mg from $0.15/capsule. drugs.com
6. GoodRx (2026). Ciprofloxacin 500mg, 14 tablets: $3.72. goodrx.com
7. AJMC (2024). Medicare Expenditures in the First Year of ALS Diagnosis. Riluzole Part D: $11,748. ajmc.com
8. Drug Topics (2022). ALS Therapy Approved by FDA. Relyvrio WAC: $158,000/year. ICER threshold: $9,100-$30,700/year. drugtopics.com
9. ClinicalTrials.gov. NCT05357950: PARADIGM Study of PrimeC in ALS. clinicaltrials.gov

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