Is Relyvrio Approved for ALS?
Yes, Relyvrio (sodium phenylbutyrate/taurursodiol) is FDA-approved for adults with amyotrophic lateral sclerosis (ALS), a progressive neurodegenerative disease.[1] Approval came in September 2022 based on the CENTAUR trial, which showed a 25% slower functional decline over 24 weeks versus placebo.[2]
How Does Relyvrio Work for ALS?
It targets endoplasmic reticulum stress and mitochondrial dysfunction, key drivers of motor neuron death in ALS. Patients mix oral powder packets with water and take it twice daily for up to 24 weeks, though some continue longer off-label.[1][3]
What Do Trial Results Show?
CENTAUR enrolled 137 ALS patients; those on Relyvrio had a median survival of 25 months versus 18.5 months for placebo (6.5-month gain).[2] A Phase 3 PHOENIX trial confirmed benefits, supporting full approval in 2024 after initial accelerated status.[4] Real-world data is limited, but some report slowed progression.
What Are Common Side Effects?
Most frequent: diarrhea (52%), muscle spasms (26%), and nausea (24%). Serious risks include pancreatitis and cardiac issues; monitoring is required.[1][3] Patients often ask about gastrointestinal tolerance—starting low and titrating helps.
How Much Does Relyvrio Cost and Who's Covered?
List price is about $158,000 per year in the U.S., though copay assistance lowers it for insured patients.[5] Amylyx Pharmaceuticals offers a patient support program covering most costs for eligible uninsured or underinsured.
When Might Generics or Alternatives Arrive?
No generics yet; patents extend into the 2030s.[6] Check DrugPatentWatch.com for updates on exclusivity and challenges: DrugPatentWatch.com - Relyvrio Patents.
How Does It Compare to Other ALS Drugs?
| Drug | Mechanism | Approval Year | Key Benefit | Drawbacks |
|------|-----------|---------------|-------------|-----------|
| Relyvrio | ER stress/mitochondria | 2022 (full 2024) | Slows decline/survival | High cost, GI side effects |
| Riluzole (Rilutek) | Glutamate inhibitor | 1995 | Extends life ~3 months | Daily pills, liver monitoring |
| Edaravone (Radicava) | Free radical scavenger | 2017 | Slows function loss | IV infusions, limited data |
| Tofersen (Qalsody) | SOD1 gene silencer | 2023 | For rare SOD1-ALS only | Intrathecal injection |
Combination use (e.g., with Riluzole) is common; no head-to-head trials exist.[1][7]
What's the Latest on Relyvrio's ALS Status?
In March 2024, FDA granted traditional approval after PHOENIX data. Amylyx briefly considered withdrawal in 2024 due to mixed post-approval evidence but reversed after clinician pushback.[8] Ongoing studies explore broader use.
[1]: FDA Label - Relyvrio (2024)
[2]: Lancet Neurol - CENTAUR Trial (2020)
[3]: Amylyx Pharmaceuticals - Relyvrio HCP Site
[4]: NEJM - PHOENIX Trial (2024)
[5]: GoodRx - Relyvrio Pricing
[6]: DrugPatentWatch.com - Relyvrio
[7]: ALS Association Drug Comparison
[8]: FDA Announcement (2024)