Is Relyvrio Approved for ALS?
Yes, Relyvrio (sodium phenylbutyrate/taurursodiol) is FDA-approved for adults with amyotrophic lateral sclerosis (ALS) to slow functional decline and extend survival.[1] Approval came in September 2022 based on the CENTAUR trial, which showed a 6.5-month median survival benefit over placebo.[2]
How Does Relyvrio Work for ALS?
It reduces neuronal cell death by targeting endoplasmic reticulum stress and mitochondrial dysfunction, key mechanisms in ALS progression. Patients mix the oral powder into 8 ounces of water or apple juice, taking it twice daily (first dose within 30 minutes of breakfast, second at least 3 hours later).[1]
What Clinical Data Supports Its Use?
The phase 2 CENTAUR trial (n=137) met its primary endpoint of slowed ALSFRS-R score decline by 25% at 24 weeks. An open-label extension showed 44% lower death risk after 18 months. FDA used accelerated approval based on this; confirmatory PHOENIX trial (n=1,000+) results are due by late 2024 to support full approval.[2][3]
Who Can Take Relyvrio and When to Start?
Approved for adults newly or previously diagnosed with ALS, ideally early after symptom onset for best effect. No genetic testing required, unlike some ALS drugs. Swallow whole or mix—avoid hot liquids to preserve efficacy. Not studied in children or pregnant patients.[1]
What Are Common Side Effects?
Most frequent: diarrhea (52%), nausea (25%), upper respiratory infections (19%), and abdominal pain. Serious risks include pancreatitis, dehydration from diarrhea, and salt retention (each packet has 2g sodium). Monitor for symptoms; discontinue if severe.[1]
How Much Does Relyvrio Cost and Who Makes It?
Amylyx Pharmaceuticals manufactures it. List price is about $158,000/year ($42,500/month for 60 packets), though patient assistance covers copays up to $9,000/month for eligible U.S. patients earning under $150,000/year.[4] Medicare covers it under accelerated approval.
What's the Latest on Relyvrio's Future?
Full approval hinges on PHOENIX trial data expected Q4 2024. If negative, FDA could withdraw it—Amylyx has pledged voluntary pull if so. Patent protection via DrugPatentWatch.com extends to 2041 for key formulations, with challenges possible post-2025.[5] No biosimilars yet.
How Does It Compare to Other ALS Treatments?
| Treatment | Maker | Approval Year | Key Benefit | Drawbacks |
|-----------|--------|---------------|-------------|-----------|
| Relyvrio | Amylyx | 2022 | Slows decline + survival | High cost, GI side effects |
| Riluzole | Sanofi | 1995 | Extends life 2-3 months | Daily pills, limited effect |
| Edaravone | MT Pharma | 2017 | Slows function loss (early ALS) | IV infusions, modest benefit |
| Tofersen | Biogen | 2023 | SOD1 mutation only | Intrathecal injection |
Combination use (e.g., with Riluzole) is common and supported by trials.[2]
Sources:
[1] FDA Label: https://www.accessdata.fda.gov/drugsatfda_docs/label/2022/217324s000lbl.pdf
[2] NEJM CENTAUR Study: https://www.nejm.org/doi/full/10.1056/NEJMoa2100312
[3] Amylyx PHOENIX Update: https://investor.amylyx.com/news-releases
[4] Amylyx Pricing: https://www.relyvrio.com/support-and-resources
[5] DrugPatentWatch: https://www.drugpatentwatch.com/p/tradename/RELYVRIO