Relyvrio™ (sodium phenylbutyrate/taurursodiol) for oral suspension received approval from the U.S. Food and Drug Administration (FDA) on Sept. 29, 2022. It is indicated to treat amyotrophic lateral sclerosis (ALS), a disease that slowly destroys the nerves involved in voluntary movement. At a dose of one packet mixed with water daily for 21 days and then one packet twice daily, it can be swallowed or given through a feeding tube. Relyvrio can be used alone, or it may be combined with other drugs that treat ALS. Amylyx Pharmaceuticals plans to distribute Relyvrio, beginning within the next four to six weeks, through a small network of specialty pharmacies that includes Accredo. For its complete prescribing information, look here.
At a Glance
- Brand (Generic) Name: Relyvrio (sodium phenylbutyrate/taurursodiol)
- Manufacturer: Amylyx Pharmaceuticals
- Date Approved: Sept. 29, 2022
- Indication: for the treatment of ALS in adults
- Dosage Forms Available: single-dose packets containing 3gm of sodium phenylbutyrate and 1gm of taurursodiol to be dissolved in eight ounces of water at room temperature for oral or feeding tube administration
- Launch Date: within four to six weeks
- Estimated Annual Cost: Pricing information is not yet available.
- In the United States, about 20,000 individuals have ALS, a progressive disease that destroys nerve cells in the brain and spinal cord (central nervous system or CNS). Patients who have it gradually lose the ability to move, speak, swallow and breathe. With most patients diagnosed between the ages of 40 years and 70 years, life expectancy is only three years to five years.
- Around 5% to 10% of ALS patients inherit a defective gene, but the majority of cases are “sporadic” – they have no obvious cause.
- The 24-week-long clinical study that prompted Relyvrio’s approval enrolled 137 patients. For patients receiving Relyvrio, the risks of being hospitalized, needing a tracheostomy or requiring permanent ventilation assistance were statistically significantly lower than for patients given a placebo. The average survival time was nearly five months longer for the patients treated with Relyvrio, as well. Many of the patients continued on their previous ALS therapy during the study.
- Study patients taking Relyvrio experienced more abdominal pain, diarrhea, nausea and upper respiratory tract infections than patients using a placebo. Because the taurursodiol component of Relyvrio is a bile acid, diarrhea may be intensified for patients who have conditions, such as gallstones or primary biliary cholangitis, which interfere with the normal flow of bile.
- Current treatment for ALS includes Radicava® (edaravone injection) for intravenous (IV) use and Radicava ORS® (edaravone oral suspension), which may help to protect nerves in the CNS from damage. Another drug, riluzole (available generically as tablets and branded as Exservan™ oral film), Rilutek® tablets, and Tiglutik® oral suspension) is believed to delay loss of function by reducing potentially damaging excess CNS levels of the neurotransmitter, glutamate.
- Approved through the FDA’s Priority Review pathway, Relyvrio also has Orphan Drug status for treating ALS.