Real-World Clinical Experience With Sodium Phenylbutyrate and Taurursodiol at a Single Amyotrophic Lateral Sclerosis Center in the United States

Abstract

Introduction/Aims: Sodium phenylbutyrate (PB) and taurursodiol (TURSO)—PB and TURSO—was approved as a treatment for amyotrophic lateral sclerosis (ALS) in the United States in 2022 based on the results of a phase 2 trial, but was voluntarily withdrawn from the market in 2024 after negative results from its phase 3 trial. The objective of our study was to describe the real-world clinical experience with PB and TURSO at one ALS clinic. Methods: This was a retrospective chart review of all ALS patients receiving a PB and TURSO prescription at the Massachusetts General Hospital ALS Clinic between October 1, 2022, and September 30, 2023. Data were extracted from patients' electronical medical records up to December 31, 2023. Results: A total of 441 ALS patients received a PB and TURSO prescription, with 329 (75%) initiating the medication. The average length of treatment was 285 days, and the rate of drug discontinuation during the study period was 41% (N=135). The most common reason for drug discontinuation was side effects (N=93, 69%), with the most common being gastrointestinal issues (N=69). No hospitalizations, deaths, or serious adverse events were considered related to treatment with PB and TURSO. Discussion: Experience in real-world clinical settings can help supplement trial data with information on the drug performance at various stages of disease progression. Adverse events impacted treatment persistence in routine clinical practice, underscoring the need for vigilant monitoring and tailored supportive interventions to optimize treatment adherence.