List Price Reductions Among Brand-Name ICS-LABA Inhalers In 2024 Were Associated With Increased Generic Uptake

Inhaled corticosteroid-long-acting beta-agonist (ICS-LABA) inhalers are widely prescribed for asthma and chronic obstructive pulmonary disease. ICS-LABAs are largely interchangeable within the class; however, the use of brand-name versions has remained high in the US even though generic versions have been marketed since 2017. Effective in January 2024, the American Rescue Plan Act of 2021 imposed new penalties for prior list price increases in Medicaid, prompting manufacturers of some ICS-LABAs to reduce list prices for these drugs. In an interrupted time series analysis, we used US nationwide prescription dispensing data to assess changes in generic uptake of ICS-LABAs after the brand-name list price reductions. Use of generic ICS-LABAs increased by 23 percentage points at the start of 2024, driven by changes in commercial plans (33 percentage points) and Medicare (24 percentage points). List price reductions may have limited the capacity for brand-name firms to offer large rebates to pharmacy benefit managers, blunting existing financial incentives that had favored brand-name over generic ICS-LABAs. These findings demonstrate how changes in list prices can promote generic competition and improve affordability for patients and payers.