Frequency of first generic drugs approved through "skinny labeling," 2021 to 2023.

BACKGROUND

Brand-name drug manufacturers receive a market exclusivity period following US Food and Drug Administration (FDA) approval, which can be extended through obtaining additional patents such as method-of-use patents. The skinny labeling pathway, in which the FDA approves generic prescriptions that carve out patent-protected indications from their labeling, has helped promote competition and timely market entry of low-cost generic prescriptions for many decades.

OBJECTIVE

To determine how the use of the skinny labeling pathway by generic prescription drug manufacturers has changed in recent years.

METHODS

Based on FDA-curated lists, we assessed the proportion of FDA-approved first generic prescriptions using the skinny labeling pathway from 2021 to 2023. We also examined whether the use of the pathway changed after a 2021 federal court decision () increased the risk of legal liability for generic manufacturers marketing skinny label generic prescriptions.

RESULTS

From 2021 to 2023, 42.9% of 21 susceptible brand-name drugs required a skinny labeled generic prescription, including 5 (56%) in 2021, 3 (43%) in 2022, and 1 (20%) in 2023.

CONCLUSIONS

Previous literature found 43% of brand-name drugs experienced skinny labeling generic prescription competition in a 2015-2019 sample, which is consistent with the rate of skinny labeled generic prescription entry early in our sample. Then, the proportion of first generic prescriptions approved with a skinny label decreased annually from 2021 to 2023. Applying this 2021 methodology in subsequent years can help determine whether the judicial decision has had a sustained chilling effect on generic prescription manufacturers' use of skinny labeling, resulting in delayed generic prescription competition as a result of fewer generic prescriptions entering the market.