14 December 2023 - Spending on biologics in 2021 represented $260 billion or 46% of all spending on prescription drugs in the US. Biosimilar competition can lower prices, but biosimilar entry is often delayed by expansive patent thickets (dozens or hundreds of patents directed toward the same product). 

Many of these patents claim innovations that are closely related to one another. Although the US Patent and Trademark Office is required to reject patents that are obvious follow-ons from earlier versions, they may grant such patents when applicants file terminal disclaimers.

Read JAMA article