Abstract
The development of biosimilar insulin products has slowly evolved with only two follow-on biologics currently available to patients in the US. Both Basaglar(®) (insulin glargine) and Admelog(®) (insulin lispro) have undergone extensive testing, and have gained significant use by patients in the US. Despite the availability of these follow-on products, the price of insulin has remained stubbornly high. New regulatory guidance under the Biologics Price Competition and Innovations Act that came into effect in March 2020 introduced an abbreviated pathway for the approval of biosimilar insulins and introduced the option to apply for interchangeability of the biosimilar insulin with the reference product. This abbreviated clinical testing may open the doors for numerous follow-on insulin products, with unknown supply-chain and fiscal ramifications. This review will highlight the development process of biosimilar insulin in the US and the recent regulatory changes that can aid this process. We will also discuss challenges for prescribers and patients who are navigating this ever-changing landscape. These new regulations for biosimilar insulins will have ramifications for patients, healthcare providers, and third-party payers, though the direction and scope of these changes is unclear.