Clinical Development Times for Biosimilars in the United States.

Biosimilars are versions of biologic drugs made by different manufacturers that can help lower spending by promoting competition. However, few biosimilars are currently available in the US. To assess the role of testing requirements in this outcome, we investigated clinical development times for 40 biosimilars that initiated phase I testing between 2012 and 2015. We found that most biosimilars underwent phase III testing with an average trial length of 22 months. Of 20 biosimilars that had been approved by October 2019, the median time from initiation of phase I testing to approval was 69.9 months. These findings reveal a high testing bar for approval that likely contributed to limited market entry.