OBJECTIVES

This study assessed trends in prices at market entry of antidepressant drugs approved by the US Food and Drug Administration (FDA) in 1978-2020.

METHODS

Antidepressant regulatory information was derived from the FDA website. Indications and Defined Daily Dose (DDD) were derived from FDA approved labels. Antidepressant wholesale acquisition cost (WAC) data were extracted from the IBM Micromedex Redbook from approval date to December 31, 2020. The consumer price index (CPI) was collected from the U.S. Bureau of Labor Statistics and the gross domestic product (GDP) from the US Bureau of Economic Analysis. The median WAC per 30-DDD was calculated for each decade.

RESULTS

The FDA approved 19 drugs for the treatment of depressive disorders in 1978-2020. One drug, aripiprazole, had FDA Orphan Drug designation at approval. The FDA used the priority review process for 3 drugs (fluoxetine, clomipramine, and esketamine). There were 10 (52.6%) drugs sponsored by US pharmaceutical companies. The median market entry 30-DDD WAC was $14.61 for imipramine hydrochloride, the only drug approved in 1978-1979; $33.00 for fluoxetine hydrochloride, the only drug approved in the 1980s; $48.30 (IQR: $16.06) for the 9 drugs approved in 1990s; $104.25 (IQR $93.54) for the 5 drugs approved in the 2000s; $133.50

for desvenlafaxine, the only drug approved in the 2010s; and $445.27 for esketamine, approved in 2020. The median 30-DDD WAC at market entry surpassed the CPI and the GDP in 1990 and continued to grow exponentially until 2020.

CONCLUSIONS

The WAC per 30-DDD at market entry of antidepressant drugs increased significantly in the period 1978-2020, exceeding the growth of both the CPI and the GDP. Price increases of new drugs at market entry limit affordability of drugs for patients and third-party payers.