OBJECTIVES: The objective of this study was to evaluate trends of average wholesale price (AWP) of immunosuppressant drugs used for kidney transplant patients.
METHODS: Regulatory information for immunosuppressants was derived from the Food and Drug Administration (FDA) website. The AWPs per unit at market entry data were derived from the Red Book (Truven Health Analytics Inc.). The AWP history for each FDA approved immunosuppressants for kidney transplant patients was collected from its date of approval to 30th of November 2017. The defined daily dose (DDD) for adult patients was obtained from WHOCC (WHO Collaborating Centre for Drug Statistics Methodology). The AWP per DDD and the AWP/DDD per year of therapy were computed. Descriptive statistics, Wilcoxon tests, t-test, and multiple linear regression were performed. The statistical significance level was set at 0.05.
RESULTS: The FDA approved 10 immunosuppressants used for kidney transplant patients. As of 30th November 2017, there were 7 new drug applications (NDAs) and 3 biologic license applications (BLAs). The FDA granted orphan designation to 4 immunosupressants. There was one immunosuppressants approved by the FDA in the 1960s, six in 1990s and three in the period 2010–2017. Inflation-adjusted median AWP per DDD was $10.25 for the first immunosuppressants (Azathioprine) that was approved in the 1968s. The median market entry inflation-adjusted AWP per DDD was $12.41 (interquartile range [IQR]= 4.51) for immunosuppressants approved in the 1990s, $71.26 (IQR=58.35) in the 2000s, and $172.56 (IQR=84.97) in the period 2010–2017.
CONCLUSIONS: The AWP per DDD for immunosupressants at market entry increased substantially over time. The increase in prices of immunosuppressants exceeded the general consumer price index.
