Evaluation of Specialty Drug Price Trends Using Data from Retrospective Pharmacy Sales Transactions

The past 25 years have seen a substantial increase in the effect of specialty drugs on patient care. These agents were initially not considered financially viable because they often served a comparatively small market of patients. However, the extended monopoly afforded to manufacturers of these drugs by the Orphan Drug Act of 1983 has made treatment of rare diseases, which specialty drugs often target, a more viable option. As a result, pharmaceutical companies began to increase research and development expenditures in this area, and the pipeline of specialty drugs began to grow in the late 1980s.

To analyze the annual change in wholesale acquisition cost (WAC) pricing of specialty drugs sold over a period of 11 years.

Pharmacy claims data, including date and WAC, were collected for each specialty drug transaction that occurred from 2002 through 2013 at the University of Illinois at Chicago Ambulatory Care Pharmacy Department. The data were organized to create a chronological sequence of WAC values from the initial to final sales of each available drug. Those values were then used to calculate annual percentage of change in WAC. These results were grouped into subsets and graphed in order to illustrate the effects that various factors had on the annual changes in price.

The price of the specialty drugs studied has generally shown a greater rate of increase since experiencing a trough rate increase in 2009 of 4.08%. The economic crisis of 2008 created a short pause in this overall trend, but increases in the rate of price growth have since rebounded. WACs increased at a rate of 7.03% or greater from 2010 through the end of the study period. There was a clear increase over the last few years of the study in the number of drugs with more than 10% annual increases in WAC, which has also shown a rebound after the economic crisis at the end of the last decade.

Specialty drugs are getting more expensive at a faster rate over time. The period from 2010 to 2013, the final year of this study, has also seen biologic agents take a more prominent role in driving these annual increases in WAC.

No funding was provided for the commission of this study. The source data was provided by the University of Illinois at Chicago Ambulatory Care Pharmacy Department and described de-identified data from customer transactions from 2002 through 2013. The authors report no conflicts of interest. Study concept and design and data interpretation were contributed by Stubbings and Penington. The manuscript was written primarily by Penington with assistance from Stubbings.