Study: Injectable Anticancer Drugs Increase in Cost Regardless of Competition

A study newly published in the Journal of Clinical Oncology found that, regardless of competition or additional approved indications, injectable anticancer drugs are subject to steady increases in price after launch.

The study, authored by Noa Gordon, MSc, MPH, and colleagues, points to the known trends of increasing launch prices of anticancer drugs, as well as the emerging trend of post-launch price increases. In this study, the researchers sought to systematically measure cost trajectories of individual anticancer drugs after launch in the United States in order to understand how market structure influences these changes, and subsequently, Medicare.

The analysis included all Medicare Part B anticancer drugs approved by the FDA between 1996 and 2012, excluding medications for pain or adverse event management, cytokine or hormonal therapies, autologous T-cell therapies, drugs that lost approval, and drugs whose patents expired during the follow-up period of 12 years. For each of the 24 drugs under consideration—including 3 monoclonal antibodies with biosimilars in development for the US marketplace: bevacizumab, trastuzumab, and rituximab—the researchers calculated the mean single dose and monthly dose based on product label instructions. To account for discounts and rebates, the average sales price (ASP) published by CMS for all Part B drugs was used to calculate a mean monthly cost.

The study found that, overall, for the follow-up period of 12 years, all 24 drugs studied saw a mean cumulative cost increase of 36.5% (95% confidence interval [CI]; range, 24.7% to 48.3%). The mean cumulative increases were 19.1% (95% CI; range, 11.0% to 27.2%) and 8.4% (95% CI; range, 1.4% to 15.4%) when adjusted for annual inflation (1.09%) and health-related inflation (1.15%), respectively. The mean annual increase in monthly cost was 3.73%.

Drugs with the highest increases in cost over baseline in 12 years were:

• Arsenic trioxide: 95.5%
• Nelarabine: 83.2%
• Rituximab: 85.2%
• Trastuzumab: 78.4%

Only 1 anticancer drug, ziv-afilbercept, saw a post-launch decrease in cost: a 12.8% drop from baseline over 3 years.

The study found no time-dependent variable (including the addition of supplemental FDA approvals, addition of off-label indications, or the introduction of competition) influenced the rate of price changes. The only variable that may have influenced price change was the time from launch; each additional year corresponded to a price increase of 0.308% in inflation-adjusted price and 0.211% in health-related inflation-adjusted price.

The authors note that the cohort of drugs examined included drugs from 4 different pharmaceutical manufacturers, but that 4 of the drugs were developed by Roche-Genentech. “A notable resemblance in cost trajectory” was present for 2 of the 4 Roche-Genentech drugs, rituximab and trastuzumab, whose cost increases “followed an almost identical pattern” over the study period.

The researchers also point out that 4 of the drugs in the cohort were approved for metastatic colorectal cancer. The first of these drugs to be FDA approved were bevacizumab (2003) and cetuximab (2004), and neither drug increased in price substantially until 2010, when their prices began to rise in tandem. The authors suggest that the increases could have been a function of market entry of a competitor, panitumumab, in 2006.

The authors concluded that anticancer drug costs in the United States can change substantially after a product’s launch even in the presence of competition, and they suggest that new regulations may be necessary to prevent additional increases in cost. The authors note, however, that their work has limitations. Medicare ASPs are published at a 6-month lag time, which could slightly distort inflation results. Additionally, using ASPs limits the findings of the analysis to the Medicare, and other payers may have different perspectives.