Prevalence of IBD Increases--Does Utilization of Biologics Increase, Too?

The prevalence of inflammatory bowel disease (IBD) among adults seems to be increasing significantly, yet there are signs that the utilization of biologics to treat patients with this chronic disease have plateaued.

In the October 28, 2016 issue of Mortality Morbidity Weekly Review, researchers from the Centers for Disease Control and Prevention (CDC) announced the findings of its 2015 National Health Interview Survey on IBD. They estimated that the prevalence of IBD in the US adult population was 3.1 million (1.3% of the total US adult population). A similar study conducted in 1999 found the figure to be 1.8 million (or 0.9% of the adult US population), a 72% increase in number and a 44% increase by proportion of the population. According to the CDC, a dominating factor in this trend is a substantially higher prevalence of IBD identified among adults aged ≥45 years, mostly in Hispanics and non-Hispanic whites, and those in lower socioeconomic levels. The NHIS is based on the survey responses of more than 33,500 American adults.

This raises the question of whether the utilization of biologics used to treat IBD has also increased over this time. Remicade^® was approved for use in 1998, and Humira^® was approved in 2002 (the anti-TNF fusion protein etanercept was also approved in 1998, but is not indicated for IBD). These remain the two most commonly used agents to treat IBD, especially Crohn’s disease, with Cimzia^® a distant third. Based on a single-center study from Stanford University, the utilization of biologics for adults and children with IBD has not increased proportionately. Use of Remicade^® peaked in 2008, and utilization of Humira continued somewhat slow growth through 2012, the end of the data collection period. Interestingly, biologic use in IBD resulted in dramatic lowering of hospitalization costs, but not in the rate of abdominal surgery in these patients. They attribute this finding to the possible erosion of drug efficacy when given chronically over the long term. However, the Stanford researchers also found that pharmaceutical therapy in IBD, particularly Crohn’s disease, is the primary cost component in health care expenditures. “Pharmacy utilization costs account for nearly one-half (45.5%) of the total CD-attributable costs, exceeding inpatient care costs. Anti-TNF agents alone comprised nearly one-third (29.5%) of total costs,” they said.

The question of whether the biologic utilization pie is growing, shrinking, or remaining the same could have implications for the brand new biosimilar market for IBD.