Cancer drug shortages remain common in the United States and may force oncologists to prioritize patients for treatment, improvise standard treatment regimens, and potentially choose unproven treatment options for patients with curable disease. Because increased competition may reduce drug shortages, the objective of our study was to investigate the association between the number of suppliers for first-line breast, colon, and lung antineoplastics and resulting drug shortages.
Among 35 antineoplastic drugs approved for first-line treatment of breast, colon, and lung cancer, we saw an overall increase in drug shortages over time (12.5%, 33.3%, and 0% of breast, colon, and lung cancer drugs experienced shortages in 2003 v 40.0%, 37.5%, and 54.5% in 2014). Having a small number of drug suppliers more than doubled the odds of shortages compared with a large number of suppliers (five or more, Table 1), although the results were only statistically significant with three to four suppliers (odds ratio = 2.6; P = .049) but not with one to two suppliers (odds ratio = 3.49; P = .105); however, one of the strongest risk factors for drug shortages was the age of the drug, with older drugs significantly more likely to experience shortages (P < .001).
Using the 2003-2014 Redbook and national drug shortage data from the University of Utah’s Drug Information Service, we used exploratory analysis and generalized mixed models to (1) quantify time trends in first-line drug suppliers and shortages by cancer site and (2) examine the association between the number of suppliers for individual drugs and resulting drug shortages.
BIAS, CONFOUNDING FACTOR(S), DRAWBACKS:
Although our study provides insights into the relationship between suppliers and drug shortages, we acknowledge the following drawbacks: (1) Information about the supply chain of raw materials, which may affect drug shortages, was not available. (2) As a result of sample size limitations, we were unable to conduct stratified analysis by cancer site. (3) As there is no regulatory requirement to disclose the manufacturer of a product, we could not distinguish drug suppliers from manufacturers as many suppliers participate in contract manufacturing. Despite these limitations, our analysis provides initial insights into the complicated relationship between drug shortages for first-line cancer treatment and the number of companies supplying these drugs.
We found that having few drug suppliers (three to four) was associated with increased likelihood of shortages compared with having a large number (five or more) of suppliers, but the relationship was nonlinear. However, we saw that older drugs were the most likely to experience drug shortages. This suggests that policies focused predominately on promoting increases in distinct suppliers and competition may not alleviate shortages of critical cancer drugs. Given the continued significant impact of these shortages on patient care, future policies should promote targeted efforts to understand underlying causes of shortages in older drugs in order to evaluate contributors to and predictors of shortages in the oncology community. These finding are important for oncologists as they demonstrate that current strategies for preventing drug shortages have limited effect. Oncologists and patient advocates can help push for more effective policy initiatives and research aimed at understanding drug shortages.
Association Between the Number of Suppliers and Reported Shortages* for FDA-Approved Antineoplastics Drugs for First-Line Treatment of Breast, Colon, and Lung Cancer (2003-2014)
NOTE. Three hundred forty-two observations for 35 drugs over a 12-year period (model 1);191 observations for 21 drugs over a 12-year period (model 2). Model 1: Random slope model adjusting for the number of suppliers, year of observation, year of approval, cancer site and if a generic equivalent of the drug was on the market in a given year for all drugs. Model 2: Random slope model adjusting for the number of suppliers, year of observation, year of approval, and cancer site for drugs which had a generic equivalent was on the market during a given year.
Abbreviations: FDA, US Food and Drug Administration; OR, odds ratio.
Information about reported drug shortages obtained from the University of Utah’s Drug Information System.
Information about the number of suppliers obtained from the 2003-2009 Redbook: Pharmacy’s Fundamental Resource and the RED BOOK Online Database for subsequent years.
Year of FDA Approval for use of drug for specific cancer site based on drug information from the National Cancer Institute’s website http://www.cancer.gov/cancertopics/druginfo/alphalist; drugs approved before 1984 were assigned the value of 1984 as year of approval.