Physicians treating certain types of cancers appeared more likely to prescribe a specific drug over other treatments if they received yearly payments from that drug’s manufacturer, according to results of a study published in The Oncologist.
“These findings add to a growing body of work that suggests physicians are more likely to use drugs made by companies that have given them money in the past,” Aaron Mitchell, MD, MPH, medical oncologist in the department of epidemiology and biostatistics at Memorial Sloan Kettering Cancer Center, said in a press release.
Payments from pharmaceutical companies to physicians are common, but factors that could decide whether these financial relationships influence practice are not known, according to study background.
In this study, Mitchell and colleagues looked specifically at the association between payments from drug companies to physicians and the prescription frequency of orally administered abiraterone (Zytiga, Janssen) and enzalutamide (Astellas, Pfizer) for prostate cancer; axitinib (Inlyta, Pfizer), everolimus (Afinitor, Novartis), pazopanib (Votrient, Novartis), sorafenib (Nexavar, Bayer) and sunitinib (Sutent, Pfizer) for renal cell cancer; afatinib (Gilotrif, Boehringer Ingelheim) and erlotinib (Tarceva, Genentech) for lung cancer; and dasatinib (Sprycel, Bristol-Myers Squibb), imatinib (Gleevec, Novartis) and nilotinib (Tasigna, Novartis) for chronic myeloid leukemia.
The analysis included 2,766 physicians (80.5% men).The number of calendar years from 2013 to 2015 in which a physician received payments from the maker of one of the drugs in the study served as the primary exposure, and the relative prescribing of that drug in 2015 compared with other drugs for the same malignancies served as the endpoint.
Researchers also evaluated practice settings at NCI-designated cancer centers, receipt of compensation payments, maximum annual dollars received and institutional conflict-of-interest policies.
Results showed that physicians who received payments for a drug in all 3 years, compared with zero years, increased their prescription of the drug for renal cell cancer (RR = 1.81; 95% CI, 1.58-2.07), CML (RR = 1.22; 95% CI, 1.08-1.39) and lung cancer (RR = 1.69; 95% CI, 1.58-1.82).
The payments did not increase the prescription of drugs for prostate cancer (RR = 0.97; 95% CI, 0.93-1.02).
During 2015, the average value of payments to physicians ranged from $1,104 in lung cancer to $3,657 in renal cell cancer.
Physicians who received compensation payments or more than $100 annually increased their prescribing of specific drugs compared with physicians not paid.
Neither NCI setting nor institutional conflict-of-interest policies appeared consistently associated with prescribing changes.
A lack of payment data before August 2013, as well as the exclusion of physicians who did not have drug claims during each year, served as limitations to this study.
“The landscape surrounding physician relationships with industry continues to evolve,” Mitchell and colleagues wrote. “Public scrutiny of the industry role in cancer research and care delivery remains high. Ideally, institutions may increasingly be able to rely on research findings in order to construct informed, data-driven policies to manage industry relationships within this changing environment.” – by John DeRosier
Disclosures: Mitchell reports no relevant financial disclosures. One study author reports employment of a spouse by GlaxoSmithKline.