U.S. physicians and hospitals receive approximately $7 billion annually from the pharmaceutical industry. According to a research letter published in JAMA Internal Medicine, this type of funding can sway cancer specialists’ prescribing patterns.
In a review of data from the Centers for Medicare & Medicaid Services (CMS) Open Payments system and the Medicare Part D program from 2013 and 2014, Aaron P. Mitchell, MD, from the Division of Hematology/Oncology at the University of North Carolina School of Medicine, and co-authors found that the likelihood of an oncologist prescribing a manufacturer’s anti-cancer drug increased if he or she received payments from the manufacturer – even when there were other treatment options available.
The investigators selected six on-patent, anti-cancer drugs that were recommended by the National Comprehensive Cancer Network and were prescribed by at least 10 physicians in 2014: sorafenib, sunitinib malate, and pazopanib hydrochloride for metastatic renal cell cancer (mRCC); and dasatinib, imatinib mesylate, and nilotinib hydrochloride monohydrate for chronic myeloid leukemia (CML).
They compared general payments (e.g., gifts, consultancy/speaker fees, meals, and travel) and research payments (e.g., preclinical research, U.S. Food and Drug Administration phase I-IV trials, and investigator-initiated studies) that oncologists received in 2013 with their prescribing patterns in 2014.
Among the 354 physicians who prescribed mRCC drugs in 2014, 9 percent (n=32) received research payments and 25.1 percent (n=89) received general payments in both 2013 and 2014. Among the 2,225 who prescribed CML drugs in 2014, 38 received research payments and 879 received general payments in both 2013 and 2014.
The odds of an oncologist choosing a manufacturer’s mRCC drug nearly doubled if he or she received any type of payment, while the likelihood of prescribing a manufacturer’s CML drug rose by 31 percent (TABLE).
Doctors who received general payments had the highest odds of choosing the manufacturer’s drug, while research payments were associated with smaller or statistically nonsignificant increases.
Specifically, the researchers observed increased prescribing for three of the six included drugs: sunitinib (50.5% vs. 34.4%; p=0.01), dasatinib (13.8% vs. 11.4%; p=0.02), and nilotinib (15.4% vs. 12.5%; p=0.01).
There were no associated increases in prescribing among doctors who received payments from the manufacturers of the remaining drugs: sorafenib, pazopanib, or imatinib. The similar prescribing rates among doctors who did and did not receive payments from imatinib’s manufacturer (72.4% vs. 75.5%; p=0.02) “may reflect a strategy by the manufacturer of imatinib (which also produces nilotinib) to promote switching to nilotinib before the patent expiration of imatinib in 2015,” the authors noted.
The authors also analyzed payments as a continuous variable and reported that increased payment amounts were associated with increased prescribing for mRCC, but only slightly increased prescribing for CML. The odds ratios (ORs) for payments types were:
General payments: 1.23 (95% CI 1.12-1.35; p<0.001) for mRCC and 1.05 (95% CI 1.03- 1.08; p<0.001) for CML
Research payments: 1.07 (95% CI 1.01-1.14; p=0.03) for mRCC and 1.01 (95% CI 0.99- 1.04; p=0.24) for CML
“Because oncology is a high-risk disease area and the drugs are very expensive, decisions about prescribing should ideally be determined by a doctor-patient discussion that is free from outside influences,” corresponding author Stacie B. Dusetzina, PhD, from Vanderbilt University Medical Center in Nashville, said in a press release accompanying the study.
The study is limited by its observational design, potential inaccuracies reported in the databases, lack of generalizability to other cancers, and absence of information on the indication for which these drugs were prescribed. The small sample size – particularly for oncologists receiving CML research payments – also limited the implications of the findings.
The corresponding authors report no financial conflicts.
Mitchell AP, Winn AN, Dusetzina SB. Pharmaceutical industry payments and oncologists’ selection of targeted cancer therapies in Medicare beneficiaries. JAMA Intern Med. 2018 April 9. [Epub ahead of print]