Industry payments not linked with prescription of prostate cancer drugs

Oncologists and urologists who received payments from the pharmaceutical industry did not write a larger number of prescriptions for major prostate cancer drugs than those who did not, according to findings published in Cancer.

“Abiraterone and enzalutamide are the 2 most widely prescribed drugs for metastatic castration-resistant prostate cancer, with $2.2 billion and $1.9 billion in sales, respectively, in 2015,” Jathin Bandari, MD, of the department of urology at the University of Pittsburgh School of Medicine, and colleagues wrote.

These prescription rates represented a 23% growth rate for abiraterone and a 199% growth rate for enzalutamide, according to the researchers.

“These rates cannot be explained by epidemiological factors alone because they exceed trends in new metastatic castration-resistant prostate cancer diagnoses,” the researchers wrote. “To the best of our knowledge, it is unclear to date what the alternative drivers to prescription adoption may be.”

Bandari and colleagues reviewed data from the 2014 CMS Open Payments/General Payments database to identify urologists and oncologists who received payments from Johnson & Johnson or Astellas Pharmaceuticals, and linked those physicians to data from Medicare claims. The researchers performed correlation analysis to determine any possible relationship between industry payments and prescription count, and stratified the prescribers into quantiles.

Researchers identified 1,812 prescribers of abiraterone, 34% (n = 615) of whom were Open Payments recipients. Researchers observed no significant difference between payment recipients and nonrecipients for total number of prescriptions (18 vs. 18; P = .66).

Of 701 prescribers of enzalutamide, 41% (n = 289) received Open Payments with no significant difference in total prescriptions between recipients and nonrecipients (15 vs. 15.5; P = .41).

Among those who received industry payments, prescribers of abiraterone and enzalutamide both received a slightly higher payment than non-prescribers ($72 vs. $56 for abiraterone; $59 vs. $31 for enzalutamide). Researchers found no association between payment amount and number of prescriptions for abiraterone, but observed a “weak” association for enzalutamide (P < .01).

“There appears to be no difference in prescription count between prescribers who received industry payments and those who did not, although there likely is an effect among outliers,” the researchers wrote. “There was a weak positive correlation noted between industry payments and prescription count for enzalutamide. Differences between abiraterone and enzalutamide may be explained by differences in ease of adoption.” – by Andy Polhamus

Disclosures: The researchers report no relevant financial disclosures.