Febuxostat (Uloric) was not associated with increased cardiovascular risk in patients with gout when compared to those who used allopurinol, in an analysis of new users of the drugs in Medicare fee-for-service claims data from the period of 2008-2016.
Dr. Seoyoung Kim
The findings, published March 25 in the Journal of the American Heart Association, update and echo the results from a similar previous study by the same Brigham and Women’s Hospital research group that covered 2008-2013 Medicare claims data. That original claims data study from 2018 sought to confirm the findings of the postmarketing surveillance CARES (Cardiovascular Safety of Febuxostat and Allopurinol in Patients With Gout and Cardiovascular Morbidities) trial that led to a boxed warning for increased risk of cardiovascular and all-cause mortality vs. allopurinol. The trial, however, did not show a higher rate of major adverse cardiovascular events (MACE) overall with febuxostat.
The recency of the new data with more febuxostat-exposed patients overall provides greater reassurance on the safety of the drug, corresponding author Seoyoung C. Kim, MD, of Brigham and Women’s Hospital and Harvard Medical School, Boston, said in an interview. “We also were able to get data on cause of death, which we did not have before when we conducted our first paper.”
Dr. Kim said she was not surprised by any of the findings, which were consistent with the results of her earlier work. “Our result on CV death also was consistent and reassuring,” she noted.
The newest Medicare claims study also corroborates results from FAST (Febuxostat Versus Allopurinol Streamlined Trial), a separate postmarketing surveillance study that was ordered by the European Medicines Agency after febuxostat’s approval in 2009. It showed that the two drugs were noninferior to each other for the risk of all-cause mortality or a composite cardiovascular outcome (hospitalization for nonfatal myocardial infarction, biomarker-positive acute coronary syndrome, nonfatal stroke, or cardiovascular death).
“While CARES showed higher CV death and all-cause death rates in febuxostat compared to allopurinol, FAST did not,” Dr. Kim noted. “Our study of more than 111,000 older gout patients treated with either febuxostat or allopurinol in real-world settings also did not find a difference in the risk of MACE, CV mortality, or all-cause mortality,” she added. “Taking these data all together, I think we can be more certain about the CV safety of febuxostat when its use is clinically indicated or needed,” she said.
Study details
Dr. Kim, first author Ajinkya Pawar, PhD, of Brigham and Women’s, and colleagues identified 467,461 people with gout aged 65 years and older who had been enrolled in Medicare for at least a year. They then used propensity-score matching to compare 27,881 first-time users of febuxostat with 83,643 first-time users of allopurinol on the primary outcome of the incidence of major adverse cardiovascular events (MACE), defined as the first occurrence of myocardial infarction, stroke, or cardiovascular mortality.
In the updated study, the mean follow‐up periods for febuxostat and allopurinol were 284 days and 339 days, respectively. Overall, febuxostat was noninferior to allopurinol with regard to MACE (hazard ratio, 0.99; 95% confidence interval, 0.93-1.05), and the results were consistent among patients with baseline CVD (HR, 0.94). In addition, rates of secondary outcomes of MI, stroke, and cardiovascular mortality were not significantly different between febuxostat and allopurinol patients, except for all-cause mortality (HR, 0.92; 95% CI, 0.87-0.98).
The study findings were limited mainly by the potential bias caused by nonadherence to medications, and potential for residual confounding and misclassification bias, the researchers noted.
However, the study was strengthened by its incident new-user design that allowed only patients with no use of either medication for a year before the first dispensing and its active comparator design, and the data are generalizable to the greater population of older gout patients, they said.
Consequently, the data from this large, real-world study support the safety of febuxostat with regard to cardiovascular risk in gout patients, including those with baseline cardiovascular disease, they concluded.
The study was supported by the division of pharmacoepidemiology and pharmacoeconomics at Brigham and Women’s Hospital. Dr. Kim disclosed research grants to Brigham and Women’s Hospital from Roche, Pfizer, AbbVie, and Bristol‐Myers Squibb for unrelated studies. Another author reported serving as the principal investigator with research grants from Vertex, Bayer, and Novartis to Brigham and Women’s Hospital for unrelated projects.