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Expert Offers Insight on Reducing Infection Risk With RA Therapies
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In a presentation at the Infectious Diseases Society of America Annual Meeting, Kevin L. Winthrop, MD, MPH, associate professor in the Divisions of Infectious Diseases, Public Health, and Preventive Medicine at Oregon Health & Science University, delivered a presentation on immunomodulators in rheumatologic diseases. Specifically, he addressed the incidence of serious infection in these patients. He focused on several main themes in both his presentation and in an interview with Healio Rheumatology.
“I wanted to offer an introduction to how different drugs increase infection risk, including biologics, [Janus kinase] JAK inhibitors and synthetic [disease-modifying antirheumatic drugs] DMARDs,” he said. “But it is important to note that much of the risk of infection lies with patients and patient factors rather than [with] their therapy.”
Infection Risk
While some of these therapies might ultimately increase infection risk, this increase is mitigated by the fact that these drugs can play the role of a prednisone-sparing agent.
“If we can just keep patients off of prednisone, we can lower infection risk,” he said.
Winthrop referenced findings from Strangfeld and colleagues who investigated infection risk in a cohort of 5,044 patients with rheumatoid arthritis (RA) and underwent therapy with tumor necrosis factor (TNF) inhibitors. Results indicated 392 serious infections occurred. Serious infection rates declined among patients treated with TNF inhibitors during the first 3 years of observation, from 4.8 to 2.2 per 100 patient-years. The researchers attributed the decline to termination of therapy, loss to follow-up among higher-risk patients and a risk reduction associated with decreased glucocorticoid doses and improved function, according to the findings. A number of factors were associated with increased infection risk, including age greater than 60 years, chronic lung or renal disease, low functional capacity, history of serious infections and treatment with glucocorticoids or TNF inhibitors.
“The results enable expected infection rates to be calculated in individual patients based on their risk profiles,” the researchers concluded.
For Winthrop, mitigating infection risk is critical to controlling disease.
“This Strangfeld paper has given us a picture of the risk factors involved,” he said. “It enabled us to see the influence of comorbidities and glucocorticoids. But, even once you control for those factors, infection risk is still elevated almost two-fold.”
Winthrop also referenced a study conducted by Yun and colleagues on which he was a researcher. The aim was to compare the subsequent risk of infections in the hospital that were associated with specific biologic agents among patients with RA who had previously been admitted for infection while undergoing treatment with anti-TNF therapy. The analysis included 10,794 hospitalized infections from 10,183 patients with RA who had at least 1 day of follow-up data from biologic exposure. Among 7,807 person-years of exposure to biologics, 333 were from abatacept; 133 from rituximab; and 7,341 from anti-TNF therapy. Of the TNF drugs, 1,797 person-years were from etanercept; 1,405 from adalimumab; and 4,139 were from infliximab.
There were 2,666 infections associated with these drugs. Multivariable analysis results indicated abatacept (Orencia, Bristol-Myers Squibb) and etanercept (Enbrel, Amgen) were associated with significantly lower infection risk compared to infliximab (Remicade, Janssen).
“This is some real-world data,” Winthrop said. “We looked at risk estimates of serious infection by drug. For the most part, they are all similar.”
In another study from one of Winthrop’s groups, Baddley and colleagues aimed to assess opportunistic infection rates among new users of TNF inhibitors compared to those using non-biologic agents. Among 33,324 new TNFI users, 80 non-viral opportunistic infections were identified. The most frequently reported infection was pneumocystis, which occurred in 16 patients. Crude numbers showed non-viral opportunistic infections occurred in 2.7 per 1,000 person-years among new TNF users and in 1.7 per 1,000 in patients who initiated DMARD use. An association was also observed between baseline corticosteroid use and non-viral opportunistic infections. Among patients with RA, infliximab yielded higher rates of these infections than patients initiating non-biologic DMARDs or etanercept.
“In the United States, the rate of non-viral [opportunistic infections] was higher among new users of TNF [inhibitors] with autoimmune diseases as compared to non-biologic DMARD users,” the researchers concluded.
Herpes Zoster
Winthrop suggested herpes zoster is an important opportunistic infection in this setting.
“JAK inhibitors have a similar infectious profile as biologics, the exception being a higher risk of viral infections like herpes zoster,” he said, and added this risk is elevated with tofacitinib (Xeljanz, Pfizer).
“It appears likely to be an issue with the class of drugs,” he said.
Using a shingles vaccine before therapy may reduce this risk, according to Winthrop. “We have data highlighting the idea that we should expose these patients to varicella,” he said.
Beyond the data, Winthrop addressed the issues at hand more broadly.
“All clinicians who use these drugs, including gastroenterologists and rheumatologists, as well as primary care providers, are responsible for ongoing risk-benefit assessment,” he said. “Rheumatologists can be driving vaccination. Primary care providers can be facilitating communication between specialties and helping to control other factors, such as diabetes. Comorbidity management is the purview of everyone.”
As soon as patients develop a serious infection, the drug should be stopped until the infection is resolved, according to Winthrop.
“This is standard practice among rheumatologists,” he said. “The questions, then, are when to go back onto the same drug or whether to switch therapies.”
He said he is often asked his opinion on these cases, but that, unfortunately, the answer is usually unclear. Current guidelines hint at this issue, but data are lacking.
“In order for there to be firm guidelines, we need more data on patients who have had prior infections,” he said. “The data are thin. They basically are comprised of just a few studies.”
Future Research
Regarding directions for future research, Winthrop acknowledged this is difficult to study in clinical trials. “Event rates for some of these infections are low,” he said, and added that population-based studies using registries and real-world data are needed.
“The best advice I can give is that if a serious infection emerges, stop the current therapy and re-evaluate.” – by Rob Volansky
- References:
- Baddley J, et al. Ann Rheum Dis. 2011;doi:10.1136/annrheumdis-2013-203407.
- Strangfeld A, et al. Ann Rheum Dis.2011; doi:10.1136/ard.2011.151043
- Yun H. Ann Rheum Dis. 2015;doi:10.1136/annrheumdis-2013-204011.
Disclosure: Winthrop reports he has received research funding from Bristol-Myers Sqibb and Pfizer; is a consultant for Amgen, AbbVie, Bristol-Myers Squibb, Genentech, Eli Lilly, Pfizer and UCB; and is on the data safety monitoring boards for Astellas, Galapagos, Janssen, Eli Lilly, Roche and UCB.