23 May 2019

Risk of nasty infections lower for psoriasis biologics

Biologics Clinical Psoriatic Athritis

The largest study yet to compare the risk of serious infection in biologics and non-biologics for psoriasis has landed on the side of biologics, clashing with what was thought about methotrexate.

The large observational registry study including 107,000 adults with psoriasis foundpatients were less likely to have a serious infection like pneumonia, encephalitis or sepsis if they were taking apremilast, etanercept or ustekinumab than if they were taking methotrexate.

The effect was statistically (and probably clinically) significant, with a 25-50% reduction in infection risk in patients on these biologics.

There was no difference in the rate of nasty infections in patients taking acitretin,adalimumab or infliximab compared with patients taking methotrexate.

Patients in this US studyhad been taking one of six biologics or methotrexate for at least six months, and the results held true after adjusting for confounding factors like comorbidities, age, medication and smoking status.

“We’ve traditionally thought of all the biologics as being higher risk,” said Dr Premarani Sinnathurai, a rheumatologist and PhD candidate studying psoriatic arthritis at Royal North Shore Hospital, Sydney.

“So, it was interesting in this paper that they actually found that a number of biologic agents had decreased overall serious infection compared to methotrexateand the rest were no different.”

All these drugs supress immune-driven inflammation. But, in doing so, they also disrupt the body’s natural response to fighting disease and raise the risk of infection.

“Etanercept has always been one that we’ve thought of as being a little bit less risky and now maybe ustekinumab also has a lower risk,” said Dr Sinnathurai.

“Apremilast is not as efficacious as the biologic agents,” she said. “It’s a different class of drug so it doesn’t surprise me that that has a lower infection risk because of its mechanism of action.”

This study would be important to consider when choosing a medication for patients with psoriasis, and possibly even patients with psoriatic arthritis, she said.

However, specialists would also keep in mind the mixed data from other studies.

A registry study from Spain showed that etanercept and infliximab had an increased risk of serious infection compared with methotrexate but no difference in risk for adalimumab and ustekinumab.

Two other studies from the UK and Ireland found a three-fold increased risk of serious infection with the use of infliximab compared with methotrexate, but no increased risk with adalimumab, etanercept or ustekinumab.

“The results have not been the same in other registry studies,” said Dr Sinnathurai.

The US registry study wasn’t randomised so the results could have been representing an indication bias, she said.

“It could be that clinicians are choosing not to use biologics and just using methotrexatein patients that they think are at higher risk of infection for other reasons,” she said.

In the study, the patients taking acitretin, apremilast, infliximab and methotrexate were older and had more comorbidities than the patients taking adalimumab, etanercept, and ustekinumab.

JAMA Dermatology 2019, 10 May