Regarding the main treatments for PsA, he noted that the evidence for the effectiveness of conventional disease-modifying anti-rheumatic drugs is fairly thin. For methotrexate, just three randomized controlled trials (RCTs) involving 93 patients have been conducted; for sulfasalazine, seven RCTs with 666 patients have been conducted; for leflunomide, one RCT with 190 patients has been conducted; and for cyclosporine, three RCTs with 206 patients have been conducted.
“I think what should probably distress you is the paucity of evidence we have to support the use of these cheap and familiar drugs whose use is very comfortable in our practice,” he said. “That has undoubtedly held us back in really optimizing the use of these agents.” In one trial on methotrexate, the primary outcome was not even met, he said.
He underscored the importance of treating each tissue involved in PsA as its own problem—the joints should be given their own attention, the skin its own attention and so on.
“In the psoriatic arthritis field we are taking on different tissues, all potentially with variable capacity to respond to any given agent,” Dr. McInnes said.
TNF-blockers tend to achieve minimal disease activity—a status based on tender joint counts, pain and other factors, and associated with less radiographic progression—30–40% of the time.2
“There is an enormous amount of unmet need,” he said.
But more attention has been paid to other targets that might be more relevant than drugs that have been derived from the rheumatoid arthritis field, he said. IL-12/23 inhibitors, as well as IL-17A inhibitors, have yielded promising results so far, he said.3,4
He said clinicians need to “systematically work our way through the patient’s different tissue response. … I think at the moment we cannot consider this a unified syndrome. We are still, I think, obliged to treat each of the tissues on its own merits.” Then, he said, “we will make a significant difference in impact of the quality of life of our patients.”
Axial Spondyloarthritis
In another talk from the session, Filip van den Bosch, MD, PhD, head of rheumatology at Ghent University, said that axial spondyloarthritis (axial SpA) needs to be treated—given the link between disease activity and structural damage and mortality later on, but he cautioned against an over-reliance on the presence of HLA‑B27 and MRI findings.5
“I would warn you against making a diagnosis of B27-itis or MRI-itis—really stick with your clinical feeling. It’s the best we have. We’re desperately looking at other factors to find out how we can more objectively measure this, but this is I think the first thing: follow your clinical judgment.”
Regarding the main treatments for PsA, the evidence for the effectiveness of conventional disease-modifying anti-rheumatic drugs is fairly thin.
Even with the advent of new therapies, such as anti-TNF and anti-IL-17 drugs, which have been shown to be effective, non-steroidal anti-inflammatory drugs (NSAIDs) are still the “cornerstone” in axial SpA, he said.6,7
