Despite an expanding arsenal of disease-modifying antirheumatic drugs (DMARDs), many patients with axial spondyloarthritis (axSpA) and psoriatic arthritis (PsA) still struggle to reach remission even after trying multiple advanced treatments.
Now, international groups of experts are working to better define these “difficult-to-treat” patients to both inform care and improve selection of participants for future clinical trials.
“The idea is rather simple, and the need is relatively ubiquitous,” Denis Poddubnyy, MD, of the Charité – Universitätsmedizin Berlin and the German Rheumatism Research Center Berlin, both in Berlin, Germany, said in an interview. He is the co-primary investigator for the ongoing Assessment of SpondyloArthritis International Society (ASAS) project to develop a consensus definition of difficult-to-treat axSpA.
According to ASAS, only 40%-50% of patients with axSpA achieve a 40% improvement in ASAS response criteria (ASAS40), and few (10%-20%) achieve remission in the first 4-6 months of treatment.
Dr. Denis Poddubnyy
“If you look into current clinical guidelines, you will see that there is no clear guidance,” on how to manage these patients, Dr. Poddubnyy continued. “In other similar recommendations for the treatment of axSpA, the only point which is clearly made with regards to nonresponders to effective anti-inflammatory treatment is to ‘check the diagnosis.’”
Multiple Reasons for Nonresponse
“While the term difficult-to-treat can refer to refractory disease, that is not the only reason why a patient might not be responding to medication. In fact, it’s likely that truly biologically refractory disease makes up only a fraction of cases that respond inadequately to treatment,” said Shikha Singla, MD, who directs the psoriatic arthritis program at the Medical College of Wisconsin in Milwaukee. She is also involved with the Group for Research and Assessment of Psoriasis and Psoriatic Arthritis (GRAPPA) initiative to define Difficult-to-Treat and Complex-to-Manage PsA.
Medical College of Wisconsin
Dr. Shikha Singla
“Apart from the persistent articular and periarticular inflammation, there could be multiple noninflammatory factors that may be contributing to this treatment-resistant disease, including comorbid conditions such as obesity, cardiovascular disease, fibromyalgia, and even social factors such as limited access to medications,” she told this news organization. “Given these complexities, it is a matter of supreme importance to recognize and carefully delineate the elements that contribute to treatment refractory disease: Is it truly the inflammation, or are there noninflammatory components that are causing the treatment failure, or a combination of the two?”
Other contributing factors could be depression, hypersensitization, and comorbidities that prevent certain treatment approaches, added Fabian Proft, MD, also of Charité – Universitätsmedizin Berlin. Dr. Proft discussed these difficult-to-treat definition efforts at the recent Spondyloarthritis Research and Treatment Network (SPARTAN) annual meeting held in Cleveland. Patients also might not be taking their medication regularly and may be seeking alternative medicine approaches, he said.
Dr. Proft
Dr. Fabian Proft
“There is a quite clear consensus within the community” that differentiation between these two groups is needed, Dr. Proft said.