Optimizing Treatment for Psoriatic Arthritis

Because psoriatic arthritis (PsA) presents “myriad manifestations across multiple different domains of disease,” an interdisciplinary approach involving rheumatologists, dermatologists, and other physician specialists is necessary to enable early diagnosis, optimize treatment, and achieve better outcomes for patients, explained Joseph F. Merola, MD, to the virtual Interdisciplinary Autoimmune Summit 2020 on July 11.

Joseph F. Merola, MD, is director of the Center for Skin and Related Musculoskeletal Diseases and the Clinical Unit for Research Innovation and Trials at Brigham and Women’s Hospital in Boston, Massachusetts, and an associate professor of medical at Harvard Medical School.

Dr Merola emphasized that any patient with psoriasis is at risk of progressing to PsA but that awareness of PsA among nonrheumatologists is lacking. Dermatologists in particular may be missing the progression of psoriasis to PsA, he noted, with some estimates indicating that up to 40% of psoriasis patients may have undiagnosed PsA.

The particular risk factors for disease progression from psoriasis to PsA are scalp psoriasis; nail pitting and psoriasis; inverse psoriasis, which occurs in body folds; severe psoriasis; a first-degree relative with PsA; obesity; and subclinical musculoskeletal inflammation.

“The landscape of treatment options in 2020 is pretty broad,” Dr Merola stated, ranging from topical therapies and steroids to anti-tumor necrosis factor (TNF) agents and targeted therapeutics such as interleukin-17 (IL-17), IL-12/23, phosphodiesterase-4, and Janus-kinase (JAK) inhibitors.

He noted that IL-17 inhibitors such as secukinumab and ixekinumab have demonstrated robust response in patients with PsA who are biologic-naïve, with patients experiencing improvement in axial disease and enthesitis and in particular “tremendous robust skin clearance data” with ixekinumab. Bimekizumab, an IL-17 A/F inhibitor still in development, has also demonstrated very robust results in clinical trials to date, Dr Merola reported.

In what he described as “a rare look at secukinumab specifically in PsA,” a study revealed a statistically significant response to this IL-17 inhibitor in patients with PsA, with an ACR20 score of 63% and a Psoriasis Area and Severity Index (PASI) score of 75. In simplified terms, Dr Merola noted, these therapeutics achieve average outcome measures of ACR20 of 60%, ACR50 of 40%, and ACR70 of 20%.

He also reported on the SPIRIT trial, which was a head-to-head comparison of ixekinumab with adalimumab specifically in patients with PsA. At week 24, the composite ACR50 and PASI 100 data showed 28% for adalimumab vs 36% for ixekinumab.

Dr Merola observed that “hot off the presses is the excitement surrounding bimekizumab, an IL-17 A/F inhibitor.” Noting that newer data is expected soon from a PsA phase 3 program, the previous phase 2 study showed “what appears to be very robust ACR20 and ACR50 responses,” including some that are “even above what we would traditionally expect in ACR50 responses.”

While IL-23 inhibitors have shown somewhat more modest results based on ACR20/50/70 data, Dr Merola reported data from trials of an anti-IL-23(p19), guselkumab, that shows significant promise.

“This is actually very exciting because the DISCOVERY program for guselkumab has really opened up a new chapter in our discussions about where this mechanism will fit in PsA.” The ACR20/50/70 data are quite robust, he stated, particularly in regard to resolution of enthesitis and improvement in axial disease. Although the therapy is not yet approved by the US Food & Drug Administration for treating PsA, the approval is expected to come through very soon.

With all these treatment options available now or coming soon, Dr Merola noted that determining the appropriate therapy for patients with PsA involves “multiple layers of decision making” that should include not only rheumatologists and dermatologists but also primary care physicians, cardiologists, psychotherapists, endocrinologists, and others. He emphasized, “It really takes a team to get these patients the right care. Helping our patients to build a team around potential comorbidities is really crucial.”

For more coverage of IAS 2020, visit the newsroom.

—Rebecca Mashaw

Reference:

Merola JF. Addressing disease progression in psoriatic arthritis: optimizing targeted therapies. Talk presented at: Interdisciplinary Autoimmune Summit 2020; July 11, 2020; virtual.