Vinod Chandran, MBBS, MD, DM, PhD
There is steady advance in the treatment of PsA. Bimekizumab is a novel monoclonal antibody that, by binding to similar sites on interleukin (IL)-17A and IL-17F, inhibits these cytokines. Ritchlin and colleagues recently reported the 52-week results from the phase 3 BE OPTIMAL study including 852 biological disease-modifying antirheumatic drug (bDMARD)-naive patients with active PsA who were randomly assigned to receive bimekizumab, adalimumab, or placebo. At week 16, 43.9% of patients receiving bimekizumab achieved ≥ 50% improvement in the American College of Rheumatology scores (ACR50), with the response being maintained up to week 52 (54.5%). Among patients who switched from placebo to bimekizumab at week 16, a similar proportion (53.0%) achieved ACR50 at week 52. No new safety signals were observed. Thus, bimekizumab led to sustained improvements in clinical response up to week 52 and probably will soon be available to patients with PsA.
The optimal management of axial PsA continues to be investigated. One major question is whether IL-23 inhibitors, which are not efficacious in axial spondyloarthritis, have efficacy in axial PsA. A post hoc analysis of the DISCOVER-2 study included 246 biologic-naive patients with active PsA and sacroiliitis who were randomly assigned to guselkumab every 4 weeks (Q4W; n = 82), guselkumab every 8 weeks (Q8W; n = 68), or placebo with crossover to guselkumab Q4W at week 24 (n = 96), Mease and colleagues report that at week 24, guselkumab Q4W and Q8W vs placebo showed significantly greater scores in the total Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) as well as Ankylosing Spondylitis Disease Activity Score (ASDAS), with further improvements noted at week 100. Thus, in patients with active PsA and imaging-confirmed sacroiliitis, 100 mg guselkumab Q4W and Q8W yielded clinically meaningful and sustained improvements in axial symptoms through 2 years.
Finally, attention is currently being paid to patients with refractory or difficult-to-treat (D2T) PsA. These patients are generally characterized as having active disease despite treatment with two or more targeted DMARD (tDMARD). Philippoteaux and colleagues have reported results from their retrospective cohort study that included 150 patients with PsA who initiated treatment with tDMARD and were followed for at least 2 years, of whom 49 patients had D2T PsA. They found that peripheral structural damage, axial involvement, and the discontinuation of bDMARD due to poor skin psoriasis control were more prevalent in patients with D2T PsA compared with in non-D2T PsA. Thus, patients with D2T PsA are more likely to have more structural damage. Early diagnosis and treatment to reduce structural damage might reduce the prevalence of D2T PsA.