The IL-23 inhibitor guselkumab has been shown to be effective in psoriatic arthritis patients including those who are biologic-naive or been previously treated with one or two anti-TNFs.
The DISCOVER trials, published in The Lancet, showed treatment with guselkumab improved the primary outcome of ACR20 and a number of secondary outcomes including skin and joint symptoms.
In DISCOVER-1, 381 patients from 86 sites across 13 countries including Australia were randomised to either 100mg guselkumab every four weeks, or every eight weeks after treatment at week 0 and week 4, or placebo.
Patients had active PsA, at least three tender and swollen joints and a CRP ≥0.3mg/dL. About a third of patients had previously been treated with up to two TNF inhibitors.
During the study, they were permitted but not required to continue stable doses of one selected nonbiologic DMARD, oral corticosteroids (≤10 mg/day of prednisone or equivalent dose), and NSAIDs or other analgesics.
The study found a higher proportion of patients in both guselkumab groups achieved ACR 20 compared to the control group (59% v 52% v 22%).
In DISCOVER-2, 716 biologic-naive patients from 118 sites across 13 countries were also randomised in a similar fashion.
They had an average of 12-13 swollen and 20-22 tender joints and a median CRP of 1·2–1·3 mg/dL.
ACR20 was achieved by 64% in the 4-weekly treatment group, 64% in the 8-weekly treatment group and 33% in the control group.
In both studies, rates of achieving ACR50 and ACR70 were also higher with guselkumab than placebo.
Other secondary outcomes such as DAS28-CRP and resolution of dactylitis, enthesitis and skin disease were also observed.