Independent from this data, the impact of use of MTX in Ustekinumab (UST) treated patients with active PsA remains unclear: No data from Randomized Clinical Trials (RCTs) are available to address the questions whether add-on of MTX to UST monotherapy, or the other way around, a withdrawal of continuous MTX therapy in patients with newly initiated UST treatment or simultaneously induction of MTX with UST in patients will influence outcome.