Harris KM, Smilek DE, Byron M, et al. - Psoriasis relapse occurring after ustekinumab withdrawal was not averted by abatacept because it failed to completely block the pathogenic psoriasis molecular pathways that resulted in relapse.

• In this parallel-design, double-blind randomized clinical trial of 91 adults with moderate to severe plaque psoriasis, patients received ustekinumab in a lead-in phase; responders to ustekinumab were further randomized 1:1 to either the continued with ustekinumab group (ustekinumab group) or the switched to abatacept group (abatacept group).

• In both groups, similar proportions of patients relapsed between weeks 12 and 88 (abatacept group: 91.1% vs ustekinumab group: 87.0%).

• Between groups, a similar median time to relapse from the last dose of ustekinumab was noted: 36 weeks (95% CI, 36-48 weeks) in the abatacept group vs 32 weeks (95% CI, 28-40 weeks) in the ustekinumab group.

• Neither psoriasis relapse prevention nor maintained suppression of the pathogenic psoriasis molecular signature post-ustekinumab withdrawal was achieved by costimulatory blockade with abatacept.