Long-term remissions and marked decreases in resident memory T cells following high induction dosing with risankizumab in randomized patients with moderate-to-severe plaque psoriasis

The phase 2 KNOCKOUT (NCT05283135) study evaluated higher-than-approved doses of risankizumab, an interleukin-23 inhibitor, for treatment of moderate-to-severe plaque psoriasis. Patients received either 300 or 600 mg of risankizumab at Weeks 0, 4, and 16 and were monitored through Week 100 without further dosing. Efficacy and safety were tracked throughout the study and RNASeq was performed on lesional/non-lesional tissue. Nine patients per treatment group completed dosing. At Weeks 28 and 52, Psoriasis Areas and Severity Index 75/90/100 responses were achieved by 94.4%/94.4%/83.3% and 77.8%/61.1%/44.4% of all patients, respectively, with no new safety signals. At Week 52, TRM cell numbers in lesional skin were markedly reduced, with numbers similar to non-lesional resident memory T cell numbers at Week 0. High skin clearance rates with higher-than-approved initial dosing of risankizumab with prolonged maintenance of skin clearance, despite the lack of continuous dosing, represent a potential novel treatment strategy for patients with psoriasis.