The results from this phase 2 study show that tildrakizumab significantly improves psoriasis in patients with PsA and is well tolerated in a mixed population of anti–TNF-naïve and –experienced patients.
By week 24, tildrakizumab significantly improved PASI 75/90/100 in patients with PsA and measurable psoriasis compared to patients treated with placebo.
Tildrakizumab is a high-affinity anti–interleukin-23p19 monoclonal antibody approved by the US Food and Drug Administration to treat moderate-to-severe plaque psoriasis.  This phase 2b study evaluated the efficacy and safety of tildrakizumab for the treatment of patients with psoriatic arthritis (PsA).
This interim analysis of the phase 2b study reports on the effect of tildrakizumab on PASI (Psoriasis Area Severity Index) 75/90/100 response rates in patients with PsA and measurable psoriasis (≥3% of the body surface area (BSA) affected at baseline).
Randomized, double-blind, multidose, placebo-controlled study in patients ≥18 years of age with active PsA (Classification of Psoriatic Arthritis criteria). 
Patients were stratified by prior anti–TNF use (yes/no) and baseline body weight (≤90 kg and ≥90 kg), and randomized 1:1:1:1:1 to receive tildrakizumab (200 mg once every 4 weeks (Q4W), 200 mg every 12 weeks (Q12W), 100 mg Q12W, or 20 mg Q12W to week 24) or placebo (PBO Q4W to week 24).
Efficacy was analyzed in the full analysis set, defined as all randomized subjects who received ≥1 dose of study drug.
Proportion of patients with ACR20 (primary endpoint), ACR50, and ACR70 responses at week 24.
The proportion of patients achieving PASI 75, PASI 90, and PASI 100 was calculated only for patients with measurable psoriasis, defined as BSA ≥3% at baseline.
Safety assessments included treatment-emergent adverse event (TEAE) monitoring.
Of the 500 patients screened, 391 patients met inclusion criteria with 77–79 per treatment arm (TIL 200 mg Q4W, TIL 200 mg Q12W, TIL 100 mg Q12W, and TIL 20 mg Q12W vs. PBO) of which, 234 patients had BSA ≥3% at baseline (41-54).
At week 24, there was a significantly greater proportion of ACR20, ACR50, and ACR70 responders among all tildrakizumab treatment arms vs. placebo.
At week 24, 61.5%/43.2%/26.0% in combined tildrakizumab arms vs. 16.7%/7.1%/4.8% in the PBO arm achieved PASI 75/90/100 responses (Figure).
There was a significantly greater proportion of PASI 75, PASI 90, and PASI 100 responders among patients receiving any dose of tildrakizumab compared to placebo.
The most frequent TEAEs included nasopharyngitis (pooled TIL arms 5.4% vs. PBO 6.3%) and upper respiratory tract infection (pooled TIL arms 3.5% vs. PBO 1.3%).
No malignancies, major adverse cardiac events, or deaths were reported.
By week 24, tildrakizumab significantly improved PASI 75/90/100 in patients with PsA and psoriasis compared to patients treated with placebo.
Numerically, 200-mg dosing led to higher PASI 75 and 90 responses by week 24 compared with 100-mg dosing in patients with mild to moderate psoriasis and PsA: further studies that are powered to compare the 100 mg vs. 200-mg dose are needed to confirm this observation.
Improvements in skin responses were significant vs. PBO as early as week 4 for PASI 75 in the TIL 200 mg Q12W arm.
Key messages/Clinical perspectives
These data provide evidence that tildrakizumab significantly improves psoriasis in patients with PsA and is well tolerated in a mixed population of anti–TNF-naïve and –experienced patients.