Zasocitinib (TAK-279) in active PsA: Results from a phase IIb trial

Results from a phase IIb, randomized, multicenter, placebo-controlled trial (NCT05153148) of zasocitinib (formerly TAK-279), a highly selective tyrosine kinase 2 (TYK2) inhibitor, were presented at the European Alliance of Associations for Rheumatology Congress 2024 by Alan Kivitz. Various doses of zasocitinib were investigated for efficacy and safety over 12 weeks in 290 patients with active psoriatic arthritis (PsA). The primary endpoint of the study was the proportion of patient achieving 20% improvement in the American College of Rheumatology score (ACR20) response at Week 12. We have previously reported results of zasocitinib in plaque psoriasis.

Key learnings:

The safety profile of zasocitinib was consistent with previous studies, and no new safety signals were observed.

The most common treatment-emergent adverse events in patients treated with zasocitinib were nasopharyngitis, upper respiratory tract infection, headache, and rash.

At Week 12, a 20% improvement in the American College of Rheumatology score was seen in 35.2%, 53.3%, and 54.2% of patients treated with zasocitinib 5 mg, 15 mg, and 30 mg, respectively, compared with 29.2% of patients treated with placebo. Significantly more patients treated with 15 mg (p = 0.005) and 30 mg (p = 0.009) zasocitinib achieved the secondary endpoint of ACR50 vs placebo.

With the lack of targeted oral therapies in PsA, zasocitinib is a promising emerging therapy in this patient population, with further studies in larger patient populations needed.