PF-06700841 shows therapeutic potential in moderate-to-severe plaque psoriasis

The oral TYK2/JAK1 inhibitor PF-06700841 appears to be effective in the treatment of patients with moderate-to-severe plaque psoriasis, with a tolerable safety profile, according to the results of a phase IIa study.

A total of 212 adult patients (69.8 percent male) were randomized to 4-week induction treatment with PF-06700841 at 30 mg once daily (QD) or 60 mg QD or placebo, then to 8-week maintenance treatment with the study drug at 10 mg QD, 30 mg QD or 100 mg once weekly (QW) or placebo. The mean baseline Psoriasis Area and Severity Index (PASI) score of the population was 20.8, while the mean Physician’s Global Assessment (PGA) score was 3.1.

Across the induction, maintenance and follow-up phases, 164 (77.4 percent) patients completed the study. Of the 48 patients who discontinued, 15 did so due to self withdrawal, 12 due to adverse events (AEs), five due to lack of efficacy, eight due to other reasons, while the remaining eight were lost to follow-up.

Active treatment led to a significant reduction in PASI score at week 12, the primary endpoint, compared with placebo. The differences observed in the five PF-06700841 treatment groups were statistically significant, with the greatest change noted in the 30-mg QD continuous group (mean change, –17.3, 95 percent confidence interval [CI], –20.0 to –14.6).

Accordingly, the proportion of patients achieving 75-percent and 90-percent reduction in PASI score at week 12 was greater in all active treatment groups vs placebo, with the highest proportion observed in the 30-mg QD continuous group (86.2 percent and 51.7 percent, respectively).

Overall, 136 patients experienced treatment-emergent AEs, including six serious AEs in five patients. None of the patients developed herpes zoster or major adverse cardiac AEs, including thromboembolic events.