Early response to ixekizumab, ustekinumab predicts long-term skin clearance in psoriasis

Early response to ixekizumab or ustekinumab was associated with stable, long-term response in moderate to severe psoriasis, according to a study.

“The identification of early treatment factors that predict the long-term success of maintenance therapy for psoriasis may help optimize individual therapy,” Mathias Augustin, MD, of the Institute for Health Services Research in Dermatology and Nursing at University Medical Center Hamburg-Eppendorf in Hamburg, Germany, and colleagues wrote.

In the post hoc subgroup analysis of the IXORA-S study, Augustin and colleagues determined any potential relationships between early treatment response rates to ixekizumab (Taltz, Eli Lilly) and ustekinumab (Stelara, Janssen) and the stability of long-term response.

Disease severity outcomes were measured by the proportion of patients who reached Psoriasis Area Severity Index 50 by week 2 or 4 — which they defined as early response — as a function of the proportion of patients who reached PASI 100 or PASI 90 skin clearance at 80% or more office visits by weeks 16 to 52, which was the long-term response.

The analysis included 132 patients treated with ixekizumab and 166 treated with ustekinumab.

Results showed that by week 4, 85.2% of patients in the ixekizumab group reached the PASI 50 benchmark, compared with just 46.4% in the ustekinumab arm. The researchers described this as a numerically higher proportion.

Regardless of early responder status, ixekizumab was associated with stronger long-term responses than ustekinumab, according to the findings. For example, 71% of patients treated with ixekizumab reached PASI 90 at 80% or more office visits, compared with just 47.6% of those treated with ustekinumab (P < .0001). Similarly, 42.2% of patients in the ixekizumab arm and 17.5% in the ustekinumab arm reached PASI 100 at 80% or more office visits (P < .0001).

That said, early responders in both treatment groups were more likely than early nonresponders or poor responders to reach either PASI 90 or PASI 100 (OR > 1).
“In patients with moderate to severe psoriasis treated with ixekizumab or ustekinumab, early response was a significant factor in maintaining stable complete or almost complete skin clearance,” the researchers concluded. “Therefore, rapid response is a clinically relevant factor to consider when optimizing individual therapeutic strategies.”