InnoCare Pharma Limited (HKEX: 09969) announced that its oral TYK2 inhibitor soficitinib (ICP-332) met the primary endpoint in a Phase III registrational trial in adults with moderate-to-severe atopic dermatitis (AD), clearing the way for a regulatory submission in China. The study also met multiple secondary endpoints, while the safety profile was consistent with previous studies and revealed no new safety signals. Detailed efficacy data will be presented at future medical meetings.
The result completes the core evidence package needed for a filing in one of dermatology's largest markets, where oral treatment options remain limited. The placebo-controlled study enrolled 579 patients, making it one of the largest Phase III trials conducted with a TYK2-selective inhibitor in AD.
Soficitinib selectively inhibits TYK2, a member of the JAK kinase family involved in IL-12, IL-23 and type I interferon signaling. Unlike JAK1 inhibitors such as AbbVie's Rinvoq (upadacitinib) and Pfizer's Cibinqo (abrocitinib), which carry FDA boxed warnings for serious infections, malignancy, major adverse cardiovascular events and thrombosis, TYK2-selective inhibitors are designed to avoid many of the off-target effects associated with broader JAK inhibition. Whether regulators ultimately view that selectivity as sufficient to differentiate safety labeling remains uncertain.
The Phase III success builds on encouraging Phase II results published in JAMA Dermatology earlier this year. In the 75-patient study, once-daily soficitinib achieved statistically significant improvements in EASI scores, EASI-75 responses and itch reduction versus placebo, with adverse events that were generally mild and comparable to placebo. Those data established proof of concept, while the registrational study now provides the evidence required to support regulatory approval.