An experimental once-daily pill for moderate to severe plaque psoriasis achieved skin clearance rates previously seen only with injectable biologics, according to late-stage trial data from Takeda.
Clearance rates rival injectable treatments
The medication, zasocitinib, met its primary goals in two phase 3 trials involving over 1,800 patients across 21 countries. After 16 weeks, about 70% of patients taking zasocitinib had clear or nearly clear skin, compared with 11% to 13% on placebo and 30% to 32% on apremilast, an existing oral therapy. Over half achieved at least a 90% reduction in psoriasis severity, while roughly 25% to 33% experienced complete clearance.
Improvement appeared quickly, with results separating from placebo by week four, and lasted through 60 weeks for more than 90% of responders. Takeda intends to submit the findings to regulators, including the FDA, later this year.
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Hard-to-treat areas respond
Zasocitinib also proved effective in areas often resistant to treatment. Roughly 75% of patients saw their scalp psoriasis clear or nearly clear, while roughly 70% improved on the palms and soles. Nail psoriasis showed statistically significant improvement over placebo. These sites carry significant impact on patients’ quality of life, and the consistency of clearance across the body supports a broader treatment benefit.
Leon Kircik, a dermatologist and principal investigator for the trials, noted that persistent symptoms in visible or sensitive areas like the scalp impact patients. “These findings show that zasocitinib delivered consistently clear skin across the hardest-to-treat areas,” he said.
The drug works by selectively blocking TYK2, a protein involved in immune pathways driving psoriasis. Lab tests showed it had over a million times greater selectivity for TYK2 than related enzymes, potentially allowing maximal TYK2 inhibition without affecting other signaling. Zasocitinib remains investigational and is not approved by any regulators.
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Oral treatments with this level of effectiveness have been uncommon. Most high-response options require injections, making a daily pill a possible alternative for patients. In another trial, zasocitinib surpassed deucravacitinib, an approved oral TYK2 inhibitor, across every end point at 16 weeks.
Regulatory review will determine the drug’s future. Takeda has not provided additional details on submission timelines beyond its plan to file with the FDA and other agencies.
