Tadashi Terui, Yukari Okubo, Satomi Kobayashi, Akimichi Morita, Shinichi Imafuku, Yayoi Tada, Masatoshi Abe, Bruce Strober, Melinda Gooderham, Wendy Zhang, Junichiro Shimauchi, Masafumi Yaguchi, Takeshi Kimura, Ryuichi Ogawa, Hamid Amouzadeh, Masamoto Murakami
BACKGROUND: Palmoplantar pustulosis (PPP) is a difficult-to-treat chronic dermatitis with limited treatment options. OBJECTIVES: To report results from a Phase 3 study of apremilast in patients with moderate to severe PPP (NCT05174065). METHODS: In this randomized, placebo-controlled, double-blind, confirmatory study, Japanese adults with PPP Area and Severity Index (PPPASI) total score ≥12, PPPASI pustules/vesicles severity score ≥2 and inadequate response to topicals were randomly assigned (1:1) to apremilast or placebo for 16 weeks, followed by an active treatment phase where all patients received apremilast through Week 52. The primary endpoint was a ≥50% reduction in PPPASI total score (PPPASI-50) at Week 16, evaluated in all randomized patients. Safety outcomes were assessed in all patients who received ≥1 dose of the study drug. RESULTS: Between March 8, 2022 to April 28, 2023, 176 patients (141 [80%] women, 35 [20%] men) were randomly assigned to apremilast (n = 88 [50%]) or placebo (n = 88 [50%]). Mean (SD) PPPASI total score at baseline was 22.1 (8.1) in the apremilast group and 22.0 (8.4) in the placebo group. A significantly greater proportion of patients achieved PPPASI-50 at Week 16 with apremilast versus placebo (60 of 88 [68%] vs. 31 of 88 [35%]; treatment difference: 32.6% [95% CI: 18.7, 46.5], p < 0.0001). Improvements were maintained through Week 52. The most common adverse events (≥10% of patients) during the double-blind phase in patients receiving apremilast were diarrhea (placebo: n = 3 [3%]; apremilast: n = 17 [19%]), feces soft (placebo: n = 1 [1%]; apremilast: n = 15 [17%]), headache (placebo: n = 2 [2%]; apremilast: n = 10 [11%]) and nausea (placebo: n = 1 [1%]; apremilast: n = 10 [11%]). There were no events of depression or fatal adverse events. CONCLUSIONS: In this Phase 3 trial, apremilast was effective in Japanese patients with moderate to severe PPP. Adverse events were consistent with the known safety profile of apremilast. CLINICALTRIALS: gov: NCT05174065.