Phase 3, Randomized Study of Apremilast in Japanese Participants with Palmoplantar Pustulosis (PPP)

- Key Inclusion Criteria • Japanese participants ≥ 18 years of age upon entry into initial screening • Palmoplantar pustulosis diagnosis with or without pustulotic arthro-osteitis (PAO) for no less than 24 weeks • PPPASI total score of ≥12 at screening and at baseline • Moderate or severe pustules/vesicles on palms or soles (PPPASI severity score ≥2) at screening and at baseline • Inadequate response (defined as repeated relapsing-remitting in the same location for a 24-week period) to topical treatments prior to or at screening - Key Exclusion Criteria • Changes in disease severity during screening (PPPASI total score change ≥ 5 improvement, from screening to baseline) • Periodontitis requiring treatment • Chronic or recurrent tonsillitis or sinusitis requiring any continuous treatment • Has a diagnosis of plaque-type psoriasis at baseline • Has the presence of pustular psoriasis on any part of the body other than the palms and soles • Has evidence of skin conditions of hand and feet at baseline that would interfere with evaluations of the effect of Investigational Product • Has unstable cardiovascular disease, defined as a recent clinical deterioration or a cardiac hospitalization within 12 weeks prior to screening • Malignancy or history of malignancy • Participant has received any procedures for focal infection within 24 weeks of baseline • Female participants who are breastfeeding or who plan to breastfeed while on study • Female participants of childbearing potential with a positive pregnancy test • Had prior treatment with apremilast • Has a prior medical history of suicide attempt at any time in the participant's lifetime prior to signing of informed consent or randomization, or major psychiatric illness requiring hospitalization within the last 3 years prior to signing of informed consent