This is a 12-week, single-arm, open-label pilot study to assess the safety and preliminary efficacy of oral roflumilast in adults with moderate-to-severe plaque psoriasis. All participants, both male and female, will receive oral roflumilast starting at 250 mcg once daily for 10 days, followed by 500 mcg once daily for the remainder of the study. The primary outcome is the mean change in Psoriasis Area and Severity Index (PASI) score from baseline to Week 12. Secondary outcomes include change in body mass index (BMI) and safety assessments, including treatment-emergent adverse events, serious adverse events, and laboratory abnormalities. Male and female participants will be analyzed as subgroups.