Inclusion Criteria:
* Male or female patients aged ≥19 years at the time of enrollment.
* Patients with moderate to severe psoriasis persisting for ≥6 months.
* Patients with a PASI (Psoriasis Area and Severity Index) score between 5 and 10, requiring pharmacological treatment.
* Patients who have been fully informed about the study, have understood the explanation, and have voluntarily signed the informed consent form.
* Patients who are considered cooperative and able to participate until the end of the study.
Exclusion Criteria:
* Patients with a history of hypersensitivity to apremilast.
* Patients with genetic disorders such as galactose intolerance, Lapp lactase deficiency, or glucose-galactose malabsorption.
* Pregnant or breastfeeding women.
* Patients (or their spouse/partner) who do not agree to use medically acceptable and appropriate methods of contraception\* during the study period.
\* Medically acceptable and appropriate methods of contraception include: hormonal contraception (implants, injectables, oral contraceptives, etc.), intrauterine devices (copper IUD, hormone-releasing intrauterine system), salpingectomy, tubal ligation, hysterectomy, vasectomy, dual barrier methods (male condom and female condom, cervical cap, diaphragm, contraceptive sponge used in combination), or single barrier method combined with spermicide.
* Patients receiving strong CYP3A4 enzyme inducers (e.g., rifampicin, phenobarbital, carbamazepine, phenytoin, St. John's Wort).
* Patients with severe renal impairment requiring hemodialysis or peritoneal dialysis.
* Patients who have previously received Apremilast (ApsoLla®) prior to enrollment, or those currently participating in another clinical trial involving an investigational medicinal product or medical device.
(However, patients enrolled in non-interventional studies or who have completed participation in another clinical trial are eligible.)
* Patients with a history of psychiatric disorders (e.g., substance abuse, depression).
* Patients who, in the opinion of the investigator, are otherwise considered unsuitable for participation in this study.
