A Phase Ⅲ Efficacy and Safety Study of Hemay005 in Subjects With Moderate to Severe Plaque Psoriasis

Inclusion Criteria:

1. At the time of signing the informed consent, the age was more than or equal to 18years old, regardless of gender；
2. Stable plaque psoriasis with a history of more than 6 months (from the time ofrandomization)；
3. Screening and baseline PSAI ≥12, sPGA≥3（Moderate to Severe）,affected body surface areaBSA≥10%；
4. All subjects must agree and commit to the use of a reliable contraceptive regimen.Women of childbearing potential must undergo monthly pregnancy testing during thestudy and agree to use two of the following methods of contraception throughout thestudy and for 90 days after the last dose of study drug. Reliable contraceptiveregimen: vasectomy, abstinence, the use of condoms, intrauterine contraceptives (IUD), (Oral administration, patch, ring, injection, implantation) Barrier methods (diaphragmwith spermicide, condom with spermicide)；
5. The subjects voluntarily participated in the study and signed the informed consent .

Exclusion Criteria:

1. Forms of psoriasis other than chronic plaque-type; (i.e., erythrodermic and guttatepsoriasis, palmar, plantar or nail disease) at screening;
2. Investigator diagnosed as drug-induced psoriasis (including but not limited to newonset or aggravation of psoriasis caused by beta blockers, calcium channel inhibitorsor lithium preparations);
3. Skin diseases, chronic diarrhea, serious digestive system diseases (such as activegastric ulcer, gastrointestinal bleeding, etc.), or other autoimmune inflammatorydiseases that may interfere with clinical evaluation, according to the investigator;
4. The screening period was accompanied with active infection (such as bacterialinfection, viral infection, fungal infection, etc., which required oral or intravenoustreatment), and the investigator assessed that participation in this study mayincrease the risk of subjects;
5. Subjects with a history of tuberculosis or active tuberculosis (there were signs orsymptoms of active tuberculosis judged by the researcher at the time of screening);
6. Use of prohibited treatments of this study;
7. History of congenital or acquired immunodeficiency;
8. Subjects couldn't limit their uv exposure during the study period ;
9. History of apremilast or Hemay005 tablets;
10. Subjects with conditions that may affect oral drug absorption, such as subtotalgastrectomy, clinically significant diabetic gastroenteropathy, or certain types ofweight-loss surgery, such as gastric bypass surgery, do not include surgery thatsimply separates the stomach into separate Chambers, such as gastric banding surgery;
11. Subjects with tumor or history of malignancy (solid organ tumor or hematological tumorincluding myelodysplastic syndrome) in the past 5 years;
12. History of alcohol or drug abuse or dependence in the past year;
13. Subjects with a history of mental illness, suicidal behavior (including positiveattempt, interrupted attempt or attempted suicide) or suicidal thoughts in the past 6months were not suitable for clinical trials after the evaluation of the investigator;subjects with severe anxiety or depression during the screening period were assessedas severe anxiety or depression;
14. There are clinically serious, progressive or uncontrollable diseases in the screeningperiod, including but not limited to respiratory system, cardiovascular system,endocrine system, blood system, musculoskeletal system and nervous system. Accordingto the assessment of investigator, participating in this study may increase the riskof subjects or interfere with data interpretation;
15. In the screening period, human immunodeficiency virus (HIV) serological positive (i.e., HIV antibody positive);Evidence of hepatitis B virus infection: hepatitis Bsurface antigen (HBsAg) positive, or hepatitis B core antibody (HBcAb) positive andHBV-DNA above the upper limit of the normal range, or hepatitis B E antibody (HBeAb)positive and HBV-DNA above the upper limit of the normal range;Evidence of hepatitis Cvirus (HCV) infection: HCV antibody positive;
16. During the screening period, there were any of the following laboratory abnormalities:
17. Aspartate aminotransferase (AST) or alanine aminotransferase (ALT) > 2 times theupper limit of normal value, or total bilirubin > 1.5 times the upper limit ofnormal value;
18. Serum creatinine > 1.2 times the upper limit of normal value;
19. The hemoglobin of male patients was less than 8.5 g / dl (85.0 g / L), and thatof female patients was less than 8.0 g / dl (80.0 g / L);
20. WBC count < 3.0 × 109 / L or ≥ 14 × 109 / L;
21. Platelet count < 100 × 109 / L
22. Female who were pregnant during lactation or pregnancy, or during the planned studyperiod, or subjects who had sperm / egg donation plans during the study period;
23. Know allergic to active ingredient or excipient of the investigational product;
24. Participated in any other interventional clinical trial within 4 weeks or 5pharmacokinetic / pharmacodynamic half lives before randomization (whichever islonger);
25. The investigator considered that there are any other conditions that are not suitablefor participating in the study.