A Clinical Study of TQH2929 Injection in Treatment With Generalized Pustular Psoriasis (GPP)

Inclusion Criteria: * Adults aged between 18 and 75 years (inclusive)，both male and female； * A known and documented history of Generalized Pustular Psoriasis diagnosed with European Rare and Severe Psoriasis Expert Network (ERASPEN) criteria in 2017； * Presenting with a moderate-severe flare of Generalized Pustular Psoriasis (GPP) * Body mass index (BMI) within 18\~36 kg/m2； * Major organ function is good; * Patients must be able to understand and sign a written informed consent document; * Patients must be able to complete study-related procedures and questionnaires; * Female and male subjects of childbearing age should agree to use contraceptive measures during the study period and within 6 months after the end of the study; Female subjects need to serum pregnancy pregnancy test within 7 days before study enrollment. Exclusion Criteria: * Patients with primary plaque psoriasis vulgaris with pustules that are restricted to psoriatic plaques； * Immediate life-threatening flare of Generalized Pustular Psoriasis or requiring intensive care treatment, according, to the judgment of the investigator； * Computed Tomography of the chest shows active or occult tuberculosis or a history of contact with an open tuberculosis (TB) subject within the past 6 months. Subjects positive for tuber closes spot(T-SPOT) (or other tuberculosis diagnostic test) result; * Active hepatitis during the screening period, or positive for hepatitis B surface antigen (HBsAg)； * History of human immunodeficiency virus (HIV) infection, or positive HIV serological results at screening during screening； * Positive antibodies to treponema pallidum during screening； * History of serious infection leading to hospitalization or intravenous infusion of antibiotics or antiviral therapy within 3 months prior to baseline; * Active systemic infections requiring systemic antibiotics or systemic antiviral therapy within 4 weeks prior to baseline; * History of opportunistic infection and parasitic infection within 6 months prior to the screening period； * History of herpes zoster infection within 2 months prior to baseline； * Subject has known or suspected autoimmune disease; * Receive major surgery within 4 weeks prior to the first dose; * Subjects with any type of active malignancy or a history of malignancy (except cervical cancer or non-metastatic cutaneous squamous cell carcinoma, basal cell carcinoma and papillary thyroid carcinoma) that has been cured for more than 5 years prior to the screening period; * Subjects have history of significant drug allergies； * Use of the following medications within the prescribed time: 1. Receive topical drugs for the treatment of skin diseases within 1 weeks prior to baseline; 2. Receive systemic therapy within 4 weeks prior to baseline; 3. Receive regular phototherapy within 4 weeks prior to baseline; 4. Within 12 weeks prior to baseline, receive live (attenuated) vaccine; 5. Receive antibiotics and antivirals within 4 weeks prior to baseline. * People who are alcoholic, drug addicts, and known drug dependents; * Pregnant or Breasting feeding subject; * Received a blood transfusion within 4 weeks prior to the first dose; * Subject is unable to tolerate intravenous infusion administration; * During the period of participation in this study, participants had planned surgical procedures; * Have participated in clinical trials of other drugs or medical devices within 4 weeks prior to baseline; * In the judgment of the investigator or sponsoring medical auditor, it is believed that there are any medical or psychiatric symptoms that put the subject at risk, interfere with participation in the study, or interfere with the interpretation of the results of the study.