A Long-term Extension Clinical Study of TLL-018 in Patients With Rheumatoid Arthritis

Inclusion Criteria:

• Subjects have completed TLL-018-301 study within 3 months;

• Age (at the time of consent):>＝18 years of age, <＝75 years of age;

• Female subjects of childbearing potential (WOCBP), who should not be pregnant orbreastfeeding, should not enter the study until after pregnancy testing (e.g., HCGbeta subunit-based monitoring);

• All subjects and their partners voluntarily use contraception as deemed effective bythe investigator for at least 90 days from the first dose of the investigationaldrug to the last dose of the investigational drug (Appendix I); no sperm or eggdonation is planned by the subject for at least 6 months from the screening periodto the last dose of the investigational drug.

• Subjects can understand the informed consent form, volunteer to participate in thestudy and sign the informed consent form.

Exclusion Criteria:

• Subjects have had severe allergic reaction related to the investigational drugduring the TLL-018-301 study;

• Subjects have had herpes zoster, a major cardiovascular event (MACE),thromboembolism, or lymphoproliferative disorders from the time of TLL-018-301 studyto the screening of OLE study;

• Subjects have a clinically significant cardiovascular, respiratory, or any otherserious and/or non-stable disease, and there is security risk for subjects toparticipate in this study judged by the investigator;

• Subjects have abnormal and clinically significant laboratory test values atscreening;

• Subjects who have taken traditional Chinese medicines, csDMARDs, immunosuppressivedrugs, potent opioids, and other JAK inhibitors (except the investigational drugs inTLL-018-301 study) within 1 week before taking the first dose of the investigationaldrug in OLE study;

• Subjects have treated with flunomide, any bDMARDs, interferon, and other injectedimmunosuppressive drugs from TLL-018-301 study to the screening of OLE study;

• Subjects who have received any live vaccine within 2 months prior to taking thefirst dose of the investigational drug or who plan to receive a live vaccine duringthe study;

• Subjects have had active tuberculosis infection without evidence of clinical cure;have suspected tuberculosis symptoms judged by the investigator; have latenttuberculosis infection (LTBI) but not received preventive treatment regimens within 3 years prior to screening or not completed a course of therapy.