To observe the safety and effectiveness of long-term use of jaktinib hydrochloride tablets in the treatment of moderate and severe atopic dermatitis

If the enrolled subjects received the treatment of jaktinib hydrochloride tablets in the ZGJAK025 trial, they will continue to use the drug at the original dosage; If the enrolled subjects received placebo treatment in the ZGJAK025 trial, they will receive 100mg BID of jaktinib hydrochloride tablets, 75mg BID of jaktinib hydrochloride tablets or placebo at a ratio of 1:1:1 at random, and continue to take the drug on an empty stomach, with the longest continuous treatment not exceeding 36 weeks.

Inclusion Criteria:

• The investigator thinks that the subject can continue to benefit from participating in the extension trial;
• Fully understand the extension trial and sign the informed consent form;
• Complete the ZGJAK025 trial for 16 weeks and have good compliance;
• It is expected that the time interval between the first administration and the last administration of ZGJAK025 trial for the subject should be ≤ 4 weeks;

Exclusion Criteria:

• Within 4 weeks before enrollment, there were any adverse events ≥ 3 levels related to the test drug that did not return to level 1 or normal;
• The investigator thinks that the subject is not suitable for the trial.