This is a phase I study of TQ05105 tablets in subjects with Hemophagocytic Lymphohistiocytosis.TQ05105 is a JAK2 inhibitors and can be used to treat JAK2 target-related diseases. The activation of the JAK/STAT pathway is related to abnormal proliferation, obstruction of apoptosis, and differentiation disorder of leukemia cells which is caused by genetic abnormalities and viral infection.

Inclusion Criteria:

• 1.18 years and older; Eastern Cooperative Oncology Group (ECOG) performance status of 0 to 3; Life expectancy ≥ 3 months.

  2. Diagnosed as new or relapsed HLH according to the HLH-2004 criteria. 3.Has received other treatments for HLH before two weeks ago, surgery before four weeks ago.

  4. Adequate laboratory indicators. 5. No pregnant or breastfeeding women, and a negative pregnancy test. 6. Understood and signed an informed consent form.

Exclusion Criteria:

• 1. Has diagnosed and/or treated additional malignancy within 5 years prior to randomization. With exception of non-melanoma, skin cancer, and carcinoma in situ.

  2. Has participated in other anticancer drug clinical trials within 4 weeks. 3. Has multiple factors affecting oral medication. 4. Has drug abuse history that unable to abstain from or mental disorders. 5. Has active hepatitis B or C, or immunodeficiency. 6. Diagnosed as hepatic failure. 7. Has arteriovenous thrombosis events within 4 weeks. 8. Has active bleeding, or a persistent decrease in hemoglobin. 9. Has received long-term and large-dose glucocorticoids or other immunosuppressive drugs within 28 days before signed the informed consent form.

  10. Has uncontrolled cardiovascular disease. 11. Has uncontrolled hypertension. 12. Has serious systemic infections. 13. According to the judgement of the researchers, there are other factors that subjects are not suitable for the study.