[Hematologic responses to avatrombopag switch in TPO-RA refractory aplastic anemia]

Objective: Short-term efficacy and safety of afatrombopag conversion therapy in patients with aplastic anemia (AA) who were previously ineffectively treated with intense immunosuppressive therapy (IST) combined with TPO receptor Agonist (TPO-RA) or who were unable to tolerate the side effects of TPO-RA. Methods: Analysis of patients with severe aplastic anemia (SAA) treated in Institute of Hematology & Blood Diseases Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College from January 2021 to December 2021 who received IST combined with TPO-RA (eltrombopag/hatrombopag) for at least 6 months, but was ineffective for at least 3 months or patients who cannot continue to use TPO-RA due to side effects, and switched from TPO-RA to avatrombopag (APAG) , and treated for at least 6 months. This study analyzed its short-term efficacy and evaluated its safety. Results: The median age was 54 (14-68) years old among the 16 patients with AA (8 male and eight female) . A total of ten patients (refractory group) who did not respond to IST combined with TPO-RA were converted to APAG median therapy for 6 (6-10) months. Only seven patients (70% ) obtained trilineage HR [four cases of complete treatment response (CTR) , one case of good treatment response (GPR) , and two cases of partial treatment response (PR) ], all of which began to take effect at 3 months of APAG treatment. There were six patients with TPO-RA intolerance, and APAG was treated for 6 (2 to 8) months. About four patients (67% ) received HR (three GPR cases and one PR case) , of which two patients received PR at 3 months and four patients received HR at 6 months of APAG treatment. No APAG-related grade 2 or more adverse events occurred during the APAG therapy, no thrombotic events occurred, no fibrologic tissue hyperplasia was found in the bone marrow pathology reexamination at 6 months of treatment, and none of the patients discontinued the drug due to adverse events. Conclusion: APAG may be a better switching treatment option for patients with AA who are refractory or are intolerant to TPO-RA.