PB2041: COMPARISON OF ELTROMBOPAG AND AVATROMBOPAG IN THE TREATMENT OF REFRACTORY/RELAPSED APLASTIC ANEMIA, A SINGLE CENTER STUDY IN CHINA

Abstract Topic: 12. Bone marrow failure syndromes incl. PNH - Clinical

Background: Eltrombopag (EPAG), one of the thrombopoietin receptor agonists (TPO-RAs), has been approved for refractory/relapsed aplastic anemia (AA), however, data on avatrombopag (AVA), another TPO-RA are limited, let alone the comparison between the two TPO-RAs.

Aims: To evaluate and compare the efficacy and safety between EPAG and AVA treatment in relapsed/refractory AA patients in a real-world setting.

Methods: Data from patients diagnosed with acquired refractory/relapsed and treated with either EPAG or AVA in our center were retrospectively collected. Refractory/relapse was defined as those who were refractory/relapsed to immunosuppressant (IST) for at least 6 months before EPAG/AVA. Patients had to be treated with EPAG or AVA alone for at least 6 months before evaluation if not responded. Baseline characters, overall response (OR) and complete response (CR), relapse, adverse events, and factors that may affect efficacy were analyzed.

Results: 75 patients were enrolled in the study, including 45 patients treated with EPAG and 30 patients treated with AVA. No difference in baseline characters between the two groups except patients with AVA had more percentage of abnormal renal or liver function compared with those with EPAG (p=0.036). No significant difference was found in time to response (P=0.256) or OR/CR rate at 1^st/2^nd/3^rd/6^th month between the two groups (P＞0.05). Patients treated with AVA who had platelet response had a shorter median time to maximum platelet level than EPAG (P=0.009), and had a higher platelet level at 2^nd month (P=0.022). However, no significant difference was found in the platelet level at other time points between the two groups (P＞0.05). AVA had less adverse events than EPAG (P=0.046). Under compatible follow-up time (P=0.572), no difference was found between EPAG and AVA group in relapse (P=1.000) or clone evolution (P=0.637). No predictive factors for overall response at 6^th month were found either for EPAG or AVA.

Summary/Conclusion: With worse liver and kidney function, AVA had similar OR/CR rate but had shorter time to maximum platelet response in responders and less adverse events for patients with relapsed/refractory AA.

Key words: relapsed/refractory, aplastic anemia, avatrombopag, eltrombopag, effects

Off-Label Disclosure:

In the presented study, avatrombopag was off-label used in relapsed/refractory aplastic anemia patients.

Keywords: Aplastic anemia, relapsed/refractory