Hetrombopag Added to Cyclosporine as the First-Line Treatment for Patients With Non-Severe Aplastic Anemia: A Phase 2 Multicenter Trial.

Non-severe aplastic anemia (NSAA) is a heterogeneous bone marrow failure syndrome with limited standardized treatment options. Cyclosporine A (CsA) monotherapy often yields suboptimal responses, highlighting an unmet clinical need for more effective therapies. Thrombopoietin receptor agonists (TPO-RAs) have shown satisfying outcomes in severe aplastic anemia (SAA), but data on their frontline use in NSAA remain scarce. We enrolled 54 adults with newly diagnosed NSAA, including 25 with transfusion-dependent NSAA (TD-NSAA) in the prospective, single-arm Phase 2 trial (NCT05660785) to evaluate the efficacy and safety of hetrombopag, an oral TPO-RA, in combination with CsA. At 24 weeks, the overall response rate (ORR) was 81.5% (44/54), comprising 72.2% partial responses and 9.3% complete responses (CRs). Notably, CR and robust partial response (robust PR) were achieved in 46.3% (25/54) of patients. In the TD-NSAA subgroup, the ORR was even higher at 88.0% (22/25) with substantial improvements in hematologic parameters and quality of life. Extending treatment from 16 to 24 weeks increased the CR and robust PR rate from 24.0% to 44.0%. The median time to achieve an initial response was 6, and 14 weeks for robust PR. Adverse events occurred in 35% of patients, predominantly Grade 1 or 2 and were manageable. Importantly, no clonal progression to myelodysplastic syndrome or leukemia was observed. These findings support hetrombopag plus CsA as a potential first-line therapeutic intervention for NSAA, especially in TD-NSAA patients.