Clinical Impact of Eltrombopag-Associated Iron Chelation in Adults with Immune Thrombocytopenia: A Multicenter Real-World Study.

BACKGROUND

Eltrombopag (ELT) is an established thrombopoietin receptor agonist (TPO-RA) for chronic immune thrombocytopenia (ITP), yet accumulating translational evidence indicates clinically relevant iron-chelating activity. Adult primary ITP-focused data characterizing longitudinal iron trajectories during ELT remain limited. We assessed whether ELT exposure is independently associated with iron deficiency (ID) in routine practice.

METHODS

In this multicenter retrospective study, adults with ITP were evaluated with longitudinal monitoring of platelet count, ferritin, transferrin saturation (Tsat), hemoglobin (Hb), and mean platelet volume (MPV). Within-patient change was defined as the difference between baseline and follow-up (Δ). Outcomes were compared by ELT exposure and dose strata. Multivariable linear regression was used to identify independent determinants of Δ-ferritin, adjusting for age, gender, relapse status, and iron replacement therapy (IRT).

RESULTS

The cohort included 283 adults with ITP; 110 received ELT (median 25 months). ELT was associated with greater declines in ferritin and Tsat (p<0.001), with a dose-graded effect across 25-75 mg and earlier iron depletion at higher dose intensity. In relapsed patients not receiving ELT, the mean Δ-ferritin was positive and did not differ by bleeding status. In multivariable linear regression, ELT was the dominant independent predictor of lower Δ-ferritin (B≈-79.8 μg/L, p<0.001), whereas age, gender, and relapse were not significant; IRT attenuated ferritin decline but did not negate ELT effects.

CONCLUSION

ELT exposure was independently associated with ID, supporting a clinically meaningful ELT-related iron chelation phenotype in routine practice. Monitoring and timely correction of ID during ELT therapy may mitigate a modifiable contributor to fatigue during follow-up.