Early initiation of second-line therapy in primary immune thrombocytopenia: insights from real-world evidence

To compare patients with primary immune thrombocytopenia (ITP) prescribed early (within 3 months of initial ITP treatment) second-line treatment (eltrombopag, romiplostim, rituximab, immunosuppressive agents, splenectomy) with or without concomitant first-line therapy to those who received only first-line therapy. This real-world retrospective cohort study of 8268 patients with primary ITP from a large US-based database (Optum^® de-identified Electronic Health Record [EHR] dataset) combined electronic claims and EHR data. Outcomes included platelet count, bleeding events, and corticosteroid exposure 3 to 6 months after initial treatment. Baseline platelet counts were lower in patients receiving early second-line therapy (10‒28 × 10⁹/L) versus those who did not (67 × 10⁹/L). Counts improved and bleeding events decreased from baseline in all treatment groups 3 to 6 months after the start of therapy. Among the very few patients for whom follow-up treatment data were available (n = 94), corticosteroid use was reduced during the 3- to 6-month follow-up period in patients who received early second-line therapy versus those who did not (39% vs 87%, p < 0.001). Early second-line treatment was prescribed for more severe cases of ITP and appeared to be associated with improved platelet counts and bleeding outcomes 3 to 6 months after initial therapy. Early second-line therapy also appeared to reduce corticosteroid use after 3 months, although the small number of patients with follow-up data on treatment precludes any substantive conclusions. Further research is needed to determine whether early second-line therapy has an effect on the long-term course of ITP.