Eltrombopag in Severe Immune Thrombocytopenia Secondary to Connective Tissue Disease: a Report of 17 Patients and Literature Review

To assess the remission rate of eltrombopag in the treatment of severe immune thrombocytopenia (ITP) secondary to connective tissue disease (CTD) and to explore factors related to drug efficacy in the context of literature reports, seventeen CTD patients accompanied with severe ITP treated with eltrombopag between June 2019 and February 2021 were included, with their follow-up information recorded. Combined with literature review, patients were divided into two groups depending on whether the treatment was effective or not to determine efficacy-related factors. Totally, 7 patients with systemic lupus erythematosus, 6 with Sjögren's syndrome, and 4 with undifferentiated connective tissue disease were enrolled. The median duration of eltrombopag treatment was 8 weeks, and the median time to response was 4 weeks. Twelve (70.6%) patients responded to eltrombopag. Patients with higher serum white blood cell counts, lower serum triglyceride levels, or previously received multiple immunosuppressants achieved a better efficacy (p < 0.05), while those with megakaryocytopenia in bone marrow tended to have lower remission rate (p = 0.08). By using pooled data including literature reported cases, we demonstrated that evidence of leukopenia, megakaryocytopenia, and being treated with fewer prior immunosuppressants were still associated with poor remission (p < 0.05). Meanwhile, there was a trend indicating the primary disease might affect the treatment efficacy (p = 0.06). Eltrombopag is a viable option for treating severe ITP secondary to CTDs, yet it may be less effective for patients with leukopenia, megakaryocytopenia, and being treated with fewer prior immunosuppressants. Key Points • Eltrombopag provides an alternative to the current treatment of CTD-ITP. • White blood cell levels, bone marrow megakaryocyte counts, and prior use of immunosuppressants may affect the efficacy of eltrombopag.