Real-World Patient Sample Finds Second-line Treatments Effective for ITP

A real-world sample of patients with immune thrombocytopenia (ITP) treated with rituximab (Rituxan), splenectomy, eltrombopag (Promacta), or romiplostim (Nplate) found that all 4 treatments were associated with significant increases in platelet count.

The study, published in Research & Practice in Thrombosis & Haemostasis, also revealed that rituximab was the predominant second-line therapy used for this patient population.

“Corticosteroids and intravenous immune globulin (IVIG) are the most commonly used first-line treatments; splenectomy, rituximab, and thrombopoietin receptor agonists (TPO-RAs) are all

acceptable second-line options,” the authors explained. “TPO-RAs, including eltrombopag, romiplostim, and avatrombopag (Doptelet), now provide an alternative option among patients for whom second-line therapy is indicated. They have been shown to be effective and safe in randomized clinical trials, and to increase health-related quality of life.”

Adults included in the study had at least 2 medical records containing ITP diagnoses and second-line eltrombopag, romiplostim, rituximab, or splenectomy. Date of treatment initiation or splenectomy was set as the index date, between July 1, 2008 and March 31, 2017. Of note, patients had first-line corticosteroid or intravenous immune globulin treatment and continuous database activity from 6 months before to 12 months after index.

The study included a total of 3332 patients (mean age, 60.5 years; 52.3% female), consisting of 5.8% treated with eltrombopag, 9.9% with romiplostim, 73.3% with rituximab, and 11.0% with splenectomy. Patients having splenectomy were found to be younger, more likely female, and commercially insured; additionally, those having splenectomy were less likely to require a third line of treatment than other medical regimen cohorts.

“The observation period in the current study was nearly 9 years; thus, the proportions of patients receiving each treatment option could have varied across such a long study period,” the authors noted. “However, a trend analysis showed significantly increased use only in eltrombopag over the years of the study; no other treatments showed statistically significant change in use. It is noteworthy that rituximab remained the predominant choice of index therapy throughout the study, even though studies suggest disappointing long-term response rates with this agent. This is an area for potential quality improvement in the care of patients with ITP.”

Overall, the proportions of patients having treatment-free (≥180 days with no second-line index or rescue agent) periods varied significantly (P = .01) by treatment regimen, with 33% for eltrombopag, 23% for romiplostim, 26% for rituximab, and 17% for splenectomy. Moreover, all of the studied regimens significantly improved platelet counts, while thrombotic events and bleeding related episode rates differed significantly (P = .03 and P = .01, respectively) when all treatment groups were compared.

Importantly though, the investigators had no way of determining whether differences in clinical outcomes observed among the treatment cohorts were due to the treatments themselves or to differences in baseline characteristics or baseline platelet values among the treatment cohorts. Given this, it was recommended that analyses with specific outcomes of interest be conducted in future studies with larger sample sizes and adjustment for confounders to account for differences among the 4 treatment groups.

Reference:

Lal LS, Said Q, Andrade K, Cuker A, et al. Second-line treatments and outcomes for immune thrombocytopenia: A retrospective study with electronic health records. Research & Practice in Thrombosis & Haemostasis. doi: 10.1002/rth2.12423