Perioperative Eltrombopag or Intravenous Immune Globulin for Patients with Immune Thrombocytopenia: A Multicenter Randomized Trial

Background: Patients with immune thrombocytopenia (ITP) may require treatment to raise the platelet count before surgery. Intravenous immune globulin (IVIG) is commonly used for this purpose, but eltrombopag, an oral thrombopoietin receptor agonist, may be a good alternative. We compared perioperative eltrombopag or IVIG for the achievement of platelet count targets for major or minor surgery.

Methods: We conducted a randomized, non-inferiority trial at 8 centers in Canada.ITP patients with a platelet count <100 x10⁹/L or <50 x10⁹/L before elective major or minor surgery, respectively, were assigned to receive daily oral eltrombopag starting 3 weeks preoperatively or IVIG 1 week preoperatively. Eltrombopag was discontinued 1 week after surgical hemostasis, and a repeat dose of IVIG was permitted up to 1 week after surgical hemostasis. The primary endpoint was the achievement of platelet count targets (90 x10⁹/L for major surgery, or 45 x10⁹/L for minor surgery) immediately before surgery and for 7 days after surgical hemostasis without rescue treatment. Intention-to-treat and per-protocol analyses were done using a one-sided test for the difference in rates of achieving perioperative platelet count targets with a non-inferiority margin of 10% at a significance level of 0.05. Patients were followed for 4 weeks postoperatively. Secondary outcomes were thrombosis, adverse events and treatment satisfaction as measured using a validated patient questionnaire.

Results: From 2013 to 2019, 38 patients were assigned to received eltrombopag and 36 patients were assigned to receive IVIG before major (n= 31) or minor (n= 43) surgery. Five patients did not complete the study. By intention to treat, 30/38 (78.9%) patients on eltrombopag achieved perioperative platelet count targets compared with 22/36 (61.1%) on IVIG (absolute risk difference, 17.8%; one-sided lower limit of the 95% confidence interval, 0.4%; p=0.005 for non-inferiority). Results were similar in the per protocol analysis (absolute risk difference: 15.8%; one-sided lower limit of the 95% CI, -2.1%; p=0.009). Eltrombopag was superior to IVIG in the intention-to-treat analysis (p=0.047) but not in the per-protocol analysis (p =0.074). One patient developed pulmonary embolism 14 days after minor surgery (skin biopsy) and 7 days after stopping eltrombopag when the platelet count was 135 x10⁹/L. Of 18 patients who underwent splenectomy on study, marked post-splenectomy thrombocytosis (platelets >1,000 x10⁹/L) occurred in 2 (11.1%) patients, both of whom were on eltrombopag. Global treatment satisfaction scores were higher for eltrombopag.

Conclusion: Eltrombopag is non-inferior and may be superior to IVIG for achieving target platelet counts perioperatively for patients with ITP. Post-operative thromboprophylaxis should be considered with eltrombopag.

Funding Source:This was an investigator-initiated trial funded by Novartis.