Pharmacokinetic Assessment and Treatment Effect of Lusutrombopag in Child–Pugh Class C Patients: Review of Patient Data from Two Clinical Studies and Post-Marketing Surveillance

Introduction Patients with thrombocytopenia and chronic liver disease are at increased risk of bleeding during invasive procedures due to low platelet counts. Lusutrombopag, an orally active thrombopoietin receptor agonist, increases platelet count and reduces the need for platelet transfusion in chronic liver disease patients with thrombocytopenia undergoing a planned invasive procedure. The safety of lusutrombopag in patients with Child–Pugh class C chronic liver disease is not known. The present analysis was performed to determine the pharmacokinetics, efficacy, and safety of lusutrombopag in patients with Child–Pugh class C chronic liver disease. Methods Data for patients with Child–Pugh class C chronic liver disease were collected from three data sets: a phase 1/2 Child–Pugh class C study ( n = 5) (JapicCTI-163289 [Japan Pharmaceutical Information Center]), a phase 3 pivotal study (L-PLUS 2, n = 3) (NCT02389621 [Clinicaltrials.gov]), and ongoing post-marketing surveillance ( n = 27) (JapicCTI-163432 [Japan Pharmaceutical Information Center]). Patients received lusutrombopag at 3 mg for up to 7 days. Safety and efficacy assessments were collected from two clinical studies and the post-marketing surveillance; pharmacokinetic data were collected from the phase 1/2 study. Results Mean C max and AUC 0– τ were lower in Child–Pugh class C patients than Child–Pugh class A and B; individual patients’ C max and AUC 0– τ values overlapped among Child–Pugh classes. In lusutrombopag patients who did not receive platelet transfusion ( n = 4 in phase 1/2, n = 1 in phase 3, n = 24 in post-marketing surveillance), the median (range) maximum platelet count was 88.5 × 10 9 /L (54–105 × 10 9 /L), 80 × 10 9 /L, and 91 × 10 9 /L (41–186 × 10 9 /L; n = 23), respectively. There were no treatment-related adverse events or treatment-related serious adverse events. One patient from the phase 1/2 study had a non-serious portal vein thrombosis, which was not considered treatment-related. Conclusions The analysis presented in this study suggests that lusutrombopag increases platelet counts in Child–Pugh class C patients and is safe and well tolerated in this patient population. Trial Registration L-PLUS 2: NCT02389621 (Clinicaltrials.gov). Phase 1/2: JapicCTI-163289 (Japan Pharmaceutical Information Center [JAPIC]). Post-marketing surveillance: JapicCTI-163432 (JAPIC).