Phase 2 study of avatrombopag in Japanese patients with chronic liver disease and thrombocytopenia

Evaluation of the Efficacy of Lusutrombopag for Chronic Liver Disease Based on Pre-Treatment Platelet Counts: A Retrospective Multicenter Study

BACKGROUND

Oral thrombopoietin receptor agonists are used to treat thrombocytopenia in patients with chronic liver disease who are scheduled for invasive procedures. The efficacy of lusutrombopag based on the pretreatment platelet count was investigated.

METHODS

Patients treated at nine hospitals from December 2015 to December 2023 were included. Efficacy was assessed by comparing the proportion of patients achieving a platelet count ≥ 50 000/μL and the change in platelet count.

RESULTS

Seventy patients were eligible for evaluation. Patients with a pretreatment platelet count < 40 000/μL had a significantly lower rate of achieving a platelet count of ≥ 50 000/μL than those with a pretreatment count of 40 000-50 000/μL (62.5% vs. 84.2%, p = 0.038); however, there was no significant difference in the change in platelet count (25 700 vs. 24 400/μL, p = 0.972). Patients with viral-related cirrhosis showed a significantly greater change in platelet count than the others (29 100 vs. 19 200/μL, p = 0.012). For patients receiving multiple lusutrombopag treatments, the change in platelet count was significantly lower in the second treatment than in the first treatment (26 900 vs. 20 800/μL, p = 0.041). The main adverse event observed was thrombosis (2.9%).

DISCUSSION

Lusutrombopag increases platelet count regardless of pretreatment levels, but efficacy, defined as achieving a platelet count of ≥ 50 000/μL, may be insufficient in patients with a pretreatment platelet count < 40 000/μL. Additionally, patients with non-viral liver disease responded less well to treatment compared to those with viral liver disease. Therefore, treatment strategies should be tailored based on pretreatment platelet counts and the etiology of liver disease.

Thrombopoietin Receptor Agonists in Post-Hematopoietic Cell Transplantation Complicated by Prolonged Thrombocytopenia: A Comprehensive Review

Hematopoietic cell transplantation (HCT) is a well-established procedure that has become a therapeutic mainstay for various hematological conditions. Prolonged thrombocytopenia following HCT is associated with a significant risk of morbidity and mortality, yet no universally recognized treatment protocol exists for such a complication. First-generation thrombopoietin receptor (TpoR) agonists as well as second-generation agents are known for their role in enhancing platelet production, and their use is expanding across various thrombocytopenic conditions. Therefore, we conducted this comprehensive review of the literature to provide an updated evaluation of the use of TpoR agonists and explore their efficacy and safety in the treatment of extended post-HCT thrombocytopenia. The literature search was conducted using PubMed database from 1996 through December 2023, using a predefined strategy with medical subject headings terms. We identified 64 reports on the utility of TpoR agonists, five of them were randomized controlled trials and the rest were retrospective observational studies and case series, with a total number of 1730 patients. Second-generation TpoR agonists appear more convenient than subcutaneous recombinant human thrombopoietin (rhTpo) as they can be orally administered and exhibit similar efficacy in platelet recovery, as indicated by recent trial results. Among these agents, avatrombopag, unlike eltrombopag, does not require any dietary restrictions, which could be more favorable for patients. However, eltrombopag remains the most extensively studied agent. TpoR agonists had promising effects in the treatment of post-HCT thrombocytopenia with a good safety profile so far, highlighting the potential benefit of their use.

Effectiveness and Safety of Avatrombopag in Liver Cancer Patients with Severe Thrombocytopenia: Real-World Data and Challenges

Background

Avatrombopag has been approved in patients who have severe thrombocytopenia (<50 × 10⁹/L) and chronic liver disease (CLD) while receiving invasive procedures. The real-world application and effectiveness of avatrombopag in the subgroup patients with liver cancer remain unknown.

Methods

Liver cancer patients (including primary liver cancer and colorectal cancer liver metastasis) who had severe thrombocytopenia and received avatrombopag were retrospectively enrolled. Avatrombopag dose, peak and absolute platelet count increase, combination treatment with other thrombopoietic agents, responder (peak count ≥50 × 10⁹/L with absolute increase ≥20 × 10⁹/L) rate, and anticancer treatment effect were analyzed. Thrombosis and bleeding events were assessed.

Results

In total, 93 patients were enrolled, with 72 and 21 in the CLD and non-CLD groups, respectively. Patients with CLD had hepatitis B or C, larger spleen volume, and a higher cirrhosis degree. Baseline platelet counts were similar between two groups (median, 37.0 × 10⁹/L vs. 39.0 × 10⁹/L; P=0.594), while patients without CLD had higher peak platelet (median, 134.0 × 10⁹/L vs. 74.0 × 10⁹/L; P=0.015) and absolute increase (median, 101.0 × 10⁹/L vs. 41.0 × 10⁹/L; P=0.020) after avatrombopag treatment. The responder rate was higher in patients without CLD (100% vs. 76.4%; P=0.010). Combined avatrombopag with other thrombopoietic agents significantly increased platelet count; repeated use of avatrombopag produced similar effects with that of initial treatment. Concerning anticancer treatment effect, patients who responded to avatrombopag had a higher disease control rate. No thrombosis or hemorrhagic events were observed, even in patients with portal vein tumor thrombosis.

Conclusion

Avatrombopag was safe and effective and ensured successful implementation of anticancer treatment in liver cancer patients with severe thrombocytopenia, accompanied with or without CLD.