Avatrombopag, a promising novel thrombopoietin receptor agonist for refractory/relapsed/intolerant non-severe aplastic anemia: a phase 2 single-arm clinical trial

Avatrombopag for the Treatment of Immune Thrombocytopenia

Avatrombopag, a second-generation thrombopoietin receptor agonist (TPO-RA), represents a significant advancement in the treatment of chronic immune thrombocytopenic purpura (cITP) and a potential therapeutic option for other thrombocytopenic disorders. Approved in both the USA and Europe, avatrombopag offers a convenient oral dosing regimen, initiated at 20 mg daily with food, to achieve and maintain platelet counts ≥ 50 × 109/L. Its favorable safety profile, characterized by minimal hepatic toxicity and the absence of dietary restrictions, distinguishes it from older TPO-RAs such as eltrombopag and romiplostim. Clinical trials and real-world data support its efficacy, with over 90% of patients that fail to standard first- and second-line treatments or become unresponsive, achieving target platelet counts, and its hepatotoxicity-free profile makes it particularly advantageous for patients with liver disease or complex comorbidities. Economic evaluations, including a budget impact analysis for the Italian National Health Service, have projected significant healthcare cost savings associated with avatrombopag use, reinforcing its value as a cost-effective therapeutic option. However, challenges remain, including limited data on long-term safety. In this review, we aim to provide a comprehensive synthesis of clinical evidence and real-world data on avatrombopag's efficacy, safety, and pharmacological advantages, while exploring its current and potential therapeutic applications, such as chemotherapy-induced thrombocytopenia and aplastic anemia.

Cyclosporine plus avatrombopag versus cyclosporine monotherapy for first-line treatment of elderly patients with transfusion-dependent non-severe aplastic anemia: a single center retrospective study

BACKGROUND

Elderly patients with transfusion-dependent non-severe aplastic anemia (TD-NSAA) face limited treatment options owing to transplantation incompatibility and safety concerns.

METHODS

Data from older patients (≥60 years) newly diagnosed with TD-NSAA and had been treated with either avatrombopag (AVA) + cyclosporine (CsA) or CsA monotherapy at our center were retrospectively collected.

RESULTS

In total, 52 patients were enrolled, with 26 receiving AVA + CsA and 26 receiving CsA monotherapy. The overall response (OR) rate was higher in the AVA + CsA group than in the CsA group at the 1st, 2nd, 3rd, 6th months, and at the end of the follow-up (all p < 0.05). The complete response (CR) rate was higher in the AVA + CsA group than in the CsA group at the 6th month and at the end of follow-up (p = 0.017 and 0.039). Patients receiving AVA + CsA had a shorter time to achieve the first response (p = 0.008) and CR (p = 0.010) than those receiving CsA monotherapy. Furthermore, patients receiving AVA + CsA exhibited a higher rate of platelet transfusion independence at the 3rd (p = 0.041), 6th (p = 0.008) months, and likewise at the end of the follow-up (p = 0.097).

CONCLUSIONS

The addition of AVA to CsA can significantly improve the OR or CR rate and platelet levels with acceptable side effects in elderly patients, which implies that the combination is a viable alternative for elderly patients with TD-NSAA.

Efficacy and safety of avatrombopag in combination with standard immunosuppressive therapy for severe aplastic anemia

Severe aplastic anemia (SAA) is a life-threatening bone marrow failure disease. The addition of eltrombopag to immunosuppressive therapy (IST) improves the response rate, but its hepatotoxicity is concerning. Avatrombopag (AVA), a small-molecule thrombopoietin-receptor agonist without hepatotoxicity, has unknown efficacy in SAA treatment. This retrospective study assessed the efficacy and safety of AVA added to IST 42 SAA patients compared to a historical cohort of 84 patients receiving IST alone, using propensity score matching. The median age was 31.5 (6.0-67.0 years) years old in group A and 26 (16.0-45.0 years) years old in group B. At 3 months, group A showed higher complete response (CR) and overall response (OR) rates than group B (CR: 19.0% vs. 4.8%, p = 0.024; OR: 54.8% vs. 39.3%, p = 0.145). Higher CR and OR rates were also found at 6 months in group A than in group B (CR: 31.0% vs. 14.3%, p = 0.145; OR 71.4% vs. 51.2%, p = 0.048). In multivariate analysis of group A, a shorter interval from disease onset to antithymocyte globulin (ATG) treatment (≤6 months) (p = 0.005) predicted better responses rate at 6 months. Event-free survival was also improved in group A (60.7% vs. 49.6%). AVA was well-tolerated, with no hepatic injury observed during treatment, even in those with pre-existing hepatic impairment. The addition of AVA to IST improves both the response rate and response quality in patients with SAA while ensuring safety.

Safety and efficacy of eltrombopag in patients with aplastic anemia: a systematic review and meta-analysis of randomized controlled trials

OBJECTIVE

This article conducts a systematic review of eltrombopag combined with immunosuppressive therapy for the treatment of aplastic anemia (AA), to demonstrate the effectiveness and safety of eltrombopag.

METHODS

PubMed, Cochrane Library, Embase, OVID, Web of Science, China National Knowledge Infrastructure, and Wanfang databases were searched. Studies that met the inclusion criteria were collected, ranging from the establishment of the database to August 2023. Two reviewers performed meta-analyses using the Cochrane systematic review method and RevMan 5.3 software.

RESULTS

This meta-analysis enrolled 5 studies with a total of 542 AA patients, including 274 in the experimental group and 268 in the control group. Meta-analyses were performed for efficacy and adverse reactions. The endpoint of effects included 6-month complete response (CR), 6-month partial response (PR), and 6-month overall response (OR). Eltrombopag combined with immunotherapy showed significant improvements in 6-month CR (OR: 2.20; 95% CI;1.54-3.12; P < 0.0001) and 6-month OR (OR = 3.66, 95% CI 2.39-5.61, P < 0.001)compared to immunosuppressive therapy for AA patients. In terms of safety, eltrombopag combined with immunosuppressive therapy showed significantly increased pigment deposition and abnormal liver function compared to immunosuppressive therapy alone.

CONCLUSION

Compared to immunosuppressive therapy alone, eltrombopag combined with immunosuppressive therapy showed significant improvements in 6-month CR and 6-month OR. However, it also resulted in increased pigment deposition and abnormal liver function in terms of safety.

Modified Delphi panel consensus recommendations for management of severe aplastic anemia

ABSTRACT

Severe aplastic anemia (SAA) is a rare hematologic condition for which there is no clear management algorithm. A panel of 11 experts on adult and pediatric aplastic anemia was assembled and, using the RAND/University of California, Los Angeles modified Delphi panel method, evaluated >600 varying patient care scenarios to develop clinical recommendations for the initial and subsequent management of patients of all ages with SAA. Here, we present the panel's recommendations to rule out inherited bone marrow failure syndromes, on supportive care before and during first-line therapy, and on first-line (initial management) and second-line (subsequent management) therapy of acquired SAA, focusing on when transplant vs medical therapy is most appropriate. These recommendations represent the consensus of 11 experts informed by published literature and experience. They are intended only as general guidance for experienced clinicians who treat patients with SAA and are in no way intended to supersede individual physician and patient decision making. Current and future research should validate this consensus using clinical data. Once validated, we hope these expert panel recommendations will improve outcomes for patients with SAA.

Avatrombopag for adults with early versus chronic immune thrombocytopenia

Avatrombopag is a newer thrombopoietin receptor agonist (TPO-RA) currently approved to treat chronic ITP (duration >12 months). No studies have yet evaluated the safety and effectiveness of avatrombopag in newly diagnosed ITP (duration <3 months) or persistent ITP (duration 3-12 months), and so its use in these populations is presently off-label worldwide. We hypothesize that avatrombopag has similar safety and effectiveness irrespective of ITP disease phase. To evaluate this, we performed a multicenter observational cohort study of adults with ITP treated with avatrombopag, comparing patient outcomes by disease phase (newly diagnosed/persistent versus chronic). Seventy-five patients were included, 23 with newly diagnosed/persistent ITP (17.7 patient-years of avatrombopag treatment) and 52 with chronic ITP (65.3 patient-years of avatrombopag treatment). On avatrombopag, 91% of newly diagnosed/persistent patients versus 96% of chronic patients (p = .58) achieved a platelet response (≥50 × 109 /L) and 86% versus 81% of patients (p = .78) achieved a complete response (≥100 × 109 /L). Median platelet counts on avatrombopag were similar between the two groups (165 × 109 /L vs. 129 × 109 /L, p = .57). Response durability was high and similar in both groups. No patients in the newly diagnosed/persistent group had a major bleeding event, thromboembolic event or avatrombopag discontinuation for adverse events, compared with 4, 1, and 2, respectively, in the chronic group. Thrombocytosis (platelets ≥400 × 109 /L) incidence was similar in the two groups. No other drug-related adverse events occurred in either group. Avatrombopag was safe and effective in patients with newly diagnosed and persistent ITP, with outcomes numerically, statistically, and clinically similar to patients receiving avatrombopag for chronic ITP.

Androgen use in bone marrow failures and myeloid neoplasms: Mechanisms of action and a systematic review of clinical data

Despite recent advancements, treatment of cytopenia due to bone marrow failures (BMF) and myeloid neoplasms remains challenging. Androgens promote renewal and maturation of blood cells and may be beneficial in these forms. Here we report a systematic review of androgens use as single agent in hematologic conditions. Forty-six studies, mainly retrospective with various androgen types and doses, were included: 12 on acquired aplastic anemia (AA), 11 on inherited BMF, 17 on myelodysplastic syndromes (MDS), and 7 on myelofibrosis. Responses ranged from 50 to 70% in inherited BMF, 40-50% in acquired AA and MDS, while very limited evidence emerged for myelofibrosis. In acquired AA, response was associated with presence of non-severe disease; in MDS androgens were more effective on thrombocytopenia or mild to moderate anemia, whilst limited benefit was observed for transfusion dependent anemia. Toxicity profile mainly consisted of virilization and liver enzyme elevation, whilst the risk of leukemic evolution remains controversial.