ELTROMBOPAG (EPAG) INDUCES HEMATOLOGIC RESPONSES FOR PATIENTS WITH POST-ALLOGENIC HEMATOPOIETIC STEM CELL TRANSPLANT POOR GRAFT FUNCTION (POST-ALLO HSCT PGF): RESULTS OF THE ELTION STUDY IN SPAIN

ABSTRACT

Background: Persistent cytopenia due to poor graft function (PGF) is a life-threatening complication in patients undergoing allogeneic HSCT (allo-HSCT). Several therapeutic approaches have been tested in this subset of patients with poor clinical results. Aims: The objective of this multicenter open-label interventional prospective phase II Novartis study (ELTION, ClinicalTrials.gov id NCT03718533), was to analyze efficacy and safety of EPAG in patients with post-allo-HSCT poor graft function. Methods: Adult patients diagnosed with PGF (defined as severe cytopenia after day +30 post-transplant, with two or more of the following platelets <20000/μL-mandatory-, ANC <1000/μL, hemoglobin< 10 g/dL), and full donor chimerism, were eligible to enter the trial. Study treatment consisted of EPAG. at 150 mg/day administered up to 36 weeks;dose adjustments were contemplated as per protocol on an individual basis. The primary efficacy endpoint was the overall hematologic response (partial and complete), as determined by platelet, hemoglobin and neutrophil counts by 16 weeks after the initiation of EPAG. Results: Although the aim of the study was to include 33 patients, recruitment stopped prematurely due to the difficulties for hospital visits posed during COVID-19 pandemic, and eventually only 10 patients were included. The decision for this premature termination is not related to any safety concern related to the drug. Patient characteristics are shown in the table 1 attached below. At EPAG. initiation, all 10 patients showed thrombocytopenia (<20000/μcL), 5 presented with anemia (Hgb <10 g/dL), and 4 had neutropenia (ANC <1000/μcL). Four patients discontinued EPAG before week 12 due to disease progression/relapse (2 patients), protocol deviation (1 patient), and CMV infection (1 patient). In none of the cases, the event was related to study drug. At week 16, 4 patients (4/10, 40%) and at week 24, 5 patients, showed improvement in at least one of the 3 hematologic cell lines (partial response), respectively. Counts pre-and post-EPAG and global response in patients who stayed on treatment > 12 weeks are displayed below Image Summary/Conclusion: In our experience, EPAG worked well in subjects with PGF, an otherwise life-threatening condition for patients, and its use at 150 mg/day is safe and well tolerated in this setting. Our data suggest that eltrombopag might improve hematologic cell counts in patients with PGF, especially in those patients who remained on treatment at week 24, however further research is warranted to extend its applicability for larger cohorts.