Galician Experience with Avatrombopag: Galician Thrombosis and Hemostasis Group

Abstract

Avatrombopag, an orally administered 2nd-generation thrombopoietin receptor agonist (TPO-RA), in Spain is indicated for the treatment of primary chronic (>12 months) immune thrombocytopenia (ITP) in adults with inadecuate response or intolerance to other therapies, and has been the first agonist approved for adults with chronic liver disease (CLD) scheduled for surgery. It presents some advantages in relation to the present TPO-RA that make it a very attractive drug such as oral administration, non-interference of divalent cations, no need to monitor liver function or rapidity of response. To assess the effectiveness of Avatrombopag in patients with chronic ITP in real life, we carried out a retrospective observational study in which patients with chronic ITP and patients with secondary thrombocytopenia were included. Data are shown as percentage, median, interquartile range (IQR), and mean ± standard deviation (SD), as appropriate. Twenty-four patients were included (mean age of 60.04 years (SD 20.38), 58.33% female). The median follow-up was 135 days (IQR 96-180). 83.33% of patients had primary ITP and in 37.5% Avatrombopag was used in second-line. The rest of the patients (62.5%) had received at least two therapies previously, a median of 3 (IQR 2-4). 37.5% was in response under other agonist when started Avatrombopag. Twenty-three patients (95.83%) started Avatrombopag at 140 mg/week, one patient at a dose of 280 mg/week. 95.83% of patients reached or maintained response (>30,000 platelets/m3) with a median number of days to reach it of 7 (IQR 6-14). At the last visit, they presented a median platelet response of 102,000/mm3 (IQR 62,000 - 147,000) and marked weekly dose variability. One patient had previously received 12 lines of treatment and only one was primary refractory. Although drug tolerance was excellent, serious adverse effects include one patient with grade 2 medullary fibrosis and one pulmonary thromboembolism . Although the sample is small and the follow-up short due to the recent approval of the drug in Spain, Avatrombopag offers an effective alternative as a TPO-RA agonist for patients on second-line treatment, as well as for subsequent lines in case of inadecuate response or intolerance to other agonists.