A phase I trial of selinexor plus FLAG-Ida for the treatment of refractory/relapsed adult acute myeloid leukemia patients.

Prognosis for relapsed or refractory (R/R) acute myeloid leukemia (AML) despite salvage therapy is dismal. This phase I dose-escalation trial assessed the safety and preliminary clinical activity of selinexor, an oral exportin-1 (XPO1) inhibitor, in combination with FLAG-Ida in younger R/R AML patients. The aim was to find the recommended phase 2 dose (RP2D) and maximum tolerated dose (MTD). Fourteen patients were included, and selinexor dosage was 60 mg (3 patients), 80 mg (3 patients), and 100 mg (7 patients) weekly. No dose-limiting toxicities were reported. Grade ≥3 non-hematologic adverse events (AEs) occurred in 78.6% of patients. Two patients were non MTD evaluable due to early death, and overall, 3 out of 14 patients (21.4%) had fatal AEs. Five out of 12 (42%) response and MTD evaluable patients achieved a complete remission (CR; n=4) or CR with incomplete hematologic recovery (CRi, n=1), and 4 patients (33%) subsequently underwent allogeneic transplantation. The median overall survival (OS) and event-free survival (EFS) were 6.0 (range 0.9-19.3) and 1.1 months (range 0.7-19.3), respectively. Using selinexor 100 mg/weekly, CR/CRi rate of 66.7%, OS 13.6 months (range, 1.6-19.3), and EFS 10.6 months (range, 0.9-19.3). At last follow-up, 3 patients were alive. Selinexor 100 mg/weekly with FLAG-Ida combination in R/R AML showed acceptable tolerability and efficacy, establishing the RP2D of this regimen in future clinical trials. ClinicalTrials.gov Identifier: NCT03661515.

A prognostic model for survival after salvage treatment with FLAG-Ida +/- gemtuzumab-ozogamicine in adult patients with refractory/relapsed acute myeloid leukaemia.

The combination of fludarabine, cytarabine, idarubicin, and granulocyte colony-stimulating factor (FLAG-Ida) is widely used in relapsed/refractory acute myeloid leukaemia (AML). We retrospectively analysed the results of 259 adult AML patients treated as first salvage with FLAG-Ida or FLAG-Ida plus Gentuzumab-Ozogamicin (FLAGO-Ida) of the Programa Español de Tratamientos en Hematología (PETHEMA) database, developing a prognostic score system of survival in this setting (SALFLAGE score). Overall, 221 patients received FLAG-Ida and 38 FLAGO-Ida; 92 were older than 60 years. The complete remission (CR)/CR with incomplete blood count recovery (CRi) rate was 51%, with 9% of induction deaths. Three covariates were associated with lower CR/CRi: high-risk cytogenetics and t(8;21) at diagnosis, no previous allogeneic stem cell transplantation (allo-SCT) and relapse-free interval <1 year. Allo-SCT was performed in second CR in 60 patients (23%). The median overall survival (OS) of the entire cohort was 0·7 years, with 22% OS at 5-years. Four independent variables were used to construct the score: cytogenetics, FLT3-internal tandem duplication, length of relapse-free interval and previous allo-SCT. Using this stratification system, three groups were defined: favourable (26% of patients), intermediate (29%) and poor-risk (45%), with an expected 5-year OS of 52%, 26% and 7%, respectively. The SALFLAGE score discriminated a subset of patients with an acceptable long-term outcome using FLAG-Ida/FLAGO-Ida regimen. The results of this retrospective analysis should be validated in independent external cohorts.