Background: Evidence that a venetoclax (VEN)-combined regimen is effective in relapsed/refractory acute myeloid leukemia (R/R AML) is emerging. However, it is unknown how VEN-combined low intensity treatment compares to intensive chemotherapy (IC) in medically fit patients with R/R AML. Methods: We compared AML patients who received IC ( n = 89) to those who received a VEN in combination with hypomethylating agents or low dose cytarabine (VEN combination) ( n = 54) as their first- or second-line salvage after failing anthracycline-containing intensive chemotherapy. Results: The median age was 49 years, and significantly more patients in the VEN combination group were in their second salvage and had received prior stem cell transplantation (SCT). Overall response rates including CR, CRi, and MLFS were comparable (44.0% for IC vs. 59.3% for VEN combination, p = 0.081), but VEN combination group compared to IC group tended to show lower treatment related mortality. The rate of bridging to SCT was the same (68.5%), but the percentage of SCT at blast clearance was significantly higher in the VEN-combined group (62.3% vs. 86.5%, p = 0.010). After median follow-up periods of 22.5 (IC) and 11.3 months (VEN combination), the median overall survival was 8.9 (95% CI, 5.4-12.4) and 12.4 months (95% CI, 9.5-15.2) ( p = 0.724), respectively. Conclusion: VEN combination provides a comparable anti-leukemic response and survival to salvage IC, and provide a bridge to SCT with better disease control in medically-fit patients with R/R AML.

Introduction: Donor lymphocyte infusion (DLI) is one of the effective options for post-transplant disease control of myelodysplastic syndrome (MDS). Its success or failure depends on the induction of antitumor immune reactions, durability of clinical responses, and severity of unwanted toxicities mainly from graft- versus-host disease (GVHD). Methods: By analyzing 61 patients receiving DLI for post-transplant MDS relapse, we assessed treatment outcomes and affecting factors, especially focusing on the level of relapse (hematological, molecular, and imminent relapse). Results: The response rate (42.1%, 36.4%, 72.7%), and overall survival (OS) at 2 years (27.8%, 45.5%, 70.1%) were different for each relapse level with imminent relapse group showing the most promising results. For OS, response to DLI or pre-DLI chemotherapy, and time to relapse were independent prognostic factors. Meanwhile, post-DLI GVHD and time to relapse were independently predictive for DLI response; post-DLI GVHD was predictive for DLI response, but not for OS, suggesting a potential detrimental impact of GVHD on survival. The incidence of GVHD and GVHD-related deaths were 37.7% and 10.0%, respectively, and CD3+ cell doses triggering GVHD tended to be lower in cases with haploidentical donor or imminent relapse. Conclusion: Despite being limited by small number of cases and its retrospective nature, this study again demonstrated the therapeutic effects of DLI in relapsed MDS, and that earlier detection and intervention at lower level relapse might possibly be associated with better results. Furthermore, we propose that tailored cell dosing schedule based on relapse level and donor source may be helpful in minimizing fatal GVHD.

Background Low‐dose azacitidine (AZA) regimens, primarily 5‐day AZA, have been used in lower risk myelodysplastic syndrome (LrMDS) but they have yet to be directly compared to the standard 7‐day, uninterrupted dosing schedule. Method In this phase 2, multicenter, randomized trial, 55 patients with adult LrMDS (low and intermediate‐1 risk by international prognostic scoring system [IPSS]) were randomly assigned and received either 5‐day (n = 26) or 7‐day (n = 29) AZA between March 2012 and August 2020. The trial was stopped prematurely because of the slow accrual of patients. The primary end point was the overall response rate (ORR) of the 5‐day AZA as compared to that of the 7‐day regimen. Results Median patient age was 59 years, and IPSS intermediate‐1 risk comprised the majority (81.8%). The median number of cycles in both arms was six. In the ITT subset (n = 53), in each of the 5‐day and 7‐day arms, the ORR of 48.0% and 39.3%, hematologic improvement of 44.0% and 39.3%, and RBC transfusion independence of 35.3% and 40.0% were observed respectively, and none of these findings were significantly different between the two arms. A cytogenetic response rate was significantly higher in the 7‐day arm (8.3% and 53.8%, p = .027). Survival and adverse events were similar between the groups, although gastrointestinal toxicities, grade ≥3 thrombocytopenia, and febrile neutropenia were less frequent in the 5‐day arm. Conclusion The 5‐day AZA in LrMDS showed comparable efficacy to a 7‐day regimen in terms of similar overall response and other outcomes, despite significantly higher rates of cytogenetic responses in the 7‐day regimen. Lay summary Azacitidine (75 mg/m2/day for 7 consecutive days per 28‐day cycle) has shown survival benefit in patients with higher risk myelodysplastic syndrome (MDS). Although the use of azacitidine is less‐well studied for lower risk MDS, it is generally accepted as a feasible option for lower risk MDS (LrMDS).