Key Points The incidence of IFIs during VEN-HMA therapy is low, and the used antifungal prophylaxis approach did not influence the risk of IFIs. The risk of IFIs is higher in nonresponders and those who were treated in the r/r AML setting.

Background : The safety and efficacy of the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) emergency-use authorized (EUA) vaccines has been confirmed in general population. However, there is no data on its safety/tolerability or efficacy in recipients of allogeneic hematopoietic stem cell transplant (HCT). Objectives : We performed this study to identify the incidence of adverse events following SARS-CoV2 EUA vaccines and the incidence of new onset GVHD or worsening of existing GVHD after EUA vaccine administration and the incidence SAR-CoV2 positivity in vaccinated HCT patients. Study Design : We retrospectively reviewed 113 HCT patients who received at least one dose of EUA vaccine to describe the safety/tolerability, any impact on graft-versus-host disease (GVHD), and incidence of SARS-CoV2 PCR positivity after vaccination. Patients received either Pfizer (BNT162b2) or Moderna (mRNA-1273) vaccines. Patients were included if they were 18 years or older and received at least one dose of vaccine in the post HCT setting. Results : Most patients presented with myalgias/arthralgias (first dose 7.7%, second dose 14.6%), fatigue (first dose 15.4%, second dose 29.2%), and injection site pain (first dose 40.4%, second dose 43.8%). Other side effects experienced by patients included: nausea, vomiting, diarrhea, headache, injection-site rash and swelling. Liver function abnormalities occurred in 18.6% of patients. The incidence of neutropenia, thrombocytopenia, and lymphopenia occurred at 13.3%, 11.5%, and 8.8% respectively. Forty percent of patients who had active chronic GVHD at the time of vaccination where worsening chronic GVHD occurred in 3.5% of patients. New chronic GVHD developed in 9.7% of patients after vaccination. Conclusion : In conclusion, the SARS-CoV2 EUA vaccines were well-tolerated in allogeneic HCT recipients.

FMS‐like tyrosine kinase 3 (FLT3) mutations are prevalent in acute myeloid leukemia (AML), and their presence confers adverse risk. FLT3‐mutated (FLT3m) AML is a challenging leukemia to manage, particularly in older and unfit patients as well as patients with relapsed/refractory (r/r) disease. We retrospectively analyzed the outcomes of 50 FLT3m AML patients (17 treatment‐naïve, 33 r/r) treated with venetoclax (VEN) and hypomethylating agents (HMA). The overall CR/CRi rate with VEN‐HMA was 60% (94% in treatment‐naïve AML and 42% in r/r AML). Early (60‐days) treatment related mortality was 2%. The r/r AML setting was an independent predictor of lower complete response (OR: 0.08; 95%CI: 0.00‐0.60, P = .03). Cytogenetics‐molecular risk, concurrent mutations, the type of FLT3 mutation (ITD vs TKD), the ITD allelic ratio, the type of HMA, age, prior exposure to HMA and receipt of prior allogeneic transplant did not independently impact response or leukemia‐free survival (LFS). Concurrent IDH mutations were associated with lower CR/CRi (P = .01), while ASXL1 or TET2 mutations showed a non‐significant association toward higher CR/CRi (P = .07, for both). However, none of the concurrent mutations were an independent predictor for response when adjusted to AML setting. In conclusion, VEN‐HMA is associated with encouraging efficacy in FLT3m AML among both newly diagnosed unfit and r/r patients.

Efficacy of PTCy after mismatched unrelated donor (MMUD) HCT is unknown. In this pilot clinical trial, we enrolled 38 patients with hematologic malignancies scheduled to undergo MMUD-HCT (≥6/8 HLA-matched donors) onto 1 of 2 conditioning strata: myeloablative using fludarabine and fractionated total body irradiation (n = 19) or reduced intensity with fludarabine/melphalan (n = 19). Graft source was peripheral blood stem cells (PBSCs), and GVHD prophylaxis was PTCy, tacrolimus, and mycophenolate mofetil. Patients’ median age was 53 years (range, 21-72 years). Median number of HLA mismatches was 2 (range, 1-4) of 12 loci. Twenty-three patients (61%) were considered racial (n = 12) or ethnic (n = 11) minorities. Median time to neutrophil engraftment was 16 days (range, 13-35 days). With a median follow-up of 18.3 months (range, 4.3-25.0 months) for surviving patients, 1-year overall survival (OS) and GVHD-free/relapse-free survival (GRFS) were 87% (95% confidence interval [CI]: 71-94) and 68% (95% CI: 51-81), respectively. Cumulative incidence of nonrelapse mortality at 100 days and 1 year were 0% and 11% (95% CI: 4-27), respectively, whereas relapse/progression was 11% (95% CI: 4-27). Cumulative incidence of 100-day acute GVHD grades 2-4 and 3-4 and 1-year chronic GVHD were 50% (95% CI: 36-69), 18% (95% CI: 9-36), and 48% (95% CI: 34-68), respectively. The rate of moderate/severe chronic GVHD was 3% in the entire cohort. We showed highly promising OS/GRFS rates with an acceptable risk profile after PBSC-MMUD-HCT with PTCy. This trial was registered at www.clinicaltrials.gov as #NCT03128359.

The availability and use of blinatumomab symbolizes a paradigm shift in the management of B-cell acute lymphoblastic leukemia (ALL). We conducted a retrospective multicenter cohort analysis of 239 ALL patients (227 relapsed refractory [RR], n = 227; minimal residual disease [MRD], n = 12) who received blinatumomab outside of clinical trials to evaluate safety and efficacy in the “real-world” setting. The median age of patients at blinatumomab initiation was 48 years (range, 18-85). Sixty-one (26%) patients had ≥3 prior therapies and 46 (19%) had allogeneic hematopoietic cell transplantation before blinatumomab. The response rate (complete remission/complete remission with incomplete count recovery) in patients with RR disease was 65% (47% MRD−). Among 12 patients who received blinatumomab for MRD, 9 (75%) patients achieved MRD negativity. In patients with RR disease, median relapse-free survival and overall survival (OS) after blinatumomab was 32 months and 12.7 months, respectively. Among patients who received blinatumomab for MRD, median relapse-free survival was not reached (54% MRD− at 2 years) and OS was 34.7 months. Grade ≥3 cytokine release syndrome, neurotoxicity, and hepatotoxicity were observed in 3%, 7%, and 10% of patients, respectively. Among patients who achieved complete remission/complete remission with incomplete count recovery, consolidation therapy with allogeneic hematopoietic cell transplantation retained favorable prognostic significance for OS (hazard ratio, 0.54; 95% confidence interval, 0.30-0.97; P = .04). In this largest “real-world” experience published to date, blinatumomab demonstrated responses comparable to those reported in clinical trials. The optimal sequencing of newer therapies in ALL requires further study.