ABSTRACT
Background: The emergence of the COVID-19 pandemic saw an increased use of cryopreserved (cryo) peripheral blood (PB) grafts for allogeneic hematopoietic stem cell transplantation (HSCT). Outcomes of patients receiving either fresh or cryo grafts have yielded heterogeneous results. Herein, we retrospectively compared the outcomes of patients receiving fresh and cryo grafts at a single center.(Table Presented)Methods: Between 2019 and 2021, we reviewed data from 380 patients;167 (44%) received a fresh, and 213 (56%) received a cryo graft. Patients underwent myeloablative or nonmyeloablative HSCT from either matched or mismatched, related or unrelated donors. Cell doses were determined by number of donor cells collected and recipient weight at infusion. Engraftment, disease risk (DR) and acute GVHD were classified based on established criteria. Donor chimerism was collected at approximately day 28 and day 80 after HSCT. Unadjusted and adjusted estimates of overall survival (OS), relapse, and non-relapse mortality (NRM) as a function of time were obtained. The adjusted odds (grades III-IV acute GVHD) and the adjusted cause-specific hazard of failure (all other outcomes) were compared between the 2 groups. with the use of logistic (Figure Presented) or Cox regression, respectively. These models were adjusted for various factors known to be associated with each outcome. Result(s): The characteristics of patients between the 2 groups are shown in Table 1. There was a higher proportion of patients with high/very high DR in the fresh graft group (Table 1). Median time to neutrophil engraftment was 17 and 18 days in fresh vs. cryo, respectively. The adjusted hazard ratio (HR) of neutrophil engraftment (fresh vs. cryo) was 1.07 (95% CI, 0.86-1.34, p=0.54). Median time to platelet engraftment was 13 and 15 days, respectively, and the adjusted HR of platelet engraftment was 1.32 (1.06-1.65, p=0.01). Day 28 chimerism data were available for 272 patients (113 fresh and 159 cryo). At day 28, donor CD3 chimerism was below 50% in 5 out of 113 (4.4%) and 17 out of 159 (10.7%) patients receiving fresh and cryo grafts, respectively (p= 0.06). At day 80, 3 out of 121 (2.5%) patients in the fresh group and 4 out of 165 (2.4%) in the cryo group had CD3 chimerism below 50%. The adjusted HRs (fresh vs. cryo) for death and NRM were 0.83 (0.54-1.28, p=0.40) and 0.71 (0.38-1.33, p=0.29), respectively (Figures 1 and 2). The adjusted HR for relapse was 0.65 (0.42-0.99, p=0.05) (Figure 3). The adjusted odds ratio (fresh vs. cryo) for grades III-IV GVHD was 1.65 (0.94-2.9, p=0.07). Conclusion(s): In this single-center retrospective study we observed numerically better outcomes with fresh grafts relative to cryo grafts for all examined endpoints with the exception of grades III-IV aGVHD, although none of the differences were definitive with the possible exception of relapse and platelet engraftment. Further studies are needed to confirm our observations.Copyright © 2023 American Society for Transplantation and Cellular Therapy
ABSTRACT
Background: Standard chemoimmunotherapy for first-line treatment of follicular lymphoma (FL) achieves high rates of disease control but is not curative and carries significant toxicities including prolonged immunosuppression that may attenuate response to vaccinations (Marcus et al., NEJM 2017). While proteasome inhibitors have shown modest activity in R/R FL (Goy et al., JCO 2005), limited data address their use frontline. The comparatively favorable toxicity profile and convenient oral dosing of ixazomib support its investigation in this space. Methods: We evaluated ixazomib and its combination with short-course rituximab (R) for FL as part of an open-label, phase II investigator-initiated trial at the University of Washington / Fred Hutch Cancer Research Center / Seattle Cancer Care Alliance (NCT 02339922). Eligibility included an indication for treatment per NCCN guidelines and no prior standard systemic FL therapy. Ixazomib was administered at 4 mg orally once a week until disease progression or unmanageable toxicity. One course of R at 4 weekly doses of 375 mg/m2 was added during the 7th 28-day cycle, after an initial 6-cycle “window” on ixazomib alone. Available pretreatment formalin-fixed, paraffin-embedded tissue biopsies were subjected to RNA extraction by standard methods and gene expression profiling (GEP) using the NanoString™ PanCancer IO 360 panel to query pathways in proteasomal degradation and lymphomagenesis. Standard GEP quality control and data processing were performed with the ROSALIND® platform. Patients vaccinated per standard of care for COVID-19 while actively receiving ixazomib and ≥ 6 mo after completing R were evaluated for serologic response ≥ 2 weeks after the final dose of vaccine using the Roche Elecsys® Anti-SARS-CoV-2 S assay against the spike protein receptor binding domain. Results: Twenty pts began therapy between Feb 2017 and January 2020. All had grade I/II FL and FLIPI score was 2 in 20% and ≥ 3 in 20%;FLIPI score in all other patients was 0 or 1. Eleven (55%) pts met GELF criteria for high tumor burden disease including 6 (30%) pts with a tumor mass ≥ 7 cm. Median follow-up was 32.1 months (range 5.7 - 51.6). The ORR by Lugano criteria was 35% (CR 5%) during the ixazomib window and 65% (CR 45%) overall. At data cut (June 15, 2021) all patients were alive and 8 (40%) remained progression-free on treatment (Figure 1). By KM estimate, median PFS was 25.8 mo and median DOR was not reached at a median follow-up of 29.6 mo. As expected, high-grade treatment-related AEs were infrequent for ixazomib and R, including grade ≥ 3 events in 3 unique pts (15%;diarrhea, transaminitis, and cytopenias). No grade ≥ 4 or serious AEs were observed. Toxicities led to study-directed drug interruptions in 4 (20%) pts and dose reduction to ixazomib 3 mg weekly in 2 pts (10%). Higher ORR to ixazomib monotherapy was associated with FLIPI > 1 (p = 0.04) and, by exploratory GEP, downregulation of components of proteasomal degradation and upregulation of NF-KB and chemokine signaling (Figure 2). High tumor burden by GELF (p = 0.89) and tumor mass ≥ 7 cm (p = 0.26) were not associated with ORR to ixazomib. All 6 of 6 patients evaluated to date for response to COVID-19 vaccination, administered at a median of 32.5 mo (range 7.0 - 41.0) after last dose of R, achieved positive anti-spike protein antibodies (median anti-S 163.8 AU/mL, range 13.3 - 1139);none was diagnosed with COVID-19. Conclusions: The simple outpatient regimen of weekly oral ixazomib and the addition of 4 doses of R shows significant long-term activity with low toxicity in untreated FL. Extended DOR is achievable especially in patients who respond to ixazomib monotherapy. Ixazomib efficacy was associated with higher FLIPI scores and gene expression signatures implicated in proteasomal degradation and B-cell signaling pathways. Ixazomib deserves further investigation as a biomarker-driven therapeutic in untreated FL, particularly as an option that prioritizes outpatient management and serologic responsiveness to im unization. (Figure Presented).