Cytomegalovirus Triplex vaccine in pediatric hematopoietic stem cell transplant patients at high risk for cytomegalovirus complications: evaluation of vaccine safety, immunogenicity and impact on viremia requiring antivirals.

Not available.

A phase II randomized, placebo-controlled, multicenter trial to evaluate the efficacy of cytomegalovirus PepVax vaccine in preventing cytomegalovirus reactivation and disease after allogeneic hematopoietic stem cell transplant.

Not available.

Lack of RBC transfusion independence by Day 30 following allogeneic hematopoietic stem cell transplant strongly predicts inferior survival and high non-relapse mortality in acute myeloid leukemia patients.

BACKGROUND: Studies have suggested that acute myeloid leukemia (AML) patients with incomplete hematologic recovery undergoing allogeneic stem cell transplantation (allo-HSCT) had inferior overall survival (OS). STUDY DESIGN AND METHODS: This single-center, retrospective study of AML patients evaluated the relationship between red blood cell (RBC) and platelet (PLT) transfusion requirements during the first 30 days and long-term outcomes after allo-HSCT through multivariate analyses. RESULTS: A total of 692 AML patients received peripheral blood stem cells (89.2%), marrow (5.6%), or umbilical cord (5.2%) from matched related (37.4%), unrelated (49.1%), or haploidentical (8.2%) donors in 2011-2017. Transfusion requirements during the first 30 days for RBC (89.5% transfused, median 3, range 1-18 units) or PLT (98.2% transfused, median 6, range 1-144 units) were variable. By Day 30, 56.7% (95% confidence interval [CI]: 52.8-60.3%) and 86.1% (95% CI: 83.2-88.5%) had achieved RBC and PLT transfusion independence, respectively. Median follow-up among survivors (n = 307) was 7.1 years (range: 2.7-11.8). Lack of RBC transfusion independence by Day 30 was strongly and independently associated with worse 5-year OS (39.2% vs. 59.6%, adjusted hazard ratio [HR] 1.83, 95% CI: 1.49-2.25), leukemia-free survival (35.8% vs. 55.5%, HR = 1.75, 95% CI: 1.43-2.14), and NRM (29.7% vs. 13.7%, HR = 2.05, 95% CI: 1.45-2.89) (p < .001). There was no difference in relapse rates among patients who achieved or did not achieve RBC (p = .34) or PLT (p = .64) transfusion independence. CONCLUSION: Prolonged RBC dependence predicted worse survival and NRM rates, but not increased relapse. Posttransplant surveillance of such patients should be adjusted with more attention to non-relapse complications.

Blocking reverse electron transfer-mediated mitochondrial DNA oxidation rescues cells from PANoptosis.

PANoptosis is a new type of cell death featured with pyroptosis, apoptosis and necroptosis, and is implicated in organ injury and mortality in various inflammatory diseases, such as sepsis and hemophagocytic lymphohistiocytosis (HLH). Reverse electron transport (RET)-mediated mitochondrial reactive oxygen species (mtROS) has been shown to contribute to pyroptosis and necroptosis. In this study we investigated the roles of mtROS and RET in PANoptosis induced by TGF-ß-activated kinase 1 (TAK1) inhibitor 5Z-7-oxozeaenol (Oxo) plus lipopolysaccharide (LPS) as well as the effects of anti-RET reagents on PANoptosis. We showed that pretreatment with anti-RET reagents 1-methoxy PMS (MPMS) or dimethyl fumarate (DMF) dose-dependently inhibited PANoptosis in macrophages BMDMs and J774A.1 cells induced by Oxo/LPS treatment assayed by propidium iodide (PI) staining. The three arms of the PANoptosis signaling pathway, namely pyroptosis, apoptosis and necroptosis signaling, as well as the formation of PANoptosomes were all inhibited by MPMS or DMF. We demonstrated that Oxo/LPS treatment induced RET and mtROS in BMDMs, which were reversed by MPMS or DMF pretreatment. Interestingly, the PANoptosome was co-located with mitochondria, in which the mitochondrial DNA was oxidized. MPMS and DMF fully blocked the mtROS production and the formation of PANoptosome induced by Oxo plus LPS treatment. An HLH mouse model was established by poly(I:C)/LPS challenge. Pretreatment with DMF (50 mg·kg-1·d-1, i.g. for 3 days) or MPMS (10 mg·kg-1·d-1, i.p. for 2 days) (DMF i.g. MPMS i.p.) effectively alleviated HLH lesions accompanied by decreased hallmarks of PANoptosis in the liver and kidney. Collectively, RET and mtDNA play crucial roles in PANoptosis induction and anti-RET reagents represent a novel class of PANoptosis inhibitors by blocking oxidation of mtDNA, highlighting their potential application in treating PANoptosis-related inflammatory diseases. PANoptotic stimulation induces reverse electron transport (RET) and reactive oxygen species (ROS) in mitochondia, while 1-methoxy PMS and dimethyl fumarate can inhibit PANoptosis by suppressing RETmediated oxidation of mitochondrial DNA.

Donor T cell STAT3 deficiency enables tissue PD-L1-dependent prevention of graft-versus-host disease while preserving graft-versus-leukemia activity.

STAT3 deficiency (STAT3-/-) in donor T cells prevents graft-versus-host disease (GVHD), but the impact on graft-versus-leukemia (GVL) activity and mechanisms of GVHD prevention remains unclear. Here, using murine models of GVHD, we show that STAT3-/- donor T cells induced only mild reversible acute GVHD while preserving GVL effects against nonsusceptible acute lymphoblastic leukemia (ALL) cells in a donor T cell dose-dependent manner. GVHD prevention depended on programmed death ligand 1/programmed cell death protein 1 (PD-L1/PD-1) signaling. In GVHD target tissues, STAT3 deficiency amplified PD-L1/PD-1 inhibition of glutathione (GSH)/Myc pathways that regulate metabolic reprogramming in activated T cells, with decreased glycolytic and mitochondrial ATP production and increased mitochondrial ROS production and dysfunction, leading to tissue-specific deletion of host-reactive T cells and prevention of GVHD. Mitochondrial STAT3 deficiency alone did not reduce GSH expression or prevent GVHD. In lymphoid tissues, the lack of host-tissue PD-L1 interaction with PD-1 reduced the inhibition of the GSH/Myc pathway despite reduced GSH production caused by STAT3 deficiency and allowed donor T cell functions that mediate GVL activity. Therefore, STAT3 deficiency in donor T cells augments PD-1 signaling-mediated inhibition of GSH/Myc pathways and augments dysfunction of T cells in GVHD target tissues while sparing T cells in lymphoid tissues, leading to prevention of GVHD while preserving GVL effects.

Tocilizumab for Cytokine Release Syndrome Management After Haploidentical Hematopoietic Cell Transplantation With Post-Transplantation Cyclophosphamide-Based Graft-Versus-Host Disease Prophylaxis.

Cytokine release syndrome (CRS) is a common complication after haploidentical hematopoietic cell transplantation (HaploHCT). Severe CRS after haploHCT leads to higher risk of non-relapse mortality (NRM) and worse overall survival (OS). Tocilizumab (TOCI) is an interleukin-6 receptor inhibitor and is commonly used as first-line for CRS management after chimeric antigen receptor T cell therapy, but the impact of TOCI administration for CRS management on Haplo HCT outcomes is not known. In this single center retrospective analysis, we compared HCT outcomes in patients treated with or without TOCI for CRS management after HaploHCT with post-transplantation cyclophosphamide- (PTCy-) based graft-versus-host disease (GvHD) prophylaxis. Of the 115 patients eligible patients who underwent HaploHCT at City of Hope between 2019 to 2021 and developed CRS, we identified 11 patients who received tocilizumab for CRS management (TOCI). These patients were matched with 21 patients who developed CRS but did not receive tocilizumab (NO-TOCI) based on age at the time of HCT (≤64 years or >65 years or older), conditioning intensity (myeloablative versus reduced-intensity/nonmyeloablative), and CRS grading (1, 2, versus 3-4). Instead of 22 controls, we chose 21 patients because there was only 1 control matched with 1 TOCI treatment patient in 1 stratum. With only 11 patients in receiving tocilizumab for CRS treatment, matching with 21 patients who developed CRS but did not receive tocilizumab, we had 80% power to detect big differences (hazard ratio [HR] = 3.4 or higher) in transplantation outcomes using a 2-sided 0.05 test. The power would be reduced to about 20% to 30% if the difference was moderate (HR = 2.0) using the same test. No CRS-related deaths were recorded in either group. Median time to neutrophil engraftment was 21 days (range 16-43) in TOCI and 18 days (range 14-23) in NO-TOCI group (HR = 0.55; 95% confidence interval [CI] = 0.28-1.06, P = .08). Median time to platelet engraftment was 34 days (range 20-81) in TOCI and 28 days (range 12-94) in NO-TOCI group (HR = 0.56; 95% CI = 0.25-1.22, P = .19). Cumulative incidences of day 100 acute GvHD grades II-IV (P = .97) and grades III-IV (P = .47) were similar between the 2 groups. However, cumulative incidence of chronic GvHD at 1 year was significantly higher in patients receiving TOCI (64% versus 24%; P = .05). Rates of NRM (P = .66), relapse (P = .83), disease-free survival (P = .86), and overall survival (P = .73) were similar at 1 year after HCT between the 2 groups. Tocilizumab administration for CRS management after HaploHCT appears to be safe with no short-term adverse effect and no effect on relapse rate. However, the significantly higher cumulative incidence of chronic GvHD, negates the high efficacy of PTCy on GvHD prophylaxis in this patient population. Therefore using tocilizumab for CRS management in the HaploHCT population with PTCy maybe kept only for patients with severe CRS. The impact on such approach on long term outcome in HaploHCT with PTCy will need to be evaluated in a larger retrospective study or a prospective manner.

Theaflavin mitigates acute gouty peritonitis and septic organ injury in mice by suppressing NLRP3 inflammasome assembly.

Activation of NLR family pyrin domain-containing 3 (NLRP3) inflammasome plays important role in defending against infections, but its aberrant activation is causally linked to many inflammatory diseases, thus being a therapeutic target for these diseases. Theaflavin, one major ingredient of black tea, exhibits potent anti-inflammatory and anti-oxidative activities. In this study, we investigated the therapeutic effects of theaflavin against NLRP3 inflammasome activation in macrophages in vitro and in animal models of related diseases. We showed that theaflavin (50, 100, 200 µM) dose-dependently inhibited NLRP3 inflammasome activation in LPS-primed macrophages stimulated with ATP, nigericin or monosodium urate crystals (MSU), evidenced by reduced release of caspase-1p10 and mature interleukin-1ß (IL-1ß). Theaflavin treatment also inhibited pyroptosis as shown by decreased generation of N-terminal fragment of gasdermin D (GSDMD-NT) and propidium iodide incorporation. Consistent with these, theaflavin treatment suppressed ASC speck formation and oligomerization in macrophages stimulated with ATP or nigericin, suggesting reduced inflammasome assembly. We revealed that theaflavin-induced inhibition on NLRP3 inflammasome assembly and pyroptosis resulted from ameliorated mitochondrial dysfunction and reduced mitochondrial ROS production, thereby suppressing interaction between NLRP3 and NEK7 downstream of ROS. Moreover, we showed that oral administration of theaflavin significantly attenuated MSU-induced mouse peritonitis and improved the survival of mice with bacterial sepsis. Consistently, theaflavin administration significantly reduced serum levels of inflammatory cytokines including IL-1ß and attenuated liver inflammation and renal injury of mice with sepsis, concomitant with reduced generation of caspase-1p10 and GSDMD-NT in the liver and kidney. Together, we demonstrate that theaflavin suppresses NLRP3 inflammasome activation and pyroptosis by protecting mitochondrial function, thus mitigating acute gouty peritonitis and bacterial sepsis in mice, highlighting a potential application in treating NLRP3 inflammasome-related diseases.

High response rates and transition to transplant after novel targeted and cellular therapies in adults with relapsed/refractory acute lymphoblastic leukemia with Philadelphia-like fusions.

Philadelphia (Ph)-like acute lymphoblastic leukemia (ALL) is associated with a poor response to standard chemotherapy. However, outcomes with novel antibody and cellular therapies in relapsed/refractory (r/r) Ph-like ALL are largely unknown. We conducted a single-center retrospective analysis of adult patients (n = 96) with r/r B-ALL and fusions associated with Ph-like who received novel salvage therapies. Patients were treated with 149 individual novel regimens (blinatumomab = 83, inotuzumab ozogamicin [InO] = 36, and CD19CAR T cells = 30). The median age at first novel salvage therapy was 36 years (range; 18-71). Ph-like fusions were IGH::CRLF2 (n = 48), P2RY8::CRLF2 (n = 26), JAK2 (n = 9), ABL-class (n = 8), EPOR::IGH (n = 4) and ETV6::NTRK2 (n = 1). CD19CAR T cells were administered later in the course of therapy compared to blinatumomab and InO (p < .001) and more frequently in recipients who relapsed after allogeneic hematopoietic cell transplantation (alloHCT) (p = .002). Blinatumomab was administered at an older age compared to InO and CAR T-cells (p = .004). The complete remission (CR)/CR with incomplete hematologic recovery (CRi) rates were 63%, 72%, and 90% following blinatumomab, InO and CD19CAR, respectively, among which 50%, 50%, and 44% of responders underwent consolidation with alloHCT, respectively. In multivariable analysis, the type of novel therapy (p = .044) and pretreatment marrow blasts (p = .006) predicted the CR/CRi rate, while the Ph-like fusion subtype (p = .016), pretreatment marrow blasts (p = .022) and post-response consolidation with alloHCT (p < .001) influenced event-free survival. In conclusion, novel therapies are effective in inducing high remission rates in patients with r/r Ph-like ALL and successfully transitioning the responders to alloHCT.

Functional SARS-CoV-2-specific T cells of donor origin in allogeneic stem cell transplant recipients of a T-cell-replete infusion: A prospective observational study.

In the current post-pandemic era, recipients of an allogeneic hematopoietic stem cell transplant (HCT) deserve special attention. In these vulnerable patients, vaccine effectiveness is reduced by post-transplant immune-suppressive therapy; consequently, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) disease (COVID-19) is often associated with elevated morbidity and mortality. Characterizing SARS-CoV-2 adaptive immunity transfer from immune donors to HCT recipients in the context of immunosuppression will help identify optimal timing and vaccination strategies that can provide adequate protection to HCT recipients against infection with evolving SARS-CoV-2 variants. We performed a prospective observational study (NCT04666025 at ClinicalTrials.gov) to longitudinally monitor the transfer of SARS-CoV-2-specific antiviral immunity from HCT donors, who were either vaccinated or had a history of COVID-19, to their recipients via T-cell replete graft. Levels, function, and quality of SARS-CoV-2-specific immune responses were longitudinally analyzed up to 6 months post-HCT in 14 matched unrelated donor/recipients and four haploidentical donor/recipient pairs. A markedly skewed donor-derived SARS-CoV-2 CD4 T-cell response was measurable in 15 (83%) recipients. It showed a polarized Th1 functional profile, with the prevalence of central memory phenotype subsets. SARS-CoV-2-specific IFN-γ was detectable throughout the observation period, including early post-transplant (day +30). Functionally experienced SARS-CoV-2 Th1-type T cells promptly expanded in two recipients at the time of post-HCT vaccination and in two others who were infected and survived post-transplant COVID-19 infection. Our data suggest that donor-derived SARS-CoV-2 T-cell responses are functional in immunosuppressed recipients and may play a critical role in post-HCT vaccine response and protection from the fatal disease. Clinical trial registration: clinicaltrials.gov, identifier NCT04666025.

Isolation of the Main Pathogens Causing Postharvest Disease in Fresh Angelica sinensis during Different Storage Stages and Impacts of Ozone Treatment on Disease Development and Mycotoxin Production.

Angelica sinensis, a Chinese herbal medicine, is susceptible to molds during storage, reducing its quality, and even generating mycotoxins with toxic effects on human health. Fresh A. sinensis was harvested from Min County of Gansu Province in China and kept at room temperature. Naturally occurring symptoms were observed during different storage stages. Molds were isolated and identified from the diseased A. sinensis using morphological and molecular biology methods. The impact of ozone treatment on postharvest disease development and mycotoxin production was investigated. The results indicated that A. sinensis decay began on day 7 of storage and progressed thereafter. Nine mold species were isolated and characterized: day 7, two Mucormycetes; day 14, Clonostachys rosea; day 21, two Penicillium species and Aspergillus versicolor; day 28, Alternaria alternata and Trichoderma atroviride; and day 49, Fusarium solani. Ozone treatment markedly inhibited the development of postharvest disease and the mycotoxin production (such as, patulin, 15-acetyl-deoxynivalenol, and sterigmatocystin) in the rotten tissue of A. sinensis inoculated with the nine isolates.

Hematopoietic stem cell donor vaccination with cytomegalovirus triplex augments frequencies of functional and durable cytomegalovirus-specific T cells in the recipient: A novel strategy to limit antiviral prophylaxis.

To enhance protective cytomegalovirus (CMV)-specific T cells in immunosuppressed recipients of an allogeneic hematopoietic cell transplant (HCT), we evaluated post-HCT impact of vaccinating healthy HCT donors with Triplex. Triplex is a viral vectored recombinant vaccine expressing three immunodominant CMV antigens. The vector is modified vaccinia Ankara (MVA), an attenuated, non-replicating poxvirus derived from the vaccinia virus strain Ankara. It demonstrated tolerability and immunogenicity in healthy adults and HCT recipients, in whom it also reduced CMV reactivation. Here, we report feasibility, safety, and immunological outcomes of a pilot phase 1 trial (NCT03560752 at ClinicalTrials.gov) including 17 CMV-seropositive recipients who received an HCT from a matched related donor (MRD) vaccinated with 5.1 × 108 pfu/ml of Triplex before cell harvest (median 15, range 11-28 days). Donor and recipient pairs who committed to participation in the trial resulted in exceptional adherence to the protocol. Triplex was well-tolerated with limited adverse events in donors and recipients, who all engrafted with full donor chimerism. On day 28 post-HCT, levels of functional vaccinia- and CMV-specific CD137+ CD8+ T cells were significantly higher (p < .0001 and p = .0174, respectively) in recipients of Triplex vaccinated MRD than unvaccinated MRD (control cohort). Predominantly, central and effector memory CMV-specific T-cell responses continued to steadily expand through 1-year follow-up. CMV viremia requiring antivirals developed in three recipients (18%). In summary, this novel approach represents a promising strategy applicable to different HCT settings for limiting the use of antiviral prophylaxis, which can impair and delay CMV-specific immunity, leading to CMV reactivation requiring treatment.

Long-term follow up of patients with hematological malignancies treated with total body irradiation using intensity modulated radiation therapy.

Background: With the advent of modern radiation treatment technologies such as intensity modulated radiation therapy (IMRT), there has been increasing interest in its use for total body irradiation (TBI) conditioning regimens for hematopoietic cell transplantation (HCT) to achieve lower doses to critical organs such as the lungs and kidneys. Although this has been reported on in early studies, long-term safety and efficacy data is limited. Methods: We performed a single institution matched-pair retrospective analysis of patients treated with IMRT TBI and standard TBI between 2010 and 2020 to provide data on long-term outcomes. Patients with hematologic malignancies, who could not tolerate standing for traditional TBI or who received prior radiation received IMRT TBI. Patients were matched based on age, diagnosis, disease status, and year of transplant, and were matched 2:1 to the standard TBI and IMRT TBI cohorts. Patient and treatment characteristics, toxicity, graft-versus-host disease (GVHD), dosimetry, and outcomes were evaluated for each cohort. Results: A total of 13 patients met inclusion criteria for the IMRT cohort, leading to 26 patients in the standard TBI cohort. There was no significant difference in relevant clinical factors between the cohorts. Reasons for using IMRT over conventional TBI included being unable to stand (n=5), prior radiation (n=5), and pediatric patient requiring anesthesia (n=3). Among living patients, median follow-up for all patients was 5.1 years in the IMRT TBI cohort and 5.5 years in the standard TBI cohort. The 5-yr estimate of OS was 68% in the IMRT TBI cohort and 60% in the standard TBI cohort (p=0.706). The 5-yr estimate of RFS was 54% in the IMRT TBI cohort and 60% in the standard TBI cohort (p=0.529). There was no clinically significant pneumonitis, nephritis, hypothyroidism, or cataracts reported in the IMRT TBI cohort. 41.7% of patients in the IMRT TBI cohort and 79.2% of patients in the standard TBI cohort experienced Grade II-IV acute GVHD (p=0.023). Conclusions: IMRT TBI appears to lead to favorable long-term outcome and dosimetry, and therefore potentially improved long-term toxicity profile compared to conventional TBI. IMRT TBI warrants further investigation as part of larger prospective trials.

Role of radiotherapy in treatment of extramedullary relapse following total marrow and lymphoid irradiation in high-risk and/or relapsed/refractory acute leukemia.

Background: Total Marrow and Lymphoid Irradiation (TMLI) is a promising component of the preparative regimen for hematopoietic cell transplantation in patients with high-risk acute myeloid leukemia (AML) and acute lymphoid leukemia (ALL). Extramedullary (EM) relapse after TMLI is comparable to TBI and non-TBI conditioning regimens. This study evaluates outcomes of patients treated with radiotherapy (RT) with EM relapse previously treated with TMLI. Methods: A retrospective analysis of five prospective TMLI trials was performed. TMLI targeted bones and major lymphoid tissues using image-guided tomotherapy, with total dose ranging from 12 to 20 Gy. EM recurrences were treated at the discretion of the hematologist and radiation oncologist using RT ± chemotherapy. Descriptive statistics and survival analysis were then performed on this cohort. Results: In total, 254 patients with refractory or relapsed AML or ALL were treated with TMLI at our institution. Twenty-one patients were identified as receiving at least one subsequent course of radiation. A total of 67 relapse sites (median=2 sites/patient, range=1-16) were treated. Eleven relapsed patients were initially treated with curative intent. Following the initial course of subsequent RT, 1-year, 3-year and 5-year estimates of OS were 47.6%, 32.7% and 16.3%, respectively. OS was significantly better in patients treated with curative intent, with median OS of 50.7 months vs 1.6 months (p<0.001). 1-year, 3-year and 5-year estimates of PFS were 23.8%, 14.3% and 14.3%, respectively. PFS was significantly better in patients treated with curative intent, with median PFS of 6.6 months vs 1.3 months (p<0.001). Following RT, 86.6% of the sites had durable local control. Conclusions: RT is an effective modality to treat EM relapse in patients with acute leukemia who relapse after HCT achieving high levels of local control. In patients with limited relapse amenable to curative intent, radiation confers favorable long-term survival. Radiation as salvage treatment for EM relapse after HCT warrants further evaluation.

FAM57A (Family with Sequence Similarity 57 Member A) Is a Cell-Density-Regulated Protein and Promotes the Proliferation and Migration of Cervical Cancer Cells.

The FAM57A (family with sequence similarity 57 member A) gene is controversially discussed to possess pro- or anti-tumorigenic potential. Here, we analyze the regulation of cellular FAM57A protein levels and study the functional role of FAM57A in HPV-positive cervical cancer cells. We find that FAM57A protein expression strongly depends on cell density, with FAM57A being readily detectable at low cell density, but undetectable at high cell density. This regulation occurs post-transcriptionally and is not mirrored by corresponding changes at the RNA level. We further show that FAM57A protein levels are highly increased in cervical cancer cells cultivated at hypoxia compared to normoxia and provide evidence that FAM57A is a hypoxia-responsive gene under control of the α-subunit of the HIF-1 (hypoxia-inducible factor-1) transcription factor. Yet, the strong relative increase of FAM57A protein levels in hypoxic cells is predominantly cell-density-dependent and occurs post-transcriptionally. Other anti-proliferative effectors besides hypoxia, such as silencing of HPV E6/E7 oncogene expression in cervical cancer cells, also result in an increase of FAM57A levels compared to untreated cells. Functional analyses reveal that FAM57A repression leads to pronounced anti-proliferative as well as anti-migratory effects in cervical cancer cells. Taken together, these results provide insights into the regulation of FAM57A protein levels and reveal that they underlie a tight cell-density-dependent control. Moreover, they identify FAM57A as a critical determinant for the phenotype of cervical cancer cells, which promotes their proliferation and migration capacities.

Total marrow irradiation (TMI): Addressing an unmet need in hematopoietic cell transplantation - a single institution experience review.

Purpose: TMI utilizes IMRT to deliver organ sparing targeted radiotherapy in patients undergoing hematopoietic cell transplantation (HCT). TMI addresses an unmet need, specifically patients with refractory or relapsed (R/R) hematologic malignancies who have poor outcomes with standard HCT regimens and where attempts to improve outcomes by adding or dose escalating TBI are not possible due to increased toxicities. Over 500 patients have received TMI at this center. This review summarizes this experience including planning and delivery, clinical results, and future directions. Methods: Patients were treated on prospective allogeneic HCT trials using helical tomographic or VMAT IMRT delivery. Target structures included the bone/marrow only (TMI), or the addition of lymph nodes, and spleen (total marrow and lymphoid irradiation, TMLI). Total dose ranged from 12 to 20 Gy at 1.5-2.0 Gy fractions twice daily. Results: Trials demonstrate engraftment in all patients and a low incidence of radiation related toxicities and extramedullary relapses. In R/R acute leukemia TMLI 20 Gy, etoposide, and cyclophosphamide (Cy) results in a 1-year non-relapse mortality (NRM) rate of 6% and 2-year overall survival (OS) of 48%; TMLI 12 Gy added to fludarabine (flu) and melphalan (mel) in older patients (≥ 60 years old) results in a NRM rate of 33% comparable to flu/mel alone, and 5-year OS of 42%; and TMLI 20 Gy/flu/Cy and post-transplant Cy (PTCy) in haplo-identical HCT results in a 2-year NRM rate of 13% and 1-year OS of 83%. In AML in complete remission, TMLI 20 Gy and PTCy results in 2-year NRM, OS, and GVHD free/relapse-free survival (GRFS) rates of 0%, 86·7%, and 59.3%, respectively. Conclusion: TMI/TMLI shows significant promise, low NRM rates, the ability to offer myeloablative radiation containing regimens to older patients, the ability to dose escalate, and response and survival rates that compare favorably to published results. Collaboration between radiation oncology and hematology is key to successful implementation. TMI/TMLI represents a paradigm shift from TBI towards novel strategies to integrate a safer and more effective target-specific radiation therapy into HCT conditioning beyond what is possible with TBI and will help expand and redefine the role of radiotherapy in HCT.

Outcomes of allogeneic hematopoietic cell transplantation in adults with fusions associated with Ph-like ALL.

Allogenic hematopoietic cell transplantation (alloHCT) is a well-established curative modality for acute lymphoblastic leukemia (ALL), yet large amounts of data describing alloHCT outcomes in Philadelphia (Ph)-like ALL are lacking. We retrospectively analyzed archived DNA samples from consecutive adults with B-cell Ph-negative ALL who underwent alloHCT in complete remission (CR) (n = 127) at our center between 2006 and 2020. Identification of fusions associated with Ph-like ALL was performed using cumulative results from RNA-seq, conventional cytogenetics, fluorescence in situ hybridization, and whole genome array studies. Fusions associated with Ph-like ALL were detected in 56 (44%) patients, of whom 38 were carrying CRLF2r. Compared with other non-Ph-like ALL (n = 71), patients with fusions associated with Ph-like ALL were more frequently Hispanic (P = .008), were less likely to carry high-risk cytogenetics (P < .001), and were more likely to receive blinatumomab prior to HCT (P = .019). With the median followup of 3.5 years, patients with Ph-like ALL fusions had comparable posttransplant outcomes compared with other B-cell ALL: 3-year relapse-free survival (RFS) (41% vs 44%; P = .36), overall survival (OS) (51% vs 50%; P = .59), and relapse (37% vs 31%; P = .47). In multivariable analysis, age (P = .023), disease status at the time of transplant (P < .001), and donor type (P = .015) influenced OS. RFS (primary endpoint) was significantly influenced by disease status (P < .001) and conditioning regimen intensity (P = .014). In conclusion, our data suggest that alloHCT consolidation results in similarly favorable survival outcomes in adult patients with Ph-like fusions and other high-risk B-cell ALL.

Long-Term Follow-Up of Multiple Myeloma Patients Treated with Tandem Autologous Transplantation Following Melphalan and Upon Recovery, Total Marrow Irradiation.

Total body irradiation in combination with melphalan for multiple myeloma (MM) has been shown to be prohibitively toxic. To ameliorate toxicity, total marrow irradiation (TMI) has been administered as the sole ablative modality during the second cycle of tandem autologous stem cell transplantation (TASCT) for MM patients on a phase I-II trial. Patients with MM in response or with stable disease and ≤18 months from diagnosis received melphalan 200 mg/m2 and autologous stem cell transplantation (ASCT) (cycle 1) and then, after recovery, TMI and another ASCT (cycle 2), followed by maintenance with an immunomodulatory drug (ImiD) and dexamethasone for up to 12 months. TMI doses were escalated from 1000 cGy to 1800 cGy in 200-cGy increments. Fifty-four patients were to receive TASCT between 2004 and 2011; 8 patients received single ASCT because of patient or physician preference. The median time between melphalan and TMI was 65 days (range, 47 to 125 days). Thirty patients (55.6%) underwent TASCT at the maximum tolerated dose of 1600 cGy. The complete response and very good partial response rates were 48.1% and 22.2%, respectively, following ASCT and maintenance. The median follow-up among survivors was 12.3 years (range, 9.2 to 15.5+ years). Progression-free survival (PFS) and overall survival at 10 years were 20.4% (95% confidence interval [CI], 10.9% to 31.9%) and 38.8% (95% CI, 25.9% to 51.5%), respectively. Secondary neoplasms included (1 each) acute myelogenous leukemia, papillary thyroid and prostate carcinoma, and melanoma, and there was 1 case of ductal carcinoma in situ and 4 cases of nonmelanoma skin cancers. TMI as part of TASCT was well tolerated, and TASCT was associated with a 20.4% PFS plateau. The inclusion of TMI as a conditioning regiment for MM before ASCT warrants further study in the context of modern induction and maintenance therapies.

Total Marrow and Lymphoid Irradiation with Post-Transplantation Cyclophosphamide for Patients with AML in Remission.

Graft-versus-host disease (GVHD) has remained the main cause of post-transplantation mortality and morbidity after allogeneic hematopoietic cell transplantation (alloHCT), adding significant economic burden and affecting quality of life. It would be desirable to reduce the rate of GVHD among patients in complete remission (CR) without increasing the risk of relapse. In this study, we have tested a novel conditioning regimen of total marrow and lymphoid irradiation (TMLI) at 2000 cGy, together with post-transplantation cyclophosphamide (PTCy) for patients with acute myeloid leukemia in first or second CR, to attenuate the risk of chronic GVHD by using PTCy, while using escalated targeted radiation conditioning before allografting to offset the possible increased risk of relapse. The primary objective was to evaluate the safety/feasibility of combining a TMLI transplantation conditioning regimen with a PTCy-based GVHD prophylaxis strategy, through the assessment of adverse events in terms of type, frequency, severity, attribution, time course, duration, and complications, including acute GVHD, infection, and delayed neutrophil/platelet engraftment. Secondary objectives included estimation of non-relapse mortality (NRM), overall survival (OS), relapse-free survival, acute and chronic GVHD, and GVHD-relapse-free survival (GRFS). A patient safety lead-in was first conducted to ensure there were no unexpected toxicities and was expanded on the basis of lack of dose-limiting toxicities. The patient safety lead-in segment followed 3 + 3 dose expansion/(de-)escalation rules based on observed toxicity through day 30; the starting dose of TMLI was 2000 cGy, and a de-escalation to 1800 cGy was considered. After the safety lead-in segment, an expansion cohort of up to 12 additional patients was to be studied. TMLI was administered on days -4 to 0, delivered in 200 cGy fractions twice daily. The radiation dose delivered to the liver and brain was kept at 1200 cGy. Cyclophosphamide was given on days 3 and 4 after alloHCT, 50 mg/kg each day for GVHD prevention; tacrolimus was given until day 90 and then tapered. Among 18 patients with a median age of 40 years (range 19-56), the highest grade toxicities were grade 2 Bearman bladder toxicity and stomatitis. No grade 3 or 4 Bearman toxicities or toxicity-related deaths were observed. The cumulative incidence of acute GVHD grade 2 to 4 and moderate-to-severe chronic GVHD were 11.1% and 11.9%, respectively. At a median follow up of 24.5 months, two-year estimates of OS and relapse-free survival were 86.7% and 83.3%, respectively. Disease relapse at 2 years was 16.7%. The estimates of NRM at 2 years was 0%. The GVHD/GRFS rate at 2 years was 59.3% (95% confidence interval, 28.8-80.3). This chemotherapy-free conditioning regimen, together with PTCy and tacrolimus, is safe, with no NRM. Preliminary results suggest an improved GRFS rate.