Noël, Pierre

Abstract Introduction Combat casualty care requires standardized proficiency criteria to ensure readiness in austere environments, yet gaps persist in defining performance thresholds for critical trauma skills. The Combat Medical Skills Sustainment Consortium (CMSSC), a novel military-civilian collaboration, aimed to validate competency thresholds for 21 Department of Defense-identified trauma skills. Materials and Methods A prospective cohort study (2022-2025) enrolled 1,495 military and civilian personnel across five academic centers, stratified by experience (novice, intermediate, expert). Skills, including cricothyroidotomy, whole blood transfusion, and ultrasound-guided vascular access, were assessed using validated checklists in Role 2-congruent simulations. Statistical analysis compared checklist performance against participant experience with a priori checklist scores estimated at 40% (novices) and 90% (experts). Results Competency thresholds were established, ranging from 77% (mechanical ventilation) to 100% (handoff). Experts achieved 85%-98% proficiency across most skills, with novices at 34%-97%. A ceiling effect was observed for less complex skills consistent with the power law of practice. Conclusion The Combat Medical Skills Sustainment Consortium validated standardized assessment tools, with potential to address readiness gaps through military-civilian synergy. Findings support consortium-guided curriculum development and highlight the need for longitudinal skill decay studies. Impact This study sets a benchmark for trauma care skills assessment, facilitating rapid adoption across military and civilian settings.

A 59‐year‐old female developed symptoms of graft‐versus‐host disease 3½ weeks after liver transplantation for primary biliary cirrhosis. Symptoms of graft‐versus‐host disease included fever, erythroderma with bullae formation, and mucosal surface ulceration. Donor lymphocytes were present in the peripheral blood. Despite treatment with equine antilymphoblast globulin, steroids and, eventually, cyclosporine withdrawal, she developed neutropenia and succumbed to sepsis. At autopsy, she had marked lymphocyte depletion involving the bone marrow and both native and donor origin lymph nodes. As expected, the liver was normal. The clinical and pathological features were remarkably similar to those of the few other reported cases of graft‐versus‐host disease after liver transplantation and transfusion‐associated graft‐versus‐host disease; therapy is usually ineffective, and progression of disease leads to pancytopenia and death from sepsis.

Abstract Introduction: Allogeneic stem cell transplantation (allo-SCT) can be curative for patients with hematologic malignancies. Despite optimization of supportive measures, the risk of non-relapse mortality is a particularly important consideration in older individuals. Sarcopenia, defined as low skeletal muscle mass, has been shown to be associated with decreased overall survival in cancer patients and may identify individuals at higher risk of treatment-related complications. Methods: Using Mayo Clinic Arizona's hematopoietic stem cell transplantation database, patients aged 60 years or older who underwent allo-SCT between 2008 and 2018 were identified. Patients who underwent abdominal computed tomography (CT) at our institution within 90 days prior to their transplant date were included in the study. The skeletal muscle area (SMA) was obtained using a fully automated algorithm for segmenting abdominal CT images to quantify body composition based on a deep learning approach (Weston et al., Radiology, 2019). The skeletal muscle index (SMI) was then calculated using the SMA and the subject's height at the time the CT was obtained. Sarcopenia was defined based on previously described consensus (Cruz-Jentoft et al., Age Ageing, 2010; Magudia et al., Radiology, 2021). T-tests and Fisher's exact tests compared patient characteristics between groups, where appropriate. Kaplan-Meier methods were used to construct survival times. Log-rank tests compared survival distributions and Cox proportional hazards models estimated hazard ratios. Results: A total of 79 patients met inclusion criteria (Table 1). Of these, 50 (63%, n=50/79) had sarcopenia, and 29 (37%, n=29/79) had normal skeletal muscle mass. Among the sarcopenia group, 43 (86%, n=43/50) had SMI measurements. No differences were seen between groups in age at transplant, sex, Karnofsky performance scale, disease risk index, or conditioning regimen intent. There was no statistically significant difference in overall survival between those with sarcopenia and those with normal skeletal muscle mass (log-rank p=0.18). Median survival was 3.3 years (95% CI: 0.8, not estimable (NE)) for those with sarcopenia and 3.6 years (95% CI: 1.3, NE) for those with normal skeletal muscle mass. Given the infrequency of events, the upper bounds of the median survival confidence intervals were not estimable. The unadjusted hazard ratio (HR) for sarcopenia versus normal skeletal muscle mass was 1.65 (95% CI: 0.79, 3.47; p=0.18). Males had a higher mean SMI than females, as expected (50.4 versus 37.5, p<0.001; mean difference 13.0, 95% CI: 8.9, 17.1). Without considering sex, higher or lower SMI was not associated with survival time in a Cox model in those with sarcopenia (HR: 0.97, 95% CI: 0.92, 1.03; p=0.32). Sex alone was also not associated with any survival benefit among these 43 patients. After adjusting for the difference seen in SMI between sexes, on average, those with higher SMI were associated with a survival benefit (HR: 0.92, 95% CI: 0.84, 0.99; p=0.039). This amounts to roughly an 8% reduction in hazard rate as SMI increased. Conclusions: The presence of sarcopenia alone was not associated with overall survival in patients 60 years and older undergoing allo-SCT for hematologic malignancy. Rating sarcopenia severity using SMI may assist in identifying high risk individuals with sarcopenia as lower sarcopenia severity was associated with improved overall survival. Further studies are warranted to explore the possible impacts of interventions directed at improving skeletal muscle mass on transplant-related outcomes. Figure 1 Figure 1. Disclosures Gaulin: DeciBio: Honoraria; Olson Research Group: Honoraria. Jain: CareDx: Other: for advisory board participation; CTI Biopharma: Research Funding; Syneos Health: Research Funding; Bristol Myers Squibb: Other: for advisory board participation; Targeted Healthcare Communications: Consultancy. Palmer: PharmaEssentia: Research Funding; Incyte: Research Funding; Sierra Oncology: Consultancy, Research Funding; CTI BioPharma: Consultancy, Research Funding; Protagonist: Consultancy, Research Funding.

Abstract Introduction: Donor T cell chimerism is tested frequently early after allogeneic hematopoietic cell transplantation (HCT). However, the predictive ability of testing this early after HCT, i.e. at day +30 or day +60, has not been well described, outside of smaller single center studies. Herein, we evaluate the correlation of early donor T cell chimerism with clinical outcomes of overall survival (OS) and relapse in patients undergoing HCT for various hematological malignancies. Methods: We identified patients who received HCT with 8/8 matched unrelated donors at our center between 2007 and 2016 and obtained the clinical data retrospectively. Chimerism studies were included for patients who had testing done at day+30 and/ or day +60. Chimerism is tested using PCR based technique. Due to limited variability in chimerism levels <100% donor chimerism, a cut-off of 100% was used for analysis. Hence, patients were divided into those who achieved full donor chimerism in CD3 fraction (100%) and those in whom CD3 donor chimerism was < 100% at the respective time points. Clinical outcomes evaluate for this abstract were OS and time to relapse. Univariate and multivariate Cox proportional hazard regression models were used using variables of interest, the later adjusted for age at HCT, use of ATG, conditioning regimen and disease risk index (DRI). Results: Baseline patient and HCT data: There were 209 patients who met the selection criteria of which 4 died within 30 days from HCT and hence, were not included in the analysis. Among the 205, 87 (42%) were women and median age at HCT was 55 (range, 18 - 74) years. The hematological malignancy diagnosis was acute myeloid leukemia (AML)/ myelodysplastic syndrome (MDS) in 112 (55%), acute lymphoblastic leukemia (ALL) in 35 (17%), chronic leukemias in 13 (6%), lymphomas in 13 (6%) and myeloproliferative neoplasm in 20 (10%); with DRI being very high in 9 (5%), high in 53 (27%), intermediate in 120 (60%) and low in 17 (9%) patients. Myeloablative conditioning was used in 81 (40%) and reduced intensity conditioning in 124 (60%). Graft versus host disease prophylaxis used was calcineurin inhibitor with methotrexate of mycophenolate in all patients while anti-thymocyte globulin was used in 125 (61%) patients. All patients received a peripheral blood graft. Outcomes: Median follow-up for all included patients was 615 (range, 30 - 3147) days. At day +30, 138 patients had achieved 100% donor CD3 chimerism of 189 patients in whom this data was available (73%) while at day +60, 131 (76%) out of 173 had 100% donor CD3 chimerism. In the univariate model, CD3 donor chimerism level at day +30 as well as day +60, was not predictive of OS (HR 1.5, 95% CI 0.82 - 2.9; p = 0.18 for day +30, HR 1.8, 95% CI 0.81 - 4.0, p = 0.15 for day +60). As for time to relapse, CD3 chimerism did not significantly affect the risk of relapse at these time points (HR 0.43, 95% CI 0.17 - 1.1, p = 0.08 for day +30; HR 0.55, 95% CI 0.18 - 1.6, p = 0.28 for day +60). In the multivariate model also, after adjustment as described above, CD3 at day +30 or at day +60 was not significantly associated with the risk of OS or time to relapse (Figure 1). Kaplan Meier curves for OS for CD3 chimerism at day +30 and day +60 are shown in Figure 2. Conclusions: In this study, T cell chimerism as early as day +30 or day +60 does not seem to predict OS or relapse in patients undergoing HCT for various hematological malignancies. Given the limitations of a smaller retrospective design, this must be validated in a larger study, possibly using registry data. If these findings are indeed confirmed, then the practice of testing chimerism early and frequently, that adds additional expense to the overall cost of HCT, must be reconsidered. Disclosures Palmer: Novartis: Research Funding.

Abstract Introduction: Primary refractory and early relapsed acute myeloid leukemia (RR-AML) continue to pose a therapeutic challenge. Salvage therapy treatment regimens for refractory and relapsed disease are not standardized but include the commonly-used mitoxantrone, etoposide, and cytarabine (MEC) and cladribine, cytarabine, filgrastim, and mitoxantrone (CLAG-M). Previous studies have suggested a potential benefit of CLAG-M, and therefore we performed an analysis of consecutive patients selected to receive either CLAG-M or MEC as salvage therapy for RR-AML. Methods: The study included 150 consecutive patients with RR-AML who received either CLAG-M or MEC between 09/01/2009 and 12/31/2017. Patients were identified through a pharmacy database based on use of mitoxantrone. Baseline disease and patient-related characteristics and clinical outcomes including allogeneic transplantation (ASCT) were obtained by systematic review of EMR. Overall survival (OS) and progression free survival (PFS) were estimated according to the Kaplan Meier method and log-rank test was used to compare outcomes between patients who received either of the two regimens. Results: There were 150 consecutive treated patients with RR-AML included in this analysis, 34 patients received CLAG-M and 116 patients received MEC. The median age was 57 years (18-76), and, and 52% were male. Forty-seven (31%) were treated for early relapsed disease (<6 months after successful induction), 17% (>6 months after induction), and the remainder had primary refractory disease (mean number of induction regimens was 1.8, range 1-6). AML risk was defined by cytogenetic criteria. There were a predominance of intermediate-risk subtypes at 47% (71/150) and followed by high-risk at 37% (55/150). Overall CR/CRi rates for CLAG-M and MEC were 74% (23/31) and 58% (63/108) in patients eligible for analysis (p=0.18). The median follow-up from relapse was 23.5 months (1-76). The median OS was 9.5 months for CLAG-M and 10.0 months for MEC (HR=0.88, 95%CI=0.54-1.41, p=0.59). In total, 76 patients (51%) were able to proceed to ASCT following salvage therapy with either CLAG-M or MEC. Among transplant recipients 56% (19/34) and 49% (57/116) were treated with CLAG-M and MEC, respectively. Median OS after ASCT was 13.0 months for CLAG-M and 31.0 months for MEC (HR=1.76, 95%CI=0.87-3.56, p=0.12). The median OS for refractory AML was 13.0 and 66.0 months for CLAG-M and MEC recipients, respectively (HR=0.92, 95%CI=0.46-1.84, p=0.24). Median OS for those with early relapse was 12.0 months for CLAG-M and 10.0 months for MEC (HR=0.69, 95%CI=0.22-2.11, p=0.51). Lastly, among those who had late relapse, median OS was 9.0 and 48.0 months for CLAG-M and MEC, respectively (HR=17.6, 95%CI=1.57-198, p<0.001). A univariate analysis was performed to investigate the impact of factors associated with OS, including treatment, age, gender, whether they proceeded to ASCT, cytogenetic risk type, and donor source. ASCT was associated with significant improvement in both PFS (HR=0.24, 95%CI=0.16- 0.37, p<0.001) and OS (HR=0.26, 95%CI=0.17-0.40, p<0.001) in this cohort. Age greater than 65 was associated with worse PFS (HR=1.02, 95%CI=1.00-1.03, p=0.04) but not OS (HR=1.01, 95%CI=1.00-1.03, p=0.06) after controlling for other variables including the impact of ASCT. Discussion: Despite a lower 30-day induction mortality we did not identify significant differences in outcomes among patients selected to receive CLAG-M vs. MEC. There was a statistically significant improvement in survival in patients who had late relapses and were treated with MEC, and a trend towards improvement in OS of those treated with MEC who proceeded to ASCT. As expected, ASCT was associated with significant improvement in OS in this cohort, and our results strongly support the use of ASCT as consolidation of remission after relapse for AML. Our data suggests that MEC may be a superior regimen, in particular including those with late relapse. Figure. Figure. Disclosures Foran: Agios: Research Funding; Xencor, Inc.: Research Funding. Al-Kali:Novartis: Research Funding. Palmer:Novartis: Research Funding.

Abstract Introduction Myelofibrosis (MF), both primary myelofibrosis (PMF) and post essential thrombocytosis/polycythemia vera myelofibrosis (post ET/PV-MF), are chronic myeloproliferative neoplasms that are incurable with standard medical therapy. The only potential curative therapeutic modality remains allogeneic stem cell transplant (ASCT), but the optimum conditioning regimen has yet to be defined and may vary due to pre-ASCT factors such as age, donor source, and comorbidities. In the past, traditional myeloablative (MA) regimens have proven toxic. Reduced intensity conditioning (RIC) regimens have generally become the accepted standard of care for patients with PMF or Post PV/ET MF in need of ASCT, but with the potential for increase in relapse especially for high risk disease. The optimal conditioning regimen has yet to be defined. The regimen of Fludarabine, BCNU, and melphalan (FBM) is considered a reduced toxicity regimen that may afford the benefit of reduction in relapse without increase in toxicity and may “bridge the gap” between MA and RIC especially in older patients. Patients with MF have high inflammatory cytokine levels which may act as mediators of MF symptom burden and may further aggravate mediators of acute GVHD, which is one of the most frequent and severe complications of ASCT. Selection of conditioning regimen and GVHD prophylaxis are keys to MF transplant outcomes. We report here the results of 16 patients who received conditioning with FBM with rATG (FBM-A) with PMF and post PV/ET MF. Methods We conducted a retrospective review of all patients from October 2009 to November 2012 with PMF or post ET/PV-MF who underwent an ASCT with FBM-A. Patient demographic and transplant data were analyzed from a comprehensive database. The use of such data for reporting purpose was approved by the Mayo Clinic Arizona Institutional Review Board. Overall survival was estimated using Kaplan-Meier. Results There were 16 patients analyzed who had PMF or post PV/ET MF or overlap syndromes. The median follow-up of surviving patients is 20.4 months (range 8 months – 46 months). The median age was 60 (range 47-68 yrs) with 56% of patients being ≥ 60yrs. There were 8 males and 8 females. The JAK2 V617F mutation was present in 64% of patients. 86% were high risk according to the DIPSS system with 14% being intermediate-2 risk. None of the patients underwent splenectomy prior to transplant. The median HCT-CI score was 1.5 with 6 (38%) of the patients having an HCT-CMI ≥3. Donors were related in 10 patients (8 matched, 2 mismatched at 1 antigen) and unrelated in 6 (matched, n=3, 1-antigen mismatch, n=3). GVHD prophylaxis consisted of tacrolimus, MMF, and ATG 2.5 – 5.0 mg/kg. The cumulative incidence of acute GVHD grades III-IV was 15.3% at 6 months, and the cumulative incidence of NIH-defined moderate-to-severe chronic GVHD was 25% at 2 years. No patient has relapsed, and no patient has developed graft failure. There have been 4 deaths, 3 from GVHD, and 1 from infection. Among the 3 patients who died from GVHD, all were unrelated donor transplants, and 2 were mismatched unrelated transplants. The 2-year Kaplan-Meier estimate of overall survival (OS) is 72% (95% CI, 45 – 91%). The cumulative incidence of TRM was 12.6% (95% CI 3.9%-34%) at 1 year. Conclusion The reduced-toxicity regimen of FBM-A in PMF, Post ET/PV MF and overlap syndromes appear to provide the benefit of an ablative regimen with the tolerance of a RIC. The 2-year overall survival of 72% in our series is encouraging in an older population of predominantly high-risk patients. Treatment failure was related predominately to GVHD, which continues to be a significant obstacle to better long-term outcomes, especially in unrelated and mismatched patients. Reduced toxicity ASCT conditioning regimens in the setting of MF warrant further investigation. Disclosures: Reeder: Celgene: Research Funding; Novartis: Research Funding; Millenium: Research Funding.

Abstract Abstract 4479 Background: In vivo T-cell depletion with antithymocyte globulin (ATG) is known to decrease the incidence of acute and chronic graft vs. host disease (GVHD) after allogeneic hematopoietic cell transplantation (HCT). However, the detailed patterns of GVHD (incidence, severity, timing, and quality) after ATG-based conditioning have not been examined in large patient cohorts, and it is unknown whether they differ from those seen in patients who do not receive ATG during conditioning therapy. Patients and Methods: We analyzed the incidence and characteristics of acute and chronic GVHD, requirements for immunosuppressive therapy (IST) and survival in a cohort of 174 patients who underwent a first HCT for hematologic malignancy with ATG as a part of their conditioning regimen. The median age was 54 years (range 19–76); all but 5 pts received PBSC, and median follow-up of survivors was 16.9 months (range 3–70 months). Donors were matched related in 18% (n=32), matched unrelated in 44% (n=77), and mismatched unrelated in 37% (n=65). Conditioning regimens were myeloablative in 33% (n=57) and reduced intensity in 67% (n=117). Additional GVHD prophylaxis included tacrolimus in all patients combined with either methotrexate (42%) or MMF (58%). Results: The cumulative incidence of grade II-IV and III-IV acute GVHD at 100 days was 34% and 7%, respectively, with the median time of onset at 43 days (range 11–98 days) after transplant. Eleven patients (6.3%) required additional immunosuppressive treatment due to steroid refractory GVHD. Late/persistent acute GVHD without any evidence of chronic occurred in 25% of patients. NIH chronic GVHD developed in 25 patients, with a cumulative incidence of 24.4% at 2 years. Forty four percent of these patients were classified as classic chronic, and 56% as overlap. The onset of chronic GVHD was quiescent in 20 (80%), progressive in 3 (12%), and de-novo in 2 (8%) patients. The global severity was mild in 9 (36%), moderate in 11 (44%) and severe in 5 (20%) cases. The median time of onset for chronic GVHD was 185 days (range 99–763). In a multivariate analysis of factors predictive for development of chronic GVHD, the only factor associated with development of chronic GVHD was prior grade II-IV acute GVHD (HR 2.5, p =.03). The most common diagnostic organ was mouth (n=16), followed by skin (n=8) and eye (n=1). The median number of sites involved during the course of chronic GVHD was 4 (range 1–7), and the median number of systemic immunosuppressive agents for treatment was 2 (range 0–4). Among the 25 chronic GVHD patients, 5 have discontinued immunosuppression at a median time of 13.1 months (range 6–26) since the diagnosis of chronic GVHD. The cumulative incidence of discontinuation of IST was 23% at one year and 50% at two years. Three deaths in the overall cohort were attributed to complications related to acute (n=2) or chronic GVHD (n=1). At 2 years, the overall survival among all 174 pts was 62.4%, cumulative incidence of relapse was 23.1%, and non-relapse mortality was 22.7%. Conclusion: These data from a large, uniformly treated and graded, predominantly peripheral blood stem cell transplant recipient population, confirm that ATG decreases both the incidence and severity of acute and chronic GVHD. In particular, the rate of moderate to severe chronic GVHD is extremely low, resulting in minimal need for tertiary treatment and decreased duration of immunosupression. Disclosures: No relevant conflicts of interest to declare.

Abstract Introduction - Allogenic hematopoietic cell transplantation (HCT) remains potential curative treatment for hematologic malignancies. Anti-thymocyte globulin (ATG) is an immunoglobulin directed to human T lymphocytes, and may decrease the risk of chronic graft versus host disease (cGVHD). Use of ATG has been associated with higher incidence of disease relapse and infection. While the optimal dosing of ATG has not been well established, higher doses (≥ 7.5 mg/kg) have a stronger association with infection and disease relapse. Our institution utilizes low dose rabbit ATG at 2.5 mg/kg for in-vivo T-cell depletion. In this retrospective study we evaluated outcomes in patients receiving low dose ATG to those not undergoing in-vivo T-cell depletion with the hypothesis that low dose ATG protects against cGVHD without impacting infectious complications or relapse. Patients and Methods - We evaluated all patients with 8/8 HLA Matched unrelated Donors (MUD) undergoing HCT between 2007 and 2016. Patients were divided in to two cohorts, those receiving low dose ATG to those that did not. Both cohorts received standard GVHD prophylaxis with calcineurin inhibition plus methotrexate or mycophenolate. The primary outcome was overall survival (OS). Secondary outcomes included relapse free survival (RFS), EBV reactivation, CMV reactivation, CMV disease, invasive fungal infection, incidence of acute GVHD (aGVHD) grades III-IV, and moderate to severe cGVHD. A subset analysis was performed to assess relapse free survival (RFS) in patients with myeloid malignancies. Descriptive statistics were utilized for baseline characteristics; and a series of univariate and multivariant Cox proportional hazard regression models were conducted for outcomes of interest. A Kaplan-Meier (K-M) survival curve was used to depict probability of survival by ATG cohort. Results - We identified 209 patients, with 129 (62%) in ATG group and 80 (38%) in non-ATG group. At baseline, there were no differences in the age at transplant, sex, ABO incompatibility, or performance status. The ATG cohort had fewer low disease risk index (DRI) patients and more patients with intermediate or high DRI (2.4%, 64.6%, 28.3% vs 18.4%, 51.3%, 23.7% respectively), and Fisher's Exact test showed that this difference between ATG groups was statistically significant, p = <0.001. The ATG cohort also had significantly different rates of myeloablative (MA) conditioning regimens from the non-ATG cohort with fewer receiving MA (31% vs 53% p < 0.01). No statistically significant differences in OS were observed between the two ATG cohorts at up to 5 years post-transplant (p=0.35; Fig. 1). The primary predictor of OS was DRI very high vs low [HR 6.0 (2-18) p < 0.01]. The ATG exposed cohort had significantly lower risk of cGVHD [HR 0.17 (0.08-0.37) p = <0.001]. There was no difference in risk of death from relapse, incidence of EBV or CMV reactivation, CMV disease, invasive fungal infection, or grade III-IV acute GVHD. Low dose ATG was not associated with inferior RFS, including in subset analysis of patients with myeloid malignancies [HR 0.85 (0.5-1.4) p = 0.549]. Conclusions - Our study shows no significant difference in survival or death from relapse for patients who receive ATG. Importantly, patients receiving ATG had a lower rate of cGVHD with no increased rates of infectious complications. Low dose ATG did not appear to increase the risk of relapse, even when considering only myeloid malignancies. These findings suggest that low dose ATG can improve cGVHD with no impact on survival, relapse, or infectious complications. Additional prospective trials using low dose ATG compared to no ATG are warranted. Disclosures Palmer: Novartis: Research Funding.