Autologous Hematopoietic Cell Transplantation Consolidation for First Response is Associated With Longer Survival Among Patients With Nodal Peripheral T Cell Lymphoma.

Nodal peripheral T cell lymphomas (PTCLs) are challenging subsets of non-Hodgkin lymphomas characterized by their heterogeneity and aggressive clinical behavior. Given the mixed outcomes reported in previous studies, the efficacy of autologous hematopoietic cell transplantation (auto-SCT) as a consolidation strategy following initial chemotherapy response remains uncertain. This study aims to evaluate the impact of upfront auto-SCT consolidation on overall survival (OS) and event-free survival (EFS) among patients with nodal PTCL who achieved a complete or partial response to initial chemotherapy. A retrospective cohort study was conducted at Moffitt Cancer Center, involving 123 patients with nodal PTCL treated between February 2005 and February 2021. Patients were stratified into 2 groups based on whether they received auto-SCT as part of their initial treatment strategy. Kaplan-Meier method and Cox proportional hazard models were used for statistical analysis to compare OS and EFS between groups. Patients undergoing auto-SCT after first response demonstrated significantly longer median OS (12.3 versus 4.3 yr; P = .035) and EFS (6.2 versus 2.2 yr; P = .003) compared to those who did not. Multivariate analyses indicated that auto-SCT at first response and younger age at diagnosis were favorable prognostic factors. The findings suggest that upfront auto-SCT consolidation can significantly improve long-term outcomes in patients with nodal PTCL, supporting the strategy of early auto-SCT consideration and referral following initial chemotherapy response. These results underscore the importance of integrating upfront auto-SCT into the treatment paradigm for nodal PTCL, emphasizing early referral to transplantation services to optimize patient outcomes.

Prevalence of baseline hypocalcemia and symptomatic hypocalcemia during leukapheresis.

Symptoms of hypocalcemia are reported in up to 50% of patients undergoing leukapheresis procedures. There is no set standard of practice for administering calcium supplementation in the prevention or treatment of hypocalcemia symptoms. The goal of this descriptive, retrospective study was to determine the prevalence of baseline hypocalcemia and symptomatic hypocalcemia during leukapheresis with acid citrate dextrose solution A and to identify patient characteristics associated with symptomatic hypocalcemia. Three percent of patients were found to have hypocalcemia before leukapheresis with 35% experiencing hypocalcemia symptoms during leukapheresis. Older age, higher albumin levels, and longer procedure time were associated with increased risk of hypocalcemia symptoms.

Early cytopenias and infections after standard of care idecabtagene vicleucel in relapsed or refractory multiple myeloma.

Idecabtagene vicleucel (ide-cel) was FDA-approved in March 2021 for the treatment of relapsed/refractory multiple myeloma after 4 lines of therapy. On the KarMMa trial, grade ≥ 3 cytopenias and infections were common. We sought to characterize cytopenias and infections within 100 days after ide-cel in the standard-of-care (SOC) setting. This multi-center retrospective study included 52 patients who received SOC ide-cel; 47 reached day-90 follow-up. Data were censored at day 100. Grade ≥ 3 cytopenia was present among 65% of patients at day 30 and 40% of patients at day 90. Granulocyte colony stimulating factor (G-CSF) was administered to 88%, packed red blood cell transfusions to 63%, platelet transfusions to 42%, thrombopoietin (TPO) agonists to 21%, intravenous immunoglobulin to 13%, and CD34+ stem cell boosts to 8%. At day 100, 19% and 13% of patients had ongoing use of TPO agonists and G-CSF, respectively. Infections occurred in 54% of patients and were grade ≥ 3 in 23%. Earlier infections in the first 30 days were typically bacterial (68%) and severe (50%). Later infections between days 31 and 100 were 50% bacterial and 42% viral; only 13% were grade ≥ 3. On univariate analysis, high pre-CAR-T marrow myeloma burden (≥ 50%), circulating plasma cells at pre-lymphodepletion (LD), and grade ≥ 3 anemia at pre-LD were associated with grade ≥ 3 cytopenia at both days 30 and 90. Longer time from last bridging treatment to LD was the only significant risk factor for infection.

Spontaneous Spinal Subdural Hematoma Secondary to Hemophilia A and Zanubrutinib.

Spontaneous spinal subdural hematomas (SSH) are rare occurrences that can occur most commonly secondary to vascular malformations or coagulopathies. Only a small fraction of spontaneous SSHs are caused by acquired coagulation disorders such as leukemia, hemophilia, and thrombocytopenia. This case report describes a patient with a history of Guillain-Barré syndrome (GBS), hemophilia A, and mantle cell lymphoma, on zanubrutinib therapy, a Bruton tyrosine kinase inhibitor associated with a risk of spontaneous hemorrhage. This patient developed a spontaneous spinal subdural hematoma, most likely due to the zanubrutinib therapy and exacerbated due to hemophilia. Treatment was delayed due to the patient's history of GBS that confounded the clinical diagnosis. This case is the first report of a spontaneous SSH in a patient on zanubrutinib, highlighting the need for a high index of suspicion for CNS hemorrhage in patients on Bruton's tyrosine kinase (BTK) inhibitor therapy.

Lack of defined apheresis collection criteria in publicly available CAR-T cell clinical trial descriptions: Comprehensive review of over 600 studies.

BACKGROUND: Chimeric antigen receptor T (CAR-T) cell successes have encouraged continued clinical study. Apheresis collection of starting material for CAR-T cell therapy product manufacturing is critical but described approaches suggest variability and clinical guidelines are currently lacking. The goal of this study was to gather and assess variability in apheresis collection descriptions in publicly available CAR T-cell therapy clinical trials. STUDY DESIGN: We searched clinicaltrials.gov (a publicly available clinical trial database) for "chimeric antigen receptor T cells" on July 01, 2020 and studies accessed July 30, 2020-August 15, 2020. Data collected included date posted, study characteristics, apheresis mentions (number, location, and context), laboratory parameters and transfusion allowances. Apheresis context was analyzed using a qualitative inductive approach of grounded theory method with open coding. Text was classified into 37 context codes, grouped into 12 categories, and then consolidated into patient, procedure, product, and miscellaneous themes. RESULTS: Apheresis was mentioned 1044 times in 322 (51.9%) of 621 total studies. Laboratory parameters mentioned included white blood cells (100 studies), absolute neutrophil count (220 studies), absolute lymphocyte count (102 studies), CD3+ cell (38 studies), hemoglobin (233 studies, 54 studies specified transfusion allowance), and platelet (269 studies, 48 studies specified transfusion allowance). CONCLUSIONS: Apheresis collection of CAR-T cell products is not well-defined in clinical study descriptions and the context is inconsistent. Laboratory parameters useful for apheresis collection are variably present and do not consistently align with current practices. Further exploration, and clinical guideline development will encourage alignment of apheresis collections for CAR-T cell products.

Patterns and Predictors of Failure in Recurrent or Refractory Large B-Cell Lymphomas After Chimeric Antigen Receptor T-Cell Therapy.

PURPOSE: Chimeric antigen receptor T-cell (CAR T) therapy is capable of eliciting durable responses in patients with relapsed/refractory (R/R) lymphomas. However, most treated patients relapse. Patterns of failure after CAR T have not been previously characterized, and may provide insights into the mechanisms of resistance guiding future treatment strategies. METHODS AND MATERIALS: This is a retrospective analysis of patients with R/R large B-cell lymphoma who were treated with anti-CD19 CAR T at a National Cancer Institute-designated Comprehensive Cancer Center between 2015 and 2019. Pre- and posttreatment positron emission/computed tomography scans were analyzed to assess the progression of existing (local failures) versus new, nonoverlapping lesions (de novo failures) and identify lesions at a high risk for progression. RESULTS: A total of 469 pretreatment lesions in 63 patients were identified. At a median follow-up of 12.6 months, 36 patients (57%) recurred. Most (n = 31; 86%) had a component of local failure, and 13 patients (36%) exhibited strictly local failures. Even when progressing, 84% of recurrent patients continued to have a subset of pretreatment lesions maintain positron emission/computed tomography resolution. Lesions at a high risk for local failure included those with a diameter ≥5 cm (odds ratio [OR], 2.34; 95% confidence interval [CI], 1.55-3.55; P < .001), maximum standardized uptake value ≥10 (OR, 2.08; 95% CI, 1.38-3.12; P < .001), or those that were extranodal (OR, 1.49; 95% CI, 1.10-2.04; P = .01). In the 69 patients eligible for survival analysis, those with any lesion ≥5 cm (n = 46; 67%) experienced inferior progression-free survival (hazard ratio, 2.41; 95% CI, 1.15-5.04; P = .02) and overall survival (hazard ratio, 3.36; 95% CI, 1.17-9.96; P = .02). CONCLUSIONS: Most patients who recur after CAR T experience a component of local progression. Furthermore, lesions with high-risk features, particularly large size, were associated with inferior treatment efficacy and patient survival. Taken together, these observations suggest that lesion-specific resistance may contribute to CAR T treatment failure. Locally directed therapies to high-risk lesions, such as radiation therapy, may be a viable strategy to prevent CAR T failures in select patients.

Impact of infused CD34+ stem cell dosing for allogeneic peripheral blood stem cell transplantation with post-transplant cyclophosphamide.

Higher infused total nucleated cell dose (TNC) in allogeneic bone marrow transplant (BMT) with post-transplant cyclophosphamide (PTCy) is associated with improved overall survival. As many centers prefer peripheral blood stem cell grafts (PBSCT) with PTCy, the effect of cell dose on outcomes with this platform also requires elucidation. We retrospectively evaluated 144 consecutive adult patients who received allogeneic T-cell replete PBSCT with PTCy-based graft-versus-host disease (GVHD) prophylaxis for a hematologic malignancy from 2012-2018. The infused CD34+ cell dose was stratified into low (<5 × 106/kg), intermediate (5-10 × 106/kg) and high (>10 × 106/kg) dose level groups. In multivariate analysis, the low CD34+ cell dose group had worse non-relapse mortality (HR = 4.51, 95% CI: 1.92-10.58, p < 0.001), progression- free survival (HR = 4.11, 95% CI: 2.07-8.15, p < 0.001), and overall survival (HR = 4.06, 95% CI: 2.00-8.25, p ≤ 0.001) compared to the intermediate group. Clinical outcomes between the intermediate and high CD34+ cell dose groups were similar. TNC and CD3+ cell dose had no significant impacts on outcomes. These findings suggest that, in patients receiving allogeneic PBSCT with PTCy, infused CD34+ cell doses >5 × 106 cells/kg may result in improved survival. Thus, this study supports targeting a CD34+ cell dose of >5 × 106 cells/kg for allogeneic PBSCT with PTCy.

Acute patient-reported outcomes in B-cell malignancies treated with axicabtagene ciloleucel.

Chimeric antigen receptor T-cell therapy with axicabtagene ciloleucel (axi-cel) has considerably improved survival in adults with relapsed/refractory large B-cell lymphoma. This study reports patient-reported outcomes (PROs) such as quality of life (QOL) and toxicity in the first 90 days after treatment. Hematologic cancer patients treated with axi-cel (N = 103, mean age = 61, 39% female) completed SF-36 or PROMIS-29 QOL questionnaires prior to treatment and 90 days after. PRO-Common Terminology Criteria for Adverse Events toxicity items were completed by patients at baseline and 14, 30, 60, and 90 days after treatment. Mixed models examined change in PROs over time. From preinfusion to 90 days later, patients reported improvements in physical functioning, pain, and fatigue (ps < 0.01), but worsening of anxiety (p = 0.02). Patient-reported toxicities worsened by day 14 with improvement thereafter. The five most severe symptoms at day 14 included fatigue, decreased appetite, dry mouth, diarrhea frequency, and problems with concentration. Results indicate improvement in some domains of QOL over time with transient patient-reported toxicities.

Immune reconstitution and associated infections following axicabtagene ciloleucel in relapsed or refractory large B-cell lymphoma.

CD19 CAR T-cell therapy with axicabtagene ciloleucel (axi-cel) for relapsed or refractory (R/R) large B cell lymphoma (LBCL) may lead to durable remissions, however, prolonged cytopenias and infections may occur. In this single center retrospective study of 85 patients, we characterized immune reconstitution and infections for patients remaining in remission after axi-cel for LBCL. Prolonged cytopenias (those occurring at or after day 30 following infusion) were common with >= grade 3 neutropenia seen in 21/70 (30-0%) patients at day 30 and persisting in 3/31 (9-7%) patients at 1 year. B cells were undetectable in 30/34 (88-2%) patients at day 30, but were detected in 11/19 (57-9%) at 1 year. Median IgG levels reached a nadir at day 180. By contrast, CD4 T cells decreased from baseline and were persistently low with a median CD4 count of 155 cells/µl at 1 year after axi-cel (n=19, range 33 - 269). In total, 23/85 (27-1%) patients received IVIG after axi-cel, and 34/85 (40-0%) received G-CSF. Infections in the first 30 days occurred in 31/85 (36-5%) patients, of which 11/85 (12-9%) required intravenous antibiotics or hospitalization ("severe") and were associated with cytokine release syndrome (CRS), neurotoxicity, tocilizumab use, corticosteroid use, and bridging therapy on univariate analyses. After day 30, 7 severe infections occurred, with no late deaths due to infection. Prolonged cytopenias are common following axi-cel therapy for LBCL and typically recover with time. Most patients experience profound and prolonged CD4 T cell immunosuppression without severe infection.

Hematopoietic Cell Transplantation in the Treatment of Newly Diagnosed Adult Acute Myeloid Leukemia: An Evidence-Based Review from the American Society of Transplantation and Cellular Therapy.

The role of hematopoietic cell transplantation (HCT) in the management of newly diagnosed adult acute myeloid leukemia (AML) is reviewed and critically evaluated in this evidence-based review. An AML expert panel, consisting of both transplant and nontransplant experts, was invited to develop clinically relevant frequently asked questions covering disease- and HCT-related topics. A systematic literature review was conducted to generate core recommendations that were graded based on the quality and strength of underlying evidence based on the standardized criteria established by the American Society of Transplantation and Cellular Therapy Steering Committee for evidence-based reviews. Allogeneic HCT offers a survival benefit in patients with intermediate- and high-risk AML and is currently a part of standard clinical care. We recommend the preferential use of myeloablative conditioning in eligible patients. A haploidentical related donor marrow graft is preferred over a cord blood unit in the absence of a fully HLA-matched donor. The evolving role of allogeneic HCT in the context of measurable residual disease monitoring and recent therapeutic advances in AML with regards to maintenance therapy after HCT are also discussed.

High metabolic tumor volume is associated with decreased efficacy of axicabtagene ciloleucel in large B-cell lymphoma.

High metabolic tumor volume (MTV) predicts worse outcomes in lymphoma treated with chemotherapy. However, it is unknown if this holds for patients treated with axicabtagene ciloleucel (axi-cel), an anti-CD19 targeted chimeric antigen receptor T-cell therapy. The primary objective of this retrospective study was to investigate the relationship between MTV and survival (overall survival [OS] and progression-free survival [PFS]) in patients with relapsed/refractory large B-cell lymphoma (LBCL) treated with axi-cel. Secondary objectives included finding the association of MTV with response rates and toxicity. The MTV values on baseline positron emission tomography of 96 patients were calculated via manual methodology using commercial software. Based on a median MTV cutoff value of 147.5 mL in the first cohort (n = 48), patients were divided into high and low MTV groups. Median follow-up for survivors was 24.98 months (range, 10.59-51.02 months). Patients with low MTV had significantly superior OS (hazard ratio [HR], 0.25; 95% confidence interval [CI], 0.10-0.66) and PFS (HR, 0.40; 95% CI, 0.18-0.89). Results were successfully validated in a second cohort of 48 patients with a median follow-up for survivors of 12.03 months (range, 0.89-25.74 months). Patients with low MTV were found to have superior OS (HR, 0.14; 95% CI, 0.05-0.42) and PFS (HR, 0.29; 95% CI, 0.12-0.69). In conclusion, baseline MTV is associated with OS and PFS in axi-cel recipients with LBCL.

Radiation Therapy as a Bridging Strategy for CAR T Cell Therapy With Axicabtagene Ciloleucel in Diffuse Large B-Cell Lymphoma.

PURPOSE: Axicabtagene ciloleucel (axi-cel) is a CD19-directed chimeric antigen receptor (CAR) T-cell therapy for relapsed or refractory diffuse large B-cell lymphoma. Bridging therapy may be required for lymphoma control during the manufacturing interval between collection of autologous T cells and final CAR T product administration. The optimal bridging therapy is not known and patients are often chemorefractory. We present a case series of patients receiving radiation as a bridge to axi-cel. METHODS AND MATERIALS: Between December 2017 and October 2018, 12 patients were intended to receive bridging radiation before axi-cel. The group was characterized by highly aggressive disease including 6 of 12 with "double hit" lymphoma and 6 of 12 with disease ≥10 cm in diameter. All patients received 2 to 4 Gy/fraction to a median dose of 20 Gy (range, 6-36.5 Gy). Half of patients received either 30 Gy in 10 fractions or 20 Gy in 5 fractions. Seven patients received concurrent chemotherapy. Eleven patients underwent axi-cel infusion and one did not. Median follow-up was 3.3 months (range, 1.1-12.0 months). RESULTS: No significant toxicities were identified during bridging radiation, and no patient experienced in-field progression of disease before axi-cel infusion. One patient experienced abdominal pain, which resolved after dose reduction. Two patients had out-of-field progression of disease during the bridging period. After axi-cel infusion, 3 of 11 patients (27%) experienced severe cytokine release syndrome or neurotoxicity. At 30 days, the objective response rate was 81.8% (11 of 12 evaluable; 1 stable disease, 1 out-of-field progression), with complete response in 27% (3 of 11). At last follow-up, the best objective response rate was 81.8%, with a complete response attained in 45% (5 of 11). Lymphocyte counts decreased slightly in 10 of 12 patients during radiation (median, 0.25 k/uL). CONCLUSIONS: Radiation (with or without concurrent chemotherapy) can be safely administered as a bridge to axi-cel in high-risk lymphoma. Caution should be taken if irradiation is started before apheresis, and lymphocyte counts should be monitored closely throughout. Future investigation is warranted to optimize the use of bridging radiation before CAR T therapy.

Clinical utilization of Chimeric Antigen Receptor T-cells (CAR-T) in B-cell acute lymphoblastic leukemia (ALL)-an expert opinion from the European Society for Blood and Marrow Transplantation (EBMT) and the American Society for Blood and Marrow Transplantation (ASBMT).

On August 30, 2017, the U.S. Food and Drug Administration (US-FDA) approved tisagenlecleucel (KYMRIAH, Novartis, Basel, Switzerland), a synthetic bioimmune product of anti-CD19 chimeric antigen receptor-T cells (CAR-T), for the treatment of children and young adults with relapsed/refractory B-cell acute lymphoblastic leukemia (B-ALL). With this new era of personalized cancer immunotherapy, multiple challenges are present ranging from implementation of a CAR-T program to safe delivery of the drug, long-term toxicity monitoring and disease assessments. To address these issues, experts representing the American Society for Blood and Marrow Transplant (ASBMT), the European Group for Blood and Marrow Transplantation (EBMT), the International Society of Cell and Gene Therapy (ISCT), and the Foundation for the Accreditation of Cellular Therapy (FACT), formed a global CAR-T task force to identify and address key questions pertinent for hematologists and transplant physicians regarding the clinical use of anti CD19 CAR-T therapy in patients with B-ALL. This article presents an initial roadmap for navigating common clinical practice scenarios that will become more prevalent now that the first commercially available CAR-T product for B-ALL has been approved.

Progression with clinical features is associated with worse subsequent survival in multiple myeloma.

Response rate and survival in multiple myeloma (MM) has improved in the era of proteasome inhibitors and immunomodulatory drugs. However, most patients eventually relapse with biochemical progression (BP) alone or with clinical features of end-organ damage (CP: clinical progression), without or without extramedullary (EM) disease. We conducted a retrospective cohort study of 252 patients with MM experiencing first relapse (time, T0 ) to evaluate survival following CP with and without EM as a function of BP. Patients were divided into three groups: BP (n = 134; 53%), CP/EM- (n = 87; 35%) and CP/EM+ (n = 31; 12%). The median time from diagnosis to T0 was significantly shorter in CP/EM+ compared to CP/EM- and BP groups (13 vs 25 vs 25 months; P < 0.001). The incidence of abnormal metaphase cytogenetics at diagnosis was significantly higher in CP/EM+ compared to CP/EM- and BP groups (46% vs 18% vs 11% respectively; P < 0.001). At a median follow-up of 26 months from T0 , median overall survival was 50, 19 and 10 months for BP, CP/EM- and CP/EM+ groups, respectively (P < 0.001). On multivariable analysis, pattern of progression was a significant prognostic factor for OS (HR for CP/EM- vs BP: 3.6; CP/EM+ vs BP: 8.7 and CP/EM+ vs CP/EM-: 2.42; P < 0.001 for all comparisons), along with age at T0 . In conclusion, progression pattern is an important prognostic factor in the current era, with subsequent survival being dismal in patients with end-organ damage or EM disease at relapse. Clinical trials in relapsed MM should consider reporting patterns of progression at baseline to ensure balance between study arms.

Clinical Utilization of Chimeric Antigen Receptor T Cells in B Cell Acute Lymphoblastic Leukemia: An Expert Opinion from the European Society for Blood and Marrow Transplantation and the American Society for Blood and Marrow Transplantation.

On August 30, 2017 the US Food and Drug Administration approved tisagenlecleucel (Kymriah; Novartis, Basel, Switzerland), a synthetic bioimmune product of anti-CD19 chimeric antigen receptor T cells (CAR-T), for the treatment of children and young adults with relapsed/refractory B cell acute lymphoblastic leukemia (B-ALL). With this new era of personalized cancer immunotherapy, multiple challenges are present, ranging from implementation of a CAR-T program to safe delivery of the drug, long-term toxicity monitoring, and disease assessments. To address these issues experts representing the American Society for Blood and Marrow Transplant, the European Society for Blood and Marrow Transplantation, the International Society of Cell and Gene Therapy, and the Foundation for the Accreditation of Cellular Therapy formed a global CAR-T task force to identify and address key questions pertinent for hematologists and transplant physicians regarding the clinical use of anti CD19 CAR-T therapy in patients with B-ALL. This article presents an initial roadmap for navigating common clinical practice scenarios that will become more prevalent now that the first commercially available CAR-T product for B-ALL has been approved.

Music Therapy for Symptom Management After Autologous Stem Cell Transplantation: Results From a Randomized Study.

High-dose chemotherapy followed by autologous stem cell transplantation (ASCT) is frequently performed in patients with hematologic malignancies. ASCT can result in significant nausea, pain, and discomfort. Supportive care has improved, and pharmacologic therapies are frequently used, but with limitations. Music has been demonstrated to improve nausea and pain in patients undergoing chemotherapy, but little data are available regarding the effects of music therapy in the transplantation setting. In a prospective study, patients with lymphoma or multiple myeloma undergoing ASCT were randomized to receive either interactive music therapy with a board-certified music therapist or no music therapy. The music therapy arm received 2 music therapy sessions on days +1 and +5. Primary outcomes were perception of pain and nausea measured on a visual analog scale. Secondary outcomes were narcotic pain medication use from day -1 to day +5 and impact of ASCT on patient mood as assessed by Profile of Mood States (POMS) on day +5. Eighty-two patients were enrolled, with 37 in the music therapy arm and 45 in the no music therapy arm. Patients who received MT had slightly increased nausea by day +7 compared with the no music therapy patients. The music therapy and no music therapy patients had similar pain scores; however, the patients who received music therapy used significantly less narcotic pain medication (median, 24 mg versus 73 mg; P = .038). Music therapy may be a viable nonpharmacologic method of pain management for patients undergoing ASCT; the music therapy patients required significantly fewer morphine equivalent doses compared with the no music therapy patients. Additional research is needed to better understand the effects of music therapy on patient-perceived symptoms, such as pain and nausea.

The association of histologic grade with acute graft-versus-host disease response and outcomes.

Consensus criteria are routinely used to clinically grade acute graft-versus-host disease (GVHD). A histologic grading system for acute GVHD is available, but there are limited data on its correlation with clinical grade and hematopoietic cell transplantation (HCT) outcomes. Among 503 patients who underwent allogeneic HCT from 2005 to 2013, we identified 300 biopsy episodes of the skin and gastrointestinal (GI) tract in 231 patients. Histologic grade was correlated with clinical grade of GVHD, day 28 treatment response, and outcome. Both skin (R = 0.32) and GI (R = 0.61) histologic grade correlated with clinical grade (P < 0.001). On multivariable analysis, histologic grade (HR 0.87, P = 0.011) and clinical grade (HR 0.86, P = 0.008) were significantly associated with day 28-treatment response. A histologic grade lower than its associated clinical grade predicted for better response (HR 1.26, P = 0.027), while a histologic grade higher than associated clinical grade had no correlation with response (P = 0.89). Both clinical and histologic GVHD grade were significant predictors of non-relapse mortality (HR 1.47, P = 0.04 and HR 1.67, P = 0.002, respectively) and all-cause mortality (HR 1.57, P = 0.001 and HR 1.29, P = 0.046, respectively). Histologic GVHD grade thus is correlated with clinical grading and treatment response, and may play a role in further predicting severity and treatment response of acute GVHD.