A systematic review and meta-analysis of nonrelapse mortality after CAR T cell therapy.

Although chimeric antigen receptor (CAR) T cell therapy represents a transformative immunotherapy, it is also associated with distinct toxicities that contribute to morbidity and mortality. In this systematic review and meta-analysis, we searched MEDLINE, Embase and CINAHL (Cochrane) for reports of nonrelapse mortality (NRM) after CAR T cell therapy in lymphoma and multiple myeloma up to March 2024. After extraction of causes and numbers of death, we analyzed NRM point estimates using random-effect models. We identified 7,604 patients across 18 clinical trials and 28 real-world studies. NRM point estimates varied across disease entities and were highest in patients with mantle-cell lymphoma (10.6%), followed by multiple myeloma (8.0%), large B cell lymphoma (6.1%) and indolent lymphoma (5.7%). Entity-specific meta-regression models for large B cell lymphoma and multiple myeloma revealed that axicabtagene ciloleucel and ciltacabtagene autoleucel were independently associated with increased NRM point estimates, respectively. Of 574 reported nonrelapse deaths, over half were attributed to infections (50.9%), followed by other malignancies (7.8%) and cardiovascular/respiratory events (7.3%). Conversely, the CAR T cell-specific side effects, immune effector cell-associated neurotoxicity syndrome/neurotoxicity, cytokine release syndrome and hemophagocytic lymphohistiocytosis, represented only a minority of nonrelapse deaths (cumulatively 11.5%). Our findings underline the critical importance of infectious complications after CAR T cell therapy and support the comprehensive reporting of NRM, including specific causes and long-term outcomes.

Subsequent Malignancies after CD19-Targeted Chimeric Antigen Receptor T cells in Patients with Lymphoma.

Chimeric antigen receptor (CAR) T cells are an established treatment for B cell non-Hodgkin lymphomas (B-NHL). With the remarkable success in improving survival, understanding the late effects of CAR T cell therapy is becoming more relevant. The aim of this study is to determine the incidence of subsequent malignancies in adult patients with B-NHL. We retrospectively studied 355 patients from two different medical centers treated with four different CAR T cell products from 2016 to 2022. The overall cumulative incidence for subsequent malignancies at 36 months was 14% (95% CI: 9.2%, 19%). Subsequent malignancies were grouped into three primary categories: solid tumor, hematologic malignancy, and dermatologic malignancy with cumulative incidences at 36 months of 6.1% (95% CI: 3.1%-10%), 4.5% (95% CI: 2.1%-8.1%) and 4.2% (95% CI: 2.1%-7.5%) respectively. Notably, no cases of T cell malignancies were observed. In univariable analysis, increasing age was associated with higher risk for subsequent malignancy. While the overall benefits of CAR T products continue to outweigh their potential risks, more studies and longer follow ups are needed to further demonstrate the risks, patterns, and molecular pathways that lead to the development of subsequent malignancies.

Anti-CD19 chimeric antigen receptor T-cell therapy has less efficacy in Richter transformation than in de novo large B-cell lymphoma and transformed low-grade B-cell lymphoma.

The activity of anti-CD19 CAR T cell therapy in chronic lymphocytic leukemia (CLL) with Richter's transformation (RT) to aggressive large B cell lymphoma (LBCL) is largely unknown. In a multicenter retrospective study, we report the safety and efficacy of CAR T cell therapy in patients with RT (n=30) compared to patients with aggressive B cell lymphoma (n=283) and patients with transformed indolent Non-Hodgkins Lymphoma (iNHL) (n=141) between April 2016 and January 2023. Two-thirds of patients received prior therapy for CLL before RT and 89% of them received B-cell receptor and B-cell lymphoma 2 (BCL-2) inhibitors. Toxicities of CAR T cell therapy in RT were similar to other lymphomas, with no fatalities related to cytokine release syndrome or immune effector-cell associated neurotoxicity synderome. The 100-day overall response rate and complete response rates in patients with RT were 57% and 47%, respectively. With a median follow up of 19 months, the median overall survival (OS) was 9.9 months in patients with RT compared to 18 months in de-novo LBCL and not reached in patients with transformed iNHL. The OS at 12 months was 45% in patients with RT compared with 62% and 75% in patients with de novo LBCL and transformed iNHL, respectively. In a multivariate analysis, worse OS was associated with RT histology, elevated LDH, and more prior lines of therapy. CAR T cell therapy can salvage a proportion of patients with CLL and RT exposed to prior targeted agents; however, efficacy in RT is inferior compared to de novo LBCL and transformed iNHL.

Donor Types and Outcomes of Transplantation in Myelofibrosis: A CIBMTR Study.

We aim to evaluate impact of donor types on outcomes of hematopoietic cell transplantation (HCT) in myelofibrosis, using CIBMTR registry data for HCTs done between 2013 and 2019. In all 1597 undergoing HCT for myelofibrosis, the use of haploidentical donors increased from 3% in 2013 to 19% in 2019. In study eligible, 1032 patients who received peripheral blood grafts for chronic phase myelofibrosis, 38% recipients of haploidentical-HCT were of non-White/Caucasian ethnicity. Matched sibling donor (MSD)-HCTs were independently associated with superior overall survival (OS) in the first 3 months [reference MSD, haploidentical HR 5.80 (95% CI 2.52-13.35), matched unrelated HR 4.50 (95% CI 2.24-9.03), and mismatched unrelated HR 5.13 (95% CI 1.44-18.31), P<0.001]. This difference in OS aligns with lower graft failure with MSD [haploidentical HR 6.11 (95%CI 2.98-12.54), matched unrelated HR 2.33 (95%CI 1.20-4.51), mismatched unrelated HR 1.82 (95%CI 0.58-5.72). There was no significant difference in OS among haploidentical, matched unrelated, and mismatched unrelated donor HCTs in the first 3 months. Donor type was not associated with differences in OS beyond 3 months post-HCT, relapse, disease-free survival or OS among patients who underwent HCT within 24 months of diagnosis. Patients who experienced graft failure had more advanced disease and commonly used nonmyeloablative conditioning. While MSDs remain a superior donor option due to improved engraftment, there is no significant difference in HCT outcomes from haploidentical and matched unrelated donors. These results establish haploidentical-HCT with posttransplantation cyclophosphamide as a viable option in myelofibrosis, especially for ethnic minorities underrepresented in the donor registries.

Impact of Primary Letermovir Prophylaxis Versus Preemptive Antiviral Therapy for Cytomegalovirus on Economic and Clinical Outcomes after Hematopoietic Cell Transplantation.

Preemptive therapy (PET) historically has been the primary strategy to reduce early-onset cytomegalovirus (CMV) reactivation after allogeneic hematopoietic cell transplantation (HCT) but is associated with antiviral-associated toxicities and increases in healthcare resource utilization and cost. Despite its high cost, letermovir (LTV) prophylaxis has largely supplanted PET due to its effectiveness and tolerability. Direct comparisons between LTV and PET approaches on economic and clinical outcomes after allogeneic HCT remain limited. Objective: To compare total cost of care (inpatient and outpatient) between LTV prophylaxis and PET through day+180 after allogeneic HCT. Adult allogeneic CMV seropositive (R+) HCT recipients who initiated LTV <30 days after HCT between 01/01/18 and 12/31/18 were matched 1:1 to allogeneic CMV R+ HCT recipients between 01/01/15 and 12/31/17 (PET cohort). Patients were grouped into high-risk (HR) or standard-risk (SR) for CMV to compare the LTV and PET cohorts. Direct costs for each patient's index HCT admission and all subsequent inpatient and outpatient care through day+180 after HCT were determined and converted into 2021 US dollars and then to Medicare proportional dollars (MPD). A secondary analysis using 2019 average wholesale price was conducted to specifically evaluate anti-CMV medication costs. There were a total of 176 patients with 54 HR CMV pairs and 34 SR CMV pairs. No differences in survival between LTV and PET for both HR and SR CMV groups were observed. The rate of clinically significant CMV infection decreased for both HR CMV (11/54, 20.4% versus 38/54, 70.4%, P < .001) and SR CMV (1/34, 2.9% versus 12/34, 35.3%, P < .001) patients who were given LTV prophylaxis with corresponding reductions in val(ganciclovir) and foscarnet (HR CMV only) use. Among HR CMV patients, LTV prophylaxis was associated with reductions in CMV-related readmissions (3/54, 5.6% versus 18/54, 33.3%, P < .001) and outpatient visits within the first 100 days after HCT (20 versus 25, P = .002), and a decreased median total cost of care ($36,018 versus $75,525, P < .001) in MPD was observed. For SR CMV patients on LTV, a significant reduction in the median inpatient cost ($15,668 versus $27,818, P < .001) was found, but this finding was offset by a higher median outpatient cost ($26,145 versus $20,307, P = .030) that was not CMV-driven. LTV prophylaxis is highly effective in reducing clinically significant CMV reactivations for both HR and SR HCT recipients. In this study, LTV prophylaxis was associated with a decreased total cost of care for HR CMV patients through day+180. Specifically, reductions in CMV-related readmissions, exposure to CMV-directed antiviral agents, and outpatient visits in the first 100 days after HCT were observed. SR CMV patients receiving LTV prophylaxis benefited by having a reduced inpatient cost of care due to lowered room and pharmacy costs.

CNS Bridging Radiotherapy Achieves Rapid Cytoreduction Prior to CAR T Cell Therapy for Aggressive B-Cell Lymphoma.

CAR T-cell therapy (CAR T) for central nervous system lymphoma (CNSL) is a promising strategy, yet responses are frequently not durable. Bridging radiotherapy (BRT) is used for extra-cranial lymphoma where it can improve CAR T outcomes through cytoreduction of high-risk lesions. We hypothesized that BRT would achieve similar, significant cytoreduction prior to CAR T for CNSL (CNS-BRT). We identified CNSL patients with non-Hodgkin B-cell lymphoma who received CNS-BRT prior to commercial CAR T. Cytoreduction from CNS-BRT was calculated as change in lesion size prior to CAR T. Twelve patients received CNS-BRT, and the median follow up among survivors is 11.8 months (IQR: 8.5 - 21.9). Ten patients had CNSL (9 secondary, 1 primary) and 2 patients had epidural disease (evaluable for toxicity). All ten patients with CNSL had progressive disease at the time of CNS-BRT. 1/12 patients experienced grade ≥ 3 cytokine release syndrome (CRS), and 3/12 patients experienced grade ≥ 3 immune effector cell-associated neurotoxicity syndrome (ICANS). CNS-BRT achieved a 74.0% (95% confidence interval: 62.0 - 86.0) mean reduction in lesion size from baseline (p = 0.014) at a median of 12 days from BRT completion and prior to CAR T infusion. Best CNS response included 8 complete responses (CR), 1 partial response (PR), and 1 progressive disease (PD). Three patients experienced CNS relapse outside the BRT field. Preliminary data suggest CNS-BRT achieves rapid cytoreduction and is associated with a favorable CNS response and safety profile. These data support further study of BRT as a bridging modality for CNSL CAR T.

Fostering next generation transplant physicians.

As opposed to the rapid expansion of hematopoietic cell transplantation (HCT) and other cellular therapies (CT), we are now facing a global shortage of transplant physicians and other professionals to support the activity of HCT/CT. To overcome this obstacle, a variety of approaches are now being undertaken in four international HCT societies. This article aims to share their current attempts to foster the next generation of transplant physicians and allied professionals needed to secure the continued global growth of HCT/CT.

Immune effector cell-associated haematotoxicity after CAR T-cell therapy: from mechanism to management.

Genetically engineered chimeric antigen receptor (CAR) T cells have become an effective treatment option for several advanced B-cell malignancies. Haematological side-effects, classified in 2023 as immune effector cell-associated haematotoxicity (ICAHT), are very common and can predispose for clinically relevant infections. As haematopoietic reconstitution after CAR T-cell therapy differs from chemotherapy-associated myelosuppression, a novel classification system for early and late ICAHT has been introduced. Furthermore, a risk stratification score named CAR-HEMATOTOX has been developed to identify candidates at high risk of ICAHT, thereby enabling risk-based interventional strategies. Therapeutically, growth factor support with granulocyte colony-stimulating factor (G-CSF) is the mainstay of treatment, with haematopoietic stem cell (HSC) boosts available for patients who are refractory to G-CSF (if available). Although the underlying pathophysiology remains poorly understood, translational studies from the past 3 years suggest that CAR T-cell-induced inflammation and baseline haematopoietic function are key contributors to prolonged cytopenia. In this Review, we provide an overview of the spectrum of haematological toxicities after CAR T-cell therapy and offer perspectives on future translational and clinical developments.

SARS-CoV-2 vaccination in the first year after hematopoietic cell transplant or chimeric antigen receptor T cell therapy: A prospective, multicenter, observational study.

BACKGROUND: The optimal timing of vaccination with SARS-CoV-2 vaccines after cellular therapy is incompletely understood. The objectives of this study are to determine whether humoral and cellular responses after SARS-CoV-2 vaccination differ if initiated <4 months versus 4-12 months after cellular therapy. METHODS: We conducted a multicenter prospective observational study at 30 cancer centers in the United States. SARS-CoV-2 vaccination was administered as part of routine care. We obtained blood prior to and after vaccinations at up to five time points and tested for SARS-CoV-2 spike (anti-S) IgG in all participants and neutralizing antibodies for Wuhan D614G, Delta B.1.617.2, and Omicron B.1.1.529 strains, as well as SARS-CoV-2-specific T cell receptors (TCRs), in a subgroup. RESULTS: We enrolled 466 allogeneic hematopoietic cell transplant (HCT; n=231), autologous HCT (n=170), and chimeric antigen receptor T cell (CAR-T cell) therapy (n=65) recipients between April 2021 and June 2022. Humoral and cellular responses did not significantly differ among participants initiating vaccinations <4 months vs 4-12 months after cellular therapy. Anti-S IgG ≥2,500 U/mL was correlated with high neutralizing antibody titers and attained by the last time point in 70%, 69%, and 34% of allogeneic HCT, autologous HCT, and CAR-T cell recipients, respectively. SARS-CoV-2-specific T cell responses were attained in 57%, 83%, and 58%, respectively. Pre-cellular therapy SARS-CoV-2 infection or vaccination were key predictors of post-cellular therapy immunity. CONCLUSIONS: These data support mRNA SARS-CoV-2 vaccination prior to, and reinitiation three to four months after, cellular therapies with allogeneic HCT, autologous HCT, and CAR-T cell therapy.

Emapalumab as salvage therapy for adults with malignancy-associated hemophagocytic lymphohistiocytosis.

Not available.

Atrial arrhythmias following CAR-chimeric antigen receptor T-cell therapy: Incidence, risk factors and biomarker profile.

Recent reports have raised concerns about the association of chimeric antigen receptor T cell (CAR-T) with non-negligible cardiotoxicity, particularly atrial arrhythmias. First, we conducted a pharmacovigilance study to assess the reporting of atrial arrhythmias following CD19-directed CAR-T. Subsequently, to determine the incidence, risk factors and outcomes of atrial arrhythmias post-CAR-T, we compiled a retrospective single-centre cohort of non-Hodgkin lymphoma patients. Only commercial CAR-T products were considered. Atrial arrhythmias were nearly fourfold more likely to be reported after CAR-T therapy compared to all other cancer patients in the FAERS (adjusted ROR = 3.76 [95% CI 2.67-5.29]). Of the 236 patients in our institutional cohort, 23 (10%) developed atrial arrhythmias post-CAR-T, including 12 de novo arrhythmias, with most (83%) requiring medical intervention. Atrial arrhythmias frequently co-occurred with cytokine release syndrome and were associated with higher post-CAR-T infusion peak levels of IL-10, TNF-alpha and LDH, and lower trough levels of fibrinogen. In a multivariable analysis, risk factors for atrial arrhythmia were history of atrial arrhythmia (OR = 6.80 [2.39-19.6]) and using CAR-T product with a CD28-costimulatory domain (OR = 5.17 [1.72-18.6]). Atrial arrhythmias following CD19-CAR-T therapy are prevalent and associated with elevated inflammatory biomarkers, a history of atrial arrhythmia and the use of a CAR-T product with a CD28 costimulatory domain.

T-Cell Malignant Neoplasms After Chimeric Antigen Receptor T-Cell Therapy.

This cohort study assesses the increase in second primary malignant neoplasms and T-cell malignant neoplasm cases associated with chimeric antigen receptor­T cells.

Real-world and clinical trial outcomes in large B-cell lymphoma with axicabtagene ciloleucel across race and ethnicity.

ABSTRACT: Axicabtagene ciloleucel (axi-cel) is an autologous anti-CD19 chimeric antigen receptor (CAR) T-cell therapy approved for relapsed/refractory (R/R) large B-cell lymphoma (LBCL). Despite extensive data supporting its use, outcomes stratified by race and ethnicity groups are limited. Here, we report clinical outcomes with axi-cel in patients with R/R LBCL by race and ethnicity in both real-world and clinical trial settings. In the real-world setting, 1290 patients who received axi-cel between 2017 and 2020 were identified from the Center for International Blood and Marrow Transplant Research database; 106 and 169 patients were included from the ZUMA-1 and ZUMA-7 trials, respectively. Overall survival was consistent across race/ethnicity groups. However, non-Hispanic (NH) Black patients had lower overall response rate (OR, 0.37; 95% CI, 0.22-0.63) and lower complete response rate (OR, 0.57; 95% CI, 0.33-0.97) than NH White patients. NH Black patients also had a shorter progression-free survival vs NH White (HR, 1.41; 95% CI, 1.04-1.90) and NH Asian patients (HR, 1.67; 95% CI, 1.08-2.59). NH Asian patients had a longer duration of response than NH White (HR, 0.56; 95% CI, 0.33-0.94) and Hispanic patients (HR, 0.54; 95% CI, 0.30-0.97). There was no difference in cytokine release syndrome by race/ethnicity; however, higher rates of any-grade immune effector cell-associated neurotoxicity syndrome were observed in NH White patients than in other patients. These results provide important context when treating patients with R/R LBCL with CAR T-cell therapy across different racial and ethnic groups. ZUMA-1 and ZUMA-7 (ClinicalTrials.gov identifiers: #NCT02348216 and #NCT03391466, respectively) are registered on ClinicalTrials.gov.

Recruitment and Retention of Hematopoietic Cell Transplantation and Cellular Therapy Physicians: A Report from the ASTCT Talent Acquisition Task Force.

A shortage of transplant and cellular therapy (TCT) physicians is expected given the expansion of TCT indications and the scope of practice of TCT programs in recent years. American Society of Transplantation and Cellular Therapy (ASTCT) conducted a survey of early career transplant physicians and trainees to assess the factors that prompted them to pursue to career in TCT. This was a cross-sectional survey conducted via emails sent to the ASTCT membership. Fifty-nine respondents completed the survey. The vast majority of respondents decided to pursue a career in TCT during their hematology/oncology fellowship (41%), followed by during residency (25%) or medical school (18%), and a majority of them had some exposure to TCT in their clinical training already. The most common reason for choosing to specialize in TCT was interest in the clinical practice of TCT (81%) closely followed by the scientific allure of the field (75%). Most respondents were extremely committed to remaining in this field of practice. We found that those in the field report high levels of satisfaction despite factors that would otherwise predispose them to burnout. A systematic and sustained effort to promote trainee engagement that could result in improved recruitment and retention in the field of TCT is needed. Professional societies in partnership with educational institutions could conduct outreach and help attract trainees from diverse backgrounds.

ASTCT Committee on Practice Guidelines Survey on Evaluation and Management of Relapsed/Refractory Multiple Myeloma after Failure of Chimeric Antigen Receptor T Cell Therapy.

Chimeric antigen receptor T cell therapy (CAR-T) has revolutionized the management of relapsed and/or refractory multiple myeloma (RRMM). However, CAR-T treatment failure is not uncommon and remains a major therapeutic challenge. There is substantial variability across transplantation and cellular therapy programs in assessing and managing post-CAR-T failures in patients with RRMM. The American Society for Transplantation and Cellular Therapy (ASTCT) Committee on Practice Guidelines conducted an online cross-sectional survey between September 2023 and December 2023 to determine myeloma, transplantation, and cellular therapy physicians' practice patterns for the surveillance, diagnosis, and management of CAR-T failure. The intent of this survey was to understand clinical practice patterns and identify areas for further investigation. Email surveys were sent to 1311 ASTCT physician members, of whom 80 (6.1%) completed the survey. The respondents were 58% white and 66% male, and 51% had >10 years of clinical experience. Most (89%) respondents were affiliated with a university/teaching center, and 56% had a myeloma-focused transplantation and/or cellular therapy practice. Post-CAR-T surveillance laboratory studies were commonly done every 4 weeks, and surveillance bone marrow biopsies and/or imaging surveillance were most commonly done at 3 months. Sixty-four percent of the respondents would often or always consider biopsy or imaging to confirm relapse. The most popular post-CAR-T failure rescue regimen was GPRC5D-directed immunotherapy (30%) for relapses occurring ≤3 months and BCMA-directed bispecific therapies (32.5%) for relapse at >3 months. Forty-one percent of the respondents endorsed post-CAR-T prolonged cytopenia as being "often" or "always" a barrier to next-line therapy; 53% had offered stem cell boost as a mitigation approach. Substantial across-center variation in practice patterns raises the need for collaborative studies and expert clinical recommendations to describe best practices for post-CAR-T disease surveillance, optimal workup for treatment failure, and choice of rescue therapies.

Conventional and novel [18F]FDG PET/CT features as predictors of CAR-T cell therapy outcome in large B-cell lymphoma.

Relapse and toxicity limit the effectiveness of chimeric antigen receptor T-cell (CAR-T) therapy for large B-cell lymphoma (LBCL), yet biomarkers that predict outcomes and toxicity are lacking. We examined radiomic features extracted from pre-CAR-T 18F-fluorodeoxyglucose positron emission tomography/computed tomography ([18F]FDG PET/CT) scans (n = 341) of 180 patients (121 male; median age, 66 years). Three conventional (maximum standardized uptake value [SUVmax], metabolic tumor volume [MTV], total lesion glycolysis [TLG]) and 116 novel radiomic features were assessed, along with inflammatory markers, toxicities, and outcomes. At both pre-apheresis and pre-infusion time points, conventional PET features of disease correlated with elevated inflammatory markers. At pre-infusion, MTV was associated with grade ≥ 2 cytokine release syndrome (odds ratio [OR] for 100 mL increase: 1.08 [95% confidence interval (CI), 1.01-1.20], P = 0.031), and SUVmax was associated with failure to achieve complete response (CR) (OR 1.72 [95% CI, 1.24-2.43], P < 0.001). Higher pre-apheresis and pre-infusion MTV values were associated with shorter progression-free survival (PFS) (HR for 10-unit increase: 1.11 [95% CI, 1.05-1.17], P < 0.001; 1.04 [95% CI, 1.02-1.07], P < 0.001) and shorter overall survival (HR for 100-unit increase: 1.14 [95% CI, 1.07-1.21], P < 0.001; 1.04 [95% CI, 1.02-1.06], P < 0.001). A combined MTV and LDH measure stratified patients into high and low PFS risk groups. Multiple pre-infusion novel radiomic features were associated with CR. These quantitative conventional [18F]FDG PET/CT features obtained before CAR-T cell infusion, which were correlated with inflammation markers, may provide prognostic biomarkers for CAR-T therapy efficacy and toxicity. The use of conventional and novel radiomic features may thus help identify high-risk patients for earlier interventions.

Altered microbial bile acid metabolism exacerbates T cell-driven inflammation during graft-versus-host disease.

Microbial transformation of bile acids affects intestinal immune homoeostasis but its impact on inflammatory pathologies remains largely unknown. Using a mouse model of graft-versus-host disease (GVHD), we found that T cell-driven inflammation decreased the abundance of microbiome-encoded bile salt hydrolase (BSH) genes and reduced the levels of unconjugated and microbe-derived bile acids. Several microbe-derived bile acids attenuated farnesoid X receptor (FXR) activation, suggesting that loss of these metabolites during inflammation may increase FXR activity and exacerbate the course of disease. Indeed, mortality increased with pharmacological activation of FXR and decreased with its genetic ablation in donor T cells during mouse GVHD. Furthermore, patients with GVHD after allogeneic hematopoietic cell transplantation showed similar loss of BSH and the associated reduction in unconjugated and microbe-derived bile acids. In addition, the FXR antagonist ursodeoxycholic acid reduced the proliferation of human T cells and was associated with a lower risk of GVHD-related mortality in patients. We propose that dysbiosis and loss of microbe-derived bile acids during inflammation may be an important mechanism to amplify T cell-mediated diseases.

Defining and Grading Infections in Clinical Trials Involving Hematopoietic Cell Transplantation: A Report From the BMT CTN Infectious Disease Technical Committee.

The Blood and Marrow Transplant Clinical Trials Network (BMT-CTN) was established in 2001 to conduct large multi-institutional clinical trials addressing important issues towards improving the outcomes of HCT and other cellular therapies. Trials conducted by the network investigating new advances in HCT and cellular therapy not only assess efficacy but require careful capturing and severity assessment of adverse events and toxicities. Adverse infectious events in cancer clinical trials are typically graded according to the National Cancer Institute's Common Terminology Criteria for Adverse Events (CTCAE). However, there are limitations to this framework as it relates to HCT given the associated immunodeficiency and delayed immune reconstitution. The BMT-CTN Infection Grading System is a monitoring tool developed by the BMT CTN to capture and monitor infectious complications and differs from the CTCAE by its classification of infections based on their potential impact on morbidity and mortality for HCT recipients. Here we offer a report from the BMT CTN Infectious Disease Technical Committee regarding the rationale, development, and revising of BMT-CTN Infection Grading System and future directions as it applies to future clinical trials involving HCT and cellular therapy recipients.

Cell-free DNA from nail clippings as source of normal control for genomic studies in hematologic malignancies.

Comprehensive genomic sequencing is becoming a critical component in the assessment of hematologic malignancies, with broad implications for patient management. In this context, unequivocally discriminating somatic from germline events is challenging but greatly facilitated by matched analysis of tumor:normal pairs. In contrast to solid tumors, conventional sources of normal control (peripheral blood, buccal swabs, saliva) could be highly involved by the neoplastic process, rendering them unsuitable. In this work we describe our real-world experience using cell free DNA (cfDNA) isolated from nail clippings as an alternate source of normal control, through the dedicated review of 2,610 tumor:nail pairs comprehensively sequenced by MSK-IMPACT-heme. Overall, we find nail cfDNA is a robust source of germline control for paired genomic studies. In a subset of patients, nail DNA may have tumor DNA contamination, reflecting unique attributes of the hematologic disease and transplant history. Contamination is generally low level, but significantly more common among patients with myeloid neoplasms (20.5%; 304/1482) compared to lymphoid diseases (5.4%; 61/1128) and particularly enriched in myeloproliferative neoplasms with marked myelofibrosis. When identified in patients with lymphoid and plasma-cell neoplasms, mutations commonly reflected a myeloid profile and correlated with a concurrent/evolving clonal myeloid neoplasm. For nails collected after allogeneic stem-cell transplantation, donor DNA was identified in 22% (11/50). In this cohort, an association with recent history of graft-vs-host disease was identified. These findings should be considered as a potential limitation for the use of nail as normal control but could also provide important diagnostic information regarding the disease process.