Assessment of Bone Marrow Involvement in B-Cell non-Hodgkin Lymphoma Using Immunoglobulin Gene Rearrangement Analysis with Next-Generation Sequencing.

BACKGROUND: Assessment of bone marrow involvement (BMI) in non-Hodgkin lymphoma (NHL) is crucial for determining patient prognosis and treatment strategy. We assessed the prognostic value of next-generation sequencing (NGS)-based immunoglobulin (Ig) gene clonality analysis as an ancillary test for BMI evaluation in NHL. METHODS: A retrospective cohort of 124 patients newly diagnosed with B-cell NHL between 2019 and 2022 was included. NGS-based Ig clonality analysis was conducted using LymphoTrak IGH FR1 Assay and IGK Assay (Invivoscribe Technologies, San Diego, CA, USA) on BM aspirate samples, and the results were compared with those of histopathological BMI (hBMI). RESULTS: Among the 124 patients, hBMI was detected in 16.9% (n = 21). The overall agreement of BMI between Ig clonality analyses and histopathological analysis for IGH, IGK, and either IGH or IGK was 86.3%, 92.7%, and 90.3%. The highest positive percent agreement was observed with clonal rearrangements of either IGH or IGK gene (90.5%), while the highest negative percent agreement was observed with clonal rearrangement of IGK gene (96.1%). For the prediction of hBMI, positive prediction value ranged between 59.1% and 80.0% and the negative prediction value ranged between 91.3% and 97.9%. CONCLUSION: NGS-based clonality analysis is an analytic platform with a substantial overall agreement with histopathological analysis. Assessment of both IGH and IGK genes for the clonal rearrangement analysis could be considered for the optimal diagnostic performance of BMI detection in B-cell NHL.

Impact of race and social determinants of health on outcomes in patients with aggressive B-cell NHL treated with CAR-T therapy.

ABSTRACT: Chimeric antigen receptor (CAR) T-cell (CAR-T) immunotherapy is an effective therapy for relapsed/refractory B-cell non-Hodgkin lymphoma (r/r B-NHL). However, data are limited on the impact of the convergence of race and social determinants of health on outcomes for patients treated with CAR-T therapy. We examined the impact of interactions between race and insurance type on health care use and outcomes in patients treated with CAR-T therapy for aggressive B-NHL. Adult patients with r/r B-NHL treated with CD19 CAR-Ts were identified between 2015 and 2021 across 13 US academic centers. Insurance type, demographic, and clinical data were collected and analyzed. In total, 466 adult patients were included in our analysis. Median follow-up after CAR-T therapy was 12.7 months. Median progression-free survival (mPFS) was longer for Caucasians (11.5 months) than for African Americans (3.5 months; hazard ratio [HR], 1.56 [1.03-2.4]; P = .04) or Asians (2.7 months; HR, 1.7 [1.02-2.67]; P = .04). Differences in median overall survival (mOS) were not significant. For Medicare (n = 206) vs Medicaid (n = 33) vs private insurance (n = 219) vs self-pay (n = 7): mPFS was 15.9 vs 4.2 vs 6.0 vs 0.9 months (P < .001), respectively; and mOS was 31.2 vs 12.8 vs 21.5 vs 3.2 months (P < .001), respectively. Our multicenter retrospective analysis showed that race and insurance status can affect outcomes for patients treated with CAR-T therapy.

Real-world adherence and discontinuation among Medicare beneficiaries initiating venetoclax vs. BTKis in relapsed/refractory chronic lymphocytic leukemia.

The treatment landscape for chronic lymphocytic leukemia (CLL) has been transformed by the availability of Bruton's tyrosine kinase inhibitors (BTKis) and the B-cell lymphoma 2 (BCL-2) inhibitor venetoclax. Despite clinical trial data supporting these novel oral agents, evidence evaluating real-world adherence is limited. This study used 2015-2019 Medicare claims data for elderly patients with relapsed/refractory CLL to assess differences in real-world adherence and discontinuation in the 12 months after treatment initiation. In the final sample of 711 venetoclax patients and 1,566 BTKi patients, we found that those initiating venetoclax tended to be younger (mean age 75.6 [SD 6.0] vs 77.6 [SD 6.9] years, p < .001) but had poorer clinical characteristics. After risk-adjustment, the venetoclax group had higher adherence (61.9% vs. 45.4%, p < .0001) and lower discontinuation when compared to the BTKi group (28.5% vs. 47.4%, p < .001). These favorable real-world findings underscore the importance of developing well-tolerated novel combinations for older adults.

Cost-Effectiveness Analysis of Relmacabtagene Autoleucel for Relapsed or Refractory Large B-Cell Lymphoma in China.

OBJECTIVES: Relmacabtagene autoleucel (relma-cel) was recently approved in China for treating relapsed or refractory large B-cell lymphoma (r/r LBCL). We conducted a cost-effectiveness analysis from the perspective of Chinese healthcare system. METHODS: A mixture-cure model was developed to project life-years (LYs), quality-adjusted LYs (QALYs), and overall direct cost with a lifetime horizon for patients with r/r LBCL treated with relma-cel versus salvage chemotherapy. Patient-level data from RELIANCE trial and published data from Collaborative Trial in Relapsed Aggressive Lymphoma extension study were used to inform the model. The incremental cost-effectiveness ratio (ICER) was estimated and cost-effectiveness was evaluated at the willingness-to-pay threshold of 3 times the national gross domestic product per capita. RESULTS: The model projected that treatment with relma-cel was associated with incremental gains of 5.11 LYs and 5.26 QALYs compared with salvage chemotherapy at an increased cost of ¥1 067 430 (∼$154 152), resulting in an ICER of ¥203 137 (∼$29 435) per QALY. The model was most sensitive to the uncertainty around the estimated cure rate. The ICER of relma-cel was within the willingness-to-pay threshold in the base case and the probability of relma-cel treatment being considered cost-effective was approximately 74%. CONCLUSIONS: Compared with salvage chemotherapy, treatment with relma-cel for r/r LBCL in patients who have failed at least 2 lines of systemic therapy is within the cost-effective range from the perspective of Chinese healthcare system and represents a good use of healthcare resources.

CAR-T Cells in Canada; Perspective on How to Ensure We Get Our Value's Worth.

New therapies in a publicly funded healthcare system are first appraised by health technology assessment agencies that provide funding recommendations to the payers. Treatment with Chimeric Antigen Receptor-T cell (CAR-T) therapy is revolutionizing the management of patients with relapsed/refractory aggressive B-cell lymphoma by providing an effective alternative to the standard of care. Yet, the implementation of CAR-T treatment has a substantial impact on the healthcare system due to its high cost, complex manufacturing process, and requirement for highly specialized services and expertise. CAR-T Cells, as a "living drug", are fundamentally different from usual medications, and their approvals and funding recommendations pose unique challenges to the health technology agency. In this paper, we explore the specific challenges that face the health technology agencies in reviewing reimbursement recommendations for CAR-T therapy. We take a Canadian perspective and use CAR-T treatment of relapse/refractory aggressive B-cell lymphoma as an example.

Clonal Characterization and Somatic Hypermutation Assessment by Next-Generation Sequencing in Chronic Lymphocytic Leukemia/Small Lymphocytic Lymphoma: A Detailed Description of the Technical Performance, Clinical Utility, and Platform Comparison.

Somatic hypermutation status of the IGHV gene is essential for treating patients with chronic lymphocytic leukemia/small lymphocytic lymphoma. Unlike the conventional low-throughput method, assessment of somatic hypermutation by next-generation sequencing (NGS) has potential for uniformity and scalability. However, it lacks standardization or guidelines for routine clinical use. We critically assessed the performance of an amplicon-based NGS assay across 458 samples. Using a validation cohort (35 samples), the comparison of two platforms (Ion Torrent versus Illumina) and two primer sets [leader versus framework region 1 (FR1)] in their ability to identify clonotypic IGHV rearrangement(s) revealed 97% concordance. The mutation rates were identical by both platforms when using the same primer set (FR1), whereas a slight overestimation bias (+0.326%) was found when comparing FR1 with leader primers. However, for nearly all patients this did not affect the stratification into mutated or unmutated categories, suggesting that use of FR1 may provide comparable results if leader sequencing is not available and allowing for a simpler NGS laboratory workflow. In routine clinical practice (423 samples), the productive rearrangement was successfully detected by either primer set (leader, 97.7%; FR1, 94.7%), and a combination of both in problematic cases reduced the failure rate to 1.2%. Higher sensitivity of the NGS-based analysis also detected a higher frequency of double IGHV rearrangements (19.1%) compared with traditional approaches.

Clinically Applicable Assessment of Tisagenlecleucel CAR T Cell Treatment by Digital Droplet PCR for Copy Number Variant Assessment.

Chimeric antigen receptor (CAR) T cell therapy is an innovative immunotherapy for treating cancers in both children and adults with proven utility in numerous clinical trials. Significantly, some CAR T cell therapies have now been approved by relevant national regulatory bodies across numerous countries for clinical therapeutic use outside of clinical trials. One such recently licensed product is tisagenlecleucel, a CAR T therapy approved for the treatment of B-cell acute lymphoblastic leukemia (B-ALL) using autologous T cells from the patient. The genetically engineered T cells target a protein called CD19, common to B cells, through a CAR incorporating a 4-1BB costimulatory domain to improve response. Since tisagenlecleucel is now a standard of care treatment for B-ALL, it is clinically essential to be able to accurately monitor these CAR T cells in patients. Assessment of the copy number variant (CNV) of the CAR T cell products allows this within a clinically acceptable timeframe for optimal patient benefit. However, no standardized method with high reproducibility and efficiency has been described within a routine clinical laboratory setting. Here, we demonstrated a novel digital droplet PCR (ddPCR)-based methodology for the study of CNV (ddPCR-CNV) in 4-1BB CD19-specific CAR T cells with universal applicability across clinical diagnostic laboratories.

Cost-Effectiveness of KTE-X19 for Adults with Relapsed/Refractory B-Cell Acute Lymphoblastic Leukemia in the United States.

INTRODUCTION: Despite currently available treatments for adults with relapsed/refractory acute lymphoblastic leukemia (R/R ALL), survival outcomes remain poor, highlighting the need for new therapeutic strategies. This study estimates the cost-effectiveness of KTE-X19 to treat adults with R/R ALL from a US payer perspective. METHODS: The model had two components: a decision-tree, where pre-infusion costs for patients who ultimately did not receive KTE-X19 are accounted for, followed by a partitioned survival analysis, where all KTE-X19 infused patients would enter the three-state (pre-progression, progressed disease, death) model. Comparators included current standard of care treatments, i.e., blinatumomab (BLIN), inotuzumab ozogamicin (INO), and salvage chemotherapy (CHEMO). Both standard parametric and mixture cure models were used to model survival. Efficacy, safety, healthcare resource utilization, and health state utility inputs were derived from the ZUMA-3 trial (NCT02614066) and literature. Cost inputs were derived from literature or publicly available sources. Outcomes and costs were discounted 3% annually. Results of KTE-X19 versus comparators are reported as total and incremental life-years (LYs), quality-adjusted life-years (QALYs), costs, and resulting incremental cost-effectiveness ratio (ICER). Deterministic and probabilistic sensitivity analyses (PSA) and key scenario analyses were also performed. RESULTS: In the base case, incremental QALYs for KTE-X19 were 2.44, 3.26, and 4.61 versus BLIN, INO, and CHEMO, respectively. Incremental costs were $50,913, $251,532, and $432,027, respectively, resulting in ICERs of $20,843/QALY (versus BLIN), $77,271/QALY (versus INO), and $93,768/QALY (versus CHEMO). Deterministic sensitivity analysis results were most sensitive to subsequent allogeneic stem cell transplant rates and post-progression utilities. PSA found that KTE-X19 is 78.4%, 74.0%, and 75.4% likely to be cost-effective versus BLIN, INO, and CHEMO, respectively. Across most scenarios, at a willingness-to-pay (WTP) threshold of $150,000/QALY, KTE-X19 was cost-effective versus all treatments. CONCLUSIONS: Compared to current options for adults with R/R ALL, KTE-X19 is cost-effective, driven primarily by improved survival.

Several treatments for adults with relapsed/refractory B-cell precursor acute lymphoblastic leukemia (R/R B-ALL) have been approved in the past decade in the US, including blinatumomab (BLIN) and inotuzumab ozogamicin (INO). However, despite the high costs associated with these treatments, survival for patients remains poor. KTE-X19, an autologous anti-CD19 chimeric antigen receptor T-cell (CAR-T) therapy, approved by the Food and Drug Administration in October 2021, has potential to improve survival, but its economic value has not yet been determined. This model comprehensively evaluated the long-term clinical and economic value of KTE-X19 versus current treatments, including BLIN, INO, and salvage chemotherapy (CHEMO). Inputs were derived from key clinical trials, the literature, and other publicly available sources. The model used the perspective of a US third party payer over a patient lifetime. Compared to BLIN, INO and CHEMO, KTE-X19 resulted in improved quality of life as measured with incremental quality-adjusted life years (QALYs) of 2.44 (vs BLIN), 3.26 (vs INO), and 4.61 (vs CHEMO). Treatment with KTE-X19 had incremental costs of $50,913 (vs BLIN), $251,532 (vs INO), and $432,027 (vs CHEMO). KTE-X19 was found to provide good value for money based on incremental cost-effectiveness ratios of $20,843/QALY (vs BLIN), $77,271/QALY (vs INO), and $93,768/QALY (vs CHEMO). These values are well below the commonly accepted thresholds to determine economic value. Results were also found to be robust across sensitivity and scenario analyses.

Unmet mental health needs in patients with advanced B-cell lymphomas.

CONTEXT: Existing research on psychological distress and mental health service utilization has focused on common types of solid tumor cancers, leaving significant gaps in our understanding of patients experiencing rare forms of hematologic cancers. OBJECTIVE: To examine distress, quality of life, and mental health service utilization among patients with aggressive, refractory B-cell lymphomas. METHOD: Patients (n = 26) with B-cell lymphomas that relapsed after first- or second-line treatment completed self-report measures of distress (Hospital Anxiety and Depression Scale) and quality of life (Short-Form Health Survey, SF-12). Patients also reported whether they had utilized mental health treatment since their cancer diagnosis. RESULTS: Approximately 42% (n = 11) of patients reported elevated levels of psychological distress. Of patients with elevated distress, only one quarter (27.2%; n = 3) received mental health treatment, while more than half did not receive mental health treatment (54.5%; n = 6), and 18.1% (n = 2) did not want treatment. Patients with elevated distress reported lower mental quality of life than patients without elevated distress [F (1, 25) = 15.32, p = 0.001]. SIGNIFICANCE OF THE RESULTS: A significant proportion of patients with advanced, progressive, B-cell lymphomas may experience elevated levels of distress. Yet, few of these distressed patients receive mental health treatment. Findings highlight the need to better identify and address barriers to mental health service utilization among patients with B-cell lymphoma, including among distressed patients who decline treatment.

Assessment of therapeutic effect of CD20-targeted immunoliposome in primary central nervous system lymphoma.

Primary central nervous system lymphoma (PCNSL) is a form of extranodal non-Hodgkin's B-cell lymphoma limited to the CNS. The treatment of PCNSL is ineffective partly due to the blood-brain barrier (BBB) restriction of delivery of many drugs including anti-CD20 (Rituximab; RTX) which is a standard treatment for systemic B-cell lymphomas. In this study, liposome with tween-80 surface modification was fabricated and conjugated with RTX for enhancing BBB penetration to target lymphoma cells in the CNS. Physicochemical characterizations of Lip/RTX were performed and spherical shape liposomes with narrow size distribution were demonstrated by TEM. An average diameter of Lip/RTX was 168.57 ± 1.57 nm with the percentage of RTX conjugation at 90.94. Cell internalization monitored by flow cytometry confirmed that conjugation of RTX promoted liposome entry into Raji cells expressing CD20. Antitumor activity of Lip/RTX was comparable to free RTX indicating that RTX moieties on liposome remained their therapeutic function. In addition, Lip/RTX inhibited tumor aggressiveness by limiting cell migration and invasion. Systemic administration of Lip/RTX significantly prolonged survival of mice harboring intracranial lymphoma xenografts. Taken together, Lip/RTX presents a new potential treatment for patients with PCNSL.

Preferential expansion of CD8+ CD19-CAR T cells postinfusion and the role of disease burden on outcome in pediatric B-ALL.

T cells expressing CD19-specific chimeric antigen receptors (CD19-CARs) have potent antileukemia activity in pediatric and adult patients with relapsed and/or refractory B-cell acute lymphoblastic leukemia (B-ALL). However, not all patients achieve a complete response (CR), and a significant percentage relapse after CD19-CAR T-cell therapy due to T-cell intrinsic and/or extrinsic mechanisms. Thus, there is a need to evaluate new CD19-CAR T-cell products in patients to improve efficacy. We developed a phase 1/2 clinical study to evaluate an institutional autologous CD19-CAR T-cell product in pediatric patients with relapsed/refractory B-ALL. Here we report the outcome of the phase 1 study participants (n = 12). Treatment was well tolerated, with a low incidence of both cytokine release syndrome (any grade, n = 6) and neurotoxicity (any grade, n = 3). Nine out of 12 patients (75%) achieved a minimal residual disease-negative CR in the bone marrow (BM). High disease burden (≥40% morphologic blasts) before CAR T-cell infusion correlated with increased side effects and lower response rate, but not with CD19-CAR T-cell expansion. After infusion, CD8+ CAR T cells had a proliferative advantage over CD4+ CAR T cells and at peak expansion, had an effector memory phenotype with evidence of antigen-driven differentiation. Patients that proceeded to allogeneic hematopoietic cell transplantation (AlloHCT) had sustained, durable responses. In summary, the initial evaluation of our institutional CD19-CAR T-cell product demonstrates safety and efficacy while highlighting the impact of pre-infusion disease burden on outcomes. This trial was registered at www.clinicaltrials.gov as #NCT03573700.

Use of Ultrasensitive RNA In Situ Hybridization for Determining Clonality in Cutaneous B-Cell Lymphomas and Lymphoid Hyperplasia Decreases Subsequent Use of Molecular Testing and Is Cost-effective.

Primary cutaneous B-cell lymphomas (PCBCLs) are diagnostically challenging entities due to significant overlap in clinical and morphologic features with reactive lymphoid proliferations. Traditional methods for evaluating clonality such as immunohistochemistry (IHC) and chromogenic in situ hybridization (CISH) are limited by low sensitivity, which leads to additional costly and time-consuming molecular clonality assays. More recent technology has introduced ultrasensitive bright-field RNA in situ hybridization (BRISH) to the field, which can detect single molecules of light-chain mRNA. The current study evaluated 274 cases of PCBCL in addition to atypical and reactive lymphoid infiltrates, with CISH or BRISH performed on 180 (65.7%). CISH was performed on 105 (58.3%), and BRISH was performed on 75 (41.7%). Significantly fewer immunoglobulin heavy-chain (IGH) rearrangement studies were performed on cases that were evaluated with BRISH as compared with CISH (P=0.02). Subgroup analysis demonstrated that cases with restriction by BRISH were significantly less likely to have subsequent IGH studies performed (P=0.01). The expected costs of cases using CISH versus BRISH were $1053.89 versus $810.32 to the patient and $245.63 versus $225.23 to the laboratory. The use of ultrasensitive BRISH to evaluate clonality in PCBCL reduced the use of IGH rearrangement studies when compared with CISH. In particular, cases with light-chain restriction by BRISH did not result in confirmatory molecular testing. Despite slightly higher costs to the laboratory to perform BRISH, routine use of this methodology can result in cost savings to both the patient and laboratory by decreasing the use of expensive molecular methods.

Blinatumomab Nonresponse and High-Disease Burden Are Associated With Inferior Outcomes After CD19-CAR for B-ALL.

PURPOSE: CD19-targeted chimeric antigen receptor T cells (CD19-CAR) and blinatumomab effectively induce remission in relapsed or refractory B-cell acute lymphoblastic leukemia (ALL) but are also associated with CD19 antigen modulation. There are limited data regarding the impact of prior blinatumomab exposure on subsequent CD19-CAR outcomes. PATIENTS AND METHODS: We conducted a multicenter, retrospective review of children and young adults with relapsed or refractory ALL who received CD19-CAR between 2012 and 2019. Primary objectives addressed 6-month relapse-free survival (RFS) and event-free survival (EFS), stratified by blinatumomab use. Secondary objectives included comparison of longer-term survival outcomes, complete remission rates, CD19 modulation, and identification of factors associated with EFS. RESULTS: Of 420 patients (median age, 12.7 years; interquartile range, 7.1-17.5) treated with commercial tisagenlecleucel or one of three investigational CD19-CAR constructs, 77 (18.3%) received prior blinatumomab. Blinatumomab-exposed patients more frequently harbored KMT2A rearrangements and underwent a prior stem-cell transplant than blinatumomab-naïve patients. Among patients evaluable for CD19-CAR response (n = 412), blinatumomab nonresponders had lower complete remission rates to CD19-CAR (20 of 31, 64.5%) than blinatumomab responders (39 of 42, 92.9%) or blinatumomab-naive patients (317 of 339, 93.5%), P < .0001. Following CD19-CAR, blinatumomab nonresponders had worse 6-month EFS (27.3%; 95% CI, 13.6 to 43.0) compared with blinatumomab responders (66.9%; 95% CI, 50.6 to 78.9; P < .0001) or blinatumomab-naïve patients (72.6%; 95% CI, 67.5 to 77; P < .0001) and worse RFS. High-disease burden independently associated with inferior EFS. CD19-dim or partial expression (preinfusion) was more frequently seen in blinatumomab-exposed patients (13.3% v 6.5%; P = .06) and associated with lower EFS and RFS. CONCLUSION: With the largest series to date in pediatric CD19-CAR, and, to our knowledge, the first to study the impact of sequential CD19 targeting, we demonstrate that blinatumomab nonresponse and high-disease burden were independently associated with worse RFS and EFS, identifying important indicators of long-term outcomes following CD19-CAR.

Chimeric antigen receptor T-cells in New Zealand: challenges and opportunities.

Chimeric antigen receptor (CAR) T-cells are a personalised cell and gene therapy for cancer that are becoming an international standard of care for some refractory B-cell leukaemias, non-Hodgkin lymphomas and myeloma. A single CAR T-cell administration can result in durable complete response for some recipients. Domestic CAR T-cell manufacturing capability was established for Aotearoa New Zealand's first CAR T-cell trial (ENABLE, ClinicalTrials.gov NCT04049513). This article outlines CAR T-cell manufacturing and logistical considerations, with a focus on New Zealand's environment for this personalised cell and gene therapy. We discuss Maori engagement in CAR T-cell trial and clinical service design, and propose enhancing Maori guardianship (kaitiakitanga) over cells and genetic material through on-shore manufacture. Strategies to safely deliver CAR T-cells within New Zealand's healthcare system are outlined. Finally, we discuss challenges to, and opportunities for, widening CAR T-cell availability and assuring equity of access. Based on our experience, we consider Aotearoa New Zealand to be in an excellent position to develop and implement investigational and commercial CAR T-cell therapies in the future.

Next-Generation Sequencing-Based Clonality Assessment of Ig Gene Rearrangements: A Multicenter Validation Study by EuroClonality-NGS.

Ig gene (IG) clonality analysis has an important role in the distinction of benign and malignant B-cell lymphoid proliferations and is mostly performed with the conventional EuroClonality/BIOMED-2 multiplex PCR protocol and GeneScan fragment size analysis. Recently, the EuroClonality-NGS Working Group developed a method for next-generation sequencing (NGS)-based IG clonality analysis. Herein, we report the results of an international multicenter biological validation of this novel method compared with the gold standard EuroClonality/BIOMED-2 protocol, based on 209 specimens of reactive and neoplastic lymphoproliferations. NGS-based IG clonality analysis showed a high interlaboratory concordance (99%) and high concordance with conventional clonality analysis (98%) for the molecular conclusion. Detailed analysis of the individual IG heavy chain and kappa light chain targets showed that NGS-based clonality analysis was more often able to detect a clonal rearrangement or yield an interpretable result. NGS-based and conventional clonality analysis detected a clone in 96% and 95% of B-cell neoplasms, respectively, and all but one of the reactive cases were scored polyclonal. We conclude that NGS-based IG clonality analysis performs comparable to conventional clonality analysis. We provide critical parameters for interpretation and discuss a first step toward a quantitative scoring approach for NGS clonality results. Considering the advantages of NGS-based clonality analysis, including its high sensitivity and possibilities for accurate clonal comparison, this supports implementation in diagnostic practice.

Multiple Immunoglobulin κ Gene Rearrangements within a Single Clone Unraveled by Next-Generation Sequencing-Based Clonality Assessment.

Clonality assessment of the Ig heavy- and light-chain genes (IGH and IGK) using GeneScan analysis is an important supplemental assay in diagnostic testing for lymphoma. Occasionally cases with an IGK rearrangement pattern that cannot readily be assigned to a monoclonal lymphoma are encountered, whereas the occurrence of biclonal lymphomas is rare, and the result of the IGH locus of these cases is in line with monoclonality. Three such ambiguous cases were assessed for clonality using next-generation sequencing. Information on the sequences of the rearrangements, combined with knowledge of the complex organization of the IGK locus, pointed to two explanations that can attribute seemingly biclonal IGK rearrangements to a single clone. In two cases, this explanation involved inversion rearrangements on the IGK locus, whereas in the third case, the cross-reactivity of primers generated an additional clonal product. In conclusion, next-generation sequencing-based clonality assessment allows for the detection of both inversion rearrangements and the cross-reactivity of primers, and can therefore facilitate the interpretation of cases of lymphoma with complex IGK rearrangement patterns.

Perspectives on outpatient administration of CAR-T cell therapy in aggressive B-cell lymphoma and acute lymphoblastic leukemia.

Chimeric antigen receptor (CAR) T-cell therapies that specifically target the CD19 antigen have emerged as a highly effective treatment option in patients with refractory B-cell hematological malignancies. Safety and efficacy outcomes from the pivotal prospective clinical trials of axicabtagene ciloleucel, tisagenlecleucel and lisocabtagene maraleucel and the retrospective, postmarketing, real-world analyses have confirmed high response rates and durable remissions in patients who had failed multiple lines of therapy and had no meaningful treatment options. Although initially administered in the inpatient setting, there has been a growing interest in delivering CAR-T cell therapy in the outpatient setting; however, this has not been adopted as standard clinical practice for multiple reasons, including logistic and reimbursement issues. CAR-T cell therapy requires a multidisciplinary approach and coordination, particularly if given in an outpatient setting. The ability to monitor patients closely is necessary and proper protocols must be established to respond to clinical changes to ensure efficient, effective and rapid evaluation either in the clinic or emergency department for management decisions regarding fever, sepsis, cytokine release syndrome and neurological events, specifically immune effector cell-associated neurotoxicity syndrome. This review presents the authors' institutional experience with the preparation and delivery of outpatient CD19-directed CAR-T cell therapy.