Axicabtagene Ciloleucel as Second-Line Therapy for Large B-Cell Lymphoma

Incidence, clinical characteristics and prognosis of tumor lysis syndrome following B-cell maturation antigen-targeted chimeric antigen receptor-T cell therapy in relapsed/refractory multiple myeloma

Background aims

B-cell maturation antigen (BCMA)-targeted chimeric antigen receptor-T cell (CAR-T) therapy is used for refractory or relapsed multiple myeloma (r/r MM). However, CAR-T-related tumor lysis syndrome (TLS) has been observed. We aimed to elucidate the incidence, clinical and laboratory characteristics, and prognosis of CAR-T cell-related TLS.

Methods

Patients (n=105) with r/r MM treated with BCMA-targeted CAR-T cell therapy were included. Patient characteristics, laboratory parameters, and clinical outcomes were assessed.

Results

Eighteen (17.1%) patients developed TLS after BCMA-targeted CAR-T cell therapy. The median time till TLS onset was 8 days. Patients with TLS had steep rise in uric acid (UA), creatinine, and lactate dehydrogenase (LDH) within 6 days following CAR-T cell infusion and presented earlier and persistent escalation of cytokines (C-reactive protein [CRP], interleukin-6 [IL-6], interferon-γ [IFN-γ], and ferritin levels). All 18 patients had cytokine release syndrome (CRS), of which 13 (72.2%) developed grade 3-4 CRS. Three of 18 patients (16.7%) developed immune effector cell-associated neurotoxicity syndrome (ICANS): two patients with grade 1 ICANS and one with grade 2 ICANS. TLS development had a negative effect on the objective response rate (77.8% in the TLS group vs. 95.4% in the non-TLS group, p<0.01). During the median follow-up of 15.1 months, the median PFS was poorer of patients with TLS (median: 3.4 months in the TLS group vs. 14.7 months in the non-TLS group, p<0.001, hazard ratio [HR]=3.5 [95% confidence interval [CI] 1.5-8.5]). Also, TLS development exhibited significant effects on OS (median: 5.0 months in the TLS group vs. 39.8 months in the non-TLS group, p<0.001, hazard ratio [HR]=3.7 [95% CI 1.3-10.3]). TLS was associated with a higher tumor burden, elevated baseline creatinine and UA levels, severe CRS, pronounced CAR-T cell expansion, and corticosteroid use.

Conclusion

TLS is a frequently observed CAR-T therapy complication and negatively influences clinical response and prognosis. Close monitoring for TLS should be implemented during CAR-T cell therapy, especially for those at high TLS risk.

Quality-Adjusted Time without Symptoms or Toxicity: Analysis of Axicabtagene Ciloleucel versus Standard of Care in Patients with Relapsed/Refractory Large B Cell Lymphoma

The quality-adjusted time without symptoms or toxicity (Q-TWiST) methodology provides a comprehensive framework for treatment comparison that partitions survival time into distinct health states reflecting both treatment toxicity and disease progression. ZUMA-7 (ClinicalTrials.gov identifier NCT03391466), a phase 3 randomized open-label multicenter study, was conducted to evaluate the efficacy of axicabtagene ciloleucel (axi-cel), a chimeric antigen receptor T cell therapy, compared with standard of care (SOC) involving platinum-based salvage chemotherapy with autologous stem cell transplantation (ASCT) consolidation as a second-line treatment for relapsed/refractory (R/R) large B cell lymphoma (LBCL), and met its primary endpoint of improved event-free survival (EFS). We aimed to use the Q-TWiST method to compare the quality-adjusted survival of R/R LBCL patients treated with axi-cel and those treated with SOC who were enrolled in ZUMA-7. The preplanned analysis of overall survival (OS) was partitioned into 3 mutually exclusive health states: time with grade ≥3 adverse events before the event as defined in the EFS analysis (TOX), time without severe toxicity before the event (TWiST), and time after the event (REL). Q-TWiST was computed as a weighted sum of mean TOX, TWiST, and REL values multiplied by state-specific quality of life (QoL) utility scores. Q-TWiST was evaluated in the intention-to-treat cohort at median follow-up. A relative Q-TWiST gain of 10% was deemed "clinically important" and a gain of ≥15% was deemed "clearly clinically important" based on established categorization. Sensitivity analyses with follow-up ranging from 3 months to the maximum follow-up and subgroup analyses by age and R/R status were explored. At a median follow-up of 23.5 months, the axi-cel cohort showed a significantly longer time without severe toxicity compared with the SOC cohort, with a mean TWiST duration of 11.18 months versus 5.39 months, respectively. The mean TOX was 1.16 months versus .74 months, and mean REL was 6.02 months versus 10.66 months. Quality-adjusted survival was significantly longer with axi-cel by 3.7 months (95% CI, 2.3 to 5.2 months), representing a relative gain of 21.9%. This was reflected across all subgroups, with estimated Q-TWiST gains of 3.1 months (95% CI, 1.5 to 4.9 months) for patients age <65 years, 5.2 months (95% CI, 2.4 to 7.9 months) for those age ≥65 years, 3.2 months (95% CI, 1.4 to 4.9 months) for those with primary refractory disease, 9.1 months (95% CI, 3.9 to months 13.5) for those who relapsed within 6 months, and 4.1 months (95% CI, 1.1 to 7.1 months) for those who relapsed between 6 and 12 months. The Q-TWiST gain for axi-cel also was statistically significant across follow-up durations, increasing from .2 month (95% CI, .1 to .3 month) at a 3-month follow-up to 4.9 months (95% CI, 2.4 to 7.8 months) at the maximum follow-up of 37.7 months. Axi-cel was associated with a statistically significant and "clearly clinically important" gain in quality-adjusted survival, regardless of the relative decline in QoL associated with treatment toxicity, disease progression, or additional cancer treatment. This finding adds to the existing evidence supporting a benefit for axi-cel as a second-line treatment for patients with R/R LBCL.

An International Survey on Grading, Diagnosis, and Management of Immune Effector Cell-Associated Hematotoxicity (ICAHT) Following CAR T-cell Therapy on Behalf of the EBMT and EHA

Hematological toxicity represents the most common grade ≥3 toxicity after chimeric antigen receptor (CAR) T-cell therapy. However, its underlying pathophysiology is incompletely understood and its grading and management remains ill-defined. To inform the forthcoming European Hematology Association/European Society for Blood and Marrow Transplantation (EHA/EBMT) guidelines on the management of "immune effector cell-associated hematotoxicity" (ICAHT), we undertook a survey of experienced clinicians using an online survey focusing on (1) grading, (2) risk-stratification and diagnostic work-up, (3) short-term, and (4) long-term management of ICAHT. There were 81 survey respondents across 18 countries. A high degree of variability was noted for cytopenia grading in regards to depth, duration, and time from CAR-T infusion. The majority of experts favored pre-CAR-T bone marrow studies, especially in case of a high-risk profile. Most respondents felt that the work-up for patients with severe hematotoxicity should rule-out viral infections (96%), substrate deficiency (80%), or coincident sHLH/MAS (serum ferritin, 92%), and should include bone marrow aspiration (86%) and/or biopsy (61%). Clinicians were divided as to whether the occurrence of coincident immunotoxicity should influence the decision to apply G-CSF, and when to initiate G-CSF support. In case of prolonged thrombocytopenia, most survey participants favored thrombopoietin agonists (86%). Conversely, autologous hematopoietic cell boosts represented the preferred choice for neutropenia (63%), although they were frequently not available and no consensus was reached regarding the optimal trigger point. These findings underline the current heterogeneity of practice patterns regarding ICAHT and invite the development of consensus guidelines, which may harmonize grading, establish standard operating procedures for diagnosis, and set management guidelines.

Upregulated Expression of ErbB1 in Diffuse Large B-Cell Lymphoma as a Predictor of Poor Overall Survival Outcome

We examined the transcript-level expression of ErbB family protein tyrosine kinases, including ERBB1, in primary malignant lymphoma cells from 498 adult patients with diffuse large B-cell lymphoma (DLBCL). ERBB1 expression in DLBCL cells was significantly higher than in normal B-lineage lymphoid cells. An upregulated expression of ERBB1 mRNA in DLBCL cells was correlated with an amplified expression of mRNAs for transcription factors that recognized ERBB1 gene promoter sites. Notably, amplified ERBB1 expression in DLBCL and its subtypes were associated with significantly worse overall survival (OS). Our results encourage the further evaluation of the prognostic significance of high-level ERBB1 mRNA expression and the clinical potential of ERBB1-targeting therapeutics as personalized medicines in high-risk DLBCL.

Diffuse Large B-Cell Lymphoma and Related Entities

BACKGROUND

Diffuse large B-cell lymphoma (DLBCL) is the most common malignant B-cell neoplasm, with an incidence of 5.6 per 100 000 persons per year and a mean age of onset of approximately 65 years. It is an aggressive type of non-Hodgkin's lymphoma requiring urgent treatment with curative intent. Evidence-based guidelines have not been available to date.

METHODS

For this first international evidence-based DLBCL-specific guideline, various systematic literature searches were performed. 5 systematic reviews, 21 randomized controlled trials (RCTs), and 36 non-randomized studies were used to formulate 42 recommendations. 142 were formulated on the basis of expert consensus. All recommendations were approved in a structured consensus-finding process.

RESULTS

For staging, combined positron emission tomography and computed tomography (PET/CT) should be performed (evidence: a prospective registry study). For all patients with a new diagnosis of DLBCL and without contraindications, R-CHOP based immunochemotherapy (rituximab, cyclophosphamide, doxorubicin, vincristine, prednisone) should be initiated with curative intent (evidence: RCTs). The individual treatment strategy is tailored to the patient's age and risk constellation. Once immunochemotherapy has been completed, PET/CT should be performed again to check for remission. Patients with PET-positive residual disease that is amenable to radiotherapy should be treated with consolidating irradiation (evidence: retrospective cohort study).

CONCLUSION

This clinical practice guideline on the diagnosis, treatment, and followup of patients with DLBCL and related entities provides a standardized clinical management approach, identifies areas where improvement would be desirable, and can serve as a basis for the development of further studies.

Integration of molecular testing for the personalized management of patients with diffuse large B-cell lymphoma and follicular lymphoma

Diffuse large B-cell lymphoma (DLBCL) and follicular lymphoma (FL) are the most common forms of aggressive and indolent lymphoma, respectively. The majority of patients are cured by standard R-CHOP immunochemotherapy, but 30%–40% of DLBCL and 20% of FL patients relapse or are refractory (R/R). DLBCL and FL are phenotypically and genetically hereterogenous B-cell neoplasms. To date, the diagnosis of DLBCL and FL has been based on morphology, immunophenotyping and cytogenetics. However, next-generation sequencing (NGS) is widening our understanding of the genetic basis of the B-cell lymphomas. In this review we will discuss how integrating the NGS-based characterization of somatic gene mutations with diagnostic or prognostic value in DLBCL and FL could help refine B-cell lymphoma classification as part of a multidisciplinary pathology work-up. We will also discuss how molecular testing can identify candidates for clinical trials with targeted therapies and help predict therapeutic outcome to currently available treatments, including chimeric antigen receptor T-cell, as well as explore the application of circulating cell-free DNA, a non-invasive method for patient monitoring. We conclude that molecular analyses can drive improvements in patient outcomes due to an increased understanding of the different pathogenic pathways affected by each DLBCL subtype and indolent FL vs R/R FL.

Real-life experiences with CAR T-cell therapy with idecabtagene vicleucel (ide-cel) for triple-class exposed relapsed/refractory multiple myeloma patients

BACKGROUND

Chimeric antigen receptor (CAR) T-cell therapy has revolutionized the treatment landscape of relapsed/refractory multiple myeloma (RRMM), leading to unprecedented responses in this patient population. Idecabtagene vicleucel (ide-cel) has been recently approved for treatment of triple-class exposed RRMM. We report real-life experiences with the commercial use of ide-cel in RRMM patients.

METHODS

We performed a retrospective analysis of the first 16 triple-class exposed RRMM patients treated with ide-cel at a single academic center. We assessed toxicities, response to treatment, CAR T expansion and soluble BCMA (sBCMA) levels.

RESULTS

We identified 16 consecutive RRMM patients treated with ide-cel between 06-10/2022. Median age was 69 years, 6 (38%) patients had high-risk cytogenetics, 3 (19%) R-ISS stage III, and 5 (31%) extramedullary disease. Median number of previous treatment lines was 6 (3-12). Manufacturing success rate was 88% (6% required second lymphapheresis, 6% received an out-of-specification product). At 3 months, the overall response rate (ORR) was 69% (44% sCR, 6% CR, 19% VGPR). Cytokine release syndrome (CRS) occurred in 15 (94%) patients (88% G1, 6% G2), immune effector-cell associated neurotoxicity syndrome (ICANS) in 1 (6% G1), febrile neutropenia in 11 (69%), and infections in 5 (31%). Prolonged hematologic toxicity occurred in 4/16 (25%) patients. Other non-hematological toxicities were elevated hepatic enzymes (38%), colitis (6%, G3) and DIC (6%, G2). Responses were more frequent in patients with higher CAR T expansion (100% vs 38%), and lack of decrease or plateau of sBCMA levels was typically observed in non-responders.

CONCLUSIONS

We report one of the first cohorts of RRMM treated with commercial ide-cel. The ORR was 69% and safety profile was manageable, but prolonged hematologic toxicity still represents a major challenge. Responses correlated with in vivo CAR T cell expansion, underlining the need of further research to optimize CAR T expansion.

Cytotoxicity of CD19-CAR-NK92 cells is primarily mediated via perforin/granzyme pathway

Chimeric antigen receptors (CARs) have improved cancer immunotherapy in recent years. Immune cells, such as Natural killer cells (NK-cells) or T cells, are used as effector cells in CAR-therapy. NK92-cells, a cell line with known cytotoxic activity, are of particular interest in CAR-therapy since culturing conditions are simple and anti-tumor efficacy combined with a manageable safety profile was proven in clinical trials. The major pathways of immune effector cells, including NK92-cells, to mediate cytotoxicity, are the perforin/granzyme and the death-receptor pathway. Detailed knowledge of CAR-effector cells' cytotoxic mechanisms is essential to unravel resistance mechanisms, which potentially arise by resistance against apoptosis-inducing signaling. Since mutations in apoptosis pathways are frequent in lymphoma, the impact on CAR-mediated cytotoxicity is of clinical interest. In this study, knockout models of CD19-CAR-NK92 cells were designed, to investigate cytotoxic pathways in vitro. Knockout of perforin 1 (Prf1) and subsequent abrogation of the perforin/granzyme pathway dramatically reduced the cytotoxicity of CD19-CAR-NK92 cells. In contrast, knockout of FasL and inhibition of TRAIL (tumor necrosis factor-related apoptosis-inducing ligands) did not impair cytotoxicity in most conditions. In conclusion, these results indicate the perforin/granzyme pathway as the major pathway to mediate cytotoxicity in CD19-CAR-NK92 cells.

Long-term outcomes following CAR T cell therapy: what we know so far

Chimeric antigen receptors (CAR) are engineered fusion proteins designed to target T cells to antigens expressed on cancer cells. CAR T cells are now an established treatment for patients with relapsed and/or refractory B cell lymphomas, B cell acute lymphoblastic leukaemia and multiple myeloma. At the time of this writing, over a decade of follow-up data are available from the initial patients who received CD19-targeted CAR T cells for B cell malignancies. Data on the outcomes of patients who received B cell maturation antigen (BCMA)-targeted CAR T cells for multiple myeloma are more limited owing to the more recent development of these constructs. In this Review, we summarize long-term follow-up data on efficacy and toxicities from patients treated with CAR T cells targeting CD19 or BCMA. Overall, the data demonstrate that CD19-targeted CAR T cells can induce prolonged remissions in patients with B cell malignancies, often with minimal long-term toxicities, and are probably curative for a subset of patients. By contrast, remissions induced by BCMA-targeted CAR T cells are typically more short-lived but also generally have only limited long-term toxicities. We discuss factors associated with long-term remissions, including the depth of initial response, malignancy characteristics predictive of response, peak circulating CAR levels and the role of lymphodepleting chemotherapy. We also discuss ongoing investigational strategies designed to improve the length of remission following CAR T cell therapy.

Surface TREM2 on circulating M-MDSCs as a novel prognostic factor for adults with treatment-naïve diffuse large B-cell lymphoma

INTRODUCTION

Circulating monocytic myeloid-derived suppressive cells (M-MDSCs) are implicated as a poor prognostic factor and cause CAR T-cell failure in diffuse large B-cell lymphoma (DLBCL). Triggering receptors expressed on myeloid cells 2 (TREM2) are a transmembrane glycoprotein that polarize macrophages to anti-inflammation phenotype but have never been explored on M-MDSCs. This study aims to elucidate the expression and clinical impact of surface TREM2 on circulating M-MDSCs derived from DLBCL adults.

METHODS

This prospective, observational study enrolled 100 adults with newly diagnosed and treatment-naïve DLBCL from May 2019 to October 2021. Human circulating M-MDSCs were obtained from freshly isolated peripheral blood, and each patient's surface-TREM2 level on M-MDSCs was normalized via a healthy control at the same performance of flow-cytometry analysis. Murine MDSCs derived from bone marrow (BM-MDSCs) were adopted to assess the link between Trem2 and cytotoxic T lymphocytes.

RESULTS

More circulating M-MDSCs at diagnosis of DLBCL predicted worse progression-free (PFS) and overall survival (OS). Patients with higher IPI scores, bone marrow involvement, or lower absolute counts of CD4⁺ or CD8⁺ T cells in PB had significantly higher normalized TREM2 levels on M-MDSCs. Additionally, normalized TREM2 levels on M-MDSCs could be grouped into low (< 2%), medium (2-44%), or high (> 44%) levels, and a high normalized TREM2 level on M-MDSCs was proven as an independent prognostic factor for both PFS and OS via multivariate Cox regression analysis and associated with worst PFS and OS. Interestingly, normalized levels of surface TREM2 on M-MDSCs were negatively associated with absolute counts of PB CD8⁺ T cells and positively correlated with levels of intracellular arginase 1 (ARG1) within M-MDSCs. Wild-type BM-MDSCs had significantly higher mRNA levels of Arg1 and showed more prominent ability to suppress the proliferation of co-cultured CD8⁺ T cells than BM-MDSCs from Trem2 knockout mice, and the suppressive ability could be impaired by adding Arg1 inhibitors (CB1158) or supplementing L-arginine.

CONCLUSION

In treatment-naïve DLBCL adults, a high surface-TREM2 level on circulating M-MDSCs is a poor prognostic factor for both PFS and OS and warrants further investigation for its potential as a novel target in immunotherapy.

Lisocabtagene maraleucel as second-line therapy for large B-cell lymphoma: primary analysis of the phase 3 TRANSFORM study

This global phase 3 study compared lisocabtagene maraleucel (liso-cel) with a standard of care (SOC) as second-line therapy for primary refractory or early relapsed (≤12 months) large B-cell lymphoma (LBCL). Adults eligible for autologous stem cell transplantation (ASCT; N = 184) were randomly assigned in a 1:1 ratio to liso-cel (100 × 106 chimeric antigen receptor-positive T cells) or SOC (3 cycles of platinum-based immunochemotherapy followed by high-dose chemotherapy and ASCT in responders). The primary end point was event-free survival (EFS). In this primary analysis with a 17.5-month median follow-up, median EFS was not reached (NR) for liso-cel vs 2.4 months for SOC. Complete response (CR) rate was 74% for liso-cel vs 43% for SOC (P < .0001) and median progression-free survival (PFS) was NR for liso-cel vs 6.2 months for SOC (hazard ratio [HR] = 0.400; P < .0001). Median overall survival (OS) was NR for liso-cel vs 29.9 months for SOC (HR = 0.724; P = .0987). When adjusted for crossover from SOC to liso-cel, 18-month OS rates were 73% for liso-cel and 54% for SOC (HR = 0.415). Grade 3 cytokine release syndrome and neurological events occurred in 1% and 4% of patients in the liso-cel arm, respectively (no grade 4 or 5 events). These data show significant improvements in EFS, CR rate, and PFS for liso-cel compared with SOC and support liso-cel as a preferred second-line treatment compared with SOC in patients with primary refractory or early relapsed LBCL. This trial was registered at www.clinicaltrials.gov as #NCT03575351.

Are dynamic or fixed FDG-PET measures of disease of greater prognostic value in patients with relapsed/refractory diffuse large B-cell lymphoma undergoing autologous haematopoietic stem cell transplantation?

Positron emission tomography (PET) response assessment using the Deauville score has prognostic utility in relapsed/refractory (R/R) diffuse large B-cell lymphoma (DLBCL) undergoing autologous stem-cell transplantation (ASCT). Improved predictive methods are required to identify patients with poor outcomes who may be better considered for other salvage options. We investigated the prognostic value of mean tumour volume (MTV) and maximum standardised uptake value (SUVmax) at pre-salvage and pre-ASCT time-points, and the quantitative changes between scans (∆MTV and ∆SUVmax). One hundred and twenty-five patients with R/R DLBCL underwent salvage immunochemotherapy and ASCT: 80 patients had pre-salvage PET and 90 had pre-ASCT PET available. With a median follow-up of 5.6 years, 5-year progression-free survival (PFS) and overall survival (OS) were 52% and 65%, respectively. For patients with PET-positive residual disease after salvage therapy, pre-ASCT MTV was a significant negative prognosticator for PFS (HR 1.19 per 100 ml, p < 0.001) and OS (HR 1.78 per 100 ml, p < 0.001). Similarly, pre-ASCT SUVmax was negatively associated with PFS (HR 1.08, p < 0.001) and OS (HR 1.08, p < 0.001). Notably, pre-salvage MTV and SUVmax and ∆MTV and ∆SUVmax were not associated with PFS or OS. In conclusion, pre-ASCT MTV and SUVmax appear to be of greater predictive value than the degree of response. Potential application may exist for PET-directed management of R/R DLBCL patients.

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.

RNA silencing of GM-CSF in CAR-T cells reduces the secretion of multiple inflammatory cytokines

Chimeric antigen receptor T (CAR-T) cell therapy has become a research hotspot in the field of hematological malignancies. However, CAR-T cell therapy can lead to immunotherapy-associated side effects including cytokine release syndrome and neurotoxicity. Gene depletion of GM-CSF in CAR-T cells was found preventive against adverse effects, but additional transfections were required to produce CAR-T cells. In this study, we interrupted GM-CSF expression in CAR-T cells by inserting the GM-CSF shRNA-expression cassette in the CAR vector. Reduction of GM-CSF in CAR-T cells could decrease the level of several proinflammatory cytokines without hampering the killing capacity. The manufacture of GM-CSF knockdown CAR-T cells does not require complicated transfections, which makes it more practical and feasible for clinical application.

CAR-T Cell Therapy: the Efficacy and Toxicity Balance

PURPOSE OF REVIEW

Chimeric antigen receptor (CAR) T cell therapy is an immunotherapy that has resulted in tremendous progress in the treatment of patients with B cell malignancies. However, the remarkable efficacy of therapy is not without significant safety concerns. Herein, we will review the unique and potentially life-threatening toxicities associated with CAR-T cell therapy and their association with treatment efficacy.

RECENT FINDINGS

Currently, CAR-T cell therapy is approved for the treatment of B cell relapsed or refractory leukemia and lymphoma, and most recently, multiple myeloma (MM). In these different diseases, it has led to excellent complete and overall response rates depending on the patient population and therapy. Despite promising efficacy, CAR-T cell therapy is associated with significant side effects; the two most notable toxicities are cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS). The treatment of CAR-T-induced toxicity is supportive; however, as higher-grade adverse events occur, toxicity-directed therapy with tocilizumab, an IL-6 receptor antibody, and steroids is standard practice. Overall, a careful risk-benefit balance exists between the efficacy and toxicities of therapies. The challenge lies in the underlying pathophysiology of CAR-T-related toxicity which relies upon the activation of CAR-T cells. Some degree of toxicity is expected to achieve an effective response to therapy, and certain aspects of treatment are also associated with toxicity. As progress is made in the investigation and approval of new CARs, novel toxicity-directed therapies and toxicity-limited constructs will be the focus of attention.

Severe cytopenia after CD19 CAR T-cell therapy: a retrospective study from the EBMT Transplant Complications Working Party

We investigated the incidence and outcome of anti-CD19 chimeric antigen receptor (CAR) T-cells-associated Common Terminology Criteria for Adverse Events (CTCAE) ≥grade 3 cytopenia. In the EBMT CAR-T registry, we identified 398 adult patients with large B-cell lymphoma who had been treated with CAR-T-cells with axicel (62%) or tisacel (38%) before August 2021 and had cytopenia status documented for the first 100 days. Most patients had received two or three previous lines of therapy, however, 22.3% had received four or more. Disease status was progressive in 80.4%, stable in 5.0% and partial/complete remission in 14.6%. 25.9% of the patients had received a transplantation before. Median age was 61.4 years (min-max; IQR=18.7-81; (52.9-69.5)).The cumulative incidence of ≥grade 3 cytopenia was 9.0% at 30 days (95% CI (6.5 to 12.1)) and 12.1% at 100 days after CAR T-cell infusion (95% CI (9.1 to 15.5)). The median time from CAR-T infusion to cytopenia onset was 16.5 days (min-max; IQR=1-90; (4-29.8)). Grade 3 and grade 4 CTCAE cytopenia occurred in 15.2% and 84.8%, respectively. In 47.6% there was no resolution.Severe cytopenia had no significant impact on overall survival (OS) (HR 1.13 (95% CI 0.74 to 1.73), p=0.57). However, patients with severe cytopenia had a poorer progression-free survival (PFS) (HR 1.54 (95% CI 1.07 to 2.22), p=0.02) and a higher relapse incidence (HR 1.52 (95% CI 1.04 to 2.23), p=0.03). In those patients who developed severe cytopenia during the first 100 days (n=47), OS, PFS, relapse incidence and non-relapse mortality at 12 months after diagnosis of severe cytopenia were 53.6% (95% CI (40.3 to 71.2)), 20% (95% CI (10.4 to 38.6)), 73.5% (95% CI (55.2 to 85.2)) and 6.5% (95% CI (1.7 to 16.2)), respectively.In multivariate analysis of severe cytopenia risk factors, only year of CAR-T infusion (HR=0.61, 95% CI (0.39 to 0.95), p=0.028) and total number of treatment lines before CAR-T infusion (one or two lines vs three or more, HR=0.41, 95% CI (0.21 to 0.83), p=0.013) had a significant positive association with the incidence of cytopenia. Other factors, such as previous transplantation, disease status at time of CAR-T, patient age and patient sex, had no significant association.Our data provide insight on frequency and clinical relevance of severe cytopenia after CAR T-cell therapy in the European real-world setting.

Combining radiotherapy and NK cell-based therapies: The time has come

Natural killer (NK) cells are innate lymphoid cells that play an essential role in the anti-tumor response through immunosurveillance, multiple mechanisms of cytotoxicity and the synthesis of cytokines modulating the immune tumor microenvironment (TME). After the dramatic advances in immunotherapy targeting T cells including the success of checkpoint inhibitors or autologous chimeric antigen receptor (CAR) expressing T cells in clinical practice, NK cells have gained growing interest for the development of new therapies. Although NK cells have shown promising responses in leukemia patients, the effects of NK-targeted therapies are currently limited in the treatment of solid tumors. Thus, radiotherapy could provide a valuable solution to improve treatments targeting NK cells. Indeed, ionizing radiations represent a powerful immuno-modulator that can either induce a pro-inflammatory and anti-tumor TME, or conversely lead to immunosuppression of effector immune cells in favor of tumor growth and therapeutic escape, depending on how it is delivered and tumor models. However, the effects of ionizing radiation on NK cells are only partially understood. Therefore, we review the effects of radiotherapy on the NK cell-mediated anti-tumor response, and propose potential strategies to reinvigorate NK cells by combining radiotherapy with NK cell-targeted therapies.

Cellular Therapies in Chronic Lymphocytic Leukemia and Richter’s Transformation: Recent Developments in Chimeric Antigen Receptor T-Cells, Natural Killer Cells, and Allogeneic Stem Cell Transplant

Cellular therapies can be viewed as both the newest and oldest techniques for treating chronic lymphocytic leukemia (CLL) and Richter’s transformation (RT). On one hand, allogeneic hematopoietic stem cell transplantation (alloHSCT) has been available for decades, though its use is diminishing with the increasing availability of effective novel targeted agents, especially in CLL. Among newer techniques, chimeric antigen receptor T-cells (CAR-T) have demonstrated astounding efficacy in several hematologic malignancies, leading to FDA approval and use in clinical practice. However, though CLL is the earliest disease type for which CAR-T were studied, development has been slower and has yet to lead to regulatory approval. Owing partially to its rarity but also due to the aggressive behavior of RT, CAR-T in RT have only been minimally explored. Here, we will focus on the applications of cellular therapies in CLL and RT, specifically reviewing more recent data related to alloHSCT in the novel-agent era and CAR-T cell development in CLL/RT, focusing on safety and efficacy successes and limitations. We will review strategies to improve upon CAR-T efficacy and discuss ongoing trials utilizing CAR-T in CLL/RT, as well as emerging technologies, such as allogeneic CAR-T and natural killer CAR (CAR NK) cells.

NTRK fusion protein expression is absent in a large cohort of diffuse large B-cell lymphoma

Background

Even though two NTRK-targeting drugs are available for the treatment of irresectable, metastatic, or progressive NTRK-positive solid tumors, less is known about the role of NTRK fusions in lymphoma. For this reason, we aimed to investigate if NTRK fusion proteins are expressed in diffuse large B-cell lymphoma (DLBCL) by systemic immunohistochemistry (IHC) screening and additional FISH analysis in a large cohort of DLBCL samples according to the ESMO Translational Research and Precision Medicine Working Group recommendations for the detection of NTRK fusions in daily practice and clinical research.

Methods

A tissue microarray of 92 patients with the diagnosis of DLBCL at the University Hospital Hamburg between 2020 and 2022 was built. The clinical data were taken from patient records. Immunohistochemistry for Pan-NTRK fusion protein was performed and positive staining was defined as any viable staining. For FISH analysis only results with quality 2 and 3 were evaluated.

Results

NTRK immunostaining was absent in all analyzable cases. No break apart was detectable by FISH.

Conclusion

Our negative result is consistent with the very sparse data existing on NTRK gene fusions in hematologic neoplasms. To date, only a few cases of hematological malignancies have been described in which NTRK-targeting drugs may provide a potential therapeutic agent. Even though NTRK fusion protein expression was not detectable in our sample cohort, performing systemic screenings for NTRK fusions are necessary to define further the role of NTRK fusions not only in DLBCL but in a multitude of lymphoma entities as long as the lack of reliable data exists.

How I treat refractory/relapsed diffuse large B-cell lymphomas with CD19-directed chimeric antigen receptor T cells

Chimeric antigen receptor (CAR) T cells targeting CD19 represent a promising salvage immunotherapy for relapsed/refractory diffuse large B-cell lymphoma (R/R DLBCL), offering ~40% of long-term responses. In everyday clinical practice, haematologists involved in CAR T cell treatment of patients with R/R DLBCL have to deal with diagnostically complex cases and difficult therapeutic choices. The availability of novel immunotherapeutic agents for R/R DLBCL and recent advances in understanding CAR T-cell failure mechanisms demand a rational approach to identify the best choice for bridging therapy and managing post-CAR T-cell therapy relapses. Moreover, positron emission tomography/computerised tomography may result in false-positive interpretation, highlighting the importance of post-treatment biopsy. In this review, we discuss all above issues, presenting four instructive cases, with the aim to provide criteria and new perspectives for CAR T-cell treatment of DLBCL.

Role of allogeneic hematopoietic cell transplant for relapsed/refractory aggressive B-cell lymphomas in the CART era

Anti-CD19 chimeric antigen receptor T cells (CART) has rapidly been adopted as the standard third-line therapy to treat aggressive B-cell lymphomas (ABCL) after failure of second-line therapy despite the lack of direct comparisons with allogeneic hematopoietic cell transplantation (alloHCT)-based strategies. Using the Grupo Español de Trasplante y Terapia Celular (GETH-TC) registry, we selected patients with the following characteristics: CART or alloHCT performed between 2016 and 2021; ≥18 years old; ABCL diagnosis; ≥2 lines of therapy; and either anti-CD19 CART or alloHCT as therapy at relapse. The analysis included a total of 316 (CART = 215, alloHCT = 101) patients. Median follow-up was 15 and 36 months for the CART and alloHCT cohorts, respectively. In the multivariate analysis, CART was confirmed to be similar to alloHCT for the primary study endpoint (progression-free survival) (hazard ratio [HR] 0.92, CI95%:0.56-1.51, p = 0.75). Furthermore, when the analysis was limited to only patients with chemo-sensitive diseases (complete and partial response) at infusion (CART = 26, alloHCT=93), no differences were reported (progression-free survival at month +18: 65% versus 55%, p = 0.59). However, CART had lower non-relapse mortality (HR 0.34, 95% CI: 0.13-0.85, p = 0.02). Given the lower toxicity and similar survival outcomes, these results suggest the use of CART before alloHCT.

Cost-Effectiveness Analysis of Frontline Polatuzumab-Rituximab, Cyclophosphamide, Doxorubicin, and Prednisone and/or Second-Line Chimeric Antigen Receptor T-Cell Therapy Versus Standard of Care for Treatment of Patients With Intermediate- to High-Risk Diffuse Large B-Cell Lymphoma

PURPOSE

Recent studies of polatuzumab vedotin and CD19 chimeric antigen receptor T-cell therapy (CAR-T) have shown significant improvements in progression-free survival over standard of care (SOC) for patients with diffuse large B-cell lymphoma. However, they are costly, and it is unclear whether these strategies, alone or combined, are cost-effective over SOC.

METHODS

A Markov model was constructed to compare four strategies for patients with newly diagnosed intermediate- to high-risk diffuse large B-cell lymphoma: strategy 1: polatuzumab-rituximab, cyclophosphamide, doxorubicin, and prednisone (R-CHP) plus second-line CAR-T for early relapse (< 12 months); strategy 2: polatuzumab-R-CHP plus second-line salvage therapy ± autologous stem-cell transplant; strategy 3: rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone plus second-line CAR-T for early relapse; strategy 4: SOC (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone plus second-line salvage therapy ± autologous stem-cell transplant). Transition probabilities were estimated from trial data. Lifetime costs, quality-adjusted life-years (QALYs), and incremental cost-effectiveness ratios (ICERs) were calculated from US and Canadian payer perspectives. Willingness-to-pay (WTP) thresholds of $150,000 US dollars (USD) or Canadian dollars (CAD)/QALY were used.

RESULTS

In probabilistic analyses (10,000 simulations), each strategy was incrementally more effective than the previous strategy, but also more costly. Adding polatuzumab-R-CHP to the SOC had an ICER of $546,956 (338,797-1,199,923) USD/QALY and $245,381 (151,671-573,250) CAD/QALY. Adding second-line CAR-T to the SOC had an ICER of $309,813 (190,197-694,200) USD/QALY and $303,163 (221,300-1,063,864) CAD/QALY. Simultaneously adding both polatuzumab-R-CHP and second-line CAR-T to the SOC had an ICER of $488,284 (326,765-840,157) USD/QALY and $267,050 (182,832-520,922) CAD/QALY.

CONCLUSION

Given uncertain incremental benefits in long-term survival and high costs, neither polatuzumab-R-CHP frontline, CAR-T second-line, nor a combination are likely to be cost-effective in the United States or Canada at current pricing compared with the SOC.

Relapse timing is associated with distinct evolutionary dynamics in DLBCL

Diffuse large B-cell lymphoma (DLBCL) is cured in over 60% of patients, but outcomes are poor for patients with relapsed or refractory disease (rrDLBCL). Here, we performed whole genome/exome sequencing (WGS/WES) on tumors from 73 serially-biopsied patients with rrDLBCL. Based on the observation that outcomes to salvage therapy/autologous stem cell transplantation are related to time-to-relapse, we stratified patients into groups according to relapse timing to explore the relationship to genetic divergence and sensitivity to salvage immunochemotherapy. The degree of mutational divergence increased with time between biopsies, yet tumor pairs were mostly concordant for cell-of-origin, oncogene rearrangement status and genetics-based subgroup. In patients with highly divergent tumors, several genes acquired exclusive mutations independently in each tumor, which, along with concordance of genetics-based subgroups, suggests that the earliest mutations in a shared precursor cell constrain tumor evolution. These results suggest that late relapses commonly represent genetically distinct and chemotherapy-naïve disease.

CAR T-cells and macrophages in large B-cell lymphoma: impact on toxicity and efficacy

Chimeric antigen receptor (CAR) T-cell therapy targeting CD19 is the current standard of care for the treatment of relapsed refractory large B cell lymphoma, demonstrating impressive response rates in the second- and third-line setting. Despite these advances, this treatment strategy can result in significant toxicities, such as cytokine release syndrome or immune effector cell associated neurotoxicity syndrome. While the exact mechanisms of these immune-mediated toxicities are not clearly understood, emerging pre-clinical and clinical studies have revealed the pivotal role of myeloid cells, particularly macrophages, as key contributors to the efficacy of treatments and as crucial mediators of toxicity. In this review, we discuss the current understanding of how macrophages mediate these effects, highlighting specific mechanisms of macrophage biology relevant to CAR T-cell therapy activity and side effects. These findings are resulting in novel treatment strategies that target macrophages, and able to mitigate toxicity while preserving CAR T-cell therapy efficacy.

Outcomes of CD19-directed Chimeric Antigen Receptor T-cell Therapy for Transformed Non-follicular Lymphoma

BACKGROUND

CD19-directed chimeric antigen receptor (CAR)-T cell therapies with axicabtagene ciloleucel (axi-cel) or tisagenlecleucel (tisa-cel) are approved for the treatment of relapsed or refractory large B-cell lymphoma (LBCL), including de novo diffuse large B-cell lymphoma (DLBCL), primary mediastinal B-cell lymphoma (PMBCL), and transformed follicular lymphoma (tFL). Transformed non-follicular lymphomas (tNFLs) (including transformed marginal zone lymphoma [tMZL] and transformed chronic lymphocytic leukemia/small lymphocytic lymphoma [tCLL/SLL]) were not included in their respective pivotal studies.

OBJECTIVES

To evaluate the outcomes of axi-cel and tisa-cel in tNFL patients, including those who received ibrutinib concomitantly through apheresis, lymphodepletion, and CAR-T infusion.

STUDY DESIGN

This single-center retrospective study included all patients with tCLL/SLL, tMZL, tFL, and DLBCL/PMBCL treated with CAR-T therapy outside of a clinical trial setting from November 2017 to May 2021 at Moffitt Cancer Center, Tampa, Florida, USA. We analyzed the outcomes in patients with tCLL/SLL or tMZL and compared that to patients with DLBCL/tFL.

RESULTS

The study included 134 patients who received a total of 136 CAR-T treatments (111 with axi-cel and 25 with tisa-cel). Ninety patients had de novo DLBCL/PMBCL; 23 had tFL; and 21 had tNFL (12 with tMZL and 9 with tCLL/SLL). The overall response and complete response rates for tCLL/SLL were 66.7% and 55.6%, respectively; and for tMZL they were 92.9% and 71.4%, respectively. The overall response and complete response rates between tNFL and the DLBCL/tFL were not different (P = .92 and .81, respectively). At a median follow-up of 21.3 months, the median progression-free survival (PFS) for tCLL/SLL was 5.4 months (95% CI, 0.8-not assessable [NA]); for tMZL, the median PFS was not reached (NR) (95% CI, 2.3-NA), and for DLBCL/tFL the median PFS was 14.3 months (95% CI, 5.6-NA) (P = .58). The estimated 1-year PFS rate for tCLL/SLL was 29.6% (95% CI, 5.2-60.7), and for tMZL was 50.0% (95% CI, 22.9-72.2). The estimated 1-year PFS rate for tNFL was 42.7% (95% CI, 22.4-61.6), and for DLBCL/tFL was 53.0% (95% CI, 42.3-62.5). The median overall survival was NR (95% CI, 9.2-NA) for tCLL/SLL, 27.1 months (95% CI, 8.5-NA) for tMZL, and NR (95% CI, 17.4-NA) for DLBCL/tFL (P = .79). Compared to the DLBCL/tFL cohort, tNFL patients were more likely to develop immune cellular-associated neurologic syndrome and receive tocilizumab (P = .04 and .01, respectively, after controlling for CAR-T product) and with possibly higher incidence of grade 3 or worse cytokine release syndrome (P = .07). Two patients in the tNFL cohort died of treatment related toxicity after receiving axi-cel. Six tNFL patients received ibrutinib concurrently with tisa-cel with one case of grade 3 or higher CRS/ICANS that rapidly resolved and no other severe toxicities.

CONCLUSION

Our case series supports the use of CD19 CAR T cell therapy in r/r tCLL/SLL and tMZL. The use of concurrent ibrutinib with tisa-cel in tNFL was associated with manageable toxicity in tNFL.

CAR T-Cells for the Treatment of Refractory or Relapsed Large B-Cell Lymphoma: A Single-Center Retrospective Canadian Study

BACKGROUND

Chimeric antigen receptor (CAR) T-cells are an important new third-line treatment option for large B-cell lymphoma (LBCL). The objective response rates in pivotal early phase clinical trials with CAR T-cells were very promising. The objective of this study was to describe the efficacy results obtained with CAR T-cells infusions in our institution and to compare the toxicities of our cohort with those of pivotal trials and studies conducted in a real-life setting.

PATIENTS AND METHODS

Efficacy and safety data were retrospectively collected from 25 patients with LBCL treated with CAR T-cells therapy at CHU de Québec-Université Laval. A literature search was then performed to identify other efficacy or safety data from a real-life setting.

RESULTS

At 3 months post infusion, the objective response rate (ORR) in our population with tisagenlecleucel and axicabtagene-ciloleucel were 20% and 47%, respectively. Bulky disease was the only negative predictor of poor response at 3 months (0% vs. 53%, P = .03). Bulky disease was associated with a median PFS of 2 months compared to 5 months for non-bulky disease (P = .0009). Grade ≥ 3 hematological toxicities were greater in patients treated with axi-cel (60% vs. 20%, P = .048), without bone marrow involvement (55% vs. 0%, P =.046), without stage IV disease (72% vs. 21%, P =.02), with refractory disease (67% vs. 10%, P =.01) or having been affected by cytokine release syndrome (58% vs. 0%, P =.02).

CONCLUSION

The poor response rate at 3 months after infusion in our cohort was influenced mainly by bulky disease. Further studies are needed to better characterize the loss of efficacy of CAR T-cells because the majority of patients will relapse over time.

Outcomes of Older Adults with Non-Hodgkin Lymphoma Undergoing Autologous Stem Cell Transplantation: A Mayo Clinic Cohort Analysis

Autologous stem cell transplantation (ASCT) is an important treatment that can offer a cure for patients with lymphoma. However, advanced age is an important factor that determines eligibility and outcomes after ASCT. Over the past decade, attributed to improved supportive care, ASCT for older patients has become more feasible. In this study, we report the single-center outcomes of older patients with lymphoma undergoing ASCT at Mayo Clinic Rochester to highlight its interval improvement over time and to help redefine the implications of ASCT in the chimeric antigen receptor T cell therapy era. This single-center retrospective study evaluated the characteristics and outcomes of older patients with lymphoma who underwent ASCT between 2000 and 2021. We report various relevant transplantation-related outcomes, including progression-free survival, overall survival (OS), relapse incidence, and nonrelapse mortality (NRM) in older patients with various lymphoma histologic subtypes. The main outcome was NRM, defined as the time from ASCT to non-lymphoma-related death, with relapse as a competing event. Of 492 patients age ≥65 years were analyzed. The median age at ASCT was 68.8 years. The most common indication for ASCT was diffuse large B cell lymphoma, accounting for 59.3% of cases. In multivariate analyses, patients undergoing ASCT in 2009 to 2021, an Eastern Cooperative Oncology Group Performance Status of 0, and low Hematopoietic Cell Transplantation Comorbidity Index (HCT-CI) (0 to 3) had a significantly lower NRM. Factors associated with OS included age, lactate dehydrogenase level, and HCT-CI. The 1-year NRM in older patients was low at 6.0%, in concordance with previous reports. Age should not be the sole factor determining a patient's ASCT eligibility. With the proper patient selection, ASCT remains a reasonable option for older patients with lymphoma.

Cellular and humoral immunotherapy in children, adolescents and young adults with non-Hodgkin lymphoma

The prognosis is dismal (2-year overall survival less than 25%) for childhood, adolescent, and young adult (CAYA) with relapsed and/or refractory (R/R) non-Hodgkin lymphoma (NHL). Novel targeted therapies are desperately needed for this poor-risk population. CD19, CD20, CD22, CD79a, CD38, CD30, LMP1 and LMP2 are attractive targets for immunotherapy in CAYA patients with R/R NHL. Novel anti-CD20 monoclonal antibodies, anti-CD38 monoclonal antibody, antibody drug conjugates and T and natural killer (NK)-cell bispecific and trispecific engagers are being investigated in the R/R setting and are changing the landscape of NHL therapy. A variety of cellular immunotherapies such as viral activated cytotoxic T-lymphocyte, chimeric antigen receptor (CAR) T-cells, NK and CAR NK-cells have been investigated and provide alternative options for CAYA patients with R/R NHL. Here, we provide an update and clinical practice guidance of utilizing these cellular and humoral immunotherapies in CAYA patients with R/R NHL.

Augmented ICE in Patients With Poor-Risk Refractory and Relapsed Lymphomas

BACKGROUND

In patients with relapsed/refractory lymphoma after first line therapy, chemosensitivity to salvage chemotherapy is the main determinant of outcome pre-autologous stem cell transplant . With novel therapies not yet widely available and poor responses to conventional dose salvage therapy such as ifosfamide, carboplatin, and etoposide (ICE) in patients with early relapse within 12 months and primary refractory disease, there is capacity to dose intensify ifosfamide and etoposide (augmented ICE).

METHODS

We retrospectively evaluated patients who received augmented ICE between 2010 and 2020 and report on response, deliverability, toxicities, and outcome. Patients were transplant eligible with diffuse large-B cell lymphoma (DLBCL) or Hodgkin lymphoma (HL) with refractory disease or relapse within 12 months. Dose of augmented ICE versus standard ICE was ifosfamide 10 versus 5 g/m² and etoposide 600 versus 300 mg/m². Carboplatin dose with a calculated area under curve of 5 was unchanged. Anti-CD20 monoclonal antibody was given in patients with CD20 positive lymphoma. Responding patients who achieved complete response or partial response proceeded to transplant.

RESULTS

Twenty-one patients with DLBCL (n = 13) and HL (n = 8) received augmented ICE. Nineteen of 21 completed 2 cycles. Overall response rates were 85% (DLBCL) and 100% (HL). Most patients required transfusion, 2 developed reversible ifosfamide encephalopathy and 86% febrile neutropenia. Eighteen patients proceeded to transplant. 5-year overall survival (OS) and progression-free survival (PFS) in DLBCL were 62% and 45%, and in HL, 100% and 88%, respectively.

CONCLUSION

Augmented ICE is associated with high response rate and transplant realization at the expense of toxicity.

Nanoscale, antigen encounter-dependent, IL-12 delivery by CAR T cells plus PD-L1 blockade for cancer treatment

BACKGROUND

Chimeric antigen receptor (CAR)-T cell therapies for the treatment of hematological malignancies experienced tremendous progress in the last decade. However, essential limitations need to be addressed to further improve efficacy and reduce toxicity to assure CAR-T cell persistence, trafficking to the tumor site, resistance to an hostile tumor microenvironment (TME), and containment of toxicity restricting production of powerful but potentially toxic bioproducts to the TME; the last could be achieved through contextual release upon tumor antigen encounter of factors capable of converting an immune suppressive TME into one conducive to immune rejection.

METHODS

We created an HER2-targeting CAR-T (RB-312) using a clustered regularly interspaced short palindromic repeats (CRISPR) activation (CRISPRa) system, which induces the expression of the IL-12 heterodimer via conditional transcription of its two endogenous subunits p35 and p40. This circuit includes two lentiviral constructs. The first one (HER2-TEV) expresses an anti-human epidermal growth factor receptor 2 (HER2) CAR single chain variable fragment (scFv), with CD28 and CD3z co-stimulatory domains linked to the tobacco etch virus (TEV) protease and two single guide RNAs (sgRNA) targeting the interleukin (IL)-12A and IL12B transcription start site (TSS), respectively. The second construct (LdCV) encodes linker for activation of T cells (LAT) fused to nuclease-deactivated Streptococcus Pyogenes Cas9 (dCas9)-VP64-p65-Rta (VPR) via a TEV-cleavable sequence (TCS). Activation of the CAR brings HER2-TEV in close proximity to LdCV releasing dCas9 for nuclear localization. This conditional circuit leads to conditional and reversible induction of the IL-12/p70 heterodimer. RB-312 was compared in vitro to controls (cRB-312), lacking the IL-12 sgRNAs and conventional HER2 CAR (convCAR).

RESULTS

The inducible CRISPRa system activated endogenous IL-12 expression resulting in enhanced secondary interferon (FN)-γ production, cytotoxicity, and CAR-T proliferation in vitro, prolonged in vivo persistence and greater suppression of HER2⁺ FaDu oropharyngeal cancer cell growth compared to the conventional CAR-T cell product. No systemic IL-12 was detected in the peripheral circulation. Moreover, the combination with programmed death ligand (PD-L1) blockade demonstrated robust synergistic effects.

CONCLUSIONS

RB-312, the first clinically relevant product incorporating a CRISPRa system with non-gene editing and reversible upregulation of endogenous gene expression that promotes CAR-T cells persistence and effectiveness against HER2-expressing tumors. The autocrine effects of reversible, nanoscale IL-12 production limits the risk of off-tumor leakage and systemic toxicity.

Outcome of Primary Mediastinal Large B Cell Lymphoma Treated with RCHOP

Purpose

Primary mediastinal large B-cell Lymphoma (PMLBCL) is a rare aggressive lymphoma with unique clinical, pathological, and molecular features. The optimal frontline therapy is subject of ongoing debate. Our study aims to evaluate the outcomes of PMLBCL treated with rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (RCHOP) at King Hussein Cancer Center.

Patients and Methods

Adult patients >18 years of age with PMLBCL treated with RCHOP from January 2011 to July 2020 were identified. All demographics, disease and treatment related variables were retrospectively collected. Correlations of clinical and laboratory variables with progression-free survival (PFS) and overall survival (OS) were determined by univariate and multivariate analyses using backward stepwise Cox regression models. The PFS and OS were plotted using Kaplan‒Meier curves.

Results

49 patients were included with a median age of 29 years. 14 (28.6%) had stage III or IV, 31 (63.3%) had mediastinal bulky disease. International prognostic index (IPI) was 0-1 in 35 (71.4%). Radiotherapy was given to 32 (65.3%) patients. End of treatment (EOT) response was complete (CR) in 32 (65.3%), partial response (PR) in 8 (16.3%) and progressive disease (PD) in 9 (18.4%). Patients who achieved CR at EOT, compared favorably with those who did not in regard to 4-year OS (92.5% vs 26.9%, p=<0.001). Overall objective response to salvage chemotherapies was 26.7%. At a median follow-up of 46 months, 4-year PFS and OS were 60% and 71% respectively. In multivariate analysis, IPI > one correlated with the EOT response (p=0.009), PFS (p=0.004) and OS (p= 0.019).

Conclusion

In PMLBCL, RCHOP chemotherapy backbone in the frontline therapy is suboptimal but can be used in patients with low IPI. Adapting more intensive chemoimmunotherapy regimens may be considered for patients with high IPI. Salvage chemotherapy has limited activity in patients with relapsed or refractory disease.

A systematic framework for predictive biomarkers in immune effector cell-associated neurotoxicity syndrome

Chimeric antigen receptor (CAR)-T cell therapy has revolutionized the management of several life-threatening malignancies, often achieving durable sustained responses. The number of patients treated with this new class of cell-based therapy, along with the number of Food and Drug Association (FDA) approved indications, are growing significantly. Unfortunately Immune Effector Cell-Associated Neurotoxicity Syndrome (ICANS) can often occur after treatment with CAR-T cells, and severe ICANS can be associated with significant morbidity and mortality. Current standard treatments are mainly steroids and supportive care, highlighting the need for early identification. In the last several years, a range of predictive biomarkers have been proposed to distinguish patients at increased risk for developing ICANS. In this review, we discuss a systematic framework to organize potential predictive biomarkers that builds on our current understanding of ICANS.

Characteristics and Outcomes of Children, Adolescents and Young Adults with Relapsed/Refractory Non-Hodgkin Lymphoma Undergoing Autologous Stem Cell Transplant

There is paucity of data regarding outcomes of children, adolescents and young adults (CAYA) patients with non-Hodgkin lymphoma (NHL) undergoing autologous hematopoietic stem cell transplantation (ASCT). We analyzed 222 patients aged 0-39 years undergoing first ASCT for NHL between 2000 and 2020. The most common histological subtypes were DLBCL (44%), T-NHL (19%) and PMBCL (19%). Younger patients (age ≤ 25) had lower incidence of DLBCL and higher incidence of PMBCL and T-NHL compared to older patients (> 25 years) (P = 0.02). None of the younger patients had DH)/DE DLBCL, as compared to 14 patients in the older group (18%, P = 0.07). Younger patients had numerically better 15-year post-transplant PFS (67% vs. 54%) and OS (71% vs. 62%) compared to older patients, without statistically significant differences (P = 0.19 and P = 0.24, respectively). In MVA, not achieving a CR prior to ASCT was independently predictive of worse PFS (P < 0.0001). DH/DE status was an independent adverse predictor of PFS in MVA (HR 5.8, p = 0.03). 10 patients(4.5%) (all aged > 25 years) developed SPM Patients aged ≤ 25 years presented a distinct NHL histology as compared to older CAYA patients. Disease status at ASCT was predictive of both PFS and OS. DH/DE status was an adverse predictor of PFS.

Bispecific antibodies for the treatment of B-cell lymphoma: promises, unknowns, and opportunities

Treatment paradigms for B-cell non-Hodgkin lymphomas (B-NHL) have shifted dramatically in the last 2 decades following the introduction of highly active immunotherapies such as rituximab. Since then, the field has continued to witness tremendous progress with the introduction of newer, more potent immunotherapeutics, including chimeric antigen receptor T-cell therapy, which have received regulatory approval for and currently play a significant role in the treatment of these diseases. Bispecific antibodies (BsAb) are a novel class of off-the-shelf T-cell redirecting drugs and are among the most promising immunotherapeutics for lymphoma today. BsAb may target various cell-surface antigens and exist in different formats. Anti-CD20xCD3 BsAb have demonstrated remarkable single-agent activity in patients with heavily pretreated B-NHL with a manageable toxicity profile dominated by T-cell overactivation syndromes. Much work remains to be done to define the optimal setting in which to deploy these drugs for B-NHL treatment, their ideal combination partners, strategies to minimize toxicity, and, perhaps most importantly, pharmacodynamic biomarkers of response and resistance. In this review, we provide an update on BsAb development in B-NHL, from discovery to clinical applications, highlighting the achievements, limitations, and future directions of the field.

CAR immune cells: design principles, resistance and the next generation

The remarkable clinical activity of chimeric antigen receptor (CAR) therapies in B cell and plasma cell malignancies has validated the use of this therapeutic class for liquid cancers, but resistance and limited access remain as barriers to broader application. Here we review the immunobiology and design principles of current prototype CARs and present emerging platforms that are anticipated to drive future clinical advances. The field is witnessing a rapid expansion of next-generation CAR immune cell technologies designed to enhance efficacy, safety and access. Substantial progress has been made in augmenting immune cell fitness, activating endogenous immunity, arming cells to resist suppression via the tumour microenvironment and developing approaches to modulate antigen density thresholds. Increasingly sophisticated multispecific, logic-gated and regulatable CARs display the potential to overcome resistance and increase safety. Early signs of progress with stealth, virus-free and in vivo gene delivery platforms provide potential paths for reduced costs and increased access of cell therapies in the future. The continuing clinical success of CAR T cells in liquid cancers is driving the development of increasingly sophisticated immune cell therapies that are poised to translate to treatments for solid cancers and non-malignant diseases in the coming years.

How I treat diffuse large B-cell lymphoma

Diffuse large B-cell lymphoma (DLBCL) is usually treated with chemoimmunotherapy in curative intention at initial diagnosis. Novel agents have improved the prognosis of high-risk patients in the front-line and relapsed setting and more accurate prognostic tools enable less intensive treatment for low-risk patients, while maintaining their good prognosis. Here, we summarize our approach to DLBCL patients in the first-line setting according to their risk profile and other common challenges in clinical practice. We recommend an abbreviated course of chemoimmunotherapy in low-risk patients and a negative interim positron emission tomography. For patients with higher-risk disease, a new combination treatment with polatuzumab vedotin has been approved and is a new option in these patients. We also discuss our approach to patients with high risk for subsequent central nervous system involvement, with leg-type lymphoma or with severe comorbidities.

The role of additional chemotherapy prior to autologous HCT in patients with relapse/refractory DLBCL in partial remission-A retrospective multicenter study

OBJECTIVES

To evaluate the role of additional chemotherapy before autologous hematopoietic cell transplantation (HCT) in patients with relapse/refractory diffuse large B-cell lymphoma (DLBCL) who achieve partial remission following first salvage therapy.

METHODS

We conducted a multicenter retrospective study of all adult patients with DLBCL who underwent HCT between 2008 and 2020 and achieved partial response (PR) after the first salvage and were either referred directly to HCT (n = 47) or received additional salvage therapy before HCT (n = 22).

RESULTS

Post-HCT CR rate and progression-free survival were comparable between the two groups (66% vs. 68%, p = .86 and median not reached vs. 10.2 months [95% confidence interval, CI 7.1-12.3], p = .27, respectively). Median overall survival (OS) and estimated 3-year OS favored patients who were directly referred to HCT (105.8 [95% CI 63-148] months vs. 14.5 [95% CI 0-44] months, p = .035, and 65% [95% CI 51%-75%] vs. 40% [95% CI 21%-53%], p = .035, respectively). In Cox regression model, while International Prognostic Index and primary refractory versus relapse disease did not impact OS, allocation to a second salvage regimen and older age were both associated with inferior survival (hazard ratio [HR] = 2.57 95% CI 1.1-5.8, p = .023 and HR = 1.04 95% CI 0.99-1.2, p = .064, respectively).

CONCLUSIONS

Referring patients with chemotherapy-sensitive disease in PR directly to HCT is associated with better OS compared to those receiving additional lines of treatment.

Lisocabtagene maraleucel for relapsed or refractory large B-cell non-Hodgkin lymphoma

INTRODUCTION

Chimeric antigen receptor T (CAR T) cell therapy epitomizes the success of T cell engineering. Today, it is an integral component of the treatment algorithm for various types of B-cell non-Hodgkin lymphoma (NHL). Large B-cell lymphoma (LBCL) is the most common subtype of NHL accounting for 30-35% of cases. A lack of response to second-line therapy portends a poor prognosis as only 7-15% of patients attain complete remission (CR) with subsequent conventional chemoimmunotherapy.

AREAS COVERED

Lisocabtagene maraleucel (liso-cel) is an autologous CD-19 directed CAR T-cell product with a 4-1BB co-stimulatory domain administered as a sequential infusion of 2 separately manufactured components: CD8⁺ and CD4⁺ CAR T-cells in equal doses. Liso-cel showed an impressive objective response rate of 73% (CR = 53%) in patients who had received a median of 3 prior therapies. Median time-to-first CR or partial response (PR) was 1 month.

EXPERT OPINION

When evaluated in the second line setting in LBCL, liso-cel demonstrated superior event-free survival (EFS) versus standard of care. While acknowledging that choice of a particular CAR T-cell is based chiefly on familiarity of the treating physician with a specific product, liso-cel definitely represents an important addition to the treatment armamentarium of R/R LBCL whether in the second-line setting or beyond.

Navigating the Evolving Treatment Landscape of Diffuse Large B-Cell Lymphoma

Diffuse large B-cell lymphoma, the most common subtype of non-Hodgkin lymphoma, comprises a heterogenous group of morphologically, genetically, and clinically distinct diseases. Several recent advances have affected the treatment landscape, which had been mostly stagnant for the past few decades. We will review the practice-changing studies in frontline (POLARIX), early relapse (ZUMA-7 and TRANSFORM), and multiple recurrent (ZUMA-1, JULIET, TRANSCEND, L-MIND, and LOTIS-2) stages and discuss how the treatment landscape may evolve with the emergence of bispecific antibodies.

Ars2-containing bispecific, Fab- and IgG1-format BAR-bodies to target DLBCL cells

Despite recent advances in the therapy of diffuse large B-cell lymphoma, not otherwise specified (DLBCL), around 30% of patients develop refractory disease or relapse after first-line treatment. Recently, Ars2 was reported as the auto-antigenic target of the B-cell receptor (BCR) in approximately 25% of activated B-cell DLBCL cases. Ars2 could be used to specifically target B cells expressing Ars2-reactive BCRs. However, the optimal therapeutic format to integrate Ars2 into has yet to be determined. To mimic therapeutic antibody formats, Ars2-containing bispecific and IgG1-like constructs (BCR antigens for reverse [BAR]-bodies) were developed. Two bispecific BAR-bodies connecting single-chain antibodies against CD16 or CD3 to the BCR-binding epitope of Ars2 were constructed. Both constructs showed strong binding to U2932 cells and induced effector cell-dependent and selective cytotoxicity against U2932 cells of up to 44% at concentrations of 20 μg/ml. Additionally, IgG1-format Ars2 BAR-bodies were constructed by replacing the variable heavy- and light-chain regions of a full-length antibody with the Ars2 epitope. IgG1-format Ars2 BAR-bodies also bound selectively to U2932 and OCI-Ly3 cells and induced selective cytotoxicity of up to 60% at 10 μg/ml. In conclusion, Ars2-containing bispecific and IgG1-format BAR-bodies both are new therapeutic formats to target DLBCL cells.

Head and Neck Cancer Immunotherapy: Molecular Biological Aspects of Preclinical and Clinical Research

Breakthrough research in the field of immune checkpoint inhibitors and the development of a human papilloma virus vaccine triggered a plethora of research in the field of cancer immunotherapy. Both had significant effects on the treatment of head and neck squamous cell carcinoma. The advent of preclinical models and multidisciplinary approaches including bioinformatics, genetic engineering, clinical oncology, and immunology helped in the development of tumour-infiltrating lymphocytes (TILs) and chimeric antigen receptor (CAR) T-cell therapy. Here, we discuss different immunotherapies such as adoptive T-cell transfer, immune checkpoint inhibitors, interleukins, and cancer vaccines for the treatment of head and neck cancer. This review showcases the intrinsic relation between the understanding and implementation of basic biology and clinical practice. We also address potential limitations of each immunotherapy approach and the advantages of personalized immunotherapy. Overall, the aim of this review is to encourage further research in the field of immunotherapy for head and neck cancer.

Relapsed or refractory large B-cell lymphoma after chimeric antigen receptor T-cell therapy: Current challenges and therapeutic options

Chimeric antigen receptor (CAR) T-cell (CAR-T) therapy can provide durable remission in patients with relapsed or refractory diffuse large B-cell lymphoma (DLBCL) after failure of chemoimmunotherapy. However, patients who are refractory or relapsing after CAR-T therapy have poor outcomes. Multiple mechanisms of CAR-T therapy failure have been proposed but management of these patients remains a challenge. As CAR-T therapy moves earlier in the treatment of DLBCL, we urgently need trials focused on patients with relapse after CAR-T therapy. Recent advances in novel immunotherapies such as bispecific antibodies, antibody-drug conjugates and next-generation CAR-T therapies may provide avenues for treatment. Here we review the available data on using these drugs after failure of CAR-T therapy and provide a framework for the ideal sequencing of these novel agents.

Multispecific CAR T Cells Deprive Lymphomas of Escape via Antigen Loss

Chimeric antigen receptor (CAR) modified T cell therapy has transformed the management of relapsed/refractory B cell malignancies. Despite high overall response rates, relapse post CAR T treatment remains a clinical challenge. Loss of target antigen, specifically CD19, is one well-defined mechanism of disease relapse. The mechanism of CD19 loss and which patients are at higher risk of CD19 loss remain poorly understood. To overcome CD19 loss, CARs targeting multiple antigens are being tested in clinical trials. CD19/20 and CD19/22 bispecific CARs demonstrate cytotoxicity against CD19-negative cells in preclinical studies. These CARs have also shown efficacy, safety, and a relatively low rate of CD19-negative relapse in phase I trials. These small studies suggest that multispecific CAR T cells can deprive lymphomas of escape via antigen loss. However, the selection of an ideal target, the right CAR construct, and whether these multispecific CARs can induce long-term remissions are still under investigation.

Spleen tyrosine kinase/FMS-like tyrosine kinase-3 inhibition in relapsed/refractory B-cell lymphoma, including diffuse large B-cell lymphoma: updated data with mivavotinib (TAK-659/CB-659)

We report an updated analysis from a phase I study of the spleen tyrosine kinase (SYK) and FMS-like tyrosine kinase 3 inhibitor mivavotinib, presenting data for the overall cohort of lymphoma patients, and the subgroup of patients with diffuse large B-cell lymphoma (DLBCL; including an expanded cohort not included in the initial report). Patients with relapsed/refractory lymphoma for which no standard treatment was available received mivavotinib 60-120 mg once daily in 28-day cycles until disease progression/unacceptable toxicity. A total of 124 patients with lymphoma, including 89 with DLBCL, were enrolled. Overall response rates (ORR) in response-evaluable patients were 45% (43/95) and 38% (26/69), respectively. Median duration of response was 28.1 months overall and not reached in DLBCL responders. In subgroups with DLBCL of germinal center B-cell (GCB) and non-GCB origin, ORR was 28% (11/40) and 58% (7/12), respectively. Median progression free survival was 2.0 and 1.6 months in the lymphoma and DLBCL cohorts, respectively. Grade ≥3 treatment-emergent adverse events occurred in 96% of all lymphoma patients, many of which were limited to asymptomatic laboratory abnormalities; the most common were increased amylase (29%), neutropenia (27%), and hypophosphatemia (26%). These findings support SYK as a potential therapeutic target for the treatment of patients with B-cell lymphomas, including DLBCL. Trial registration: ClinicalTrials.gov number: NCT02000934.

Emerging targeted and cellular therapies in the treatment of advanced and metastatic synovial sarcoma

Synovial sarcoma is a soft tissue sarcoma accounting for approximately 1,000 cases per year in the United States. Currently, standard treatment of advanced and metastatic synovial sarcoma is anthracycline-based chemotherapy. While advanced synovial sarcoma is more responsive to chemotherapy compared to other soft tissue sarcomas, survival rates are poor, with a median survival time of less than 18 months. Enhanced understanding of tumor antigen expression and molecular mechanisms behind synovial sarcoma provide potential targets for treatment. Adoptive Cell Transfer using engineered T-cell receptors is in clinical trials for treatment of synovial sarcoma, specifically targeting New York esophageal squamous cell carcinoma-1 (NY-ESO-1), preferentially expressed antigen in melanoma (PRAME), and melanoma antigen-A4 (MAGE-A4). In this review, we explore the opportunities and challenges of these treatments. We also describe artificial adjuvant vector cells (aAVCs) and BRD9 inhibitors, two additional potential targets for treatment of advanced synovial sarcoma. This review demonstrates the progress that has been made in treatment of synovial sarcoma and highlights the future study and qualification needed to implement these technologies as standard of care.

Lisocabtagene maraleucel in the treatment of relapsed/refractory large B-cell lymphoma

Lisocabtagene maraleucel (liso-cel) is one of the three US FDA-approved chimeric antigen receptor T-cell therapies for the treatment of relapsed/refractory (R/R) large B-cell lymphoma (LBCL). TRANSCEND is the landmark trial that led to the approval of liso-cel in the third-line setting for R/R diffuse LBCL, primary mediastinal B-cell lymphoma, follicular lymphoma grade 3B and transformed lymphoma. The TRANSFORM and PILOT studies evaluated the use of liso-cel in the second-line treatment of R/R LBCL. This review details the structure and manufacturing process of liso-cel that make it distinct from other approved chimeric antigen receptor constructs, outlines results from landmark trials of liso-cel in LBCL and discusses liso-cel toxicity.

Efficacy of chimeric antigen receptor T cell therapy and autologous stem cell transplant in relapsed or refractory diffuse large B-cell lymphoma: A systematic review

Background

We aimed to compare the efficacy of chimeric antigen receptor T (CAR-T) cell therapy with that of autologous stem cell transplantation (auto-HSCT) in relapsed/refractory diffuse large B cell lymphoma (R/R DLBCL).

Research design and methods

We searched eligible publications up to January 31st, 2022, in PubMed, Cochrane Library, Springer, and Scopus. A total of 16 publications with 3484 patients were independently evaluated and analyzed using STATA SE software.

Results

Patients who underwent CAR-T cell therapy showed a better overall response rate (ORR) and partial response (PR) than those treated with auto-HSCT (CAR-T vs. auto-HSCT, ORR: 80% vs. 73%, HR:0.90,95%CI:0.76-1.07,P = 0.001; PR: 20% vs. 14%, HR:0.65,95%CI:0.62-0.68,P = 0.034). No significant difference was observed in 6-month overall survival (OS) (CAR-T vs. auto-HSCT, six-month OS: 81% vs. 84%, HR:1.23,95%CI:0.63-2.38, P = 0.299), while auto-HSCT showed a favorable 1 and 2-year OS (CAR-T vs. auto-HSCT, one-year OS: 64% vs. 73%, HR:2.42,95%CI:2.27-2.79, P < 0.001; two-year OS: 54% vs. 68%, HR:1.81,95%CI:1.78-1.97, P < 0.001). Auto-HSCT also had advantages in progression-free survival (PFS) (CAR-T vs. auto-HSCT, six-month PFS: 53% vs. 76%, HR:2.81,95%CI:2.53-3.11,P < 0.001; one-year PFS: 46% vs. 61%, HR:1.84,95%CI:1.72-1.97,P < 0.001; two-year PFS: 42% vs. 54%, HR:1.62,95%CI:1.53-1.71, P < 0.001). Subgroup analysis by age, prior lines of therapy, and ECOG scores was performed to compare the efficacy of both treatment modalities.

Conclusion

Although CAR-T cell therapy showed a beneficial ORR, auto-HSCT exhibited a better long-term treatment superiority in R/R DLBCL patients. Survival outcomes were consistent across different subgroups.