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

Overcoming the challenges of primary resistance and relapse after CAR-T cell therapy

INTRODUCTION

While CAR T-cell therapy has led to remarkable responses in relapsed B-cell hematologic malignancies, only 50% of patients ultimately have a complete, sustained response. Understanding the mechanisms of resistance and relapse after CAR T-cell therapy is crucial to future development and improving outcomes.

AREAS COVERED

We review reasons for both primary resistance and relapse after CAR T-cell therapies. Reasons for primary failure include CAR T-cell manufacturing problems, suboptimal fitness of autologous T-cells themselves, and intrinsic features of the underlying cancer and tumor microenvironment. Relapse after initial response to CAR T-cell therapy may be antigen-positive, due to CAR T-cell exhaustion or limited persistence, or antigen-negative, due to antigen-modulation on the target cells. Finally, we discuss ongoing efforts to overcome resistance to CAR T-cell therapy with enhanced CAR constructs, manufacturing methods, alternate cell types, combinatorial strategies, and optimization of both pre-infusion conditioning regimens and post-infusion consolidative strategies.

EXPERT OPINION

There is a continued need for novel approaches to CAR T-cell therapy for both hematologic and solid malignancies to obtain sustained remissions. Opportunities for improvement include development of new targets, optimally combining existing CAR T-cell therapies, and defining the role for adjunctive immune modulators and stem cell transplant in enhancing long-term survival.

CAR T-cell therapy induces a high rate of prolonged remission in relapsed primary CNS lymphoma: Real-life results of the LOC network

The prognosis of relapsed primary central nervous system lymphoma (PCNSL) remains dismal. CAR T-cells are a major contributor to systemic lymphomas, but their use in PCNSL is limited. From the LOC network database, we retrospectively selected PCNSL who had leukapheresis for CAR-T cells from the third line of treatment, and, as controls, PCNSL treated with any treatment, at least in the third line and considered not eligible for ASCT. Twenty-seven patients (median age: 68, median of three previous lines, including ASCT in 14/27) had leukapheresis, of whom 25 received CAR T-cells (tisa-cel: N = 16, axi-cel: N = 9) between 2020 and 2023. All but one received a bridging therapy. The median follow-up after leukapheresis was 20.8 months. The best response after CAR-T cells was complete response in 16 patients (64%). One-year progression-free survival from leukapheresis was 43% with a plateau afterward. One-year relapse-free survival was 79% for patients in complete or partial response at CAR T-cell infusion. The median overall survival was 21.2 months. Twenty-three patients experienced a cytokine release syndrome and 17/25 patients (68%) a neurotoxicity (five grade ≥3). The efficacy endpoints were significantly better in the CAR T-cell group than in the control group (N = 247) (median PFS: 3 months; median OS: 4.7 months; p < 0.001). This series represents the largest cohort of PCNSL treated with CAR T-cells reported worldwide. CAR T-cells are effective in relapsed PCNSL, with a high rate of long-term remission and a reassuring tolerance profile. The results seem clearly superior to those usually observed in this setting.

Postinfusion PD-1+ CD8+ CAR T cells identify patients responsive to CD19 CAR T-cell therapy in non-Hodgkin lymphoma

ABSTRACT

Chimeric antigen receptor (CAR) T-cell therapy has revolutionized treatment for relapsed/refractory B-cell non-Hodgkin lymphoma (NHL). Robust biomarkers and a complete understanding of CAR T-cell function in the postinfusion phase remain limited. Here, we used a 37-color spectral flow cytometry panel to perform high dimensional single-cell analysis of postinfusion samples in 26 patients treated with CD28 costimulatory domain containing commercial CAR T cells for NHL and focused on computationally gated CD8+ CAR T cells. We found that the presence of postinfusion Programmed cell death protein 1 (PD-1)+ CD8+ CAR T cells at the day 14 time point highly correlated with the ability to achieve complete response (CR) by 6 months. Further analysis identified multiple subtypes of CD8+ PD-1+ CAR T cells, including PD-1+ T cell factor 1 (TCF1)+ stem-like CAR T cells and PD-1+ T-cell immunoglobulin and mucin-domain containing-3 (TIM3)+ effector-like CAR T cells that correlated with improved clinical outcomes such as response and progression-free survival. Additionally, we identified a subset of PD-1+ CD8+ CAR+ T cells with effector-like function that was increased in patients who achieved a CR and was associated with grade 3 or higher immune effector cell-associated neurotoxicity syndrome. Here, we identified robust biomarkers of response to CD28 CAR T cells and highlight the importance of PD-1 positivity in CD8+ CAR T cells after infusion in achieving CR.

Risk of Second Tumors and T-Cell Lymphoma after CAR T-Cell Therapy

BACKGROUND

The risk of second tumors after chimeric antigen receptor (CAR) T-cell therapy, especially the risk of T-cell neoplasms related to viral vector integration, is an emerging concern.

METHODS

We reviewed our clinical experience with adoptive cellular CAR T-cell therapy at our institution since 2016 and ascertained the occurrence of second tumors. In one case of secondary T-cell lymphoma, a broad array of molecular, genetic, and cellular techniques were used to interrogate the tumor, the CAR T cells, and the normal hematopoietic cells in the patient.

RESULTS

A total of 724 patients who had received T-cell therapies at our center were included in the study. A lethal T-cell lymphoma was identified in a patient who had received axicabtagene ciloleucel therapy for diffuse large B-cell lymphoma, and both lymphomas were deeply profiled. Each lymphoma had molecularly distinct immunophenotypes and genomic profiles, but both were positive for Epstein-Barr virus and were associated with DNMT3A and TET2 mutant clonal hematopoiesis. No evidence of oncogenic retroviral integration was found with the use of multiple techniques.

CONCLUSIONS

Our results highlight the rarity of second tumors and provide a framework for defining clonal relationships and viral vector monitoring. (Funded by the National Cancer Institute and others.).

Cardiotoxic profiles of CAR-T therapy and bispecific T-cell engagers in hematological cancers

BACKGROUND

Chimeric antigen receptor (CAR) T-cell therapy and bispecific T-cell engagers, which redirect T-cells to tumor antigens, have immensely benefitted patients with relapsed/refractory B-cell cancers. How these therapies differ in cardiotoxicity is underexplored. We used the World Health Organization pharmacovigilance database, VigiBase, to compare cardiotoxicity profiles between CD19-targeted CAR-T therapy and blinatumomab (a CD19/CD3-targeted bispecific T-cell engager).

METHODS

Safety reports in VigiBase were filtered for diffuse large B-cell lymphoma (DLBCL, n = 17,479) and acute lymphocytic leukemia (ALL, n = 28,803) for all adverse reactions. Data were further filtered for patients taking CAR-T therapy or blinatumomab. Reporting odds ratios (ROR) and fatality rates were compared between CAR-T cell products (e.g. tisagenlecleucel and axicabtagene ciloleucel), and between CAR-T therapy and blinatumomab.

RESULTS

Tisagenlecleucel is associated with cardiac failure (IC025 = 0.366) with fatality rates of 85.7% and 80.0% in DLBCL and pediatric ALL patients respectively. For DLBCL patients, axicabtagene ciloleucel has greater reporting for hypotension than tisagenlecleucel (ROR: 2.54; 95% CI: 1.28-5.03; p = 0.012), but tisagenlecleucel has higher fatality rates for hypotension than axicabtagene ciloleucel [50.0% (tisagenlecleucel) vs 5.6% (axicabtagene ciloleucel); p < 0.001]. Blinatumomab and tisagenlecleucel have similar fatality rates for hypotension in pediatric ALL patients [34.7% (tisagenlecleucel) vs 20.0% (blinatumomab); p = 0.66].

CONCLUSIONS

Tisagenlecleucel is associated with severe and fatal adverse cardiac events, with higher fatality rates for hypotension compared to axicabtagene ciloleucel in DLBCL patients, but similar hypotension fatality rates compared to blinatumomab in pediatric ALL patients. Effective management necessitates experienced physicians, including cardio-oncologists, skilled in interdisciplinary approaches to manage these toxicities.

Axicabtagene ciloleucel vs standard of care in second-line large B-cell lymphoma: outcomes by metabolic tumor volume

ABSTRACT

Metabolic tumor volume (MTV) assessed using 2-deoxy-2-[18F]fluoro-d-glucose positron emission tomography, a measure of tumor burden, is a promising prognostic indicator in large B-cell lymphoma (LBCL). This exploratory analysis evaluated relationships between baseline MTV (categorized as low [median or less] vs high [greater than median]) and clinical outcomes in the phase 3 ZUMA-7 study (NCT03391466). Patients with LBCL relapsed within 12 months of or refractory to first-line chemoimmunotherapy were randomized 1:1 to axicabtagene ciloleucel (axi-cel; autologous anti-CD19 chimeric antigen receptor T-cell therapy) or standard care (2-3 cycles of chemoimmunotherapy followed by high-dose chemotherapy with autologous stem cell transplantation in patients who had a response). All P values are descriptive. Within high- and low-MTV subgroups, event-free survival (EFS) and progression-free survival (PFS) were superior with axi-cel vs standard care. EFS in patients with high MTV (vs low MTV) was numerically shorter with axi-cel and was significantly shorter with standard care. PFS was shorter in patients with high MTV vs low MTV in both the axi-cel and standard-care arms, and median MTV was lower in patients in ongoing response at data cutoff vs others. Median MTV was higher in patients treated with axi-cel who experienced grade ≥3 neurologic events or cytokine release syndrome (CRS) than in patients with grade 1/2 or no neurologic events or CRS, respectively. Baseline MTV less than or equal to median was associated with better clinical outcomes in patients receiving axi-cel or standard care for second-line LBCL. The trial was registered at www.clinicaltrials.gov as #NCT03391466.

Outcomes of subsequent antilymphoma therapies after second-line axicabtagene ciloleucel or standard of care in ZUMA-7

ABSTRACT

The optimal management of patients with relapsed/refractory large B-cell lymphoma (LBCL) after disease progression or lack of response to second-line (2L) therapy remains unclear. Here, we report outcomes among patients who received subsequent antilymphoma therapy per investigator discretion separately by their randomized 2L arm in ZUMA-7, namely axicabtagene ciloleucel (axi-cel) vs standard of care (SOC). Progression-free survival (PFS) and overall survival (OS) were calculated from 3L therapy initiation. In the SOC arm, 127 of 179 randomized patients (71%) received 3L therapy. Median PFS among those who received 3L cellular immunotherapy (n = 68) vs those who did not (n = 59) was 6.3 vs 1.9 months, respectively; median OS was 16.3 vs 9.5 months, respectively. In the axi-cel arm, 84 of 180 randomized patients (47%) received 3L therapy. Median PFS among those who received 3L chemotherapy (n = 60) vs cellular immunotherapy (n = 8) was 1.7 vs 3.5 months, respectively; median OS was 8.1 months vs not reached, respectively. Of the 60 patients who received 3L chemotherapy, 10 underwent stem cell transplantation (SCT) after salvage chemotherapy. Median PFS was 11.5 vs 1.6 months, and median OS was 17.5 vs 7.2 months for those who did vs did not reach SCT, respectively. Eight patients received 3L cellular immunotherapy after 2L axi-cel. Of these, 6 patients received subsequent SCT in any line; all 6 were alive at data cutoff. These findings help inform subsequent treatment choices after 2L therapy failure for relapsed/refractory LBCL. The trial was registered at www.clinicaltrials.gov as #NCT03391466.

Clonal Hematopoiesis is Associated with Severe Cytokine Release Syndrome in Patients Treated with Chimeric Antigen Receptor T-cell (CART) Therapy

BACKGROUND

Among patients receiving CD19 or B-cell maturation antigen (BCMA) CAR T therapy, inflammation pre- and post-CAR T infusion is implicated in the development of toxicities including cytokine release syndrome (CRS), immune effector cell-associated neurotoxicity syndrome (ICANS), and likely contributes to prolonged cytopenias. Clonal hematopoiesis (CH), the clonal expansion of hematopoietic stem cells harboring somatic mutations, has been associated with inflammasome upregulation.. Herein, we examined the prevalence of pre-CAR T CH in a predominantly transplant-naïve cohort of recipients with non-Hodgkin lymphoma (NHL) or multiple myeloma (MM), and assessed the relationship between the presence of CH mutations and CAR T-related outcomes including CRS, ICANS, prolonged cytopenia, progression-free survival (PFS), and overall survival (OS).

METHODS

This study included 62 patients with NHL or MM who underwent CD19 or BCMA CAR T therapy from 2017 to 2022 at City of Hope and had available pre-CAR T cryopreserved peripheral blood mononuclear cells (PBMCs). DNA was isolated with QIAamp DNA Mini Kit (Qiagen) from PBMC samples (94% collected <30d of CART infusion), on which we performed targeted exome sequencing (108 pre-defined gene panel with 1000x sequencing depth) to determine the presence of CH (variant allele frequency [VAF] ≥2%). Multivariable logistic regression was used to examine the association between CH and absolute neutrophil count (ANC) recovery at day +30 and +60, maximum grade CRS and ICANS, grade <2 vs 2+, and OS and PFS at 1y. Covariates considered were age at CART, baseline ANC, sex, race, CAR-HEMATOTOX, LDH, bridging therapy (Y/N), and number of prior lines of therapy.

RESULTS

Fifteen (24%) patients had at least one pathogenic CH mutation; 2 (13%) had ≥2 CH mutations concurrently. DMT3A mutations were the most common; 29% of mutations had VAFs >10%. Patients with CH were significantly more likely to develop grade ≥2 CRS (60% vs. 28%, p=0.03) compared to those without CH (odds ratio [OR] 3.9, 95% CI 1.2-13.2; p=0.027). Accounting for baseline ANC (which was higher among the CH cohort and associated with delayed ANC recovery, p=0.02) patients with CH did not have a significantly different rate of delayed ANC recovery compared to those without CH (adjusted OR 0.37, 95% CI 0.09-1.5; p=0.17). There was no association between CH and ICANS, nor with 1y PFS or OS.

CONCLUSION

CH was frequent (24%) in this cohort of CAR T recipients and was associated with a higher risk of development of grade ≥2 CRS after CAR T. Additional validation studies are currently underway, which may set the stage for consideration of pre-CAR T CH as a biomarker for risk stratification towards more proactive CRS prophylaxis. Translational studies could aim to prove a direct relationship between CH-mutated myeloid cells and CRS.

Anti-CD19 Chimeric Antigen Receptor T-Cell Therapy for Richter Transformation: An International, Multicenter, Retrospective Study

PURPOSE

Outcomes for Richter transformation (RT) are poor with current therapies. The efficacy and safety of anti-CD19 chimeric antigen receptor T-cell therapy (CAR-T) for RT are not established.

METHODS

We performed an international multicenter retrospective study of patients with RT who received CAR-T. Patient, disease, and treatment characteristics were summarized using descriptive statistics, and modeling analyses were used to determine association with progression-free survival (PFS) and overall survival (OS). PFS and OS were estimated from the date of CAR-T infusion.

RESULTS

Sixty-nine patients were identified. The median age at CAR-T infusion was 64 years (range, 27-80). Patients had a median of four (range, 1-15) previous lines of therapy for CLL and/or RT, including previous Bruton tyrosine kinase inhibitor and/or BCL2 inhibitor therapy in 58 (84%) patients. The CAR-T product administered was axicabtagene ciloleucel in 44 patients (64%), tisagenlecleucel in 17 patients (25%), lisocabtagene maraleucel in seven patients (10%), and brexucabtagene autoleucel in one patient (1%). Eleven patients (16%) and 25 patients (37%) experienced grade ≥3 cytokine release syndrome and immune effector cell-associated neurotoxicity syndrome, respectively. The overall response rate was 63%, with 46% attaining a complete response (CR). After a median follow-up of 24 months, the median PFS was 4.7 months (95% CI, 2.0 to 6.9); the 2-year PFS was 29% (95% CI, 18 to 41). The median OS was 8.5 months (95% CI, 5.1 to 25.4); the 2-year OS was 38% (95% CI, 26 to 50). The median duration of response was 27.6 months (95% CI, 14.5 to not reached) for patients achieving CR.

CONCLUSION

CAR-T demonstrates clinical efficacy for patients with RT.

Comparative analysis of Bcl-2 family protein overexpression in CAR T cells alone and in combination with BH3 mimetics

Approximately 50% of patients with hematologic malignancies relapse after chimeric antigen receptor (CAR) T cell treatment; mechanisms of failure include loss of CAR T persistence and tumor resistance to apoptosis. We hypothesized that both of these challenges could potentially be overcome by overexpressing one or more of the Bcl-2 family proteins in CAR T cells to reduce their susceptibility to apoptosis, both alone and in the presence of BH3 mimetics, which can be used to activate apoptotic machinery in malignant cells. We comprehensively investigated overexpression of different Bcl-2 family proteins in CAR T cells with different signaling domains as well as in different tumor types. We found that Bcl-xL and Bcl-2 overexpression in CAR T cells bearing a 4-1BB costimulatory domain resulted in increased expansion and antitumor activity, reduced exhaustion, and decreased apoptotic priming. In addition, CAR T cells expressing either Bcl-xL or a venetoclax-resistant Bcl-2 variant led to enhanced antitumor efficacy and survival in murine xenograft models of lymphoma and leukemia in the presence or absence of the BH3 mimetic venetoclax, a clinically approved BH3 mimetic. In this setting, Bcl-xL overexpression had stronger effects than overexpression of Bcl-2 or the Bcl-2(G101V) variant. These findings suggest that CAR T cells could be optimally engineered by overexpressing Bcl-xL to enhance their persistence while opening a therapeutic window for combination with BH3 mimetics to prime tumors for apoptosis.

Anti-CD19 chimeric antigen receptor T-cell therapy in older patients with relapsed or refractory large B-cell lymphoma: A multicenter study

Chimeric antigen receptor T-cell (CAR-T) therapy, despite being a potentially curative therapy in relapsed or refractory (RR) large B-cell lymphoma (LBCL), remains underutilized in older patients due to limited clinical data. We therefore studied the safety and efficacy of CAR-T therapy in older patients with RR LBCL in the real-world setting. Patients aged ≥65 years with RR LBCL, treated with anti-CD19 CAR-T therapy at 7 US institutions were included in this multicenter, retrospective, observational study. In total, 226 patients were included. Median age at infusion was 71 years (range 65-89). Best objective and complete response rates were 86% and 62%, respectively. Median follow-up after infusion was 18.3 months. The median progression-free survival (PFS) was 6.9 months, with 6- and 12-month PFS estimates of 54% and 44%, respectively. The nonrelapse mortality (NRM) rate was 10.9% at day 180, primarily due to infections, and not impacted by the age groups. Grade ≥3 cytokine release syndrome and neurotoxicity occurred in 7% and 26%, respectively. In univariate analysis, no significant difference in PFS was seen regardless of the age groups or CAR-T type, whereas ECOG PS ≥2, elevated LDH, bulky disease, advanced stage, extranodal involvement, the need for bridging therapy, and prior bendamustine exposure were associated with shorter PFS. These findings support the use of CAR-T in older patients, including those aged ≥80 years. The age at CAR-T therapy did not influence safety, survival, and NRM outcomes. Older patients should not be excluded from receiving CAR-T therapy solely based on their chronological age.

Hematopoietic stem cell transplantation and cellular therapy in persons living with HIV

PURPOSE OF REVIEW

Summarize the latest research of both stem cell transplantation and cellular therapy and present the implications with respect to persons with HIV (PWH), hematologic malignancies, and HIV-1 cure.

RECENT FINDINGS

Allogeneic (alloSCT) and autologous (autoSCT) stem cell transplantation have been shown to be well tolerated and effective regardless of HIV-1 status. AlloSCT leads to a decrease in the HIV-1 latently infected reservoir orders of magnitude below that achieved with antiretroviral therapy (ART) alone. Utilization of CCR5Δ2/Δ32 donors in an alloSCT has resulted in HIV-1 cures. In the last 12 months, three cases of cure have been published, giving further insight into the conditions required for HIV-1 control. Other advances in the treatment of hematological cancers include chimeric antigen receptor T-cell (CART) therapy, which are active in PWH with lymphoma.

SUMMARY

Here we discuss the advances in SCT and cellular therapy in PWH and cancer. Additionally, we discuss how these technologies are being utilized to achieve HIV-1 cure.

FDA Approval Summary: Lisocabtagene Maraleucel for Second-Line Treatment of Large B-Cell Lymphoma

In June 2022, the FDA extended the indication for lisocabtagene maraleucel (liso-cel) to include adults with large B-cell lymphoma (LBCL) who have refractory disease or relapse within 12 months of first-line chemoimmunotherapy (CIT), as well as transplant-ineligible adults with refractory disease or relapse after first-line CIT. Two clinical trials evaluating a single infusion of liso-cel preceded by lymphodepleting chemotherapy supported the second-line indications. TRANSFORM is a randomized, phase 3, open-label trial comparing liso-cel with standard second-line therapy, including planned autologous hematopoietic stem cell transplantation (HSCT), in 184 transplant-eligible patients. On interim analysis, event-free survival (EFS) by independent review committee (IRC) assessment was statistically significantly improved for the liso-cel arm, with a stratified hazard ratio of 0.34 [95% confidence interval (CI), 0.22-0.51; P < 0.0001]; the estimated median EFS was 10.1 months in the liso-cel arm versus 2.3 months in the control arm. PILOT is a single-arm phase 2 trial of second-line liso-cel in patients who were transplant-ineligible due to age or comorbidities but had adequate organ function for chimeric antigen receptor (CAR) T-cell therapy. Among 61 patients who received liso-cel (median age, 74 years), the IRC-assessed complete response rate was 54% (95% CI, 41-67). Among patients achieving complete response, the estimated 1-year rate of continued response was 68% (95% CI, 45-83). Of the 268 patients combined who received liso-cel as second-line therapy for LBCL, cytokine release syndrome occurred in 45% (Grade 3, 1.3%) and CAR T-cell-associated neurologic toxicities occurred in 27% (Grade 3, 7%), warranting a continued risk evaluation and mitigation strategy.

Bispecific antibodies in the treatment of relapsed/refractory large B-cell lymphoma

INTRODUCTION

The management of relapsed and/or refractory (R/R) large B-cell lymphoma (LBCL) has witnessed dramatic changes in the recent past. Despite the availability of multiple novel immunotherapies in R/R setting, there remains an unmet need for off-the-shelf therapies, particularly in patients with primary refractory, multiply relapsed disease or those experiencing cellular immunotherapy failure. To harness the power of the T-cell mediated immunity, a novel class of drugs called bispecific antibodies (BsAbs) have been developed. These BsAbs are currently under investigation both in frontline and R/R setting and hold the potential to revolutionize the management of LBCL.

AREAS COVERED

This review article summarizes the currently available BsAbs, their mode of action, efficacy, and safety data for untreated and R/R LBCL. In addition, the role of these BsAbs in combination with currently available chemoimmunotherapy regimens is also discussed.

EXPERT OPINION

Two BsAbs have secured FDA approval for R/R LBCL, with expected approval of more BsAbs (including in earlier treatment lines). These drugs provide a highly efficacious and relatively safe treatment option for patients with highly pretreated disease including relapse after cellular immunotherapies. In addition, these BsAbs provide a platform for chemotherapy-free regimen for older/frail patients.

Patient-Reported Outcomes in Phase 3 Clinical Trials for Blood Cancers: A Systematic Review

Importance

Published research suggests that patient-reported outcomes (PROs) are neither commonly collected nor reported in randomized clinical trials (RCTs) for solid tumors. Little is known about these practices in RCTs for hematological malignant neoplasms.

Objective

To evaluate the prevalence of PROs as prespecified end points in RCTs of hematological malignant neoplasms, and to assess reporting of PROs in associated trial publications.

Evidence Review

All issues of 8 journals known for publishing high-impact RCTs (NEJM, Lancet, Lancet Hematology, Lancet Oncology, Journal of Clinical Oncology, Blood, JAMA, and JAMA Oncology) between January 1, 2018, and December 13, 2022, were searched for primary publications of therapeutic phase 3 trials for adults with hematological malignant neoplasms. Studies that evaluated pretransplant conditioning regimens, graft-vs-host disease treatment, or radiotherapy as experimental treatment were excluded. Data regarding trial characteristics and PROs were extracted from manuscripts and trial protocols. Univariable analyses assessed associations between trial characteristics and PRO collection or reporting.

Findings

Ninety RCTs were eligible for analysis. PROs were an end point in 66 (73%) trials: in 1 trial (1%) as a primary end point, in 50 (56%) as a secondary end point, and in 15 (17%) as an exploratory end point. PRO data were reported in 26 of 66 primary publications (39%): outcomes were unchanged in 18 and improved in 8, with none reporting worse PROs with experimental treatment. Trials sponsored by for-profit entities were more likely to include PROs as an end point (49 of 55 [89%] vs 17 of 35 [49%]; P < .001) but were not significantly more likely to report PRO data (20 of 49 [41%] vs 6 of 17 [35%]; P = .69). Compared with trials involving lymphoma (18 of 29 [62%]) or leukemia or myelodysplastic syndrome (18 of 28 [64%]), those involving plasma cell disorders or multiple myeloma (27 of 30 [90%]) or myeloproliferative neoplasms (3 of 3 [100%]) were more likely to include PROs as an end point (P = .03). Similarly, compared with trials involving lymphoma (3 of 18 [17%]) or leukemia or myelodysplastic syndrome (5 of 18 [28%]), those involving plasma cell disorders or multiple myeloma (16 of 27 [59%]) or myeloproliferative neoplasms (2 of 3 [67%]) were more likely to report PROs in the primary publication (P = .01).

Conclusions and Relevance

In this systematic review, almost 3 of every 4 therapeutic RCTs for blood cancers collected PRO data; however, only 1 RCT included PROs as a primary end point. Moreover, most did not report resulting PRO data in the primary publication and when reported, PROs were either better or unchanged, raising concern for publication bias. This analysis suggests a critical gap in dissemination of data on the lived experiences of patients enrolled in RCTs for hematological malignant neoplasms.

Claudin18.2-specific CAR T cells in gastrointestinal cancers: phase 1 trial final results

Claudin18.2 (CLDN18.2) is highly expressed with the development of various malignant tumors, especially gastrointestinal cancers, and is emerging as a new target for cancer treatment. Satricabtagene autoleucel (satri-cel)/CT041 is an autologous chimeric antigen receptor (CAR) T cell targeting CLDN18.2, and the interim results of the CT041-CG4006 trial were reported in June 2022. Here we present the final results of this single-arm, open-label, phase 1 trial, which evaluated the safety and efficacy of satri-cel in patients with CLDN18.2-positive advanced gastrointestinal cancers. This trial included a dose-escalation stage (n = 15) and a dose-expansion stage in four different cohorts (total n = 83): cohort 1, satri-cel monotherapy in 61 patients with standard chemotherapy-refractory gastrointestinal cancers; cohort 2, satri-cel plus anti-PD-1 therapy in 15 patients with standard chemotherapy-refractory gastrointestinal cancers; cohort 3, satri-cel as sequential treatment after first-line therapy in five patients with gastrointestinal cancers; and cohort 4, satri-cel monotherapy in two patients with anti-CLDN18.2 monoclonal antibody-refractory gastric cancer. The primary endpoint was safety; secondary endpoints included efficacy, pharmacokinetics and immunogenicity. A total of 98 patients received satri-cel infusion, among whom 89 were dosed with 2.5 × 108, six with 3.75 × 108 and three with 5.0 × 108 CAR T cells. Median follow-up was 32.4 months (95% confidence interval (CI): 27.3, 36.5) since apheresis. No dose-limiting toxicities, treatment-related deaths or immune effector cell-associated neurotoxicity syndrome were reported. Cytokine release syndrome occurred in 96.9% of patients, all classified as grade 1-2. Gastric mucosal injuries were identified in eight (8.2%) patients. The overall response rate and disease control rate in all 98 patients were 38.8% and 91.8%, respectively, and the median progression-free survival and overall survival were 4.4 months (95% CI: 3.7, 6.6) and 8.8 months (95% CI: 7.1, 10.2), respectively. Satri-cel demonstrates therapeutic potential with a manageable safety profile in patients with CLDN18.2-positive advanced gastrointestinal cancer. ClinicalTrials.gov identifier: NCT03874897 .

Secondary central nervous system involvement in patients with diffuse large B-cell lymphoma treated with rituximab combined CHOP therapy - a supplementary analysis of JCOG0601

Secondary central nervous system involvement (sCNSi) in diffuse large B-cell lymphoma (DLBCL) is fatal. However, its features in patients with sCNSi who are categorized as lower risk by international prognostic index (IPI) or CNS-IPI are not yet fully understood. In the present analysis, we evaluated DLBCL patients who developed sCNSi at their first progression and who participated in JCOG0601, most of whom were lower risk by IPI. Of 409 patients, 21 (5.1%) developed sCNSi during a median follow-up of 4.9 years. Five-year cumulative incidence of sCNSi were 5.1%; and 4.0%, 5.3%, and 11.5% at low, intermediate, and high risk of CNS-IPI, respectively. The most common locations of extranodal lesions at the time of registration in patients with sCNSi were the stomach (n = 4), paranasal cavity (n = 3), and bone marrow (n = 2). In univariable analysis, paranasal cavity lesion was a high-risk factor for sCNSi (subdistribution hazard ratio, 4.34 [95% confidence interval 1.28-14.73]). Median overall survival after sCNSi was 1.3 years, with a 2-year overall survival rate of 39.3%. The incidence of sCNSi in DLBCL patients at lower risk of CNS-IPI was low, as previously reported, but paranasal cavity lesion might indicate high risk for organ involvement. CLINICAL TRIAL REGISTRATION: JCOG0601 was registered in the UMIN Clinical Trials Registry (UMIN000000929, date of registration; December 04, 2007) and the Japan Registry of Clinical Trials (jRCTs031180139, date of registration; February 20, 2019).

Advances in research on factors affecting chimeric antigen receptor T-cell efficacy

Chimeric antigen receptor T-cell (CAR-T) therapy is becoming an effective technique for the treatment of patients with relapsed/refractory hematologic malignancies. After analyzing patients with tumor progression and sustained remission after CAR-T cell therapy, many factors were found to be associated with the efficacy of CAR-T therapy. This paper reviews the factors affecting the effect of CAR-T such as tumor characteristics, tumor microenvironment and immune function of patients, CAR-T cell structure, construction method and in vivo expansion values, lymphodepletion chemotherapy, and previous treatment, and provides a preliminary outlook on the corresponding therapeutic strategies.

The value of bispecific antibodies in relapsed and refractory DLBCL

Diffuse large B-cell lymphoma (DLBCL) may be cured with anti-CD20 based chemoimmunotherapy in the majority of cases, however, relapsed/refractory disease occurs in 30-40% patients, and despite significant recent therapeutic advances, continues to represent an unmet clinical need. Bispecific antibodies represent a novel class of therapy currently in development for relapsed/refractory B-cell lymphoma. This review discusses the background clinical need, mechanism of action, and clinical data including efficacy and toxicity for bispecific antibodies in DLBCL, focusing on the most advanced class in development; CD20 targeting T-cell engaging antibodies. Emerging possibilities for future use of bispecific antibodies is also discussed, including novel and cytotoxic combination regimens in relapsed and first-line settings.

Safety and Toxicity Profiles of CAR T Cell Therapy in Non-Hodgkin Lymphoma: A Systematic Review and Meta-Analysis

BACKGROUND

The application of CD19-directed chimeric antigen receptor T (CAR T) cell therapy has improved outcomes for thousands of patients with non-Hodgkin B cell lymphoma (NHL). The toxicities associated with various CAR T cell products, however, can be severe and difficult to anticipate.

METHODS

In this systematic review and meta-analysis, we set out to determine whether there are measurable differences in common toxicities, including cytokine release syndrome (CRS), immune effector cell associated neurotoxicity syndrome (ICANS), cytopenias, and infections, between CAR T products that are commercially available for the treatment of NHL.

RESULTS

After a stringent study selection process, we used a cohort of 1364 patients enrolled in 15 prospective clinical trials investigating the use of axicabtagene ciloleucel (axi-cel), lisocabtagene maraleucel (liso-cel), and tisagenlecleucel (tisa-cel). We found that the rates of CRS and ICANS were significantly higher with axi-cel as compared to both liso-cel and tisa-cel. Conversely, we demonstrated that rates of all-grade and severe neutropenia were significantly greater with liso-cel. Febrile neutropenia and all-grade infection rates did not differ significantly between products though rates of severe infection were increased with axi-cel.

CONCLUSIONS

Overall, this study serves as the first to delineate toxicity profiles associated with various available CAR T products. By better understanding associated toxicities, it may become possible to tailor therapies towards individual patients and anticipate the development of toxicities at earlier stages.

Glofitamab as a salvage treatment for B-cell lymphomas in the real world: A multicenter study in Taiwan

BACKGROUND

Glofitamab is a bispecific antibody with promise for treating relapsed/refractory B-cell lymphoma according to a phase 1/2 clinical trial. This study examined its real-world effectiveness.

METHODS

This was an investigator-initiated, multicenter retrospective study including 34 patients who had relapsed/refractory B-cell lymphomas after at least three prior lines of therapy and received glofitamab monotherapy in a compassionate use program in Taiwan between January 2021 and October 2022.

RESULTS

At a median follow-up of 15.9 months, 56% of patients responded to glofitamab and 23% achieved complete remission. Response to the previous line of therapy significantly correlated with response to glofitamab (p = .020). Most responses were durable; only five out of the 19 responders had documented disease recurrence at the data cutoff date. The estimated progression-free survival (PFS) was 3.2 months, and the estimated 1-year PFS was 33% for the entire cohort. PFS was better for responders than nonresponders (median PFS, 16.9 vs. 1.8 months; 1-year PFS, 60% vs. 0%). Forty-three cytokine release syndrome (CRS) events were observed, three of which were grade 3; all were manageable without glofitamab discontinuation. No immune effector cell-associated neurotoxicity was reported. Among seven hepatitis B virus (HBV) carriers (six had antiviral prophylaxis) and 14 patients with remote HBV (four had antiviral prophylaxis), no HBV reactivation was observed.

CONCLUSIONS

In this real-world cohort, glofitamab exhibited effectiveness comparable to trial results without excessive CRS or new safety issues. With appropriate prophylaxis, glofitamab-treated patients with chronic or remote HBV infection are unlikely to experience virus reactivation.

Bispecific antibodies and autologous chimeric antigen receptor T cell therapies for treatment of hematological malignancies

In recent years, the therapeutic landscape for hematological malignancies has markedly advanced, particularly since the inaugural approval of autologous chimeric antigen receptor T cell (CAR-T) therapy in 2017 for relapsed/refractory acute lymphoblastic leukemia (ALL). Autologous CAR-T therapy involves the genetic modification of a patient's T cells to specifically identify and attack cancer cells, while bispecific antibodies (BsAbs) function by binding to both cancer cells and immune cells simultaneously, thereby triggering an immune response against the tumor. The subsequent approval of various CAR-T therapies and BsAbs have revolutionized the treatment of multiple hematological malignancies, highlighting high response rates and a subset of patients achieving prolonged disease control. This review explores the mechanisms underlying autologous CAR-T therapies and BsAbs, focusing on their clinical application in multiple myeloma, ALL, and non-Hodgkin lymphoma. We provide comprehensive insights into their individual efficacy, limitations concerning broad application, and the potential of combination therapies. These upcoming strategies aim to propel the field forward, paving the way for safer and more effective therapeutic interventions in hematological malignancies.

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 experience of commercial relmacabtagene autoleucel (relma-cel) for relapsed/refractory central nervous system lymphoma: a multicenter retrospective analysis of patients in China

BACKGROUND

Relapsed/refractory (R/R) central nervous system lymphomas (CNSLs) are associated with a poor prognosis. Relmacabtagene autoleucel (relma-cel), expressing the same chimeric antigen receptor (CAR) as lisocabtagene maraleucel, with an optimized commercial-ready process developed in China, demonstrated remarkable efficacy and manageable safety in the pivotal RELIANCE study. However, no published data are available on the "real-world" use of relma-cel, especially for patients with CNS involvement.

PATIENTS AND METHODS

Retrospective analyses were conducted for commercial relma-cel used in patients with R/R CNSL at 12 clinics. The primary endpoint was to evaluate the proportion of patients who achieved complete response (CR) at 3 months. Secondary endpoints included best complete response (BCR), progression-free survival (PFS), duration of response (DOR), overall survival (OS), and the incidence of adverse events.

RESULTS

Among the 22 CNSL patients (12 primary CNSLs; 10 secondary CNSLs), the best overall response rate was 90.9% and the BCR rate was 68.2%. With median follow-up of 316 days (range, 55-618 days), the estimated 1-year PFS rate, DOR, and OS rate were 64.4%, 71.5%, and 79.2%, respectively. Significant clinical benefits were observed in patients who were in durable CR or partial response to the most recent prior therapy preleukapheresis and received relma-cel as consolidation therapy (n=8), with 1-year PFS rate of 100.0% versus 41.7% (p=0.02). In addition, in terms of primary endpoint, non-CR at 3 months postinfusion seemed to be predictive of a worse prognosis, with an estimated 1-year PFS of 83.3% versus 37.0% (p=0.03), respectively. CRS occurred in 72.9% of patients (grade 3: 4.5%) and immune effector cell-associated neurotoxicity syndrome in 36.4% of patients (grade 3: 4.5%). With the add-on agent PD-1 inhibitor (tislelizumab) to the ongoing BTKi, significant re-expansions of CAR T-cell were detected by quantitative PCR or flow cytometry after a median of 2 weeks (range, 12-32 days).

CONCLUSIONS

This study was the first and largest real-world study of commercial relma-cel for R/R CNSL, demonstrating promising efficacy and acceptable safety. We reaffirmed the benefit of immuno-agents such as BTKi or PD-1 inhibitor on CAR T-cell re-expansion and hypothesized a dual-agent CAR-T related combinatorial therapies, which warrants further validation. Most importantly, we highlighted the earlier use of CAR T-cell therapy as a consolidative therapy for patients sensitive to salvage therapy, which provided an impetus and inspired-future strategy.

Novel CAR T cell therapies for patients with large B cell lymphoma

Approximately 60-70% of patients with large B cell lymphoma (LBCL) achieve long-term remission or a cure after initial treatment. However, patients who relapse or are refractory to initial treatment have a poor prognosis. Chimeric antigen receptor (CAR) T cell therapy has recently attracted attention for its potential to provide a cure or long-term remission even for LBCL that has relapsed or is refractory to conventional chemotherapy. Currently, three CAR T cell products are clinically available for LBCL: tisagenlecleucel (tisa-cel), axicabtagene ciloleucel (axi-cel) and lisocabtagene maraleucel (liso-cel). These CAR T cell products were initially approved as third- or later-line therapies worldwide. Recently, axi-cel and liso-cel have become feasible as second-line therapies for patients with early relapsed or refractory disease after first-line chemotherapy. Although a large body of data on CAR T cell therapy has been accumulated, the clinical question of how to choose between these three available CAR T cell products has yet to be resolved. The appropriate approach to treatment selection for patients who relapse after CAR T cell therapy also remains unclear. This review discusses treatment strategies to maximize the benefits of CAR T cell therapy.

CAR-T cell therapy: Efficacy in management of cancers, adverse effects, dose-limiting toxicities and long-term follow up

Chimeric Antigen Receptor T-cell (CAR-T) therapy has emerged as a groundbreaking and highly promising approach for the management of cancer. This paper reviews the efficacy of CAR-T therapy in the treatment of various hematological malignancies, also, with a mention of its effect on solid tumors, for which they have not received FDA approval yet. Different common and uncommon side effects are also discussed in this paper, with attention to the effect of each drug separately. By reviewing the recommendations of the FDA for CAR-T therapy research, we have extensively discussed dose-limiting toxicities. This further highlights the need for precise dosing strategies, striking a balance between therapeutic benefits and potential risks. Additionally, we reviewed the long-term follow-up of patients receiving CAR-T therapy to gain valuable insights into response durability and late-onset effects.

Peripheral CX3CR1+ T cells combined with PD-1 blockade therapy potentiates the anti-tumor efficacy for lung cancer

Identifying tumor-relevant T cell subsets in the peripheral blood (PB) has become a potential strategy for cancer treatment. However, the subset of PB that could be used to treat cancer remains poorly defined. Here, we found that the CX3CR1+ T cell subset in the blood of patients with lung cancer exhibited effector properties and had a higher TCR matching ratio with tumor-infiltrating lymphocytes (TILs) compared to CX3CR1- T cells, as determined by paired single-cell RNA and TCR sequencing. Meanwhile, the anti-tumor activities, effector cytokine production, and mitochondrial function were enhanced in CX3CR1+ T cells both in vitro and in vivo. However, in the co-culture system of H322 cells with T cells, the percentages of apoptotic cells and Fas were substantially higher in CX3CR1+ T cells than those in CX3CR1- T cells. Fas-mediated apoptosis was rescued by treatment with an anti-PD-1 antibody. Accordingly, the combination of adoptive transfer of CX3CR1+ T cells and anti-PD-1 treatment considerably decreased Fas expression and improved the survival of lung xenograft mice. Moreover, an increased frequency of CX3CR1+ T cells in the PB correlated with a better response and prolonged survival of patients with lung cancer who received anti-PD-1 therapy. These findings indicate the promising potential of adoptive transfer of peripheral CX3CR1+ T cells as an individual cancer immunotherapy.

Mechanisms and management of CAR T toxicity

Chimeric antigen receptor (CAR) T cell therapies have dramatically improved treatment outcomes for patients with relapsed or refractory B-cell acute lymphoblastic leukemia, large B-cell lymphoma, follicular lymphoma, mantle cell lymphoma, and multiple myeloma. Despite unprecedented efficacy, treatment with CAR T cell therapies can cause a multitude of adverse effects which require monitoring and management at specialized centers and contribute to morbidity and non-relapse mortality. Such toxicities include cytokine release syndrome, immune effector cell-associated neurotoxicity syndrome, neurotoxicity distinct from ICANS, immune effector cell-associated hemophagocytic lymphohistiocytosis-like syndrome, and immune effector cell-associated hematotoxicity that can lead to prolonged cytopenias and infectious complications. This review will discuss the current understanding of the underlying pathophysiologic mechanisms and provide guidelines for the grading and management of such toxicities.

Efficacy and safety of chimeric antigen receptor T-cell (CAR-T) therapy in hematologic malignancies: a living systematic review (protocol)

Objective

To determine the efficacy and safety of CAR-T therapy in the treatment of patients with hematologic malignancies, in comparison with other current therapies.

Design

A living systematic review.

Methods

We will include randomized trials evaluating the effect of CAR-T therapy versus other active treatments, hematopoietic stem cell transplantation, best supportive care or any other intervention in patients with hematologic malignancies. Non-randomized primary studies will be searched in case we found no direct evidence from randomized controlled trials. Two reviewers will independently screen each study for eligibility, extract data, and assess the risk of bias. Efficacy measures will include overall survival rate, overall response rate, complete response/remission (CR) rate, partial response/remission (PR) rate, relapse from CR, progression-free survival, and time from CAR-T infusion to transplantation. Safety measures will include serious adverse events, the incidence of cytokine release syndrome, graft-versus-host disease, neurotoxicity, and total adverse events. Quality of life will also be assessed. Meta-analyses will be carried out to summarize the results. We will apply the GRADE approach to assess the certainty of the evidence for each outcome. A living, web-based version of this review will be openly available until there is solid evidence to respond to the review objective. We will resubmit it for publication every time the conclusions change or whenever there are substantial updates.

Current understanding and management of CAR T cell-associated toxicities

Chimeric antigen receptor (CAR) T cell therapy has revolutionized the treatment of several haematological malignancies and is being investigated in patients with various solid tumours. Characteristic CAR T cell-associated toxicities such as cytokine-release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS) are now well-recognized, and improved supportive care and management with immunosuppressive agents has made CAR T cell therapy safer and more feasible than it was when the first regulatory approvals of such treatments were granted in 2017. The increasing clinical experience with these therapies has also improved recognition of previously less well-defined toxicities, including movement disorders, immune effector cell-associated haematotoxicity (ICAHT) and immune effector cell-associated haemophagocytic lymphohistiocytosis-like syndrome (IEC-HS), as well as the substantial risk of infection in patients with persistent CAR T cell-induced B cell aplasia and hypogammaglobulinaemia. A more diverse selection of immunosuppressive and supportive-care pharmacotherapies is now being utilized for toxicity management, yet no universal algorithm for their application exists. As CAR T cell products targeting new antigens are developed, additional toxicities involving damage to non-malignant tissues expressing the target antigen are a potential hurdle. Continued prospective evaluation of toxicity management strategies and the design of less-toxic CAR T cell products are both crucial for ongoing success in this field. In this Review, we discuss the evolving understanding and clinical management of CAR T cell-associated toxicities.

SOHO State of the Art Updates and Next Questions | Current Evidence and Future Directions for Bispecific Antibodies in Large B-Cell Lymphoma

The CD20xCD3 bispecific antibodies (bsAb) are "off-the-shelf" T-cell re-directing therapies that demonstrate remarkable single-agent clinical activity in B-cell lymphomas. Two agents, epcoritamab (epcor) and glofitamab (glofit) have recent global approvals for patients with relapsed/refractory DLBCL (RR DLBCL) following 2 prior treatment lines. Both agents demonstrate activity in patients with prior exposure to chimeric antigen receptor T-cell (CAR-T) treatment. As multiyear follow-up data become available, it is clear that the majority of patients achieving complete remissions do not relapse and that outcomes are similar between epcor and glofit. CD20xCD3 bsAb have a safety profile that reflect their mechanism of action, with cytokine release syndrome (CRS) the key management issue. Neurotoxicity is far less common than observed with CD19-directed CAR-T. BsAbs are attractive, rapidly available, treatment options for patients with RR DLBCL, without the practical and financial challenges seen with autologous CAR-T therapies. Recent data also demonstrate the feasibility and potential efficacy of bsAb in combination with chemoimmunotherapy with large randomized trials evaluating bsAb-chemotherapy combinations underway. There are open questions about the future role of bsAB for LBCL, the optimal duration of therapy, optimal CRS risk mitigation strategies, and potential resistance mechanisms. In this review we seek to describe the current evidence for bsAb in LBCL, and offer opinion regarding these open questions.

Pooled screening for CAR function identifies novel IL13Rα2-targeted CARs for treatment of glioblastoma

Chimeric antigen receptor therapies have demonstrated potent efficacy in treating B cell malignancies, but have yet to meaningfully translate to solid tumors. Here, we utilize our pooled screening platform, CARPOOL, to expedite the discovery of CARs with anti-tumor functions necessary for solid tumor efficacy. We performed selections in primary human T cells expressing a library of 1.3×10 6 3 rd generation CARs targeting IL13Rα2, a cancer testis antigen commonly expressed in glioblastoma. Selections were performed for cytotoxicity, proliferation, memory formation, and persistence upon repeated antigen challenge. Each enriched CAR robustly produced the phenotype for which it was selected, and one enriched CAR triggered potent cytotoxicity and long-term proliferation upon in vitro tumor rechallenge. It also showed significantly improved persistence and comparable antigen-specific tumor control in a microphysiological human in vitro model and a xenograft model of human glioblastoma. Taken together, this work demonstrates the utility of extending CARPOOL to diseases beyond hematological malignancies and represents the largest exploration of signaling combinations in human primary cells to date.

Stealth transgenes enable CAR-T cells to evade host immune responses

BACKGROUND

Adoptive cell therapy, such as chimeric antigen receptor (CAR)-T cell therapy, has improved patient outcomes for hematological malignancies. Currently, four of the six FDA-approved CAR-T cell products use the FMC63-based αCD19 single-chain variable fragment, derived from a murine monoclonal antibody, as the extracellular binding domain. Clinical studies demonstrate that patients develop humoral and cellular immune responses to the non-self CAR components of autologous CAR-T cells or donor-specific antigens of allogeneic CAR-T cells, which is thought to potentially limit CAR-T cell persistence and the success of repeated dosing.

METHODS

In this study, we implemented a one-shot approach to prevent rejection of engineered T cells by simultaneously reducing antigen presentation and the surface expression of both Classes of the major histocompatibility complex (MHC) via expression of the viral inhibitors of transporter associated with antigen processing (TAPi) in combination with a transgene coding for shRNA targeting class II MHC transactivator (CIITA). The optimal combination was screened in vitro by flow cytometric analysis and mixed lymphocyte reaction assays and was validated in vivo in mouse models of leukemia and lymphoma. Functionality was assessed in an autologous setting using patient samples and in an allogeneic setting using an allogeneic mouse model.

RESULTS

The combination of the Epstein-Barr virus TAPi and an shRNA targeting CIITA was efficient and effective at reducing cell surface MHC classes I and II in αCD19 'stealth' CAR-T cells while retaining in vitro and in vivo antitumor functionality. Mixed lymphocyte reaction assays and IFNγ ELISpot assays performed with T cells from patients previously treated with autologous αCD19 CAR-T cells confirm that CAR T cells expressing the stealth transgenes evade allogeneic and autologous anti-CAR responses, which was further validated in vivo. Importantly, we noted anti-CAR-T cell responses in patients who had received multiple CAR-T cell infusions, and this response was reduced on in vitro restimulation with autologous CARs containing the stealth transgenes.

CONCLUSIONS

Together, these data suggest that the proposed stealth transgenes may reduce the immunogenicity of autologous and allogeneic cellular therapeutics. Moreover, patient data indicate that repeated doses of autologous FMC63-based αCD19 CAR-T cells significantly increased the anti-CAR T cell responses in these patients.

Outpatient administration of CAR T-cell therapy: a focused review with recommendations for implementation in community based centers

Chimeric Antigen Receptor T-cell (CAR-T) therapy has transformed the treatment landscape for hematological malignancies, showing high efficacy in patients with relapsed or refractory (R/R) disease and otherwise poor prognosis in the pre-CAR-T era. These therapies have been usually administered in the inpatient setting due to the risk of cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS). However, there is a growing interest in the transition to outpatient administration due to multiple reasons. We review available evidence regarding safety and feasibility of outpatient administration of CD19 targeted and BCMA targeted CAR T-cell therapy with an emphasis on the implementation of outpatient CAR-T programs in community-based centers.

B-cell non-Hodgkin lymphomas

B-cell lymphomas occur with an incidence of 20 new cases per 100 000 people per year in high-income countries. They can affect any organ and are characterised by heterogeneous clinical presentations and courses, varying from asymptomatic, to indolent, to very aggressive cases. Since the topic of B-cell non-Hodgkin lymphomas was last reviewed in The Lancet in 2017, a deeper understanding of the biological background of this heterogeneous group of malignancies, the availability of new diagnostic methods, and the development and implementation of new targeted and immunotherapeutic approaches have improved our ability to treat patients. This Seminar provides an overview of the pathobiology, classification, and prognostication of B-cell non-Hodgkin lymphomas and summarises the current knowledge and standard of care regarding biology and clinical management of the most common subtypes of mature B-cell non-Hodgkin lymphomas. It also highlights new findings in deciphering the molecular background of disease development and the implementation of new therapeutic approaches, particularly those targeting the immune system.

Chimeric antigen receptor T cell therapy: a new emerging landscape in autoimmune rheumatic diseases

Chimeric antigen receptor T cell (CAR-T) therapy, an innovative immune cell therapy, has revolutionized the treatment landscape of haematological malignancies. The past 2 years has witnessed the successful application of CD19-targeting CAR constructs in refractory cases of autoimmune rheumatic diseases, including systemic lupus erythematosus, systemic sclerosis and anti-synthetase syndrome. In comparison with existing B cell depletion therapies, targeting CD19 has demonstrated a more rapid and profound therapeutic effect, enabling drug-free remission with manageable adverse events. These promising results necessitate validation through long-term, large-sample randomized controlled studies. Corroborating the role of CAR-T therapy in refractory rheumatological disorders and affirming safety, efficacy and durability of responses are the aims of future clinical studies. Optimizing the engineering strategies and better patient selection are also critical to further refining the successful clinical implementation of CAR-T therapy.

Prognostic differences between carmustine, etoposide, cytarabine and melphalan (BEAM) and carmustine, etoposide, cytarabine, melphalan and fludarabine (BEAMF) regimens before autologous stem cell transplantation plus chimeric antigen receptor T therapy in patients with refractory/relapsed B-cell non-Hodgkin-lymphoma

BACKGROUND AIMS

The combination therapy of autologous hematopoietic stem cell transplantation (ASCT) and chimeric antigen receptor T-cell (CART) therapy has been employed to improve outcomes for relapsed or refractory (R/R) B-cell non-Hodgkin-lymphoma (B-NHL). The widely used conditioning regimen before ASCT plus CART therapy reported in the literature was carmustine, etoposide, cytarabine and melphalan (BEAM). However, whether adding fludarabine to the BEAM regimen (BEAMF) can improve the survival of patients with R/R B-NHL remains unknown.

METHODS

In total, 39 and 19 patients with R/R B-NHL were enrolled to compare clinical outcomes in the BEAM and BEAMF regimens before ASCT plus CD19/22 CART therapy, respectively.

RESULTS

The objective response (OR) rates at 3 months to BEAM and BEAMF regimens before ASCT plus CD19/22 CART therapy were 71.8% and 94.7%, respectively (P = 0.093). The BEAMF regimen showed a trend towards a superior duration of response compared with the BEAM regimen (P = 0.09). After a median follow-up of 28 months (range: 0.93-51.9 months), the BEAMF regimen demonstrated superior 2-year progression-free survival (PFS) (89.5% versus 63.9%; P = 0.048) and 2-year overall survival (OS) (100% vs 77.3%; P = 0.035) compared with the BEAM regimen. In the multivariable Cox regression analysis, OR at month 3 (responders) was remarkably correlated with better OS (hazard ratio: 0.112, P = 0.005) compared with OR (non-responders).

CONCLUSIONS

For patients with R/R B-NHL, the BEAMF regimen before ASCT plus CD19/22 CART therapy was correlated with superior PFS and OS than the BEAM regimen, and the BEAMF regimen is a promising alternative conditioning regimen for ASCT plus CAR-T therapy.

Finding Your CAR: The Road Ahead for Engineered T Cells

Adoptive cellular therapy using chimeric antigen receptors (CARs) has transformed immunotherapy by engineering T cells to target specific antigens on tumor cells. As the field continues to advance, pathology laboratories will play increasingly essential roles in the complicated multi-step process of CAR T-cell therapy. These include detection of targetable tumor antigens by flow cytometry or immunohistochemistry at the time of disease diagnosis and the isolation and infusion of CAR T cells. Additional roles include: i) detecting antigen loss or heterogeneity that renders resistance to CAR T cells as well as identifying alternative targetable antigens on tumor cells, ii) monitoring the phenotype, persistence, and tumor infiltration properties of CAR T cells and the tumor microenvironment for factors that predict CAR T-cell therapy success, and iii) evaluating side effects and biomarkers of CAR T-cell cytotoxicity such as cytokine release syndrome. This review highlights existing technologies that are applicable to monitoring CAR T-cell persistence, target antigen identification, and loss. Also discussed are emerging technologies that address new challenges such as how to put a brake on CAR T cells. Although pathology laboratories have already provided companion diagnostic tests important in immunotherapy (eg, programmed death-ligand 1, microsatellite instability, and human epidermal growth factor receptor 2 testing), we draw attention to the exciting new translational research opportunities in adoptive cellular therapy.

Current Challenges in Chimeric Antigen Receptor T-cell Therapy in Patients With B-cell Lymphoid Malignancies

Chimeric antigen receptor (CAR) T-cell therapy is a promising immunotherapy based on genetically engineered T cells derived from patients. The introduction of CAR T-cell therapy has changed the treatment paradigm of patients with B-cell lymphoid malignancies. However, challenging issues including managing life-threatening toxicities related to CAR T-cell infusion and resistance to CAR T-cell therapy, leading to progression or relapse, remain. This review summarizes the issues with currently approved CAR T-cell therapies for patients with relapsed or refractory B-cell lymphoid malignancies, including lymphoma and myeloma. We focus on unique toxicities after CAR T-cell therapy, such as cytokine-related events and hematological toxicities, and the mechanisms underlying post-CAR T-cell failure.

The potential and promise for clinical application of adoptive T cell therapy in cancer

Adoptive cell therapy has revolutionized cancer treatment, especially for hematologic malignancies. T cells are the most extensively utilized cells in adoptive cell therapy. Currently, tumor-infiltrating lymphocytes, T cell receptor-transgenic T cells and chimeric antigen receptor T cells are the three main adoptive T cell therapies. Tumor-infiltrating lymphocytes kill tumors by reinfusing enlarged lymphocytes that naturally target tumor-specific antigens into the patient. T cell receptor-transgenic T cells have the ability to specifically destroy tumor cells via the precise recognition of exogenous T cell receptors with major histocompatibility complex. Chimeric antigen receptor T cells transfer genes with specific antigen recognition structural domains and T cell activation signals into T cells, allowing T cells to attack tumors without the assistance of major histocompatibility complex. Many barriers have been demonstrated to affect the clinical efficacy of adoptive T cell therapy, such as tumor heterogeneity and antigen loss, hard trafficking and infiltration, immunosuppressive tumor microenvironment and T cell exhaustion. Several strategies to improve the efficacy of adoptive T cell therapy have been explored, including multispecific chimeric antigen receptor T cell therapy, combination with immune checkpoint blockade, targeting the immunosuppressive tumor microenvironment, etc. In this review, we will summarize the current status and clinical application, followed by major bottlenecks in adoptive T cell therapy. In addition, we will discuss the promising strategies to improve adoptive T cell therapy. Adoptive T cell therapy will result in even more incredible advancements in solid tumors if the aforementioned problems can be handled.

Immunologic tumor microenvironment modulators for turning cold tumors hot

Tumors can be classified into distinct immunophenotypes based on the presence and arrangement of cytotoxic immune cells within the tumor microenvironment (TME). Hot tumors, characterized by heightened immune activity and responsiveness to immune checkpoint inhibitors (ICIs), stand in stark contrast to cold tumors, which lack immune infiltration and remain resistant to therapy. To overcome immune evasion mechanisms employed by tumor cells, novel immunologic modulators have emerged, particularly ICIs targeting cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) and programmed cell death protein 1/programmed death-ligand 1(PD-1/PD-L1). These agents disrupt inhibitory signals and reactivate the immune system, transforming cold tumors into hot ones and promoting effective antitumor responses. However, challenges persist, including primary resistance to immunotherapy, autoimmune side effects, and tumor response heterogeneity. Addressing these challenges requires innovative strategies, deeper mechanistic insights, and a combination of immune interventions to enhance the effectiveness of immunotherapies. In the landscape of cancer medicine, where immune cold tumors represent a formidable hurdle, understanding the TME and harnessing its potential to reprogram the immune response is paramount. This review sheds light on current advancements and future directions in the quest for more effective and safer cancer treatment strategies, offering hope for patients with immune-resistant tumors.

Axicabtagene ciloleucel treatment is more effective in primary mediastinal large B-cell lymphomas than in diffuse large B-cell lymphomas: the Italian CART-SIE study

Axicabtagene ciloleucel showed efficacy for relapsed/refractory large B-cell lymphomas (LBCL), including primary mediastinal B-cell lymphomas (PMBCL); however, only few PMBCLs were reported. Aim was to evaluate efficacy and safety of axicabtagene ciloleucel in patients with PMBCL compared to those with other LBCL, enrolled in the Italian prospective observational CART-SIE study. PMBCLs (n = 70) were younger, with higher percentage of bulky and refractory disease, compared to other LBCLs (n = 190). Median follow-up time for infused patients was 12.17 months (IQR 5.53,22.73). The overall (complete + partial) response rate (ORR,CR + PR) after bridging was 41% for PMBCL and 28% for other LBCL, p = 0.0102. Thirty days ORR was 78% (53/68) with 50% (34) CR in PMBCL, and 75% (141/187) with 53% (100) CR in other LBCL, p = 0.5457. Ninety days ORR was 69% (45/65) with 65% (42) CR in PMBCL, and 54% (87/162) with 47% (76) CR in other LBCL; progressive disease was 21% in PMBCL and 45% in other LBCL, p = 0.0336. Twelve months progression-free survival was 62% (95% CI: 51-75) in PMBCL versus 48% (95% CI: 41-57) in other LBCL, p = 0.0386. Twelve months overall survival was 86% (95% CI: 78-95) in PMBCL versus 71% (95% CI: 64-79) in other LBCL, p = 0.0034. All grade cytokine release syndrome was 88% (228/260); all grade neurotoxicity was 34% (88/260), with 6% of fatal events in PMBCL. Non-relapse mortality was 3%. In conclusion, PMBCLs achieved significantly better response and survival rates than other LBCLs.

[T-cell recruiting immunotherapies in B-cell lymphoma - the future backbone for all therapy lines?]

The introduction of immunologically targeted therapies has represented a significant advancement in the treatment of B-cell lymphomas, particularly aggressive B-cell lymphoma. CD19 CAR-T cells such as Axicabtagen-Ciloleucel (Axi-cel) and Lisocabtagen Maraleucel (Liso-cel) have been approved since 2022 and 2023, respectively, for second-line therapy of Diffuse Large B-Cell Lymphomas (DLBCL), when there is primary refractory disease or relapse within 12 months after the end of first-line therapy. These therapies result in a significant improvement in progression-free survival compared to the previous standard therapy (salvage chemotherapy followed by high-dose chemotherapy and autologous stem cell transplantation). Especially in elderly patients or patients with underlying medical conditions, CAR-T cell therapies like Axi-cel and Liso-cel demonstrate acceptable tolerability and high efficacy.Furthermore, bispecific T-cell-engaging antibodies ("bispecifics") such as Glofitamab, Epcoritamab, and Mosunetuzumab also represent promising treatment options for patients with relapsed disease after failure of second- or later line therapy and show efficacy even in a subset of patients relapsing after CD19 CAR-T cells. However, randomized study results for these substances are not yet available. They are expected to be used in earlier lines of therapy in the future, especially in combination with standard chemotherapy regimens. Common side effects of bispecific antibody therapies are cytokine release syndrome (CRS) and immune-mediated cytopenias, whereas immune-cell associated neurotoxicity syndrome (ICANS) is relatively rare compared to CD19 CAR T cells. In summary, bispecifics represent a novel, highly effective immunotherapy for the treatment of lymphomas with a very favourable toxicity profile.

Synthetic dual co-stimulation increases the potency of HIT and TCR-targeted cell therapies

Chimeric antigen receptor T cells have dramatically improved the treatment of hematologic malignancies. T cell antigen receptor (TCR)-based cell therapies are yet to achieve comparable outcomes. Importantly, chimeric antigen receptors not only target selected antigens but also reprogram T cell functions through the co-stimulatory pathways that they engage upon antigen recognition. We show here that a fusion receptor comprising the CD80 ectodomain and the 4-1BB cytoplasmic domain, termed 80BB, acts as both a ligand and a receptor to engage the CD28 and 4-1BB pathways, thereby increasing the antitumor potency of human leukocyte antigen-independent TCR (HIT) receptor- or TCR-engineered T cells and tumor-infiltrating lymphocytes. Furthermore, 80BB serves as a switch receptor that provides agonistic 4-1BB co-stimulation upon its ligation by the inhibitory CTLA4 molecule. By combining multiple co-stimulatory features in a single antigen-agnostic synthetic receptor, 80BB is a promising tool to sustain CD3-dependent T cell responses in a wide range of targeted immunotherapies.

Benefit of axicabtagene ciloleucel versus chemoimmunotherapy in older patients and/or patients with poor ECOG performance status with relapsed or refractory large B-cell lymphoma after 2 or more lines of prior therapy

Axicabtagene ciloleucel (axi-cel) in trials has demonstrated favorable efficacy compared with historical controls after ≥2 lines of therapy for the treatment of relapsed or refractory (R/R) large B cell lymphoma (LBCL). Herein, we compared the real-world effectiveness of axi-cel with efficacy and effectiveness of chemoimmunotherapy (CIT) in patients aged ≥65 years and patients with Eastern Cooperative Oncology Group performance status (ECOG PS) of 2. A total of 1146 patients treated with commercial axi-cel for R/R LBCL with ≥2 lines of prior therapy were included from the Center for International Blood and Marrow Transplantation Research prospective observational study, and 469 patients treated with CIT for R/R LBCL after ≥2 lines of prior therapy were included from SCHOLAR-1 (an international, multicohort, retrospective study). After propensity score matching, at a median follow-up of 24 months for patients receiving axi-cel and 60 months for patients receiving CIT, 12-month overall survival rates were 62% and 28%, respectively (hazard ratio, 0.30 [95% CI, 0.24-0.37]). Objective response rate (ORR) was 76% (complete response [CR] rate 58%) in patients receiving axi-cel versus 28% (CR rate 16%) for those receiving CIT. A 57% difference in ORR (55% difference in CR rate) favoring axi-cel over CIT was observed among patients aged ≥65 years. Increased magnitude of benefit in response rates for axi-cel versus CIT was also observed among patients with ECOG PS = 2. These findings further support the broader use of axi-cel in older patients and patients with ECOG PS = 2 with R/R LBCL.