CAR-T Cell Therapy in Large B Cell Lymphoma

Ugo Testa1, Giuseppe Leone3, Elvira Pelosi1, Germana Castelli1 and Stefan Hohaus2,3.

Istituto Superiore di Sanità, Roma.
2 Dipartimento Di Diagnostica per Immagini, Radioterapia Oncologica Ed Ematologia, Fondazione Policlinico Universitario Agostino Gemelli IRCCS, Roma, Italy. Sezione Di Ematologia.
3 Dipartimento Di Scienze Radiologiche Ed Ematologiche, Università Cattolica Del Sacro Cuore, Roma, Italy.

Correspondence to: Ugo Testa. E-mail: 

Published: November 01, 2023
Received: October 09, 2023
Accepted: October 16, 2023
Mediterr J Hematol Infect Dis 2023, 15(1): e2023066 DOI 10.4084/MJHID.2023.066

This is an Open Access article distributed under the terms of the Creative Commons Attribution License
(, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Large B-cell lymphomas (LBCLs) are among the most frequent (about 30%) non-Hodgkin’s lymphoma. Despite the aggressive behavior of these lymphomas, more than 60% of patients can be cured with first-line chemoimmunotherapy using the R-CHOP regimen. Patients with refractory or relapsing disease show a poor outcome even when treated with second-line therapies.
CD19-targeted chimeric antigen receptor (CAR) T-cells are emerging as an efficacious second-line treatment strategy for patients with LBCL. Three CD19-CAR-T-cell products received FDA and EMA approval. CAR-T cell therapy has also been explored for treating high-risk LBCL patients in the first-line setting and for patients with central nervous system involvement.
Although CD19-CAR-T therapy has transformed the care of refractory/relapsed LBCL, about 60% of these patients will ultimately progress or relapse following CD19-CAR-T; therefore, it is fundamental to identify predictive criteria of response to CAR-T therapy and to develop salvage therapies for patients relapsing after CD19-CAR-T therapies. Moreover, ongoing clinical trials evaluate bispecific CAR-T cells targeting both CD19 and CD20 or CD19 and CD22 as a tool to improve the therapeutic efficacy and reduce the number of refractory/relapsing patients.


Chimeric antigen receptors (CARs) are engineered receptors that enable T lymphocytes with the capacity to specifically recognize an antigen and induce a cytotoxic reaction against tumor cells based on their expression of this antigen.
Antitumor adaptive therapies represent a key strategy in the treatment of tumors. Some of these immunotherapies were based on the use of genetically engineered cells. Particularly, two different types of immunotherapies have been developed using genetically modified T lymphocytes: (i) T-cell receptor-engineered cells enabled to recognize specific membrane antigens in a HLA-restricted manner; (ii) CAR-T transduced T lymphocytes that interact with specific membrane antigens in a HLA-unrestricted manner and antibody-specific manner.
The molecular architecture of a CAR molecule implies four components: i) an extracellular target antigen-binding domain (ABD); ii) a hinge region; iii) a transmembrane region; iv) one or more intracellular signaling domains. ABD is the part of the CAR molecule that confers specificity in antigen recognition and is usually derived from the variable heavy (VH) and light (VL) chains of monoclonal antibodies, connected through a flexible linker to generate a single-chain variable fragment (scFv). The hinge component is a spacer region that extends the ABD from the ABD to the transmembrane region and confers sufficient flexibility to avoid steric hindrance. The transmembrane region is required to anchor the CAR molecule to the cell membrane of T lymphocytes. The intracellular signaling domains play an important role in the modulation of CAR-T cell activity; a large part of CARs is based on the activation of T lymphocytes using CD3-derived immunoreceptor tyrosine-based activation motifs.[1]
The procedure for generating CAR-T cells evolved over time with 5 different CAR-T generations from the first procedures in late 1990 to the most recent developments.[1] The first generation of CAR-T was based on the CD3-ζ
intracellular domain, in the absence of costimulatory domains; the second generation of CAR-T cells contained a costimulatory domain, such as CD28, in the intracellular domain; the third generation was based on the presence of multiple costimulatory domains; the fourth generation involved the production of T cell redirected for general universal cytokine-mediated killing (TROCKs), a property obtained through IL-12 production, either constitutive or after CAR-T activation; the fifth generation also included a STAT3 binding site required for generation of three activation signals acting on the cell signaling, costimulatory and cytokine signaling domains.[1] Compared to the first generation, the consistent advantages of second- and third-generation CAR-T cells consisted of enhanced proliferation, cytotoxicity, and lifespan in vivo.[1] The last generations of CAR-T cells showed superior in vivo persistence and enhanced antitumor effects in leukemia and solid tumor models compared to initial CAR-T cell generations and are expected to demonstrate superior antitumor effects with reduced toxicity in the clinic.[2]
The key role of CD19 targeting by CAR-T for the therapy of B-cell malignancies. The human CD19 antigen is a B-lymphocyte antigen belonging to the immunoglobulin superfamily, whose expression is restricted to the B-cell lineage starting from the early stages of B cell development corresponding to heavy chain immunoglobulin rearrangement to the late stages of B cell differentiation; CD19 expression increases during B cell differentiation.[3-4] On the cell membrane of B-lymphoid cells, CD19 forms a transduction complex with CD21, CD81, and Leuk-13.[5] Furthermore, CD81 regulates the expression of CD19 during B cell development.[6]
FDA and EMA approved CAR-T cell therapies for B lymphoid malignancies. Four CAR products are commercially available for patients with B cell lymphomas: Axicabtagene ciloleucel (Axi-Cel), Brexacubtagene autoleucel (Brexa-Cel), Lisocabtagene maroleucel (Liso-Cel) and Tisagenlecleucel (Tisa-Cel); two for B-ALL: Brexa-Cell and Tisa-Cel. All these products are based on a second-generation CAR construct (see Figure 1) and involve the presence of an intracellular component containing a T-cell activation domain (CD3ζ) and a costimulatory domain (CD28 in Axi-Cell and Brexa-Cel, 4-1BB in Tisa-Cel and Liso-Cel).

Figure 1
Figure 1. Schematic representation of CD19-CAR constructs currently available commercially and used for the therapy of DLBCL patients. 
All these products have a second-generation CAR construct, consisting of an antigen-binding domain, a hinge region, a transmembrane 
region, a costimulatory domain and a T-cell activation domain.

The structure of Axi-Cel and Brexa-Cel is identical, but their manufacturing process is different in that the procedure of production of Brexa-Cel also implies a step of removal of malignant cells from the apheresis sample; both these CAR genes are delivered to T lymphocytes using a gammaretrovirus. The CAR gene used for Tisa-Cel and Liso-Cel is delivered using lentiviruses; particularly, Liso-Cel is delivered to a defined CD4/CD8 T cell composition.
Clinical studies on CAR-T cells in DLBCL. Large B cell lymphomas are among the most frequent (about 30%) non-Hodgkin's lymphoma. Gene expression studies, based on cell-of-origin, have identified two main subtypes of DLBCLs with distinct clinical and molecular features: activated B-cell (ABC) and germinal center B cell (GCB).[7] Analysis of genomic alterations has shown an additional heterogeneity of ABC and GCB subgroups. Within GCB-DLBCLs, lymphomas with EZH2 mutations and BCL2 translocations have a poor outcome. Lymphomas harboring both MYC and BCL2 and/or BCL6 rearrangements are identified as high-grade B-cell lymphomas double-hit or triple-hit (HGBL-DH and HGBL-TH) and show an aggressive clinical-biological phenotype. Within the ABC-DLBCL group, lymphomas with NOTCH1 mutations or co-occurring MYD88 and CD79B mutations have a poor prognosis.[7]

Clinical studies using CAR-T in DLBCL

Several studies have explored the safety and efficacy of CAR-T in diffuse large B-cell lymphomas (DLBCL). These patients may be cured with first-line therapy; however, up to 30% to 40% of them may become refractory or relapse.
Clinical studies with Axi-Cel. The ZUMA-1 and ZUMA-7 trials evaluated the safety and efficacy of Axi-Cel in different clinical settings of patients with LBCL. The ZUMA-7 study is a phase III trial in which patients with early relapsed or refractory DLBCL were randomized to receive either Axi-Cel (180 patients) or standard care (179 patients) that consisted of salvage chemotherapy followed by high-dose chemotherapy with autologous stem cell transplantation (ASCT) in second-line therapy.[8] At the latest median follow-up explored (47.2 months), the following results were observed: 82 deaths in the Axi-Cel group and 95 in the standard-care group; median overall survival (mOS) not reached in the Axi-Cel group and 31.1 months in the standard-care group; median progression-free survival (mPPFS) was 14.7 months in the Axi-Cel group and 3.7 months in the standard-care group.[8-9] A subgroup analysis of the ZUMA-7 study limited to patients 65 years of age or older showed a higher rate of ORR and CRR in the Axi-Cel group compared to the standard care group (ORR 88% vs 52%, respectively; CRR 75% vs 33%, respectively).[10] In particular, no grade 5 cytokine release syndrome or neurologic events occurred in this group of patients who are more fragile and at risk for complications.[10]
The ZUMA-7 trial was preceded by the ZUMA-1 trial exploring the efficacy of Axi-Cel in third-line therapy. ZUMA-1 was a single-arm phase I/II study enrolling LBCL patients with refractory or relapsed disease after autologous stem cell transplantation; the patients received a target dose of 2x106 CAR-T cells per Kg of body weight after conditioning chemotherapy with fludarabine and cyclophosphamide.[11] One hundred one patients were enrolled in this study, and after a median follow-up of 63.1 months, the following results were observed: 83% of ORR, with 58% of CRR; mOS was 25.8 months, with a disease-specific survival at 5 years of 51%.[11-12] These results suggested a curative potential of Axi-Cel in a subset of LBCL patients.[11-12] A comparison of 2-year outcomes with CAR-T cells of patients enrolled in the ZUMA-1 trial showed better results observed with CAR-T cell therapy compared to salvage chemotherapy in a comparable group of patients (ORR 83% vs. 34% and CRR 54% vs. 20%, respectively).[13] The 2-year survival rate was 54% with Axi-Cel and 20% with salvage therapy.[13]
The analysis of the clinical results observed in a real-world setting of 275 relapsed-refractory DLBCL patients receiving Axi-Cel confirmed the results observed in the ZUMA-1 study, with ORR 82% and CRR 64%. At a median follow-up of 12.9 months, the PFS was 8.3 months.[14]
The 58% achieved a complete response rate following treatment with Axi-Cel in LBCL patients participating to the ZUMA-1 study offered the opportunity to explore the existence of tumor-related and tumor-associated parameters differentially expressed in responding and non-responding patients. Thus, many studies have shown the existence of several clinical, biochemical, and biological parameters that either negatively or positively affect the response to Axi-Cel.
A high tumor burden, measured through evaluation of baseline metabolic tumor volume (MTV) on 18F fluorodeoxyglucose positron emission tomography, was associated with decreased efficacy of Axi-Cel in LBCL patients.[15] A second study based on the analysis of patients enrolled in the ZUMA-1 study subdivided patients into three subgroups (responders, non-responders, and relapsed). Low baseline tumor burden, high CAR-T cells/tumor burden ratio, low systemic inflammation, and high product CD8 and CCR7
+, CD45RA+ T cells were associated with better tumor response.[16] A third study showed that resistance to Axi-Cel is related to immune dysregulation that is frequently observed in LBCL and leads to insufficient in vivo Axi-Cel expansion consisting of high blood levels of monocytic myeloid-derived suppressor cells (M-MDSCs) and tumor interferon signaling, giving rise also to expression of immune checkpoint ligands.[17] Finally, a fourth study provided evidence that tumor immune contexture is a major determinant of Axi-Cel efficacy. In particular, clinical response and overall survival were associated with immunological parameters that can be identified using Immunoscore (tumor-infiltrating T cell density) and Immunosign 21 (immune-related gene expression profile).[18] Furthermore, circulating CAR-T cell levels were associated with post-treatment T cell exhaustion in the tumor microenvironment.[18]
Clinical studies with Liso-Cel. Several studies have evaluated Liso-Cel in the treatment of relapsed or refractory LBCLs. The phase I TRASCEND study evaluated 269 LBCL patients with relapsed/refractory disease who received at least two previous lines of therapy and were treated with Liso-Cel using three different dose levels (50x10
6 or 100x106 or 150x106 CAR-T cells).[19] The first results of this study showed high response rates (ORR 73%, CRR 53%), with a low incidence of grade 3 or worse cytokine release syndrome and neurological events.[19]
The TRANSFORM phase III trial randomized 184 LBCL relapsed/refractory patients, candidates for autologous SCT, to treatment with either standard-of-care therapy or Liso-Cel (100x10
6 CAR-T cells).[20] With a median follow-up of 6.2 months, the EFS was 10.1 months in the Liso-Cel group compared to 2.3 months in the standard-of-care group.[20] An analysis of the results observed in this trial after a follow-up of 17.5 months showed: a CRR of 74% in the Liso-Cel arm compared to 43% in the SOC arm; a PFS not reached in the Liso-Cel group compared to 6.2 months in the SOC group; a mOS not reached in the Liso-Cel arm compared to 29.9 months in the SOC arm.[21] The safety profile of treatment with Liso-Cel was favorable, with grade 3 cytokine release syndrome and neurological events occurring in 1 and 4% of patients, respectively.[21]
An analysis of the parameters related to the quality of life (QoL) showed that the Liso-Cel arm showed a higher improvement in QoL parameters and a lower deterioration than the SOC arm.[22]
Olson and coworkers explored tumor biology and microenvironment from lymph node biopsies of DLBCL patients undergoing treatment with Liso-Cel. The authors compared gene expression profiles between responding and non-responding patients.[23] Tumor microenvironment and tumor-associated macrophage stromal gene signatures had been previously associated with adverse outcomes to standard chemoimmunotherapy treatment in DLBCL.[24] Their study was carried out on 78 patients with DLBCL included in the TRASCEND NHL 001 trial and showed that pre-treatment biopsies from patients achieving a complete response showed higher expression levels of T-cell and stroma-associated genes and lower expression of cell-cycle-related genes in the responding patients, post-treatment biopsies had higher levels of CAR-T-cell densities and CAR gene expression, general immune infiltration, and immune activation.[23]
Clinical studies with Tisa-Cel. Other studies have explored the safety and efficacy of Tisa-Cel in adult relapsed/refractory DLBCL patients. The phase II multicentre JULIET study initially explored the safety and the efficacy of Tisa-Cel in a group of 93 patients with relapsed/refractory DLBCL, showing 52% of ORR, with 40% of CR and 12% of PR; 22% of patients displayed a cytokine release syndrome and 12% neurologic events.[25] Analysis of long-term outcomes in the JULIET trial extended to 115 patients treated with Tisa-Cel showed the following results: an ORR and a CRR in 53% and 39% of cases, respectively; mPFS and mOS were 2.9 months and 11.1 months, respectively; among 34 patients with CR at 6 months, only 3 relapsed within 12 months. Post-hoc analysis showed that PFS and OS were not reached among patients reaching a CR after 6 months.[26]
A comparison of the results of the JULIET trial with historical results (CORAL study) observed in a similar patient group treated with standard chemotherapy supported the superiority of CAR-T-based treatment compared to chemotherapy (mOS of 12.48 months compared to 4.40 months, respectively).[27]
The BELINDA phase III clinical trial randomized 322 patients with aggressive B-cell lymphomas (about 70% of the patients had DLBCLs) to treatment with Tisa-Cel or with standard of care (salvage chemotherapy and autologous HSCT). The ORR and EFS were similar in the two groups of patients.[28] Tisa-Cel was not superior to standard salvage therapy in this trial.
In a retrospective study, 418 relapsed/refractory DLBCL patients, included in the French DESCART-T registry, were treated with CAR-T cell therapy either using Axi-Cel or Tisa-Cel. Treatment results were compared after 1:1 propensity score matching. With a median follow-up of 11.7 months, the 1-year PFS was 46.6% for Axi-Cel and 33.2% for Tisa-Cel, 1-year OS was 63.5% for Axi-Cel and 48.8% for Tisa-Cel, the ORR was 80% for Axi-Cel compared to 66% for Tisa-Cel and the CRR was 60% for Axi-Cel compared to 42% for Tisa-Cel.[29] However, immune effector cell-associated neurotoxicity syndrome (ICANS) and cytokine release syndrome (CRS) were more frequent in the Axi-Cel than in the Tisa-Cel group.[29] In conclusion, this retrospective study supports a higher efficacy and higher Axi-Cel toxicity than Tisa-Cel.[29]
The analysis of the safety profile of DLBCL patients treated with Tisa-Cel-based CAR-T in the context of the JULIET trial showed the occurrence of manageable long-term (LT) adverse events: 14% of responding patients displayed LT cytopenias lasting 90 days; patients treated with rituximab displayed hypogammaglobulinemia that in some patients was exacerbated by CAR-T treatment; few responding patients had LT infections (severe or opportunistic infections).[30]
The phase Ib PORTIA study explored the safety and the efficacy of Tisa-Cel in association with the anti-PD-1 inhibitor pembrolizumab in relapsed/refractory DLBCL patients; the patients enrolled in this study were subdivided into three cohorts: 4 patients were treated with pembrolizumab on day 15, 4 on day 8 and 4 patients on day -1, for CAR-T cell infusion.[31] The best response rates were observed in patients treated with pembrolizumab before Tisa-Cel, but definitive conclusions cannot be drawn given the limited number of patients studied; the drug association displayed a manageable safety profile; pembrolizumab did not stimulate the cellular expansion of Tisa-Cel but delayed peak expansion in the day -1 cohort.[31]
Comparative analysis of the results obtained in phase III studies on CAR-T cell therapy in the second-line. Three prospective randomized phase III clinical trials, ZUMA-7 (Axi-Cel), TRANSFORM (Liso-Cel), and BELINDA (Tiso-Cel), have compared CAR-T cell therapy to standard of care (high-dose chemotherapy with auto-HSCT) in DLBCL patients with early relapsed/refractory disease (<12 months after chemoimmunotherapy). The ZUMA-7 study reported an improved event-free survival in the Axi-Cel arm compared to the SOC arm (8.3 months vs 2.0 months).[8-9] In the TRANSFORM study, median EFS was longer in the Liso-Cel arm than in the SOC arm (not reached vs 2.4 months).[19-20] In contrast, in the BELINDA study, no difference in median EFS was observed between Lisa-Cel and SOC arm (3.0 vs 3.0 months).[28] Based on these data in 2022, the FDA and EMA approved Axi-Cel and Lisa-Cel for DLBCL patients with refractory disease or relapsed within 12 months of first-line treatment. In the BELINDA study, the Tisa-Cel arm included a higher proportion of patients with intermediate or higher IPI scores and double-hit lymphoma compared to the SOC arm (65.4% vs 57.5%, respectively).[28]
CAR-T cell therapy in first-line treatment of DLBCL. In addition to the studies carried out in second and third-line refractory/relapsed DLBCL patients, a recent study explored the safety and the efficacy of Axi-Cel in first-line therapy in a population of high-risk DLBCL patients.[32] This study enrolled 40 patients: 22 with DLBCL, 16 with double- or triple-hit lymphomas, and 2 with high-grade B-cell lymphoma (HGBL) not otherwise specified.[32] Double-hit or triple-hit lymphomas correspond to a subtype of DLBCLs with MYC rearrangement concurrent with a rearrangement in BCL2, BCL6, or both. They are associated with poor outcome after standard chemotherapy treatment.[7] All treated patients received two cycles of one previous systemic therapy, most commonly R-CHOP or DA-EPOCH-R; 40% had PD, suggesting a primary chemorefractory disease.[32] The following results were observed: a CRR of 78%, with a median time to CR of 30 days; an ORR of 89%, with a median time to objective response of 29 days; the estimated rates for DoR, PFS, EFS, and OS at 12 months were 81%, 75%, 73%, and 91%, respectively.[32] Grade 3 cytokine release syndrome and grade 3 neurologic events were observed in 8% and 18% of patients, respectively.[32]
Given the results observed in the ZUMA-12 study, the ZUMA-23 trial was proposed as a phase III randomized controlled trial involving the evaluation of Axi-Cel as a first-line regimen in comparison with standard of care in about 300 LBCL adult patients with a high-risk disease, defined as International Prognostic Index 4-5.[33]

Figure 2
Figure 2. Patients DCBL Disease-free Survival and Overall Survival of the three randomized trials of 19-CAR T-cell vs. Standard Care: BELINDA, Engl J Med
2022, 386(7): 629-639; ZUMA-7, N Engl J Med 2023, 2023 Jul 13;389(2):148-157; TRANSFORM, Blood 2023; 141(14): 1675-1684. No differences in the 
Belinda trial; significant differences in the two other trials, mostly evident for Disease free survival.

CAR-T with double targeting. Failure to achieve sustained responses is observed in about 60-70% of relapsed/refractory LBCL patients treated with CD19-directed CAR-T cells. This result is due to different mechanisms: (i) CD19-negative relapse due to antigen downregulation or loss of CAR-T selection pressure; (ii) impaired CAR-T cell expansion and T-cell exhaustion; (iii) overexpression of programmed cell death protein 1 (PD-1) and/or high expression of PD-L1. One of the possible strategies to bypass these resistance mechanisms consists of dual antigen targeting, such as dual targeting of CD19 and CD22 with bicistronic CAR-T cells. Thus, AUTO3, a dual-targeting, humanized, second-generation autologous CD19/CD22 CAR-T product, was developed using a bicistronic vector encoding CD19 CAR and CD22 CAR within a single construct.[34] In the phase I ALEXANDER trial AUTO3 plus PD-1 blockade with pembrolizumab was evaluated as third-line therapy in 52 adult patients with relapsed/refractory LBCL.[34] AUTO3 administration was well tolerated with only rare events of drug-related toxicity.[34] The ORR was 66%, with 54% of CR; the mDoR was 8.3 months; for patients with CR, the mDoR was not reached; mPFS was 3.3 months and the mOS was 13.8 months.[34]
The results of this study indicated that dual-targeting CAR-T and pembrolizumab as third-line therapy was able to induce a significant therapeutic response in 55% of relapsed/refractory LBCL patients and future studies will attempt to develop a new generation of AUTO3, endowed with a higher capacity of in-vivo expansion.[34]
Other studies have explored another strategy based on the combined targeting of CD19 and CD20 on the surface of B-lymphoid cells. In this context, Tong et al. reported the development of optimized tandem CD19/CD20 CAR-engineered T cells (TanCAR7 T cells) that target these two antigens simultaneously or separately.[35] TanCAR7 T cells were shown to possess a marked antitumor activity in vitro; furthermore, early clinical evidence demonstrated an acceptable safety profile and clinical efficacy: 28 patients with relapsed/refractory NHLs, including 16 patients with DLBCL, were treated with TanCAR7 T cells.[35] 75% of patients with DLBCL had a response, with an mPFS not reached, and 75% of patients showed no disease progression at 12 months after infusion.[35] Concerning the safety profile, 14% of patients displayed a grade 3 CRS and no cases of grade 3 T-cell-related encephalopathy syndrome were observed.
A more recent study reported the results obtained with this strategy in 87 NHL patients (66% with DLBCL).[36] Among DLBCL patients, 78% of objective responses were observed, with a CRR of 71%, a median DoR not reached 74% of patients remaining in remission 12 months after having a response, a median PFS of 23.5 months, and 59% of patients showing no disease progression at 12 months after infusion.[36] The mOS was not reached, and the probability of survival was 88% at 6 months and 75% at 12 months.[36]
The DALY II multicenter trial evaluated the safety and efficacy of bispecific targeted CD20/CD19 therapy with ZAMTO-CEL in 22 patients with relapsed/refractory DLBCL (68% with high-risk disease with IPI ≥3 and 13% exposed to previous CAR-T cell therapy).[37] At 3 months post-treatment, the ORR was 52% with 38% CR and 14% PR.[37]
Role of bridging therapy during CAR-T cell therapy. Bridging therapy (BT) is the anticancer therapy administered in patients during CAR-T cell manufacturing. It is a tool to stabilize or debulk disease between leukapheresis and CAR-T cell administration.[38] However, there is no clear indication for administering or not BT, and the use of BT is guided by physician and patient preferences. A recent study explored BT modality and response in 375 patients undergoing treatment with either Axi-Cel or Lisa-Cel; most patients received BT as chemotherapy or radiotherapy.[39] This analysis showed that complete or partial response to BT conferred a 42% reduction in disease progression and death after CD19 CAR-T therapy.[39] The best responses to BT were observed in patients treated with polatuzumab-containing chemotherapy regimens.[39]
The decision to perform bridging therapy should be individualized at the level of the single patient, taking into account several factors, such as tumor burden, number and types of previous lines of therapy, and the expected timing for CAR-T cell infusion compared to apheresis.[38]
Hubblings and coworkers have evaluated the role of bridging therapy based on radiotherapy in a group of 33 DLBCL patients undergoing CD19 CAR-T cell therapy.[40] Bridging radiotherapy induced a significant reduction of the diameter of lymphoma lesions, MTV, SUV (standard uptake value), and LDH levels, all predictors of poor outcomes post-CAR-T therapy outcomes.[40] Therefore, bridging radiotherapy may help to convert poor-risk LBCL patients into patients with better risk.[40]

Clonal Hematopoiesis and CAR-T Cell Therapy

A recent study explored the potential risk caused by clonal hematopoiesis (CH) in DLBCL patients undergoing treatment with anti-CD19 CAR-T cells. CH is a condition of clonal expansion of hematopoietic stem/progenitor cells bearing somatic gene mutations.[41] CH is associated with an increased risk of hematological malignancies, cytopenias, and nonhematological conditions such as atherosclerosis and cardiovascular and cerebrovascular disease.[41]
Sinai et al. explored 114 LBCL patients undergoing treatment with CAR-T cells (105 with Axi-Cel and 9 with Tisa-Cel) for CH detected in 36.8% of cases. The two most frequently mutated genes were PPMN1D (19/114) and TP53 (13/114).[42] The incidence of therapy-related neurotoxicity was higher in CH-positive than in CH-negative patients (45.2% vs 25.0%, respectively). Higher neurological toxicities were preferentially associated with DNMT3A, TET2, and ASXL1 genes.[41] A higher incidence of grade ≥3 cytokine release syndrome was observed in the CH-positive than in CH-negative patients (17.7% vs 4.2%, respectively).[42] Finally, the 24-month cumulative incidence of therapy-related myeloid neoplasms after CAR-T cell therapy was higher in CH-positive than in CH-negative patients (19% vs 4.2%, respectively).[42]
Other studies have reported myeloid malignancies development in LBCL patients undergoing anti-CD19 CAR-T cell treatments.[43-44] The precise mechanism behind the increased risk of tMN has to be elucidated and remains subject to speculation. It remains unclear whether the particular immune dysregulation in patients after CAR-T plays an important role or whether the occurrence of tMN is simply the consequence of genetic damage induced by the precedent lines of therapy in these mostly heavily pretreated patients.

Autologous Stem Cell Transplantation vs CAR-T Cell Treatment for DLBCL Patients in Partial Remission

Randomized clinical trials have evaluated CAR-T treatment's safety and efficacy in a subset of DLBCL patients with early treatment failure. These patients were randomized to salvage therapy followed by auto-HSCT consolidation in responding patients or directly to CAR-T treatment without attempting salvage therapy. However, the efficacy of auto-HSCT and CAR-T treatment was not comparatively evaluated in a population of DLBCL patients achieving a partial response to initial standard therapy. DLBCL patients achieving only partial response after chemoimmunotherapy show durable remissions after autologous HSCT with a 5-year PFS of 41% and an OS of 51%-63%.[45]
In a retrospective analysis carried out in a group of patients with DLBCL patients in partial response post-salvage therapy, auto HSCT (266 patients) and CAR-T cell therapy with Axi-Cel (145 patients) gave 2-year PFS of 52% vs 42% and OS of 69% vs 47%, respectively.[46] Therefore, this study showed a slightly longer PFS and OS in DLBCL patients in partial response after salvage therapy treated with auto-HSCT compared to CAR-T cell therapy.[46]
At variance with the findings of this study, Akhtar et al. performed a retrospective analysis on 125 older (
65 years) DLBCL patients in partial response after salvage therapy undergoing treatment with either auto-HSCT or CAR-T infusion: no statistically significant differences between auto-HSCT and CAR-T groups in 1-year OS (68% vs 72%, respectively) and 1-year PFS (56% vs 59%, respectively) were observed.[47] Furthermore, patients in the CAR-T group showed a trend to lower non-relapse mortality compared to those in the auto-HSCT group.[47] According to these observations, the authors suggest that in older patients with refractory/relapsed DLBCL patients achieving a partial response to salvage chemotherapy, CAR-T treatment resulted in outcomes comparable to auto-HSCT.[47]

Allogeneic HSCT and CAR-T Therapy after Auto-HSCT Failure in DLBCL

A retrospective noncomparative registry study analyzed outcomes in 584 patients with DLBCL undergoing a reduced intensity allo-HSCT or CAR-T therapy with Axi-Cel after a prior auto-HSCT failure. The 1-year relapse, non-relapse mortality, overall survival, and progression-free survival after auto-HSCT failure were: for CAR-T treatment, 39.5%, 4.8%, 73.4%, and 55.7%, respectively; for the allo-HSCT cohort, 26.2%, 20.0%, 65.6%, and 53.8%, respectively.[48] Therefore, both CAR-T cell treatment and allo-HSCT can provide durable remissions in a subset of DLBCL patients relapsing after auto-HSCT.[48]    

Table 1
Table 1. Main CD19-CAR-T cell therapies. Four CAR products are currently available commercially and three of them were approved for the treatment of 
DLBCL patients.

Therapy of DLBCL after CAR-T Failure

Over 60% of LBCL patients ultimately progress or relapse following CD19-CAR-T cell therapy. The treatment of patients relapsing after CAR-T cell therapy failure is extremely challenging and largely undefined.
Tomas et al. explored 182 LBCL patients experiencing disease recurrence or progression after CAR-T therapy; 74% received anticancer treatment post-CAR-T failure, with a mOS of 8 months.[49] Most of these patients were treated with standard chemotherapy, polatuzumab-based therapies, or lenalidomide-based therapies: no CRs were observed in patients treated with conventional chemotherapy, while 30% CRs were observed among patients treated with polatuzumab- or lenalidomide-based therapies.[49] Factors associated with poor overall survival among patients treated post-CAR-T failure were represented by pre-CAR-T bulky disease, lack of response to CAR-T therapy, age >65 years, and elevated LDH at post-CAR-T treatment: the presence of 2 of these factors was associated with lower OS compared to ≤1.[49]
Another study retrospectively evaluated 83 patients with LBCL receiving an allo-HSC after anti-CD19 CAR-T cell therapy failure.[49] The median number of lines of therapy between CAR-T infusion and allo-HSCT was 1; low-intensity conditioning was used in 77% of cases, and peripheral blood was the most common graft source; the most common donor types were matched unrelated donor (39%), followed by haploidentical (30%) and matched-related donor (26%).[50] One year OS, PFS, and GVHD were 59%, 45%, and 39%, respectively.[50] These findings concluded that allo-HSCT after CAR-T failure can provide durable remissions in a subset of patients.[50]

CAR-T Therapy in DLBCL: Prognostic Factors and Mechanisms of Relapse

Identifying a subgroup of DLBCL patients who benefit from anti-CD19 CAR-T cell therapy remains a key challenge. The clinical trials with Axi-Cel and Tisa-Cel failed to identify clinical covariates predictive of efficacy.

Table 2
Table 2. Main clinical trials carried out in DLBCL patients using CD19-CAR-T cells. Abbreviations: SOC (standard-of-care); ORR (Overall Response Rate); 
CRR (Complete Response Rate); NR (Not Reported); PFS (Progression-Free-Survival); OS (Overall Survival); EFS (Event-Free Survival).

Clinical factors. Vercellino and coworkers have investigated the predictive factors for early progression after CAR-T cell therapy in 116 refractory/relapsed LBCL patients; 55 of these patients failed treatment, and 49% of these patients relapsed within the early months after CAR-T cell therapy and therefore are early progressors.[51] Risk factors identified for early progression at the time of diagnosis and at the time of treatment are represented by extranodal site involvement (2 sites) and lymphoma tumor burden as measured by total metabolic tumor volume (TMTV) assessment and LDH levels.[51]
As discussed above, the tumor burden is a major determinant of outcomes of DLBCL patients at the moment of CAR-T cell therapy with Axi-Cel.[14-15] In line with these observations, Nastoupil et al., in a retrospective analysis, showed an association between achieving CR at 12 months after Axi-Cel treatment and no need for bridging therapy.[13] Since the need for bridging therapy reflects either a higher tumor burden or a more rapidly progressive disease, it is evident why it emerges as a negative prognostic factor.
Hirayama and coworkers have explored some prognostic factors associated with durable responses in patients with aggressive NHL (mostly DLBCL and HGBL-DH or TH). These patients received lymphodepletion with cyclophosphamide and fludarabine, followed by CAR-T cell infusion.[52] This analysis identified lower serum lactate dehydrogenase and a favorable cytokine profile (defined as serum day 0 monocyte chemoattractant protein-1 (MCP-1) and interleukin-7 (IL-7) above the median level) as serum biomarkers associated with a better PFS.[52]
CAR-T cell therapy is associated with two main early toxicities represented by cytokine release syndrome and neurotoxicity; the frequency and severity of these toxicities are partly associated with baseline disease and patient characteristics. Both the Cumulative Illness Rating Scale (CIRS) and the International Prognostic Index (IPI) are associated with outcomes in DLBCL patients after CAR-T cell therapy.[53-54] A recent study used the CIRS to define a prognostic score predictive of outcomes of CAR-T cell therapy in DLBCL patients.[55] Particularly, a CIRS 
3 in the respiratory, upper gastrointestinal, hepatic, or renal system, defined as "severe 4", predicted shorter PFS and OS and a CRS of grade 3.[55] Therefore, a simplified CIRS-derived comorbidity index may predict adverse outcomes in DLBCL patients undergoing CAR-T cell therapy.
CD19 antigen escape is one of the mechanisms of relapse observed in some DLBCL patients relapsing after CAR-T cell therapy. In this context, Plaks and coworkers explored [20] DLBCL patients treated in the ZUMA-1 trial with Axi-Cel for CD19 expression at RNA and protein level and for CD19 gene mutational status.[56] 30% of these patients showed a relapse characterized by negative/low CD19 expression; the mechanism responsible for the generation of a CD19-negative relapse seems to be related to indirect treatment-related selection of tumor cells with low-very low CD19 protein expression in the context of removal of antigen-positive tumor cells rather than alternative splicing or CD19 mutation.[56]
Tumor-related genomics. Typical tumor-related features, such as double- or triple-hit translocations, activated B-cell-like, and cells of origin phenotype, are not informative of outcomes in LBCL patients undergoing CAR-T cell treatment. To identify tumor-related factors that could be associated with response to CAR-T cell therapy, Shouval et al. have characterized the mutational profile of 153 LBCL patients undergoing CD19-CAR-T cell therapy; 37% of these patients displayed TP53 alterations (either mutations and/or copy number alterations): the 1-year OS of 
TP53-altered LBCL was 44% compared to 1-year OS of 76% among TP53WT patients.[57] Transcriptomic studies showed that TP53 alterations are associated with dysregulation of pathways associated with CAR-T-cell cytotoxicity and reduced CD8 T-cell tumor infiltration.[57]
Jain and coworkers have analyzed the genomic profile of 49 LBCL patients undergoing CAR-T cell therapy by whole-genome sequencing.[58] The analysis showed that the pre-treatment presence of complex structural variants, APOBEC mutational signatures, and genomic damage deriving from reactive oxygen species predict CAR-T resistance; furthermore, the recurrent 3p21.31 chromosomal deletion englobing the RHOA tumor suppressor gene was markedly enriched in patients with failure to CAR-T cell therapy.[58]
Zhou et al. have used low-pass whole genome sequencing of ct-DNA to explore copy number alterations (CNAs) in pre-treatment plasma samples of 122 LBCL patients before CAR-T cell therapy.[59] A high focal CNA score, denoting genomic instability, was the most significant pre-treatment CNA associated with inferior 3-month CRR, PFS, and OS.[59] Among the 34 unique focal CNAs observed in these patients, deletion at 10q23.2, determining the loss of the FAS death receptor, was most significantly associated with poor outcomes.[59]
Other studies have evaluated the residual tumor disease in DLBCL patients undergoing CAR-T cell therapy using noninvasive monitoring for treatment response and predicting disease relapse after therapy. Routine surveillance by tumor imaging for DLBCL patients achieving remission is of limited utility. In contrast, molecular disease evaluation by immunoglobulin high-throughput sequencing from peripheral blood provides a more sensitive strategy for surveillance. Molecular disease can be detected in peripheral blood cells and plasma; molecular disease detection often precedes PET/CT detection of relapse in patients initially achieving remission.[60]
Frank et al. have evaluated the role of monitoring circulating tumor DNA in detecting relapse following CAR-T cell therapy with Axi-Cel. 69 LCBL patients with a tumor clonotype were explored by analysis of ctDNA: high pre-treatment ctDNA concentrations were associated with progression after Axi-Cel infusion and development of CRS and immune effector cell-associated neurotoxicity syndrome; 70% of patients with durable response compared to 13% of progressing patients showed non-detectable ctDNA one week after Axi-Cel infusions. At day 28, patients with detectable ctDNA compared to those with undetectable ctDNA had a PFS of 3 months vs not reached and an OS of 19 months vs not reached; ctDNA was detected at or before radiographic relapse in 94% of patients, while 100% of durably responding patients had undetectable ctDNA; in patients with radiographic PR or stable disease, 10% of those with concurrently undetectable ctDNA relapsed and 92% of those with concurrently detectable ctDNA relapsed.[61]
A recent study by Sworder et al. provided fundamental information on the genomic mechanisms of resistance to CAR-T cell therapy observed in 138 relapsed/refractory LBCL patients undergoing treatment with Axi-Cel.[62] In this study, a peculiar methodology was developed for the simultaneous assessment of ctDNA, cell-free CAR19 (cfCAR19) retroviral fragments (for evaluation of CAR-T cell expansion and functional persistence in vivo after their infusion), and cell-free T cell receptor rearrangements (cfTCR) that enabled noninvasive profiling and integration of tumor dynamics and of T cell expansion and TCR diversification in CAR19 patients.[62] Baseline and dynamic ctDNA levels were prognostic for outcome: patients experiencing disease progression had significantly higher pre-treatment ctDNA levels; at 4 weeks post-infusion, patients that achieved a ctDNA major molecular response showed significantly better outcomes.[62] The analysis of cfCAR19 showed similar levels between patients responding or not to CAR-T cell therapy, without any significant difference between these two groups.[62] However, cfTCR levels at 4 weeks after CAR19 infusion were higher in patients with durable response than in patients with disease progression.[62] The analysis of the mutational profile showed that mutations in several genes are significantly associated with inferior event-free survival, such as alterations of TMEM30A, IRF8, PAX5, TP53, and DXT1 genes; other mutations appeared in patients relapsing after CAR-T therapy, such as multiple CD19 alterations and PPM1D mutations.[62] Relapsing patients also displayed gene amplifications of PD-L1 or PD-L2. These somatic mutations affect CAR-T cell therapy at various levels, including CAR-T cell expansion, persistence, and tumor microenvironment. Resistant DLBCL tumors may display either abundant infiltrating CAR-T cells or low/absent CAR-T cells: tumors with high infiltration demonstrate different microenvironmental and inflammatory signatures compared to tumors with low CAR-T infiltration, thus suggesting different mechanisms of resistance.[62]
Gene expression studies. Several biological mechanisms contribute to the heterogeneity of DLBCL, such as cell-of-origin subtypes, genomic alterations, and differences in composition and activation of cellular elements present in the tumor microenvironment.
Gene expression profiling (GEP) studies have refined the molecular classification of DLBCL. GEP studies have characterized the consistent heterogeneity in the lymphoma microenvironment. In this context, Kotlov and coworkers have analyzed the publicly available gene expression profiles of 4655 DLBCL patients; using this approach, they have identified 25 functional gene expression signatures (FGES) corresponding to subtypes of the microenvironment, non-cellular components of the tumor microenvironment, biological processes, and signaling pathways.[63] According to these FGES, four types of lymphoma microenvironment were identified: a germinal center-like LME1 (15%), with the presence of 
FGES of cell types present in germinal centers; a mesenchymal LME2 (33%), due to the presence of stromal and extracellular matrix pathways; an inflammatory LME3 (25%), due to the presence of FGES associated with inflammatory cells and pathways; and a depleted LME4 (27%), due to the low presence of microenvironment-related FGES and to the presence of proliferation-related FGES.[63] The four LME categories of DLBCLs are associated with specific genomic alterations and distinct clinical outcomes: a better PFS and OS for LME1 and LME2 than for LME3 and LME4.[63]
Steen and coworkers have implemented a machine learning algorithm, termed Eco Typer, to integrate transcriptomic deconvolution and single-cell RNA sequencing to define states and ecosystems present in DLBCLs.[64] B-cell states were defined by COO subtypes GBC and ABC and subdivided into centrocytes, centroblasts, memory B cells, and plasmablasts. This approach identified five different cell states of malignant B cell differentiation associated with differences in prognosis.[64]
Several studies have shown that the heterogeneous characteristics of the TME in LBCL are associated with clinical responses to anti-CD19 CAR-T cell therapy. Scholler et al. have explored the dynamic changes in TME occurring in LBCL patients undergoing treatment with Axi-Cel in the context of the ZUMA-1 trial.[18] In this analysis the patients were subdivided into two groups, responders and non-responders; responders showed an early and rapid increase of cytotoxic T cell-related genes, such as CD8α, T cell growth factor genes such as IL-15, interferon-γ-regulated immune checkpoint encoding genes (CD274, CD276 and CTLA-4), myeloid-related genes and chemokines; in non-responders, no increase in immune-related genes was observed, except for pro-inflammatory chemokines such as CXCL10 and CXCL11.[18] Immunohistochemical studies in a few patients have confirmed these observations by gene expression analysis, showing higher T cell densities among responders reflecting pre-treatment T cell density.[18] The infiltration of TME with exhausted T cytotoxic lymphocytes observed in non-responding patients correlated with poor CAR-T cell expansion in blood. The pre-treatment quantification of tumor-infiltrating T cell density by Immunoscore and of a panel of immune genes by Immunosign 21 positively correlated with overall survival after CAR-T cell therapy.[18]
Batlevi and coworkers extensively characterized 49 DLBCL patients treated with CD19-CAR-T cell therapy using whole exome sequencing performed on tumor samples, defining the cell of origin, assessing double hit gene signatures and the lymphoma microenvironment, analyzing gene expression according to Kotlov et al.[63] In these patients, the overall response at 3 months was 77.6%, with 59.2% CR and 18.4% PR, PFS at 6 months was 49%; prognostic biomarkers to CAR-T therapy, such as LDH levels, MTV, and SUV were confirmed.[65] The major findings of this study were that: PIK3CA amplification was associated with improved PFS; increased MHCII expression, associated with centrocyte-like phenotype,[66] was higher in DLBCL patients with GCB phenotype responsive to CD19-CAR-T therapy; DLBCL patients with GCB phenotype and with higher SMAD1 expression are usually responsive to CD19-CAR-T cell therapy; germinal-center-like and mesenchymal LME subtypes exhibited increased OS compared to those with inflamed and depleted LME subtypes.[65]
Haradhval et al. used single-cell RNA sequencing to explore cellular dynamics associated with response to CAR-T therapy for DLBCL using Axi-Cel or Tisa-Cel.[66] Axi-Cel and Tisa-Cel, as discussed above, differ for many characteristics related to differences in CAR design (4-1BB vs. CD28 costimulatory domain, CD8 vs. CD28 transmembrane domain for Tisa-Cel vs Axi-Cel, respectively), in vectors used for their delivery, and in manufacturing processes (fresh vs frozen apheresis products, activation by antibody-coated beads vs soluble antibody and cytokines). This study showed that Tisa-Cel responses were associated with the expansion of central-memory CD8 cell populations, while Axi-Cel responders displayed more heterogeneous cell populations.[67] Despite these differences in cell types associated with response, both Axi-Cel and Tisa-Cel CAR-T cells displayed at day seven after infusion a remarkable increase in the expression of genes related to cellular proliferation and activation.[67] In Axi-Cel non-responders, a population of regulatory T-cells with CAR transcripts in the infusion product was expanded in vivo and could exert an immunosuppressive activity.[67]
Gene expression studies have also contributed to understanding the consistent heterogeneity of CAR-T products obtained from different DLBCL patients. Deng and coworkers analyzed the cellular and molecular features of CAR-T infusion cell products prepared using Axi-Cel to identify transcriptomic (by single-cell RNA sequencing) features associated with efficacy and toxicity in 24 LBCL patients. 50% of these patients had progressive disease, 4% a partial response and 38% a complete response.[68] Patients achieving a complete response at 3 months had 3-fold higher frequencies of CD8 T cells expressing memory signatures compared to patients with partial responses or progressive disease.68 Molecular responses at day 8 post-infusion were significantly associated with the clinical response signature of CD8 T-cell exhaustion associated with a poor molecular response.[67] Finally, a rare cell population with monocytic features was associated with ICANS occurrence.[68]
Hematologic toxicity. Hematologic toxicity is frequently observed in DLBCL patients undergoing CAR-T cell therapy. In 258 patients receiving CD19-CAR-T cell therapy, profound neutropenia was observed in 72% of cases and prolonged neutropenia in 64% of patients; in these patients, predictive biomarkers of hematologic toxicity were baseline cytopenia (thrombocytopenia) and inflammatory state (hyperferritinemia). [69] According to these observations, a predictive model for hematologic toxicity (CAR-HEMATOTOX) was generated based on markers associated with hematopoietic reserve, such as platelet count, absolute neutrophil count, and hemoglobin level, and baseline inflammation markers, such as C-reactive protein and ferritin.[68] A high CAR-HEMATOTOX score predicted a longer neutropenia duration and a higher incidence of thrombocytopenia and anemia.[69]
Infectious complications represent the key determinant of non-relapse mortality after CAR-T cells. They are favored not only by neutropenia but also by the immune disturbance caused by the T-CAR cells. The temporal distribution of these risk factors shapes different infection patterns early versus late post-CAR-T-cell infusion. Furthermore, due to the expression of their targets on B lineage cells at different stages of differentiation, CD19 and B-cell maturation antigen (BCMA), CAR-T cells induce distinct immune deficits that could require different prevention strategies. Infection incidence is the highest during the first-month post-infusion and decreases afterward. However, infections remain relatively common even a year after infusion. Bacterial infections predominate early after CD19, while an equal distribution between bacterial and viral causes is seen after BCMA CAR-T-cell therapy, and fungal infections are universally rare. Cytomegalovirus (CMV) and other herpesviruses are increasingly reported.[70]
Toxicity associated with the immune effector response. CAR T cells can result in significant toxicities directly associated with the induction of powerful immune effector responses. Cytokine release syndrome (CRS), neurotoxicity,[71-73] or more rarely cardiotoxicity[74] represent the most frequent manifestations of this toxicity, which is in relationship with the immunological effects of CAR T cells.[71-73] Toxicities may be related both to the activation of T cells with the release of high levels of cytokines and the interaction between CAR and CAR-target antigens expressed on non-malignant cells. Cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS) are well-known inflammatory side effects of CAR T-cell therapy.[71-73] CRS typically presents with constitutional symptoms such as fever, myalgia, and arthralgia or constitutional symptoms such as rigors, fatigue, malaise, and anorexia. However, rapid progression to hemodynamic instability, respiratory failure, organ dysfunction, shock, and hemophagocytic lymphohistiocytosis has also been reported.[71,72] Depending on the product, CRS typically occurs within 1–2 weeks of CART-cell infusion but can occur as early as a few hours post-infusion.[71,72] CRS has a reported incidence between 37% and 93% across different studies. Factors associated with CRS include the product type, tumor burden, disease indication, elevation in baseline inflammatory markers (i.e., ferritin, C-reactive protein), and concomitant infection. In cases where CRS develops early and is higher grade, severe ICANS is more likely. This occurrence may be partly associated with a high dose of CART cells or usually robust and rapid CART-cell expansion. Notably, ICANS can also infrequently develop in the absence of CRS. ICANS presents as dysgraphia, word-finding difficulties, headache, tremor, confusion, somnolence, expressive aphasia, seizure, and coma. Rarely, death from cerebral edema has been reported (1%–2% estimated incidence).[71-73] Rubin et al.[73] reported that among 100 treated cases, the most commonly occurring neurological symptoms were encephalopathy (57%), headache (42%), tremor (38%), aphasia (35%) and focal weakness (11%). Focal neurological deficits were frequently observed after chimeric antigen receptor T-cell therapy and are associated with regional EEG abnormalities, FDG-PET hypometabolism, and elevated velocities on transcranial Doppler ultrasound. In contrast, structural imaging was typically normal, ICANS may co-occur with CRS or immediately following CRS. Neurologic signs and symptoms typically begin 3–6 days after CART-cell infusion and peak around day 7 or 8, with complete symptom resolution by days 14–21. The rate and grade of ICANS toxicity varies greatly among CAR T-cell products. ICANS occurs in 20%–70% of patients treated with CD19 CART cells.[71-73] Inflammatory cytokines released by macrophages, specifically IL-6 and IL-1, have been widely identified as critical components in the pathogenesis of CRS and ICANS, respectively.[71-72] Elevated serum levels of IL-6 are one of the most correlated findings with CRS Activated CART cells release IFN-γ, TNF-α, and granulocyte-macrophage colony-stimulating factor (GM-CSF) to induce tumor cell cytolysis. However, these cytokines also activate macrophages, which release IL-6 and TNF-α.[71,72]
Cardiotoxicity hits about 10% of patients and manifests as cardiomyopathy, heart failure, arrhythmias, and myocardial infarction. Patients undergoing T-cell therapies should be screened for cardiovascular conditions that may not be able to withstand the hemodynamic perturbations imposed by CRS.[74]
Brammer JE et al.[75] report 102 CAR-T-treated patients; of them, 90 were identified as treated with single-agent therapy, of which 88.9% developed toxicity (80 CRS, 41 neurotoxicity, and 17 cardiotoxicity), including 28.9% with high-grade (≥3) events. The most common manifestations were hypotension at 96.6% and fever at 94.8%. Among patients with cardiac events, there was a non-significant trend toward a higher prevalence of concurrent or preceding high-grade (≥3) CRS. 50.0% required tocilizumab or corticosteroids. The median time to toxicity was 3 days; high-grade CRS development was associated with cardiac and neurotoxicity. In multivariable regression, accounting for disease severity and traditional predictors of disease response, moderate (maximum grade 2) CRS development was associated with higher complete response at 1 year (HR: 2.34; p=0.07), and longer PFS (HR: 0.41; p=0.02, in landmark analysis), and OS (HR: 0.43; p=0.03). Among those with CRS, relative blood pressure (HR: 2.25; p=0.004), respectively, was also associated with improved PFS. No difference in disease outcomes or maximum toxicity grade (CRS, neurotoxicity, or cardiotoxicity) was observed based on the presence or absence of early CRS-directed therapies. Therefore, moderate toxicity predicts a good outcome. Nonhematological toxicity also depends on tumor burden; patients with DLBCL without residual lymphoma at the time of CD19 CAR T-cell therapy show low toxicity and excellent outcomes.[76]
Anti-inflammatory therapy, specifically targeting IL6, has become the cornerstone of CRS management.[77,78] Tocilizumab, a humanized IgG1k anti-IL-6R antibody, binds to both soluble and membrane-bound IL-6R, blocking the downstream signal transduction pathways implicated in CRS. It is currently the only anti-IL6 therapy approved by the FDA for treating severe or life-threatening CAR T cell–induced CRS.[77,78] While it is approved for severe or life-threatening CRS, current guidelines and product information recommend initiating tocilizumab for treating grade ≥ 2 or grade 1 CRS in patients at high risk of early and severe CRS or those whose symptoms persist greater than 24 h. For severe (grade ≥ 3) or refractory CRS, the addition of steroids is recommended.[78] A recent analysis[77] of the ZUMA-1 study of axicabtagene-ciloleucel (axi-cel) shows prophylactic corticosteroids and earlier corticosteroid and/or tocilizumab intervention resulted in no grade 3 or higher CRS, a low rate of grade 3 or higher NEs and high response rates in this study population. 95% and 80% objective and complete response rates, respectively, for patients who received prophylactic steroids (dexamethasone 10 mg on day 0 (pre-infusion), day 1 and 2) or early addition of steroids to tocilizumab for CRS[77] Although tocilizumab and steroids are first-line interventions for prevention and treatment of CRS and ICANS, with high response, data for outlining the treatment of refractory CRS and/or ICANS, are lacking. However, there is an emerging use of anakinra and an improvement of mitigation strategies and supportive care measures to ameliorate outcomes of patients who develop these refractory toxicities.[79]


The studies carried out in the last ten years have clearly supported and defined a role for CD19-CAR-T cells in the therapy of DLBCL patients with refractory/relapsed disease. This therapeutic role was established for patients with refractory disease and early relapse. For DLBCL patients with partial response after salvage therapy, CD19-CAR-T cells also have shown consistent therapeutic activity, but additional studies are required to compare their efficacy to auto-HSCT carefully. Similarly, CD19-CAR-T cells have shown efficacy in treating high-risk DLBCL patients in first-line, but additional studies are required to assess their efficacy compared to standard treatments. At present, there are no data suggesting which of the four CAR products commercially available for patients with B cell lymphomas: Axicabtagene ciloleucel (Axi-Cel), Brexacubtagene autoleucel (Brexa-Cel), Lisocabtagene macrolevel (Liso-Cel) and Tisagenlecleucel (Tisa-Cel), could be the best in term of efficacy and side effects. The results of the contemporary publication in the NEJM of two randomized trials employing one the Tisa-Cel,[28] the other the Axi-Cel,[8] could induce to think a superior efficacy of Axi-Cel; however, the criteria for enrollment of patients are different, so no comparison is possible.[80,81] Another problem is the cost of this therapy. Utilization of CAR T cell therapy is very expensive, but papers comparing the Cost-Effectiveness ratio of the different products are rare.[82] However, the best standard salvage care requires fewer resources in comparison with CAR-T.[83]
Although the efficacy of CD19-CAR-T cell therapy in refractory/relapsed DLBCL patients was well documented, only about 40% of relapsed/refractory DLBCL patients are responding to this treatment, and the remaining are refractory or rapidly relapse. Several strategies seem to be required to improve the outcomes of these patients: (i) decrease tumor burden using novel bridging therapies that include chemoimmunotherapy or radiation therapy prior to CAR-T cell therapy; (ii) use CAR-T cells engineered with double targeting activity, such as CD19/CD20 or CD19/CD22; (iii) optimize CAR-T cell expansion and persistence by increasing the number of infusions or the dosing of infused cells; (iv) modify the therapy in patients who do not show an adequate clearing of lymphoma cells following CAR-T cell infusion; (v) define alternative treatments in DLBCL patients displaying genomic alterations predicting resistance to CAR-T cell therapy.


  1. Wei W, Wang D, Chen X, Liang D, Zou L, Zhao X. Chimeric antigen receptor T-cell therapy for T-ALL and AML. Front Oncol 2022; 12: 967754. PMid:36523990 PMCid:PMC9745195  
  2. Sterner RC, Sterner RM. CAR-T cell therapy: current limitations and potential strategies. Blood Cancer J 2021; 11: 69. PMid:33824268 PMCid:PMC8024391  
  3. Sato S, Ono N, Steeber DA, Pisetsky DS, Tedder TF. CD19 regulates B lymphocyte signaling thresholds critical for the development of B-1 lineage cells and autoimmunity. J Immunol 1996; 157(10): 4371-4378. PMid:8906812  
  4. Sato S, Steeber DA, Jansen PJ, et al. CD19 expression levels regulate B lymphocyte development: human CD19 restores normal function in mice lacking endogenous CD19. J Immunol 1997; 158(10): 4662-4669. PMid:9144478  
  5. Tedder TF, Inaoki M, Sato S. The CD19-CD21 complex regulates signal transduction thresholds governing humoral immunity and autoimmunity. Immunity 1997; 6(2): 107-118. PMid:9047233  
  6. Shoham T, Rajapaska R, Boucheix C, Rubinstein E, Poe JC, Tedder TF, Levy S. The tetraspanin CD81 regulates the expression of CD19 during B cell development in a postendoplasmic reticulum compartment. J Immunol 2003; 171(8): 4062-4072. PMid:14530327  
  7. Sehn LH, Salles G. Diffuse large B-cell lymphoma. N Engl J Med 2012; 384: 842- 858. PMid:33657296 PMCid:PMC8377611  
  8. Locke FL, Miklos DB, Jacobson CA, Perales MA, Kersten MJ, Oluwole OO, Ghobadi A, Papoport AP, et al. Axicabtagene ciloleucel as second-line therapy for large B-cell lymphoma. N Engl J Med 2022; 386(7): 640-654. PMid:34891224  
  9. Westin JR, Oluwole OO, Kersten MJ, Miklos DB, Perales MA, Ghobadi A, Rapoport AP, Sureda A, Jacobson CA, et al. Survival with axicabtagene ciloleucel in large B-cell lymphoma. N Engl J Med 2023, 2023 Jul 13;389(2):148-157 PMid:37272527  
  10. Westin JR, Locke FL, Dickinson M, Ghobadi A, Elsawy M, van Meerten T, Miklos DB, Ulrickson ML, Perales MA, et al. Safety and efficacy of axicabtagene ciloleucel versus standard of care patients 65 years of age or older with relapsed/refractory large B-cell lymphoma. Clin Cancer Res 2023; 29(10): 1894-1905. PMid:36999993 PMCid:PMC10183830  
  11. Locke FL, Ghobadi A, Jacobson CA, Miklos DB, Lekakis LJ, Oluwole OO, Lin Y, Braunscweig I, Hill BT, Timmerman JM, et al. Long-term safety and activity of axicabtagene ciloleucel in refractory large B-cell lymphoma (ZUMA-1): a single-arm, multicentre, phase 1-2 trial. Lancet Oncol 2019; 20(1): 31-42. PMid:30518502  
  12. Neelapu SS, Jacobson, C.A.; Ghobadi A.; Miklos, D.B.; Lekakis, L.J.; Oluwole OO, Lin Y, Braunschweig I, Hill BT, Timmerman JM, et al. Five-year follow-up of ZUMA-1 supports the curative potential of axicabtagene ciloleucel in refractory large B-cell lymphoma. Blood 2023; 141(19): 2307-2315. PMid:36821768  
  13. Neelapu SS, Locke FL, Barlett NL, Lekakis LJ, Reagan PM, Miklos DB, Jacobson CA, Braunschweig I, Oluwole OO, Siddiqi T, et al. Comparison of 2-year outcomes with CAR T cells (ZUMA-1) vs salvage chemotherapy in refractory large B-bell lymphoma. Blood Adv 2021; 5: 4149-4155. PMid:34478487 PMCid:PMC8945634  
  14. Nastoupil L.J, Jain MD, Feng L, Spiegel JY, Ghobadi A, Lin Y, Dahiya S, Lunning M, Lekakis L, Reagan P, et al. Standard-of-care axicabtagene ciloleucel for relapsed or refractory large B-cell lymphoma: results from the US lymphoma CAR T consortium. J Clin Oncol 2020; 38(27): 3119-3128. PMid:32401634 PMCid:PMC7499611  
  15. Dean EA, Mhaskar RS, Lu H, Mousa, MS, Krivenko GS, Lazaryan A, Bachmeier CA, Chavez JC, Nishihori T, Davila Ml, et al. High metabolic tumor volume is associated with decreased efficacy of axicabtagene ciloleucel in large B-cell lymphoma. Blood Adv 2020; 4: 3268-3274. PMid:32702097 PMCid:PMC7391155  
  16. Locke FL, Rossi JM, Neelapu SS, Jacobson CA, Miklos DB, Ghobadi A, Oluwole OO, Reagan PM, Lekakis LJ, Lin Y, et al. Tumor burden, inflammation, and product attributes determine outcomes of axicabtagene ciloleucel in large B-cell lymphoma. Blood Adv 2020; 4: 4898-4908. PMid:33035333 PMCid:PMC7556133  
  17. Jain MD, Zhao H, Wang X, Atkins R, Menges M, Reid K, Spitler K, Faramand R, Bachmeier C, Dean EA, Cao B, et al. Tumor interferon signaling and suppressive myeloid cells are associated with CAR T-cell failure in large B-cell lymphoma. Blood 2023; 137(19): 2621-2633. PMid:33512407 PMCid:PMC8120145  
  18. Scholler N, Perbopst R, Locke FL, Jain MD, Turcan S, Danan C, Chang EC, Neelapu SS, Miklos DB, Jacobson CA, et al. Tumor immune contexture is a determinant of anti-CD19 CAR T cell efficacy in large B cell lymphoma. Nat Med 2022; 28(9): 1872-1882. PMid:36038629 PMCid:PMC9499856  
  19. Abramson JS, Palomba ML, Gordon LI, Lunning MA, Wang M, Amason J, Mehta A, Purev E, Maloney DG, et al. Lisocabtagene maraleucel for patients with relapsed or refractory large B-cell lymphomas (TRASCEND NHL 001): a multicentre seamless design study. Lancet 2020; 396(10254): 839-852. PMid:32888407  
  20. Kamdar M, Solomon SR, Arnason J, Johnston PB, Glass B, Bachanova V, Ibrahimi S, Mielke S, Mutsaer P. Lisocabtagene maraleucel versus standard of care with salvage chemotherapy followed by autologous stem cell transplantation as second-line treatment in patients with relapsed or refractory large B-cell lymphoma (TRANSFORM): results from an interim analysis of an open-label, randomized, phase 3 trial. Lancet 2022; 399(10343): 2294-2308. PMid:35717989  
  21. Abramson JS, Solomon SR, Arnason J, Johnston PB, Glass B, Bachanova V, Ibrahimi S, Mielke S, Mulsaers P. Lisocabtagene maraleucel as second-line therapy for large B-cell lymphoma: primary analysis of the phase 3 TRANSFORM study. Blood 2023; 141(14): 1675-1684. PMid:36542826  
  22. Abramson JS, Johnston PB, Kamdar M, Ibrahimi S, Isutzu K, Arnason J, Glass B, Mutsaers P, Lunning M, Braverman J. Health-related quality of life with licabtagene maraleucel vs standard of care in relapsed or refractory LBCL. Blood Adv 2022, 6(23): 5969-5979. PMid:36149968 PMCid:PMC9713278  
  23. Olson NE, Ragan SP, Reiss DJ, Thorpe J, Kim Y, Abramson JS, McCoy C, Newwali KJ, Fox BA. Exploration of tumor biopsy gene signatures to understand the role of the tumor microenvironment in outcomes to lisocabtaegne maraleucel. Mol Cancer Ther 2023; 22: 406-418. PMid:36595660 PMCid:PMC9978882  
  24. Lenz G, Wright G, Dave SS, Xiao W, Powell J, Zhao H, Xu W, Tan B, Goldschmidt N, Iqbal J, et al. Stromal gene signatures in large-B-cell lymphomas. N Engl J Med 2008; 359(22): 2313-2323. PMid:19038878 PMCid:PMC9103713  
  25. Schuster SJ, Bishop MR, Tam CS, Waller EK, Borchmann P, McGuink JP, et al. Tisagenleceucel in adult relapse or refractory diffuse large B-cell lymphoma. N Engl J Med 2019; 380: 45-56. PMid:30501490  
  26. Schuster SJ, Tam CS, Borchmann P, Worel N, McGuirk JP, Holte H, et al. Long-term clinical outcomes of tisagenlecleucel in patients with relapsed or refractory aggressive B-cell lymphoma (JULIET): a multicentre, open label, single-arm, phase 2 study. Lancet Oncol 2021; 22(10): 1403-1415. PMid:34516954  
  27. Maziarz RT, Zhang J, Yang H, Chai X, Yuan C, Schwartz E, Jakovach M, Martinez-Prieto M, Agarwal A, Degtyarev E, et al. Indirect comparison of tisagenlecleucel and historical treatments for relapsed/refractory diffuse large B-cell lymphoma. Blood Adv 2022; 6: 2536-2542. PMid:35030634 PMCid:PMC9043930  
  28. Bishop MR, Dickinson M, Purtill D, Barba P, Santoro A, Hamad N, Kato K, Sureda A, Greil R, Thieblemont C. Second-line tisagenlecleucel or standard care in aggressive B-cell lymphoma. N Engl J Med 2022, 386(7): 629-639. PMid:34904798  
  29. Bachy E, Le Gouill S, Di Blasi R, Sesques P, Manson G, Cartron G, Beauvais D, Roulin L, Gros FX, et al. A real-world comparison of tisagenlecleucel and axicabtagene ciloleucel CAR T cells in relapsed or refractory diffuse large B cell lymphoma. Nature Med 2022; 28: 2145-2154. PMid:36138152 PMCid:PMC9556323  
  30. Jaeger U, Tam CS, Borchmann P, McGuirk JP, Johansen M, Waller EK, Jaglowski S, Andreadis C, Foley SR, Westing JR, et al. Long-term safety for patients with tisagenlecleucel-treated relapsed/refractory diffuse large B-cell lymphoma. Blood Adv 2022; 6(16): 4816-4820. PMid:35687492 PMCid:PMC9631665  
  31. Jaeger U, Worel N, McGuirk JP, Riedell PA, Fleury I, Du Y, Han X, Pearson D, Redondo S, Waller EK. Safety and efficacy of tisagenleucleucel plus pembrolizumab in patients with r/r DLBCL: phase 1b PORTIA study results. Blood Adv 2023; 7(11): 2283-2286. PMid:36044388 PMCid:PMC10225880  
  32. Neelapu SS, Dickinson M, Munoz J, Ulrickson ML, Thieblemont C, Oluwole OO, Herrera AF, Ujjani CS, Lin Y, Riedell PA, et al. Axicabtagene ciloleucel as first-line therapy in high-risk large B-cell lymphoma: the phase 2 ZUMA-12 trial: Nat Med 2022; 29: 735-742. PMid:35314842 PMCid:PMC9018426  
  33. Westin J, Jacobson CA, Chavez JC, Sureda A, Morschhauser F, Glab B, Dickinson M,Davies A, Flinn IW, Maloney DG, Chamuleau M, et al. ZUMA-23: a global, phase 3, randomized controlled study of axicabtagene ciloleucel versus standard of care as first-line therapy in patients with high-risk large B-cell lymphoma. J Clin Oncol 2023; 142 (suppl 16): TPS 7578. PMCid:PMC10429721  
  34. Roddie C, Lekakis LJ, Marzolini M, Ramakrishnan A, Zhang Y, Hu Y, Peddoreddigari V, Khokhafr N, Chen R, Basilico S, et al. Dual targeting of CD19 and CD22 with bistronic CAR-T cells in patients with relapsed/refractory large B-cell lymphoma. Blood 2023; 141: 2470-2482. PMid:36821767  
  35. Tong C, Zhang Y, Liu Y, Ji X, Zhang W, Guo Y, Han X, Ti D, Dai H, Wang C, et al. Optimized tandem CD19/CD20 CAR-engineered T cells in refractory/relapsed B-cell lymphoma. Blood 2020; 136(14): 1632-1644. PMid:32556247 PMCid:PMC7596761  
  36. Zhang Y, Wang Y, Liu Y, Tong C, Wang C, Guo Y, Ti D, Yang Q, Qiao S, Wu Z, Han W. Long-term activity of tandem CD19/CD20 CART Therapy in relapsed, refractory B-cell lymphoma: a single-arm, phase 1-2 trial. Leukemia 2022; 36(11): 189-196. PMid:34272481 PMCid:PMC8727291  
  37. Interim analysis of a phase II study of administered fresh bispecific anti-CD20/CD19 CAR T-cell therapy-Zamtocabtagene Autocel (zamto-cel) for relapsed/refractory (R/R) DLBCL (DAY II USA NCT04792489).
  38. Bhaskar ST, Dholaria BR, Sengsayadeth SM, Savani BN, Oluwole OO. Role of bridging therapy during chimeric antigen receptor T cell therapy. eJHaem 2022; 3(suppl1): 39-45. PMid:35844303 PMCid:PMC9175845
  39. Roddie C, Neill L, Osborne W, Lyengar S, Thilouli E, Irvine D, Chaganti S, Besley C, Bloor A, Joens C, et al. Effective bridging therapy can improve CD19 CAR-T outcomes while maintaining safety in patients with large B-cell lymphoma. Blood Adv 2023; 7: 2872-2880. PMid:36724512 PMCid:PMC10300297  
  40. Hubbeling H, Silverman EA, Michaud L, Tomas AA, Shouval R, Flynn J, Devlin S, Wiejtunga NA, Tringale KR, Batlevi C, et al. Bridging radiation rapidly and effectively cytoreduces high-risk relapsed/refractory aggressive B cell lymphomas prior to chimeric antigen receptor T cell therapy. Tranplant Cell Ther 2023; PMid:36587744  
  41. Mangaonkar AA, Patnaik MM. Clonal hematopoiesis of indetermeninate potential and clonal cytopenias of undeterminated significance: 2023 update on clinical associations and management recommendations. Am J Hematol 2023; 98(6): 951-964. PMid:36938794  
  42. Saini NY, Swoboda DM, Greenbaum U, Ma J, Patel RD, Devashish K, Das K, Tanner MR, Starti P, Nair R, et al. Clonal hematopoiesis is associated with increased risk of severe neurotoxicity in axicabtagene ciloleucel therapy of large B-cell lymphoma. Blood Cnecr Discov 2022; 3: 385-393. PMid:35533245 PMCid:PMC9445749  
  43. Eder LN, Mrtinovic D, Mazzeo P, Ganster C, Hasenkamp J, Thomson J, Trummer A, Haase D, Wulf G. Fata progression of muated TP53-associated clonal hematopoiesis following anti-CD19 CAR-T cell therapy. Curr Oncol 2023; 30: 1146-1150. PMid:36661736 PMCid:PMC9858310  
  44. Accorsi Buttini E, Farina M, Lorenzi L, Polverelli N, Radici V, Morello E, Colnaghi F, Almici C, Ferrari E, et al. High risk-myelodysplastic syndrome following CAR T-cell therapy in a patient with relapsed diffuse large B cell lymphoma: a care report and literature review. Front Oncol 2023; 13: 1036455. PMid:36741006 PMCid:PMC9897055  
  45. Shah NN, Ahn KW, Litovich C, He Y, Sauter C, Fenske TS, Hamadani M. Is autologous transplant in relapsed DLBCL patients achieving only a PET+ PR appropriate in the CAR T-cell era? Blood 2021; 137: 1416-1423. PMid:33120429 PMCid:PMC7955408  
  46. Shadman M, Pasquini M, Ahn KW, Chen Y, Turtle CJ, Hematti P, Chen JB, Khimani F, Ganguly S, Merrymar RW, et al. Autologous transplant vs chimeric antigen receptor T-cell therapy for relapsed DLBCL in partial remission. Blood 2022; 139: 1330-1339. PMid:34570879 PMCid:PMC8900276  
  47. Akhtar OS, Cao B, Wang X, Torka P, Al-Jamayli M, Locke FL, Freeman CL. CAR T-cell therapy has comparable efficacy to autologous transplantation in older adults with DLBCL in partial response. Blood Adv 2013; in press.  
  48. Hamadani M, Gopal AK, Pasquini M, Kim S, Qiu X, Ahmed S, Lazaryan A, Raj Bhatt V, Daly A, Lulla P, et al. Allogeneic transplant and CAR-T therapy after autologous transplant failure in DLBCL: a noncomparative cohort analysis. Blood Adv 6(2): 486-494. PMid:34673903 PMCid:PMC8791562  
  49. Zurko J, Ramdial J, Shadman M, Ahmed S, Szabo A, Iovino L, Tomas AA, Sauter C, Perales MA, Shah NN, et al. Allogeneic transplant following CARt-cell therapy for large B-cell lymphoma. Haematologica 2023; 108(1): 98-109. PMid:35833303 PMCid:PMC9827150
  50. Tomas AA, Fein JA, Fried S, Flynn JR, Devlin SM, Fingrut WB, Anagfnostou T, Alperovich A, Shah N, Fraint E, et al. Outcomes of first therapy after CD19-CAR-T treatment failure in large B-cell lymphoma. Leukemia 2023; 37(1): 154-163. PMid:36335261 PMCid:PMC9892211  
  51. Vercellino L, Di Blasi R, Kanoun S, Tessoulin B, Rossi C, D'Aveny-Piney M, Obéric L, Bodet-Milin C, Bories P, Olivier P, et al. Predictive factors of early progression after CAR T-cell therapy in relapsed/refractory diffuse large B-cell lymphoma. Blood Adv 2020; 5(22): 5607-5676. PMid:33180899 PMCid:PMC7686887  
  52. Hirayama AV, Gauthier J, Hay KA, Voutsinas JM, Wu Q, Gooley T, Li D, Cherian S, Chen X, Pender BS, et al. The response to lymphodepletion impacts PFS in patients with aggressive non-Hodgkin lymphoma treated with CD19 CAR T cells. Blood 2019; 133(17): 1876-1887. PMid:30782611 PMCid:PMC6484391  
  53. Kittai AS, Huang Y, Gordon M, Denlinger N, Mian A, Fritzgerald L, Bishop J, Nagle S, Stephens DB, Jaglowski S, et al. Comorbidities predict inferior survival in aptients receiving chimeric antigen recptor T cell therapy for diffuse large B cell lymphoma : a mlticenter analysis. Transplant Cell Ther 2021; 27: 46-52. PMid:33002640
  54. Garcia-Recio M, Wudhikarn K, Pennisi M, Alonso-Trillo R, Flynn J, Shouval R, Afuye AO, Silberberg ML, Batlevi CW, Dahi et al. The international prognostic index is associated with outcomes in diffuse large B cell lymphoma after chimeric antigen receptor T cell therapy. Transplant Cell Ther 2021; 27: 233-240. PMid:33781518 PMCid:PMC8010220
  55. Shouse G, Kaempf A, Gordon MJ, Artz A, Yashar D, Sigmung AM, Smilnak G, Bair S, Mian A, Fitzgerald L, et al. A validated comorbidity index predicts outcomes of CAR T-cell therapy in patients with diffuse large B cell lymphoma. Blood Adv 2023; in press. PMid:36735393 PMCid:PMC10362276
  56. Plaks V, Rossi JM, Chou J, Wang L, Poddar S, Han G, Wang Z, Kuang SQ, Chu F, Davis RE, et al. CD19 target evasion as a mechanism of relapse in large B-cell lymphoma treated with axicabtagene ciloleucel. Blood 2021; 138(12): 1081-1085. PMid:34041526 PMCid:PMC8462361  
  57. Shouval R, Tomas AA, Fein JA, Flynn JR, Markovits E, Mayer S, Afuye AO, Alperovich A, Anagnostou T, Besser MJ, et al. Impact of TP53 genomic alterations il large B-cell lymphoma treated with CD19-chimeric antigen receptor T-cell therapy. J Clin Oncol 2021; 40: 369-381. PMid:34860572 PMCid:PMC8797602  
  58. Jain MD, Zicheddu B, Coughlin CA, Faramand R, Griswold AJ, Reid KM, Menges M, Zhang Y, Cen L, Wang X, et al. Whole-genome sequencing reveals complex genomic features underlying anti-CD19 CAR T-cell treatment failures in lymphoma. Blood 2022; 140(5): 491-503. PMid:35476848 PMCid:PMC9353150  
  59. Cherng HJ, Sun R, Sugg B, Irwin R, Yang H, Le CC, Deng Q, Fayad L, Fowler NH, Parmar S, et al. Risk assessment with low-pass whole-genome sequencing of cell-free DNA before CD19 CAR T-cell therapy for large B-cell lymphoma. Blood 2022; 140(5): 504-515. PMid:35512184 PMCid:PMC9353148  
  60. Kurtz DM, Green MR, Bratman SV, Scherer F, Liu CL, Kunder CA, Takahashi K, Glover C, Keane K, Kihira S, et al. Noninvasive monitoring of diffuse large B-cell lymphoma by immunoglobulin high-throughput sequencing. Blood 125(24): 3679-3687. PMid:25887775 PMCid:PMC4463733  
  61. Frank MJ, Hossain NM, Bukhari A, Dean E, Spiegel JY, Claire GK, Kirsc I, Jacob AP, Mullins CD, Lee LW, et al. Monitoring of circulating tumor DNA improves early relapse detection after axicabtagene ciloleucel infusion in large B-cell lymphoma: results of a prospective multi-institutional trial. J Clin Oncol 2021; 39: 3034-3043. PMid:34133196 PMCid:PMC10166351  
  62. Sworder BJ, Kurtz DM, Alig SK, Frank MJ, Shukla N, Garofalo A, Maculay CW. Esfahani MS, Olsen MNB, Hamilton J, et al. Detrminants of resistance to engineered T-cell therapies targeting CD19 in large B cell lymphomas. Cancer 2023; 41(1): 210-225. PMid:36584673  
  63. Kotlov N, Bagaev A, Revuelta MV, Phillip JM, Cacciapuoti MT, Antysheva Z, Svekollin V, Tikhonova E, Miheecheva N, Kuzkina N, et al. Clinical and biological subtypes of B-cell lymphoma revealed by microenvironmental signatures. Cancer Discov 2021; 11(6):1468-1489. PMid:33541860 PMCid:PMC8178179  
  64. Steen CB, Luca BA, Esfahani MS, Azizi A, Sworder BJ, Nabet BY, Kurtz DM, Liu CL, Khameneh F, Advani RH, et al. The landscape of tumor cell states and ecosystems in diffuse large B cell lymphoma. Cancer 2021; 39(19): 1422-1437. PMid:34597589 PMCid:PMC9205168
  65. Batlevi CL, Nos G, Kotlov N, Sorokina M, Okwali M, Bagaev A, Michaud L, Shah GL, Shouval R, Tomas AA, et al. Correlative biomarkers for CART19 response in patients with relapsed or refractory diffuse large B-cell lymphoma. Blood 2022; 140 (suppl 1): 9228-9230.  
  66. Dybkaer K, Bogsted M, Falgreen S, Bodekr JS, Kjeldsen MK, Schmitz A, Bilgrau AE, Xu-Monette ZY, Li L, Bergkvist KS, et al. Diffuse large B-cell lymphoma classification system that associates normal B-cell subset phenotypes with prognosis. J Clin Oncol 2015; 33(12): 1379-1388. PMid:25800755 PMCid:PMC4397280  
  67. Haradhvala NJ, Leich MB, Maurer K, Gohil SH, Larson RC, Yao N, Gallagher K, Katsis K, F Rigault M, Southard J, et al. Distinct cellular dynamics associated with response to CAR-T therapy for refractory. B-cell lymphoma. Nat Med 2022; 28(9): 1848-1859. PMid:36097221 PMCid:PMC9509487  
  68. Deng Q, Han G, Puebla-Orosio N, Ma MCJ, Strati P, Chasen B, Dai E, Dang M, Jain N, Yang H, et al. Characteristics of anti-CD19 CAR T-cell infusion products associates with efficacy and toxicity in patients with large B-cell lymphomas. Nat Med 2020; 26(12): 1878-1888. PMid:33020644 PMCid:PMC8446909  
  69. Rejeski K, Perez A, Sesques P, Hoster E, Berger C, Jentzsch L, Mougiakakos D, Frolich L, Ackermann J, Bucklein V, et al. CAR-HEMATOTOX: a model for CAR T-cell-cell related hematologic toxicity in relapsed/refractory large B-cell lymphoma. Blood 2021; 138(24): 2499-2508. PMid:34166502 PMCid:PMC8893508  
  70. Kampouri E, Little JS, Rejeski K, Manuel O, Hammond SP, Hill JA. Infections after chimeric antigen receptor (CAR)-T-cell therapy for hematologic malignancies. Transpl Infect Dis. 2023 Oct 3:e14157 PMid:37787373  
  71. Morris EC, Neelapu SS, Giavridis T, Sadelain M. Cytokine release syndrome and associated neurotoxicity in cancer immunotherapy. Nat Rev Immunol. 2022 Feb;22(2):85-96. doi: 10.1038/s41577-021-00547 PMid:34002066 PMCid:PMC8127450  
  72. Makos OL, D'Angelo CR. The shifting roles and toxicities of cellular therapies in B-cell malignancies. Transpl Infect Dis. 2023 :e14145. PMid:37676749  
  73. Rubin DB, Danish HH, Ali AB, et al. Neurological toxicities associated with chimeric antigen receptor T-cell therapy. Brain.2019;142(5):1334-1348. PMid:30891590  
  74. Ganatra S, Dani SS, Yang EH, Zaha VG, Nohria A. Cardiotoxicity of T-Cell Antineoplastic Therapies: JACC: CardioOncology Primer. JACC CardioOncol. 2022 Dec 20;4(5):616-623. PMid:36636447 PMCid:PMC9830211  
  75. Brammer JE, Braunstein Z, Katapadi A, Porter K, Biersmith M, Guha A, Vasu S, Yildiz VO, Smith SA, Buck B, Haddad D, Gumina R, William BM, Penza S, Saad A, Denlinger N, Vallakati A, Baliga R, Benza R, Binkley P, Wei L, Mocarski M, Devine SM, Jaglowski S, Addison D. Early toxicity and clinical outcomes after chimeric antigen receptor T-cell (CAR-T) therapy for lymphoma. J Immunother Cancer. 2021; 9:e002303 PMid:34429331 PMCid:PMC8386216  
  76. Wudhikarn K, Tomas AA, Flynn JR, Devlin SM, Brower J, Bachanova V, Nastoupil LJ, McGuirk JP, Maziarz RT, Oluwole OO, Schuster SJ, Porter DL, Bishop MR, Riedell PA, Perales MA. Low toxicity and excellent outcomes in patients with DLBCL without residual lymphoma at the time of CD19 CAR T-cell therapy. Blood Adv. 2023; 7: 3192-3198 PMid:36355838 PMCid:PMC10338201  
  77. Oluwole OO, Bouabdallah K, Muñoz J, De Guibert S, Vose JM, Bartlett NL, Lin Y, Deol A, McSweeney PA, Goy AH, Kersten MJ, Jacobson CA, Farooq U, Minnema MC, Thieblemont C, Timmerman JM, Stiff P, Avivi I, Tzachanis D, Kim JJ, Bashir Z, McLeroy J, Zheng Y, Rossi JM, Johnson L, Goyal L, van Meerten T. Prophylactic corticosteroid use in patients receiving axicabtagene ciloleucel for large B-cell lymphoma. Br J Haematol. 2021 Aug;194(4):690-700. PMid:34296427 PMCid:PMC8457222
  78. Mucha SR, Rajendram P. Management and Prevention of Cellular-Therapy-Related Toxicity: Early and Late Complications. Curr Oncol. 2023 May 15;30(5):5003-502 PMid:37232836 PMCid:PMC10217595  
  79. Jain MD, Smith M, Shah NN. How I treat refractory CRS and ICANS after CAR T-cell therapy. Blood. 2023 ;141:2430-2442. PMid:36989488 PMCid:PMC10329191  
  80. Gauthier J, Gazeau N, Hirayama AV, et al. Impact of CD19 CAR T-cell product type on outcomes in relapsed or refractory aggressive B-NHL. Blood. 2022;139(26):3722-3731. PMid:35439295 PMCid:PMC9247364  
  81. Roschewski M, Longo DL, Wilson WH. CAR T-Cell Therapy for Large B-Cell Lymphoma - Who, When, and How? N Engl J Med. 2022 Feb 17;386(7):692-696. PMid:34904797 PMCid:PMC9295142  
  82. Parker C, Liu FF, Deger KA, Franco-Villalobos C, Proskorovsky I, Keating SJ, Sorensen S. Cost-Effectiveness of Lisocabtagene Maraleucel Versus Axicabtagene Ciloleucel and Tisagenlecleucel in the Third-Line or Later Treatment Setting for Relapsed or Refractory Large B-cell Lymphoma in the United States. Adv Ther. 2023 May;40(5):2355-2374. PMid:36947328 PMCid:PMC10129927
  83. Foglia, E.; Garagiola, E.; Ladisa, V.; Rambaldi, A.; Cairoli, R.; Sammassimo, S.; Salè, E.O.; Zinzani, P.L.; Esposti, M.; Alberti, L.; et al. Multidimensional Results and Reflections on CAR-T: The Italian Evidence. Int. J. Environ. Res. Public Health 2023, 20, 3830. PMid:36900841 PMCid:PMC10001656