CD19/CD22 Chimeric Antigen Receptor T Cell Cocktail Therapy following Autologous Transplantation in Patients with Relapsed/Refractory Aggressive B Cell Lymphomas

Combination of chidamide and PD-1 blockade in Refractory/Relapsed aggressive large B-cell lymphomas with high risk of failing CAR-T therapy

BACKGROUND

Refractoriness and relapse after chimeric antigen receptor T-cell therapy have emerged as major challenges for immunotherapy of aggressive large B-cell lymphoma. Thus far, there is no consensus on how to address treatment failure and whether to administer maintenance therapy following CAR-T cell therapy.

METHODS

From August 2017 through November 2022, 52 patients with refractory/relapsed aggressive LBCL who had a high risk of resistance to CAR-T cell therapy were given chidamide in combination with a PD-1 inhibitor as maintenance therapy following either CAR19/22 T-cell cocktail therapy or CAR19/22 T-cell cocktail therapy plus autologous stem cell transplantation (ASCT). Another 52 aggressive LBCL patients who had comparable baseline characteristics and received similar therapeutic regimens but did not receive any interventions following CAR-T cell therapy or CAR-T cell therapy plus ASCT were regarded as the control group to evaluate the efficacy and safety of the combination of chidamide and a PD-1 inhibitor.

RESULTS

Among the 52 patients who received chidamide and a PD-1 inhibitor as maintenance therapy, with a median follow-up of 26.5 months (range: 1.1-53.8), neither the median progression-free survival (PFS) nor overall survival (OS) was reached, and the expected 2-year OS and PFS rates were 89 % and 77 %, respectively, which were superior to those of the control group (p < 0.001). Long-term chidamide administration and a specific genetic subtype of EZB were strongly associated with a better response after chidamide plus PD-1 blockade therapy. Additionally, long-term chidamide administration was significantly associated with prolonged persistence and reactivation of CD19-directed CAR-T cells in the peripheral blood. Adverse effects (AEs) were moderate and reversible, and no treatment-related deaths occurred.

CONCLUSION

Our results indicate that the combination of chidamide and PD-1 blockade as maintenance therapy could improve the outcomes of aggressive LBCL patients at high risk of failing CAR-T cell 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.

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.

Recent advances in CAR-T cell therapy for acute myeloid leukaemia

Acute myeloid leukaemia (AML) is a fatal and refractory haematologic cancer that primarily affects adults. It interferes with bone marrow cell proliferation. Patients have a 5 years survival rate of less than 30% despite the availability of several treatments, including chemotherapy, allogeneic haematopoietic stem cell transplantation (Allo-HSCT), and receptor antagonist drugs. Allo-HSCT is the mainstay of acute myeloid leukaemia treatment. Although it does work, there are severe side effects, such as graft-versus-host disease (GVHD). In recent years, chimeric antigen receptor (CAR)-T cell therapies have made significant progress in the treatment of cancer. These engineered T cells can locate and recognize tumour cells in vivo and release a large number of effectors through immune action to effectively kill tumour cells. CAR-T cells are among the most effective cancer treatments because of this property. CAR-T cells have demonstrated positive therapeutic results in the treatment of acute myeloid leukaemia, according to numerous clinical investigations. This review highlights recent progress in new targets for AML immunotherapy, and the limitations, and difficulties of CAR-T therapy for AML.

Venetoclax plus dose-adjusted R-EPOCH (VR-DA-EPOCH) or G-EPOCH bridging to subsequent cellular therapy for the patients with transformed lymphoma a single center clinical experience

Indolent lymphoma, including chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) and follicular lymphoma (FL), can undergo histological transformation into an aggressive subtype, typically diffuse large B-cell lymphoma (DLBCL). The prognosis of transformed lymphoma is poor. In this study, we reported the efficacy and toxicity of a combination of venetoclax, dose-adjusted rituximab or obinutuzumab, etoposide, prednisone, vincristine, doxorubicin, and cyclophosphamide (VR-DA-EPOCH or VG-DA-EPOCH) in 11 patients with biopsy-proven histology transformation into DLBCL, including 8 patients with RT and 3 with transformed FL (tFL). The study was conducted between October 2019 and March 2023 at our single center. The median age of participants at enrolment was 53 years. Six patients (85.7%, 6/7) achieved complete remission (CR) at the end of treatment. The best overall response rate (ORR) and CR rate were both 72.7%, respectively. Two patients received autologous hemopoietic stem cell transplant (ASCT) while two patients received ASCT concurrently with CAR-T therapy for consolidation. With a median follow-up of 13.5 (range, 2.4-29.8) months after enrollment, the median event-free survival, progression-free survival, and overall survival were 9.4, 11.5, and 17.5 months, respectively. Hematologic toxicities of grade ≥3 consisted of neutropenia (90.9%, 10/11), thrombocytopenia (63.6%, 7/11), and febrile neutropenia (54.5%, 6/11). In conclusion, VR-DA-EPOCH or VG-DA-EPOCH was a promising strategy to achieve an early remission, bridging to cellular therapy within this population.

Adverse Reactions in Relapsed/Refractory B-Cell Lymphoma Administered with Chimeric Antigen Receptor T Cell Alone or in Combination with Autologous Stem Cell Transplantation

(1) Background: The combination of CAR-T with ASCT has been observed to enhance the efficacy of CAR-T cell therapy. However, the impact of this combination on adverse reactions is still uncertain. (2) Methods: Between January 2019 and February 2023, 292 patients diagnosed with r/r B-cell lymphoma received either CAR-T therapy alone or in combination with ASCT at our institution. We evaluated the incidence of CRS and CRES and utilized a logistic regression model to identify factors contributing to severe CRS (grade 3-4) and CRES (grade 3-4). (3) Results: The overall incidence of CRS and CRES was 78.9% and 8.2% in 147 patients receiving CAR-T alone, and 95.9% and 15.2% in 145 patients receiving CAR-T combined with ASCT, respectively. The incidence of overall CRS (p < 0.0001) and mild CRS (grade 1-2) (p = 0.021) was elevated in the ASCT combined with CAR-T group. No significant difference was observed in severe CRS and CRES between the groups. Among the 26 cases of lymphoma involving the central nervous system (CNS), 96.2% (25/26) developed CRS (15.4% grade 3-4), and 34.6% (9/26) manifested CRES (7.7% grade 3-4). Female patients had a lower incidence of severe CRS but a higher incidence of severe CRES. Lymphomas with CNS involvement demonstrated a higher risk of CRES compared to those without central involvement. (4) Conclusions: The combination of ASCT with CAR-T demonstrated a preferable option in r/r B-cell lymphoma without an increased incidence of severe CRS and CRES.

Novel and multiple targets for chimeric antigen receptor-based therapies in lymphoma

Chimeric antigen receptor (CAR) T-cell therapy targeting CD19 in B-cell non-Hodgkin lymphoma (NHL) validates the utility of CAR-based therapy for lymphomatous malignancies. Despite the success, treatment failure due to CD19 antigen loss, mutation, or down-regulation remains the main obstacle to cure. On-target, off-tumor effect of CD19-CAR T leads to side effects such as prolonged B-cell aplasia, limiting the application of therapy in indolent diseases such as chronic lymphocytic leukemia (CLL). Alternative CAR targets and multi-specific CAR are potential solutions to improving cellular therapy outcomes in B-NHL. For Hodgkin lymphoma and T-cell lymphoma, several cell surface antigens have been studied as CAR targets, some of which already showed promising results in clinical trials. Some antigens are expressed by different lymphomas and could be used for designing tumor-agnostic CAR. Here, we reviewed the antigens that have been studied for novel CAR-based therapies, as well as CARs designed to target two or more antigens in the treatment of lymphoma.

Combinational therapy of CAR T-cell and HDT/ASCT demonstrates impressive clinical efficacy and improved CAR T-cell behavior in relapsed/refractory large B-cell lymphoma

BACKGROUND

Approximately two-thirds of patients with relapsed or refractory large B-cell lymphoma (R/R LBCL) do not respond to or relapse after anti-CD19 chimeric antigen receptor T (CAR T)-cell therapy, leading to poor outcomes. Previous studies have suggested that intensified lymphodepletion and hematological stem cell infusion can promote adoptively transferred T-cell expansion, enhancing antitumor effects. Therefore, we conducted a phase I/II clinical trial in which CNCT19 (an anti-CD19 CAR T-cell) was administered after myeloablative high-dose chemotherapy and autologous stem cell transplantation (HDT/ASCT) in patients with R/R LBCL.

METHODS

Transplant-eligible patients with LBCL who were refractory to first-line immunochemotherapy or experiencing R/R status after salvage chemotherapy were enrolled. The study aimed to evaluate the safety and efficacy of this combinational therapy. Additionally, frozen peripheral blood mononuclear cell samples from this trial and CNCT19 monotherapy studies for R/R LBCL were used to evaluate the impact of the combination therapy on the in vivo behavior of CNCT19 cells.

RESULTS

A total of 25 patients with R/R LBCL were enrolled in this study. The overall response and complete response rates were 92.0% and 72.0%, respectively. The 2-year progression-free survival rate was 62.3%, and the overall survival was 68.5% after a median follow-up of 27.0 months. No unexpected toxicities were observed. All cases of cytokine release syndrome were of low grade. Two cases (8%) experienced grade 3 or higher CAR T-cell-related encephalopathy syndrome. The comparison of CNCT19 in vivo behavior showed that patients in the combinational therapy group exhibited enhanced in vivo expansion of CNCT19 cells and reduced long-term exhaustion formation, as opposed to those receiving CNCT19 monotherapy.

CONCLUSIONS

The combinational therapy of HDT/ASCT and CNCT19 demonstrates impressive efficacy, improved CNCT19 behavior, and a favorable safety profile.

TRIAL REGISTRATION NUMBERS

ChiCTR1900025419 and NCT04690192.

EBV-associated lymphoproliferative disease post-CAR-T cell therapy

Epstein-Barr virus (EBV)-associated lymphoproliferative diseases (EBV-LPDs) are common complications that occur after solid organ transplantation or allogeneic hematopoietic stem-cell transplantation (HSCT). However, their occurrence and treatment post-chimeric antigen receptor-modified T (CAR-T) cell therapy has not been reported. Two patients had been diagnosed with EBV-positive aggressive B-cell lymphoma and experienced relapses after multiple lines of treatment. After receiving CAR-T cell therapy in tandem with autologous HSCT, the patients achieved complete remission. However, with a median time of 38.5 months after CAR-T cell therapy, B-cell-derived EBV-LPDs were diagnosed, and they were relieved through the administration of immune checkpoint inhibitor or B-cell-depleting agents. Collectively, our report suggests that EBV-LPDs may represent a long-term adverse event after CAR-T cell therapy, especially in patients who previously had EBV-positive disorders, and they can be resolved by immune normalization strategy or B-cell depleting therapy.

Case Report: CD19 CAR T-cell therapy following autologous stem cell transplantation: a successful treatment for R/R CD20-negative transformed follicular lymphoma with TP53 mutation

Background

Follicular lymphoma (FL), a common indolent B-cell lymphoma, has the potential to transform into an aggressive lymphoma, such as diffuse large B-cell lymphoma (DLBCL). The outcome of patients with transformed follicular lymphoma (tFL) is poor, especially in patients with transformed lymphoma after chemotherapy and patients with progression within 24 months (POD24). Chimeric antigen receptor (CAR) T-cell therapy combined with autologous stem cell transplantation (ASCT) has promising antitumor efficacy.

Case presentation

Here, we described a 39-year-old male patient who was initially diagnosed with FL that transformed into DLBCL with POD24, CD20 negativity, TP53 mutation, and a bulky mass after 3 lines of therapy, all of which were adverse prognostic factors. We applied a combination approach: CD19 CAR T-cell infusion following ASCT. Ibrutinib was administered continuously to enhance efficacy, DHAP was administered as a salvage chemotherapy, and ICE was administered as a bridging regimen. The patient underwent BEAM conditioning on days -7~ -1, a total of 3.8 × 106/kg CD34+ stem cells were infused on days 01~02, and a total of 108 CAR T cells (relmacabtagene autoleucel, relma-cel, JWCAR029) were infused on day 03. The patient experienced grade 2 cytokine release syndrome (CRS), manifesting as fever and hypotension according to institutional standards. There was no immune effector cell-associated neurotoxicity syndrome (ICANS) after CAR T-cell infusion. Finally, the patient achieved CMR at +1 month, which has been maintained without any other adverse effects.

Conclusion

This case highlights the amazing efficacy of CD19 CAR T-cell therapy following ASCT for R/R tFL, thus providing new insight on therapeutic strategies for the future.

Chimeric Antigen Receptor T-Cell Therapy in Aggressive B-Cell Lymphoma

Chimeric antigen receptor (CAR) T-cell therapy is a revolutionary therapy increasingly used in the treatment of non-Hodgkin B-cell lymphoma. This review focuses on the use of CAR T-cell therapy in aggressive B-cell lymphoma including clinical indications, known short- and long-term toxicity, mechanisms of CAR T-cell efficacy and tumor resistance, and future directions in the treatment of aggressive lymphoma with CAR T-cell therapy.

CAR-T Cell Therapy in the Treatment of Pediatric Non-Hodgkin Lymphoma

Non-Hodgkin lymphomas (NHL) are a group of cancers that originate in the lymphatic system, especially from progenitor or mature B-cells, T-cells, or natural killer (NK) cells. NHL is the most common hematological malignancy worldwide and also the fourth most frequent type of cancer among pediatric patients. This cancer can occur in children of any age, but it is quite rare under the age of 5 years. In recent decades, available medicines and therapies have significantly improved the prognosis of patients with this cancer. However, some cases of NHL are treatment resistant. For this reason, immunotherapy, as a more targeted and personalized treatment strategy, is becoming increasingly important in the treatment of NHL in pediatric patients. The objective of the following review is to gather the latest available research results, conducted among pediatric and/or adult patients with NHL, regarding one immunotherapy method, i.e., chimeric antigen receptor (CAR) T cell therapy. We focus on assessing the effectiveness of CAR-T cell therapy, which mainly targets B cell markers, CD19, CD20, and CD22, their connections with one another, sequential treatment, or connections with co-stimulatory molecules. In addition, we also evaluate the safety, aftermath (especially neurotoxicities) and limitations of CAR-T cell therapy.

Effectiveness and safety of CD22 and CD19 dual-targeting chimeric antigen receptor T-cell therapy in patients with relapsed or refractory B-cell malignancies: A meta-analysis

BACKGROUND

The efficacy of CD22 or CD19 chimeric antigen receptor T (CAR-T) cells in the management of acute lymphoblastic leukemia (ALL) and non-Hodgkin lymphoma (NHL) was observed. Because antigen loss and lack of CAR-T-cell persistence are the leading causes of progressive disease following single-antigen targeting, we evaluated CD22/CD19 dual-targeting CAR-T-cell therapy efficacy and safety in relapsed/refractory B-cell malignancies.

METHODS

The Web of Science, PubMed, Cochrane, and Embase databases were searched until July 2022. Patients confirmed with any relapsed/refractory B-cell hematological malignancies were included regardless of age, gender, or ethnicity, receiving CD22 and CD19-dual-targeting CAR-T-cell therapy. The studies conducted on patients with coexisting other cancer were excluded. We used random-effect models to explore the outcome, and heterogeneity was investigated by subgroup analysis.

RESULTS

Fourteen studies (405 patients) were included. The pooled overall response (OR) and complete remission (CR) were 97% and 93%, respectively, for ALL patients. The 1-year proportions of overall survival (OS) and progression-free survival (PFS) were 70% and 49%, respectively. For NHL, OR occurred in 85% of patients, and 57% experienced CR. The results illustrated that the 1-year OS and 1-year PFS were 77% and 65%, respectively. The subgroup analysis showed that the dual-targeting modality achieved higher CR in the following cases: coadministration of CD22/CD19-CAR-T cells and third-generation CAR-T cells combined with ASCT and BEAM pretreatment. The ALL and NHL groups seemed similar in treatment-related toxicity: all grade cytokine release syndrome (CRS), severe CRS, and neurotoxicity occurred in 86%, 7%, and 12% of patients, respectively.

CONCLUSIONS

Our meta-analysis demonstrated that the CD22/CD19 dual-targeting CAR-T-cell strategy has high efficiency with tolerable adverse effects in B-cell malignancies.

Case report: Sandwich therapy of CAR-T combined with ASCT: Sequential CAR-T cell therapy with ASCT after remission with CAR-T therapy caused long-term survival in a patient with relapsed/refractory Burkitt’s lymphoma with TP53 mutations

Burkitt’s lymphoma (BL) with TP53 mutation often has poor outcome after standard chemoimmunotherapy. Adoptive chimeric antigen receptor (CAR)-T cell therapy may be a new paradigm for treating refractory/relapsed (r/r) BL, but its therapeutic effects remain inconclusive. Here, we report a patient with r/r BL who failed to achieve complete remission (CR) and progressed rapidly after multiple protocol chemotherapy. The patient achieved CR with CAR19 and CAR22 T-cell cocktail therapy and obtained long-term disease-free survival after autologous hematopoietic stem cells (ASCT) and subsequential CAR19 and CAR22 T-cell cocktail therapy. The clinical evolution and genetic features of this case may provide some guidance for CAR-T therapy in overcoming relapses associated with TP53 gene mutations.

Multispecific CAR T Cells Deprive Lymphomas of Escape via Antigen Loss

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

A systematic review and meta-analysis of CD22 CAR T-cells alone or in combination with CD19 CAR T-cells

Chimeric antigen receptor (CAR) T-cells are an emerging therapy for the treatment of relapsed/refractory B-cell malignancies. While CD19 CAR-T cells have been FDA-approved, CAR T-cells targeting CD22, as well as dual-targeting CD19/CD22 CAR T-cells, are currently being evaluated in clinical trials. This systematic review and meta-analysis aimed to evaluate the efficacy and safety of CD22-targeting CAR T-cell therapies. We searched MEDLINE, EMBASE, Web of Science, and the Cochrane Central Register of Controlled Trials from inception to March 3rd 2022 for full-length articles and conference abstracts of clinical trials employing CD22-targeting CAR T-cells in acute lymphocytic leukemia (ALL) and non-Hodgkin's lymphoma (NHL). The primary outcome was best complete response (bCR). A DerSimonian and Laird random-effects model with arcsine transformation was used to pool outcome proportions. From 1068 references screened, 100 were included, representing 30 early phase studies with 637 patients, investigating CD22 or CD19/CD22 CAR T-cells. CD22 CAR T-cells had a bCR of 68% [95% CI, 53-81%] in ALL (n= 116), and 64% [95% CI, 46-81%] in NHL (n= 28) with 74% and 96% of patients having received anti-CD19 CAR T-cells previously in ALL and NHL studies respectively. CD19/CD22 CAR T-cells had a bCR rate of 90% [95% CI, 84-95%] in ALL (n= 297) and 47% [95% CI, 34-61%] in NHL (n= 137). The estimated incidence of total and severe (grade ≥3) CRS were 87% [95% CI, 80-92%] and 6% [95% CI, 3-9%] respectively. ICANS and severe ICANS had an estimated incidence of 16% [95% CI, 9-25%] and 3% [95% CI, 1-5%] respectively. Early phase trials of CD22 and CD19/CD22 CAR T-cells show high remission rates in ALL and NHL. Severe CRS or ICANS were (1)rare and dual-targeting did not increase toxicity. Variability in CAR construct, dose, and patient factors amongst studies limits comparisons, with long-term outcomes yet to be reported.

Systematic review registration

https://www.crd.york.ac.uk/prospero, identifier CRD42020193027.

Overcoming resistance to anti-CD19 CAR T-cell therapy in B-cell malignancies

Anti-CD19 chimeric antigen receptor (CAR) T-cell therapy has rapidly changed current treatment pattern, providing a better option for individuals with primary refractory or relapsed B-cell non-Hodgkin lymphoma (r/r B-NHL) and B-cell acute lymphoblastic leukemia (r/r B-ALL). However, despite the outstanding efficacy, a high relapse rate is still found in some B-cell malignancies after anti-CD19 CAR T-cell therapy, which emerges as a main barrier for improving the overall response and long-term outcomes. Understanding the resistance mechanism is crucial to improve current CAR T products, better incorporate them into the current therapy system and develop novel CAR approaches. Herein, we discuss the latest advances in understanding the mechanisms limiting efficacy of CAR T-cell therapy, resulting in CD19 negative (CD19^- ) and CD19 positive (CD19⁺ ) relapses. We also provide a whole scenario of current potential strategies to overcome these barriers.

Autologous stem cell transplantation in tandem with Anti-CD30 CAR T-cell infusion in relapsed/refractory CD30+ lymphoma

Background

Long-term outcome is unfavourable for relapsed/refractory (r/r) lymphoma patients who are resistant to salvage chemotherapy, even after subsequent autologous stem-cell transplantation (ASCT). Although anti-CD30 chimeric antigen receptor (CAR30) T-cell therapy induces high response rates in these patients, the duration of response is relatively limited.

Methods

This open-label, single-center and single-arm pilot study investigated the safety and efficacy of ASCT in tandem with CAR30 T-cell infusion in r/r CD30⁺ lymphoma. The primary endpoint was safety and key secondary endpoint was overall response rate, overall survival, progression-free survival, and duration of response.

Results

Five classical Hodgkin lymphoma (cHL) patients and 1 anaplastic lymphoma kinase (ALK)-negative anaplastic large cell lymphoma (ALCL) patient were enrolled. The median age was 24 years. No patient had prior ASCT. Three patients (50.0%) relapsed for ≥ 2 times and 3 patients (50.0%) had primary refractory diseases. All had a Deauville score of 4 or 5, and 5 patients (83.3%) had a stable or progressive disease (SD/PD) at enrollment. All patients received myeloablative chemotherapy and infused CD34-positive hematopoietic stem cells (HSCs) and CAR30 T cells in tandem, with a median dose of 3.9 × 10⁶/kg and 7.6 × 10⁶/kg, respectively. Five paitents presented with cytokine release syndrome (CRS), all of which were grade 1. No neurotoxicity was observed. All patients had successful HSCs engraftment and reached an objective response, including 5 (4 cHL and 1 ALCL, 83.3%) with a complete response (CR) and 1 with a partial response (PR). With a median follow-up of 20.4 (range, 12.1–34.4) months, all remained alive and maintained their responses.

Conclusion

Our work demonstrates the combined administration of ASCT and CAR30 T-cell therapy is well-tolerate and highly effective in r/r cHL and ALCL, even in PET-positive or chemorefractory patients who are expected to have inferior outcome after ASCT, although further large-scaled validation in prospective clinical trial is warranted.

Trial registration The trial was registered with the Chinese Clinical Trial Registry (ChiCTR, number ChiCTR2100053662).

Supplementary Information

The online version contains supplementary material available at 10.1186/s40164-022-00323-9.

Relapse after CAR-T cell therapy in B-cell malignancies: challenges and future approaches

Chimeric antigen receptor-T (CAR-T) cell therapy, as a novel cellular immunotherapy, has dramatically reshaped the landscape of cancer treatment, especially in hematological malignancies. However, relapse is still one of the most troublesome obstacles to achieving broad clinical application. The intrinsic factors and superior adaptability of tumor cells mark a fundamental aspect of relapse. The unique biological function of CAR-T cells governed by their special CAR construction also affects treatment efficacy. Moreover, complex cross-interactions among CAR-T cells, tumor cells, and the tumor microenvironment (TME) profoundly influence clinical outcomes concerning CAR-T cell function and persistence. Therefore, in this review, based on the most recent discoveries, we focus on the challenges of relapse after CAR-T cell therapy in B-cell malignancies from the perspective of tumor cells, CAR-T cells, and the TME. We also discuss the corresponding basic and clinical approaches that may overcome the problem in the future. We aim to provide a comprehensive understanding for scientists and physicians that will help improve research and clinical practice.

Chimeric antigen receptor T cell therapy for cancer: clinical applications and practical considerations

Chimeric antigen receptor T cells have revolutionized the treatment of hematological malignancies during the past five years, boasting impressive response rates and durable remissions for patients who previously had no viable options. In this review, we provide a brief historical overview of their development. We focus on the practical aspects of a patient’s journey through this treatment and the unique toxicities and current best practices to manage those. We then discuss the key registration trials that have led to approvals for the treatment of relapsed/refractory acute lymphoblastic leukemia (ALL), diffuse large B cell lymphoma (DLBCL), follicular lymphoma, mantle cell lymphoma (MCL), and multiple myeloma. Finally, we consider the future development and research directions of this cutting edge therapy.

Combination strategies to optimize the efficacy of chimeric antigen receptor T cell therapy in haematological malignancies

Chimeric antigen receptor (CAR) T cell therapy has revolutionized the therapeutic landscape of haematological malignancies. However, resistance and relapse remain prominent limitations, and they are related to the limited persistence and efficacy of CAR T cells, downregulation or loss of tumour antigens, intrinsic resistance of tumours to death signalling, and immune suppressive microenvironment. Rational combined modality treatments are regarded as a promising strategy to further unlock the antitumor potential of CAR T cell therapy, which can be applied before CAR T cell infusion as a conditioning regimen or in ex vivo culture settings as well as concomitant with or after CAR T cell infusion. In this review, we summarize the combinatorial strategies, including chemotherapy, radiotherapy, haematopoietic stem cell transplantation, targeted therapies and other immunotherapies, in an effort to further enhance the effectiveness of this impressive therapy and benefit more patients.

Decitabine-primed tandem CD19/CD22 CAR-T therapy in relapsed/refractory diffuse large B-cell lymphoma patients

Chimeric antigen receptor T cell (CAR-T) therapy has emerged as highly effective in relapsed/refractory (R/R) diffuse large B-cell lymphoma (DLBCL), but only about 40% patients have achieved sustained responses. Here, we conducted a phase II clinical trial testing efficacy and toxicities of CAR-T therapy in R/R non-Hodgkin’s lymphoma patients (NCT03196830). Among enrolled patients, 33 R/R DLBCL patients pretreated with DFC (decitabine, fludarabine plus cyclophosphamide) lymphodepletion chemotherapy and infused with tandem CD19-CD22 based CAR-T cells were drawn out for efficacy and toxicities of CAR-T therapy evaluation. With a median follow-up of 10.9(0.6-29.0) months, the best overall response and complete remission (CR) rates were 90.9% and 63.6%, respectively. The median progression-free survival (PFS) was 10.2 months and overall survival (OS) was undefined. The 2-year OS and PFS rates were 54.3% and 47.2%, respectively. No severe grade 4 cytokine release syndrome (CRS) was observed and grade 3 CRS was observed in only 7 patients; 3 patients developed mild immune effect or cell-associated neurotoxic syndrome. All toxicities were transient and reversible and no CAR-T-related mortality. Further subgroup analysis showed that achieving CR was an independent prognostic factor associated with favorable PFS and OS. The 2-year OS and PFS for patients who achieved CR within 3 months (undefined versus undefined P=0.021 and undefined versus undefined P=0.036) or during the follow-up period were significantly longer than those who did not (undefined versus 4.6 months P < 0.0001 and undefined versus 2.0months P<0.001). While severe CRS was also an independent prognostic factor but associated with inferior PFS and OS. The 2-year OS and PFS for patients with grade 3 CRS were significantly shorter than those with grade 0-2 CRS (4.1 months versus undefined P<0.0001 and 1.7 months versus undefined P=0.0002). This study indicated that CD19/CD22 dual-targeted CAR-T therapy under a decitabine-containing lymphodepletion regimen may be a safe, potent effective approach to R/R DLBCL patients.

Chimeric Antigen Receptor-Modified T Cell Immunotherapy for Relapsed and Refractory Adult Burkitt Lymphoma

Patients with Burkitt lymphoma who are refractory to initial therapy or who relapse after undergoing intensive chemotherapy and autologous stem cell transplantation (ASCT) usually have a poor prognosis. While there has been considerable progress in the use of chimeric antigen receptor-modified (CAR) T cell immunotherapy for the treatment of relapsed and refractory (r/r) malignancies, explicit data on adult patients with r/r Burkitt lymphoma are limited. We conducted two single-arm clinical trials to evaluate the clinical efficacy and toxicity of CD19/CD22 CAR T cell immunotherapy both alone (trial A) and in combination with ASCT (trial B) in adult patients with r/r Burkitt lymphoma. In total, 28 adult patients with r/r Burkitt lymphoma were enrolled [trial A (n = 15) and trial B (n = 13)]. The median doses of CD22 and CD19 CAR T cell infusions were 4.1 × 10⁶/kg and 4.0 × 10⁶/kg, respectively. Subsequently, after CAR T cell infusion, overall and complete responses were observed in 19 (67.9%) and 16 (57.1%) patients, respectively. The cumulative incidence rates of grade 2–4 cytokine release syndrome and immune effector cell-associated neurotoxicity syndrome were 39.3% (11/28) and 10.7% (3/28), respectively. After a median follow-up duration of 12.5 months, 16 patients (5 in trial A and 11 in trial B) survived. Both the estimated 1-year progression-free and overall survival rates were 55.6%. Our preliminary results indicated that salvage therapy with CD19/CD22 CAR T cell infusion alone and that in combination with ASCT are effective in treating some adult patients with r/r Burkitt lymphoma.

Sequential CAR T-Cell Therapy After Autologous Stem Cell Transplantation for the Treatment of Relapsed/Refractory Intravascular Large B-Cell Lymphoma With Central Nervous System Involvement: A Case Report

Background

Intravascular large B-cell lymphoma (IVLBCL) is a rare, aggressive, large B-cell non-Hodgkin’s lymphoma. The prognosis of IVLBCL in patients with central nervous system recurrence after first-line chemotherapy treatment is extremely poor. Among immunotherapies, chimeric antigen receptor (CAR) T-cell immunotherapy has been recently found to be a highly effective treatment for B-cell lymphoma, especially for relapsed or refractory diffuse large B-cell lymphoma. However, no guidelines are available that provide a clear consensus regarding the management of patients with relapsed/refractory IVLBCL. Here, we report, for the first time, the use of autologous hematopoietic stem cell transplantation (ASCT) and CAR T-cell therapy in a patient with relapsed/refractory IVLBCL.

Case Presentation

A 42‐year‐old woman was diagnosed with IVLBCL based on liver biopsy and developed central nervous system (CNS) progression. The patient received ASCT combined with murine monoclonal anti-CD19 and anti-CD22 CAR T-cell therapy. She achieved complete remission for 22 months so far with negative minimal residual disease and continues to be followed up.

Conclusion

ASCT combined with CAR T-cell therapy was the best choice for treatment of relapsed/refractory IVLBCL, as it allowed the achievement of a lasting complete remission.

T Cell Defects: New Insights Into the Primary Resistance Factor to CD19/CD22 Cocktail CAR T-Cell Immunotherapy in Diffuse Large B-Cell Lymphoma

Despite impressive progress, a significant portion of patients still experience primary or secondary resistance to chimeric antigen receptor (CAR) T-cell immunotherapy for relapsed/refractory diffuse large B-cell lymphoma (r/r DLBCL). The mechanism of primary resistance involves T-cell extrinsic and intrinsic dysfunction. In the present study, a total of 135 patients of DLBCL treated with murine CD19/CD22 cocktail CAR T-therapy were assessed retrospectively. Based on four criteria (maximal expansion of the transgene/CAR-positive T-cell levels post-infusion [Cmax], initial persistence of the transgene by the CAR transgene level at +3 months [Tlast], CD19+ B-cell levels [B-cell recovery], and the initial response to CAR T-cell therapy), 48 patients were included in the research and divided into two groups (a T-normal group [n=22] and a T-defect [n=26] group). According to univariate and multivariate regression analyses, higher lactate dehydrogenase (LDH) levels before leukapheresis (hazard ratio (HR) = 1.922; p = 0.045) and lower cytokine release syndrome (CRS) grade after CAR T-cell infusion (HR = 0.150; p = 0.026) were independent risk factors of T-cell dysfunction. Moreover, using whole-exon sequencing, we found that germline variants in 47 genes were significantly enriched in the T-defect group compared to the T-normal group (96% vs. 41%; p<0.0001), these genes consisted of CAR structure genes (n=3), T-cell signal 1 to signal 3 genes (n=13), T cell immune regulation- and checkpoint-related genes (n=9), cytokine- and chemokine-related genes (n=13), and T-cell metabolism-related genes (n=9). Heterozygous germline UNC13D mutations had the highest intergroup differences (26.9% vs. 0%; p=0.008). Compound heterozygous CX3CR1I249/M280 variants, referred to as pathogenic and risk factors according to the ClinVar database, were enriched in the T-defect group (3 of 26). In summary, the clinical characteristics and T-cell immunodeficiency genetic features may help explain the underlying mechanism of treatment primary resistance and provide novel insights into CAR T-cell immunotherapy.

New Indications and platforms for CAR-T therapy in lymphomas beyond DLBCL

CD19 directed chimeric antigen receptor T-cell therapy (CAR-T) represents a significant advancement for patients with relapsed/refractory large B-cell lymphoma (LBCL). Long term follow-up confirms durable remissions in nearly half of the patients, a population which was previously estimated to have a median survival of around 6 months with standard salvage therapy. This initial success of CAR-T has led to significant expansion across other lymphoma histologies resulting in the recent regulatory approval of CAR-T in mantle cell lymphoma and follicular lymphoma. Additionally, multiple novel platforms of CAR-T therapy are under development to improve efficacy and limit toxicity such dual antigen targeting, allogeneic and natural killer CAR's. In this review, we focus on the new indications of CAR-T in lymphomas beyond LBCL as well as emerging platforms of CAR-T therapy.