Radiation prior to chimeric antigen receptor T-cell therapy is an optimizing bridging strategy in relapsed/refractory aggressive B-cell lymphoma

Hyper-fractionated radiotherapy as a bridging strategy to enhance CAR-T efficacy by regulating T-cell co-stimulatory molecules in relapsed/refractory diffuse large B-cell lymphoma

Background

Bridging therapy can prevent patients from disease progression while waiting for CAR-T cell preparation. Hyper-fractionated radiotherapy can achieve an effective target dose within a short period, minimize radiation damage, and may modify immune environment compared to conventional radiotherapy.

Aims

This study aims to investigate the efficacy and safety of bridging hyper-fractionated radiotherapy in combination with CAR-T therapy for relapsed/refractory diffuse large B-cell lymphoma. The potential mechanisms were explored.

Methods

This is a prospective pilot study. After T-cell collection, the patients underwent hyper-fractionated radiotherapy at lesion sites with 1.5 Gy twice daily for 10 days before CAR-T cell infusion. Peripheral blood immune cell subsets and quantitative serum proteomics were assessed before radiotherapy and after radiotherapy before CAR-T cell infusion.

Results

A total of 13 patients have been enrolled. The median follow-up time was 6 (3-24) months after CAR-T infusion. At 3-month follow-up, 9/13(69%) patients had CR, 1/13(8%) patient had PR, 1/13(8%) patient remained SD, and 2/13(15%) patients died of disease progression. The local recurrence rate was 1/13(8%). Seven patients have been followed up for more than 6 months, and they remain in CR. The median PFS and OS were not reached. No grade 3-4 CRS or ICANS were reported. After hyper-fractionated radiotherapy, peripheral PD1+CD8+T/T ratio significantly decreased while quantitative serum proteomics profiling showed a decrease in sCD28.

Conclusion

Hyper-fractionated radiotherapy can rapidly control tumor progression sites without delaying the infusion time. This approach can improve the ORR and does not increase the incidence of CRS and ICANS. The mechanism may be related to the regulation of T-cell co-stimulatory molecules, which demands further exploration.

Clinical outcomes of chimeric antigen receptor T-cell therapy following autologous hematopoietic stem cell transplantation in 38 patients with refractory/relapsed primary or secondary central nervous system lymphoma

BACKGROUND

Several reports have indicated that chimeric antigen receptor (CAR) T-cell therapy following autologous hematopoietic stem cell transplantation (ASCT) is a promising strategy for refractory/relapsed (r/r) central nervous system lymphoma (CNSL), but the number of reported cases is limited.

METHODS

The cohort in this retrospective study consisted of 38 patients with r/r CNSL who received CAR T-cell therapy following ASCT at our center between January 2019 and April 2024. Group comparisons of continuous variables were tested using the unpaired Student's t-test or the Mann-Whitney U-test, while categorical variables were analyzed using Fisher's exact test. The Kaplan-Meier method was employed to estimate survival curves, and group comparisons were performed using the log-rank test.

RESULTS

The cohort comprised 38 patients with r/r CNSL, all of whom had active CNS involvement. After therapy, the best overall response rate (ORR) of all patients was 78.9%. Subgroup analysis found that a lower ORR was observed in patients with lactate dehydrogenase levels above the upper limit of normal (60.0% vs. 91.3%, P = 0.039). With a median follow-up of 37.5 months, the estimated 1-year overall survival (OS) and progression-free survival (PFS) rates were 72.8% and 57.4%, respectively. The risk factors associated with PFS was no response to current therapy (adjusted hazard ratio: 22.87, P < 0.001). The incidence rates of severe cytokine release syndrome and immune effector cell-associated neurotoxicity syndrome were both 13.2%. Among the 25 patients with secondary CNSL (SCNSL), the best ORRs were 91.7% for those with CNS lesions only and 61.5% for those with CNS and systemic lesions (P = 0.160), while the estimated 1-year PFS rates were 83.3% and 38.5%, respectively (P = 0.030).

CONCLUSIONS

CAR T-cell therapy following ASCT shows promising efficacy for r/r CNSL patients. Besides, SCNSL patients with CNS and systemic lesions have inferior treatment efficacy compared to those with CNS lesions only.

Revolutionizing the treatment for nasopharyngeal cancer: the impact, challenges and strategies of stem cell and genetically engineered cell therapies

Nasopharyngeal carcinoma (NPC) is a distinct malignancy of the nasopharynx and is consistently associated with the Epstein-Barr virus (EBV) infection. Its unique anatomical location and complex aetiology often result in advanced-stage disease at first diagnosis. While radiotherapy (RT) and chemotherapy have been the mainstays of treatment, they often fail to prevent tumour recurrence and metastasis, leading to high rates of treatment failure and mortality. Recent advancement in cell-based therapies, such as chimeric antigen receptor (CAR)-T cell therapy, have shown great promise in hematological malignancies and are now being investigated for NPC. However, challenges such as targeting specific tumour antigens, limited T cell persistence and proliferation, and managing treatment-related toxicities must be addressed. Extensive research is needed to enhance the effectiveness and safety of these therapies, paving the way for their integration into standard clinical practice for better management of NPC and a better quality of life for human health.

Outcomes of patients with R/R B-cell NHL and limited (<5 sites) pre-CART disease bridged with or without radiotherapy

ABSTRACT

Unirradiated patients with relapsed/refractory (R/R) B-cell non-Hodgkin lymphoma (NHL) who undergo anti-CD19 chimeric antigen receptor T-cell therapy (CART) have a predominant localized pattern of relapse, the significance of which is heightened in individuals with limited/localized disease before CART. This study reports on the outcomes of patients with R/R NHL and limited (<5 involved sites) disease bridged with or without radiotherapy. A multicenter retrospective review of 150 patients with R/R NHL who received CART with <5 disease sites before leukapheresis was performed. Bridging treatment, if any, was administered between leukapheresis and CART infusion. Study end points included relapse-free survival (RFS), event-free survival (EFS), and overall survival. Before CART infusion, 48 patients (32%) received bridging radiotherapy (BRT), and 102 (68%) did not. The median follow-up was 21 months. After CART infusion, BRT patients had higher objective response (92% vs 78%; P = .046) and sustained complete response rates (54% vs 33%; P = .015). Local relapse in sites present before CART was lower in the BRT group (21% vs 46%; P = .003). BRT patients had improved 2-year RFS (53% vs 44%; P = .023) and 2-year EFS (37% vs 34%; P = .039) compared with patients who did not receive BRT. The impact of BRT was most prominent in patients who had ≤2 pre-CART involved disease sites, with 2-year RFS of 62% in patients who received BRT compared with 42% in those who did not (P = .002). BRT before CART for patients with limited (<5 involved disease sites) R/R NHL improves response rate, local control, RFS, and EFS without causing significant toxicities.

Role of radiation in chimeric antigen receptor T-cell therapy for patients with relapsed/refractory non-Hodgkin lymphoma: Current studies and future prospects

Chimeric antigen receptor T-cell (CAR-T) therapy has revolutionized the treatment approach for patients with relapsed/refractory non-Hodgkin lymphoma (R/R NHL). However, the long-term prognosis has been discouraging. Moreover, the urgent resolution of two critical issues is necessary: minimize tumor burden before CAR-T infusion and control fatal toxicities post CAR-T therapy. By combining radiotherapy (RT), the safety and efficacy of CAR-T can be improved. RT can serve as bridging therapy, reducing the tumor burden before CAR-T infusion, thus enabling safe and successful CAR-T infusion, and as salvage therapy in cases of CAR-T therapy failure. This review aims to discuss the current evidence supporting the use of RT in CAR-T therapy for patients with R/R NHL. Although most studies have shown a positive role of RT in combined modality treatments for patients undergoing CAR-T therapy, the synergy gained from these remains uncertain. Furthermore, the optimal dose/fraction and radiation response require further investigation.

Comprehensive Bridging Radiotherapy for Limited Pre-CART Non-Hodgkin Lymphoma

This cohort study examines the role of comprehensive bridging radiotherapy in the setting of chimeric antigen receptor T-cell therapy for non-Hodgkin lymphoma.

The Next Chapter in Immunotherapy and Radiation Combination Therapy: Cancer-Specific Perspectives

Immunotherapeutic agents have revolutionized cancer treatment over the past decade. However, most patients fail to respond to immunotherapy alone. A growing body of preclinical studies highlights the potential for synergy between radiation therapy and immunotherapy, but the outcomes of clinical studies have been mixed. This review summarizes the current state of immunotherapy and radiation combination therapy across cancers, highlighting existing challenges and promising areas for future investigation.

Incorporating radiation with anti-CD19 chimeric antigen receptor T-cell therapy for relapsed/refractory non-Hodgkin lymphoma: A multicenter consensus approach

Anti-CD19 chimeric antigen receptor T-cell therapy (CART) has revolutionized the outcomes of relapsed and/or refractory B-cell non-Hodgkin lymphoma. However, CART is still limited by its availability, toxicity, and response durability. Not all patients make it to the CART infusion phase due to disease progression. Among those who receive CART, a significant number of patients experience life-threatening cytokine release syndrome toxicity, and less than half maintain a durable response with the majority relapsing in pre-existing sites of disease present pre-CART. Radiation therapy stands as a promising peri-CART and salvage treatment that can improve the outcomes of these patients. Evidence suggests that bridging radiotherapy prior to CART controls the disease during the manufacturing period, augments response rates and local control, cytoreduces/debulks the disease and decreases the severity of cytokine release syndrome, and may prolong disease-free intervals and survival especially in patients with bulky disease. Consolidative radiotherapy for residual post-CART disease alters the pattern of relapse and improves local recurrence-free and progression-free survivals. Salvage radiotherapy for relapsed post-CART disease has favorable survival outcomes when delivered comprehensively for patients with limited relapsed disease and palliates symptoms for patients with diffuse relapsed disease. The biology of the disease during the peri-CART period is poorly understood, and further studies investigating the optimal timing and dosing of radiation therapy (RT) are needed. In this review, we tackle the most significant challenges of CART, review and propose how RT can help mitigate these challenges, and provide The Mayo Clinic experts' approach on incorporating RT with CART.

A comprehensive review on the composition, biogenesis, purification, and multifunctional role of exosome as delivery vehicles for cancer therapy

All forms of life produce nanosized extracellular vesicles called exosomes, which are enclosed in lipid bilayer membranes. Exosomes engage in cell-to-cell communication and participate in a variety of physiological and pathological processes. Exosomes function via their bioactive components, which are delivered to target cells in the form of proteins, nucleic acids, and lipids. Exosomes function as drug delivery vehicles due to their unique properties of innate stability, low immunogenicity, biocompatibility, biodistribution, accumulation in desired tissues, low toxicity in normal tissues, and the stimulation of anti-cancer immune responses, and penetration capacity into distance organs. Exosomes mediate cellular communications by delivering various bioactive molecules including oncogenes, oncomiRs, proteins, specific DNA, messenger RNA (mRNA), microRNA (miRNA), small interfering RNA (siRNA), and circular RNA (circRNA). These bioactive substances can be transferred to change the transcriptome of target cells and influence tumor-related signaling pathways. After considering all of the available literature, in this review we discuss the biogenesis, composition, production, and purification of exosomes. We briefly review exosome isolation and purification techniques. We explore great-length exosomes as a mechanism for delivering a variety of substances, including proteins, nucleic acids, small chemicals, and chemotherapeutic drugs. We also talk about the benefits and drawbacks of exosomes. This review concludes with a discussion future perspective and challenges. We hope that this review will provide us a better understanding of the current state of nanomedicine and exosome applications in biomedicine.

Reappraisal of the role of radiation therapy in lymphoma treatment

Radiation therapy (RT) for lymphomas has improved dramatically with modern imaging and treatment techniques, encompassing only the necessary volume with minimal doses to normal structures. Prescribed radiation doses are reduced, and fractionation schedules are under revision. With effective systemic treatment only initial macroscopic disease is irradiated. With no or less effective systemic treatment, possible microscopic disease is also included. Risks of long-term side effects of RT have diminished dramatically and should be weighed against risks from more systemic treatment or increased risk of relapse. Lymphoma patients are often elderly, they tolerate modern limited RT very well. Lymphomas refractory to systemic treatments often remain radioresponsive, and brief, mild RT may offer effective palliation. New roles for RT are emerging with immune therapies. RT for "bridging," keeping the lymphoma under control while waiting for immune therapy, is well established. Enhancement of the immune response to lymphomas, so-called "priming," is being intensively researched.

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

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