Sequential CD7 CAR T-Cell Therapy and Allogeneic HSCT without GVHD Prophylaxis.

BACKGROUND: Patients with relapsed or refractory hematologic cancers have a poor prognosis. Chimeric antigen receptor (CAR) T-cell therapy as a bridge to allogeneic hematopoietic stem-cell transplantation (HSCT) has the potential for long-term tumor elimination. However, pre-HSCT myeloablation and graft-versus-host disease (GVHD) prophylaxis agents have toxic effects and could eradicate residual CAR T cells and compromise antitumor effects. Whether the integration of CAR T-cell therapy and allogeneic HSCT can preserve CAR T-cell function and improve tumor control is unclear. METHODS: We tested a novel "all-in-one" strategy consisting of sequential CD7 CAR T-cell therapy and haploidentical HSCT in 10 patients with relapsed or refractory CD7-positive leukemia or lymphoma. After CAR T-cell therapy led to complete remission with incomplete hematologic recovery, patients received haploidentical HSCT without pharmacologic myeloablation or GVHD prophylaxis drugs. Toxic effects and efficacy were closely monitored. RESULTS: After CAR T-cell therapy, all 10 patients had complete remission with incomplete hematologic recovery and grade 4 pancytopenia. After haploidentical HSCT, 1 patient died on day 13 of septic shock and encephalitis, 8 patients had full donor chimerism, and 1 patient had autologous hematopoiesis. Three patients had grade 2 HSCT-associated acute GVHD. The median follow-up was 15.1 months (range, 3.1 to 24.0) after CAR T-cell therapy. Six patients remained in minimal residual disease-negative complete remission, 2 had a relapse of CD7-negative leukemia, and 1 died of septic shock at 3.7 months. The estimated 1-year overall survival was 68% (95% confidence interval [CI], 43 to 100), and the estimated 1-year disease-free survival was 54% (95% CI, 29 to 100). CONCLUSIONS: Our findings suggest that sequential CD7 CAR T-cell therapy and haploidentical HSCT is safe and effective, with remission and serious but reversible adverse events. This strategy offers a feasible approach for patients with CD7-positive tumors who are ineligible for conventional allogeneic HSCT. (Funded by the National Natural Science Foundation of China and the Key Project of Science and Technology Department of Zhejiang Province; ClinicalTrials.gov numbers, NCT04599556 and NCT04538599.).

Relapsed/Refractory Peripheral T-Cell Lymphoma-Associated Hemophagocytic Lymphohistiocytosis With UNC13D and CD27 Germline Mutations.

Hemophagocytic lymphohistiocytosis (HLH) is a severe hyperinflammatory disease characterized by familial and acquired forms. Here, we present the case of a 26-year-old male patient with relapsed/refractory peripheral T-cell lymphoma and concurrent HLH. Whole-exon sequencing revealed germline mutations associated with HLH, including those in critical genes such as CD27 and UNC13D and other germline heterozygous variants (NOTCH2, NOTCH3, IL2RA, TYK2, AGL, CFD, and F13A1). CD107a analyses consistently demonstrated impaired degranulation of cytotoxic T-lymphocytes and natural killer (NK) cells. Examination of the patient's family pedigree revealed that his father and mother harbored UNC13D and CD27 mutations, respectively; his brother carried the same CD27 heterozygous mutation. However, none of them manifested the disease. Despite the missense mutation of CD27 (c.779C>T; p.Pro260Leu) lacking previous documentation in databases, comprehensive analysis suggested non-pathogenic mutations in the CD27 variant, indicating minimal impact on T- and NK-cell functions. These results ultimately supported the option of hematopoietic stem cell transplantation (HSCT) as a successful curative therapeutic approach. As of this report, the patient has remained free of lymphoma and quiescent HLH 15.2 months post-HSCT. This study underscores the efficacy of genetic tests in identifying significant mutations and confirming their etiologies, providing an early basis for treatment decisions and the selection of suitable transplant donors.

Donor-derived stem cell infusion for sustained pancytopenia after CD19 CAR-T therapy for relapsed patients post allogeneic stem cell transplantation.

OBJECTIVES: To investigate the effectiveness of donor-derived chimeric antigen receptor T (CAR-T) cells in the treatment of relapsed cases after allogeneic hematopoietic stem cell transplantation (allo-HSCT), and whether donor-derived peripheral blood stem cells (PBSCs) have a therapeutic effect on pancytopenia after CAR-T cell therapy. METHODS: We analyzed data from five adults with B-cell acute lymphoblastic leukemia (ALL) who had relapse after allo-HSCT and received donor-derived CAR-T cell therapy and donor-derived PBSCs to promote hematopoietic recovery. RESULTS: All patients had negative minimal residual disease after CAR-T therapy, grade 1-2 cytokine release syndrome, and developed grade 4 hematologic toxicity. During the pancytopenia stage after CAR-T cell therapy, donor-derived PBSCs were transfused without graft-versus-host disease (GVHD) prophylaxis. Four patients had grade I-II acute GVHD (aGVHD). After corticosteroid treatment, aGVHD resolved and hematopoiesis was restored. Although steroids in combination with etanercept and ruxolitinib relieved symptoms in one patient with grade IV aGVHD, complete hematopoietic recovery was not achieved, and the patient died due to severe infection. CONCLUSIONS: Donor-derived CAR-T cell therapy is safe and effective in patients with relapsed/refractory ALL after allo-HSCT. Donor-derived PBSCs infusion could achieve hematopoietic recovery with controllable aGVHD in patients with persistent pancytopenia.

Cytokine profiles are associated with prolonged hematologic toxicities after B-cell maturation antigen targeted chimeric antigen receptor-T-cell therapy.

BACKGROUND AIMS: The considerable efficacy of B-cell maturation antigen-targeted chimeric antigen receptor (CAR)-T-cell therapy has been extensively demonstrated in the treatment of relapsed or refractory multiple myeloma. Nevertheless, in clinical practice, prolonged hematologic toxicity (PHT) extends hospital stay and impairs long-term survival. METHODS: This retrospective study reviewed 99 patients with relapsed or refractory multiple myeloma who underwent B-cell maturation antigen CAR-T-cell therapy at our institution between April 2018 and September 2021 (ChiCTR1800017404). RESULTS: Among 93 evaluable patients, the incidence of prolonged hematologic toxicities was high after CAR-T-cell infusion, including 38.71% (36/93) of patients with prolonged neutropenia, 22.58% (21/93) with prolonged anemia and 59.14% (55/93) with prolonged thrombocytopenia. In addition, 9.68% (9/93) of patients experienced prolonged pancytopenia. Our multivariate analyses identified that cytokine profiles were independent risk factors for PHTs, whereas a sufficient baseline hematopoietic function and high CD4/CD8 ratio of CAR-T cells were protective factors for PHTs after CAR-T-cell infusion. Subgroup analyses found that the kinetics of post-CAR-T hematologic parameters were primarily determined by the collective effects of cytokine release syndrome and baseline hematopoietic functions, and showed influential weights for the three lineages. CONCLUSIONS: Our findings improve the understanding of the impact of cytokines on hematopoietic functions, which could contribute to the mechanism investigation and exploration of potential intervention strategies.

Comparable outcomes in patients with B-cell acute lymphoblastic leukemia receiving haploidentical hematopoietic stem cell transplantation: Pretransplant minimal residual disease-negative complete remission following chimeric antigen receptor T-cell therapy versus chemotherapy.

Introduction: Chimeric antigen receptor (CAR) T-cell (CAR-T) therapy followed by haploidentical hematopoietic stem cell transplantation (haplo-HSCT) markedly improves the long-term survival of patients with refractory/relapsed (R/R) B-cell acute lymphoblastic leukemia (B-ALL). Methods: We performed a parallel comparison of transplant outcomes in 168 B-ALL patients undergoing haplo-HSCT after achieving minimal residual disease (MRD)-negative complete remission (CR) from CAR-T therapy (n = 28) or chemotherapy (n = 140) between January 2016 and August 2021. We further divided the chemotherapy group into the first CR group (chemo+CR1, n = 118) and a second or more CR group (chemo+≥CR2, n = 22). Results: With a median follow-up period of 31.0 months, the 2-year overall survival (OS), leukemia-free survival (LFS), non-relapse mortality (NRM), and relapse rates in the CAR-T and chemotherapy groups did not differ significantly (OS, 87.9% vs. 71.5 %; LFS, 72.0% vs. 66.8%; NRM, 3.9% vs. 13.7%; relapse, 24.1% vs. 19.4%). Multivariate analysis confirmed that ≥CR2 at transplantation following chemotherapy was an independent risk factor associated with poor OS (hazard ratio (HR) 4.22 [95% CI, 1.34-13.293], p = 0.014) and LFS (HR 2.57 [95% CI, 1.041-6.343], p = 0.041). The probabilities of OS and LFS at 2 years in the CAR-T group were comparable to those in the chemo+CR1 group but significantly higher than those in the chemo+≥CR2 group (OS, 87.9% vs. 37.8%, p = 0.007; LFS, 72.0% vs. 41.7%, p = 0.043). No significant differences in the incidences of NRM were noted among the three groups. Conclusions: Our results demonstrated that patients with R/R B-ALL receiving haplo-HSCT after CAR-T therapy achieved comparable outcomes to patients transplanted post-chemotherapy-based MRD-negative CR1, without increased risk of transplant-related mortality and toxicity.

CAR-T cell therapy-related cytokine release syndrome and therapeutic response is modulated by the gut microbiome in hematologic malignancies.

Immunotherapy utilizing chimeric antigen receptor T cell (CAR-T) therapy holds promise for hematologic malignancies, however, response rates and associated immune-related adverse effects widely vary among patients. Here we show, by comparing diversity and composition of the gut microbiome during different CAR-T therapeutic phases in the clinical trial ChiCTR1800017404, that the gut flora characteristically differs among patients and according to treatment stages, and might also reflect patient response to therapy in relapsed/refractory multiple myeloma (MM; n = 43), acute lympholastic leukemia (ALL; n = 23) and non-Hodgkin lymphoma (NHL; n = 12). We observe significant temporal differences in diversity and abundance of Bifidobacterium, Prevotella, Sutterella, and Collinsella between MM patients in complete remission (n = 24) and those in partial remission (n = 11). Furthermore, we find that patients with severe cytokine release syndrome present with higher abundance of Bifidobacterium, Leuconostoc, Stenotrophomonas, and Staphylococcus, which is reproducible in an independent cohort of 38 MM patients. This study has important implications for understanding the biological role of the microbiome in CAR-T treatment responsiveness of hematologic malignancy patients, and may guide therapeutic intervention to increase efficacy. The success rate of CAR-T cell therapy is high in blood cancers, yet individual patient characteristics might reduce therapeutic benefit. Here we show that therapeutic response in MM, ALL and NHL, and occurrence of severe cytokine release syndrome in multiple myeloma are associated with specific gut microbiome alterations.

Efficacy and safety of CD19 CAR-T cell therapy for patients with B cell acute lymphoblastic leukemia involving extramedullary relapse.

OBJECTIVE: To evaluate the efficacy and safety of CD19 chimeric antigen receptor (CAR) T cell therapy for patients with B cell acute lymphoblastic leukemia (B-ALL) involving extramedullary relapse. METHODS: Fifteen patients with B-ALL involving extramedullary relapse who received CD19 CAR-T cell therapy in the First Affiliated Hospital, Zhejiang University School of Medicine from January 2016 to October 2021 were enrolled in this study. The overall survival and leukemia-free survival of patients were analyzed using Kaplan-Meier curves, and the response of extramedullary lesions in different locations following the CD19 CAR-T cell therapy was observed. Cytokine release syndrome (CRS), hematological toxicity, and immune effector cell-associated neurotoxicity syndrome (ICANS) during CD19 CAR-T cell therapy were analyzed. RESULTS: The median follow-up time was 7 (3-71) months, and 11 cases (73.3%) achieved complete response, median duration of complete response was 6 (2-27) months; 3 cases (20.0%) achieved partial response; 1 case (6.7%) got progressive disease. The overall response rate was 93.3% (14/15), and the overall survival rate was 80.0% (12/15) at the end of follow-up. The cumulative incidence of relapse was 40.0% (6/15) and relapse mortality rate was 20.0% (3/15). Until last follow-up date, 9 cases (60.0%) were still in disease-free survival. Among the 15 patients, 13 cases (86.7%) developed cytokine release syndrome (CRS) after cell infusion, including 7 cases with grade 1-2 CRS, 6 cases with grade 3 CRS; 1 case suffered from reversible ICANS; 15 cases (100.0%) developed B cell dysplasia; 12 cases (80.0%) developed severe hematologic adverse reactions; 2 cases (13.3%) had abnormal liver function; 1 case (6.7%) had abnormal renal function; 4 cases (26.7%) developed infection. The adverse reactions mentioned above were well controlled. CONCLUSION: CD19 CAR-T cell therapy shows explicit efficacy and controllable adverse reactions for B-ALL patients with extramedullary relapse.

Genetically modified CD7-targeting allogeneic CAR-T cell therapy with enhanced efficacy for relapsed/refractory CD7-positive hematological malignancies: a phase I clinical study.

Chimeric antigen receptor (CAR)-T cell therapy against T cell malignancies faces major challenges including fratricide between CAR-T cells and product contamination from the blasts. Allogeneic CAR-T cells, generated from healthy donor T cells, can provide ready-to-use, blast-free therapeutic products, but their application could be complicated by graft-versus-host disease (GvHD) and host rejection. Here we developed healthy donor-derived, CD7-targeting CAR-T cells (RD13-01) with genetic modifications to resist fratricide, GvHD and allogeneic rejection, as well as to potentiate antitumor function. A phase I clinical trial (NCT04538599) was conducted with twelve patients recruited (eleven with T cell leukemia/lymphoma, and one with CD7-expressing acute myeloid leukemia). All patients achieved pre-set end points and eleven proceeded to efficacy evaluation. No dose-limiting toxicity, GvHD, immune effector cell-associated neurotoxicity or severe cytokine release syndrome (grade ≥ 3) were observed. 28 days post infusion, 81.8% of patients (9/11) showed objective responses and the complete response rate was 63.6% (7/11, including the patient with AML). 3 of the responding patients were bridged to allogeneic hematopoietic stem cell transplantation. With a median follow-up of 10.5 months, 4 patients remained in complete remission. Cytomegalovirus (CMV) and/or Epstein-Barr virus (EBV) reactivation was observed in several patients, and one died from EBV-associated diffuse large B-cell lymphoma (DLBCL). Expansion of CD7-negative normal T cells was detected post infusion. In summary, we present the first report of a Phase I clinical trial using healthy donor-derived CD7-targeting allogeneic CAR-T cells to treat CD7+ hematological malignancies. Our results demonstrated the encouraging safety and efficacy profiles of the RD13-01 allogeneic CAR-T cells for CD7+ tumors.

Cytomegalovirus Retinitis and Retinal Detachment following Chimeric Antigen Receptor T Cell Therapy for Relapsed/Refractory Multiple Myeloma.

Cytomegalovirus (CMV) retinitis is a rare end-organ disease of CMV infection and is a marker of severe immunosuppression, especially in human immunodeficiency virus (HIV)-positive patients. In multiple myeloma (MM) patients, CMV retinitis has been reported in the post-transplant setting, with an incidence lower than 0.2%, and in patients receiving lenalidomide. Here, we describe the first case of CMV retinitis in myeloma patients following B-cell maturation antigen (BCMA)-targeted chimeric antigen receptor T (BCMA CAR-T) cell therapy. In addition to CMV, the patient developed multiple infections including a mouth ulcer, pneumonia, and fungal enteritis. While the complete remission (CR) status of MM was maintained, he regained a visual acuity of 20/1000 after appropriate ophthalmologic treatment. This single case illustrates the potential of BCMA CAR-T therapy to induce profound humoral immunosuppression, and demonstrates an imperative need for an established standard of monitoring and prophylaxis of post-CAR-T infections.

Nutritional status alterations after chimeric antigen receptor T cell therapy in patients with hematological malignancies: a retrospective study.

PURPOSE: The influence of innovative chimeric antigen receptor T cell (CAR-T) therapy for hematological malignancies on nutritional status remains unknown. Therefore, we aim to explore the alterations of nutritional status after CAR-T cell therapy in patients with hematological malignancies. METHODS: We retrospectively collected the data of patients with acute leukemia (AL), lymphoma, and multiple myeloma (MM), who underwent CAR-T therapy at our hospital from 2018 to 2020. The serum albumin, triglyceride, and cholesterol before and 7, 14, and 21 days after CAR-T cell infusion were compared and analyzed. RESULT: A total of 117 patients were enrolled, consisting of 39 AL, 23 lymphoma, and 55 MM patients. The baseline albumin, triglyceride, and cholesterol were 37.43 ± 5.08 mg/L, 1.63 ± 0.74 mmol/L, and 3.62 ± 1.03 mmol/L, respectively. The lowest albumin level was found at 7 days after CAR-T cell infusion compared with baseline (P < 0.001), while the levels of triglyceride increased at 14 and 21 days (P < 0.001, P = 0.036). The levels of cholesterol at 7, 14, and 21 days after CAR-T cell infusion were lower than baseline (all P < 0.05). Spearman's correlation coefficient showed cytokine release syndrome grade was negatively correlated with the levels of albumin at 7 days and cholesterol at 21 days after CAR-T cell infusion (r = - 0.353, P < 0.001; r = - 0.395, P = 0.002). CONCLUSION: The alterations of different nutrition-related biochemical parameters varied after CAR-T cell therapy. The levels of albumin and total cholesterol after CAR-T cell infusion were negatively correlated with the grade of cytokine release syndrome. Specific screening and intervention for malnutrition in patients receiving CAR-T cell therapy need to be explored in further studies.

BCMA CAR-T Therapy Is Safe and Effective for Refractory/Relapsed Multiple Myeloma With Central Nervous System Involvement.

Central nervous system (CNS) involvement is a rare complication of multiple myeloma (MM) that portends an extremely poor prognosis. Although chimeric antigen receptor (CAR)-T cell therapy is considered a promising strategy for patients with MM, the role of CAR-T cell therapy in MM involving the CNS has not been fully elucidated. In this study, we retrospectively analyzed 4 cases of B-cell maturation antigen CAR-T cell therapy for patients with relapsed/refractory MM involving the CNS. Patients received a range of 2-7 lines of prior therapy, including 1 autologous hematopoietic stem cell transplant. The most common adverse event was cytokine release syndrome, which was observed in all 4 patients, including 2 with grade 1 and 2 with grade 2. No patient was complicated with immune effector cell-associated neurotoxicity syndrome. Within the follow-up (median: 257 d, range: 116-392 d), 3 of 4 patients reached complete remission (CR), and 1 patient reached partial response. At the data cutoff, 1 patient continued to remain in CR at day 220, and the patient with partial response died at day 116. The other 2 patients relapsed at 317 and 111 days with CR durations of 287 and 81 days, respectively. Our results show promising effectiveness and acceptable safety of CAR-T cell therapy for heavily pretreated patients with CNS MM.

Successful BCMA CAR-T Therapy for Multiple Myeloma With Central Nervous System Involvement Manifesting as Cauda Equina Syndrome-A Wandering Road to Remission.

Multiple myeloma (MM) with central nervous system (CNS) involvement is rare with only 1% incidence. So far, there is no standard or effective treatment for CNS MM, and the expected survival time is fewer than 6 months. Here, we report a case of MM with CNS involvement presented with cauda equina syndrome (CES) who achieved complete remission after anti-B-cell maturation antigen (BCMA) chimeric antigen receptor T (CAR-T) cell therapy (Chictr.org.cn, ChiCTR1800017404). The expansion of BCMA CAR-T cells was observed in both peripheral blood (PB) and cerebrospinal fluid (CSF). The CAR-T cells peaked at 2.4 × 106/l in CSF at day 8 and 4.1 × 109/l in PB at day 13. The peak concentration of interleukin (IL)-6 in CSF was detected 3 days earlier, and almost five times higher than that in PB. Next, morphological analysis confirmed the elimination of nucleated cells in CSF 1 month after CAR-T cell treatment from 300 cells/µl, and the patient achieved functional recovery with regressed lesion shown in PET-CT. The case demonstrated that BCMA CAR-T cells are effective and safe in this patient population.

Efficacy and Safety of Chimeric Antigen Receptor T Cells in Acute Lymphoblastic Leukemia With Post-Transplant Relapse.

Twenty patients with relapsed B-ALL after HSCT were treated with CAR T cell therapy and were evaluated for efficacy and safety. Twelve patients previously received haploidentical transplantation, while 8 patients received HLA-matched transplantation. The median relapse time was 12 months (range, 4 to 72). Thirteen patients received autologous CAR T cells, and 7 patients received allogeneic CAR T cells, which were derived from transplant donors. The median infusion dose was 2.9×106/kg (range, 0.33 to 12×106/kg). Nineteen patients were evaluated for efficacy, among which 17 patients (89.5%) achieved MRD negative. The CR rates in the HLA-matched transplantation group and haploidentical transplantation group were 100% (7/7) and 83.3% (10/12), respectively. The median follow-up time was 9.80 months (range, 2.40 to 64.97). Ten patients (50%) died of relapse, 3 patients (15%) died of infection, and 1 patient (5%) died of aGVHD. Fifteen patients (75%) developed CRS, including 3 (20%) grade 1 CRS, 6 (40%) grade 2 CRS, and 6 (40%) grade 3 CRS. Ten patients (50%) developed aGVHD, including 1 (10%) grade I aGVHD, 6 (60%) grade II aGVHD, and 3 (30%) grade III aGVHD. The log rank test showed that CAR T cell origin was correlated with aGVHD occurrence in the haploidentical transplantation group (P = 0.005). The authors' study indicated that the initial efficacy and safety of CAR T cell therapy for patients with post-transplant relapse were satisfactory. However, aGVHD was a concern in patients with a history of haploidentical transplantation occupied with allogeneic CAR T cells, which warrants clinical attention.

Risk Factors Associated with Durable Progression-Free Survival in Patients with Relapsed or Refractory Multiple Myeloma Treated with Anti-BCMA CAR T-cell Therapy.

PURPOSE: B-cell maturation antigen (BCMA) chimeric antigen receptor (CAR) T-cell therapy results in high remission rates in patients with relapsed/refractory (R/R) multiple myeloma. However, the factors associated with prognosis following CAR T-cell therapy are unknown. PATIENTS AND METHODS: Between July 1, 2018 and July 31, 2020, 61 patients with R/R multiple myeloma received anti-BCMA CAR T-cell therapy (Chictr.org number, ChiCTR1800017404). Step-wise multivariate Cox regression and competing risk analyses were conducted to identify poor prognosis-associated risk factors. RESULTS: Sixty patients (98.4%) experienced cytokine release syndrome (CRS), including 33, 23, and 4 cases of CRS grades 1 to 2, 3, and 4, respectively. The objective response rate (ORR) was 98.3%, and the complete remission (CR) rate was 70.3%. With a median follow-up period of 21.1 months, the 1-year overall survival (OS) and progression-free survival (PFS) rates were 78.0% and 50.2%, respectively. The median PFS was 12.7 months. Cox modeling revealed that poor PFS was associated with extramedullary disease [HR = 2.59, 95% confidence interval (95% CI) = 1.29-5.21, P = 0.008], light chain multiple myeloma (HR = 2.53, 95% CI = 1.03-5.97, P = 0.035), high-risk cytogenetics (HR = 2.80, 95% CI = 1.27-6.14, P = 0.01), and prior treatment with more than 3 therapeutic lines (HR = 3.14, 95% CI = 1.34-7.34, P = 0.008). Among the 41 CR cases, competing risk analyses demonstrated higher relapse predispositions in those with extramedullary disease (HR = 4.51, 95% CI = 1.86-10.9, P = 0.001), light chain multiple myeloma (HR = 4.89, 95% CI = 1.52 - 15.7, P = 0.008), or high-risk cytogenetics (HR = 5.09, 95% CI = 1.63-15.9, P = 0.005). CONCLUSIONS: Anti-BCMA CAR T-cell therapy is safe and effective for R/R multiple myeloma. For patients with high-risk factors, improvements to extend remission and more specific individualized therapies are needed.

Serial surveillance by circulating tumor DNA profiling after chimeric antigen receptor T therapy for the guidance of r/r diffuse large B cell lymphoma precise treatment.

Background: Circulating tumor DNA (ctDNA) released from tumor cells carries the tumor-associated genetic and epigenetic characteristics of cancer patients. Next-generation sequencing (NGS) facilitates the application of ctDNA profiling for identification and monitoring of minimal residual disease (MRD) in cancer, and can serve as the guidance for precise treatment. Methods: In this study, we profiled genomic alterations in the baseline, relapsed, and progressive tumor samples of eight diffuse large B cell lymphoma (DLBCL) patients (NCT03118180) after chimeric antigen receptor T (CAR-T) cell therapy. Results: The median follow-up was 41 months. 4 (50%) patients achieved complete remission (CR), 1 (12.5%) patient achieved partial remission (PR), and the other 3 (37.5%) patients showed no response. 3 of 5 patients who achieved remission relapsed within 4 months after CAR-T therapy, while the rest 2 patients remained CR for more than 3 years. Based on the positron emission tomography-computed tomography (PET-CT) scan, the current gold standard for evaluating response to therapy in lymphoma, the sensitivity and specificity of our ctDNA profiling in detecting tumor-related ctDNA mutations were 94.7% and 83.3%, respectively. The median numbers of baseline plasma ctDNA mutations in patients who remained long-term CR and patients who relapsed or became refractory to CAR-T therapy were 3 and 14.3, respectively. GNA13, SOCS1, TNFAIP3 and XPO1 mutations appeared to be associated with poor prognosis after CAR-T cell therapy. Our results also suggested that lenalidomide might relieve relapsed lymphoma with mutations in NFKBIA 202C>T (p.Q68*) and NFKBIE 433A>T (p.K145*) by targeting NF-Kappa B signaling. In addition, the inhibitor selinexor may be another choice for refractory or relapse (r/r) DLBCL patients after CAR-T cell treatment. Conclusion: Serial ctDNA monitoring is an emerging technology for the surveillance of disease status and prognosis prediction. In this work, we demonstrated the use of serial ctDNA monitoring in r/r DLBCL patients after CD19-targeted CAR-T cell therapy. Our longitudinal NGS profiling revealed the changes of ctDNA mutation in accordance with prognosis, and shed some light on exploring more targeted treatment options together with CAR-T cell therapy.

Tumor Burden Measured by 18F-FDG PET/CT in Predicting Efficacy and Adverse Effects of Chimeric Antigen Receptor T-Cell Therapy in Non-Hodgkin Lymphoma.

Chimeric antigen receptor (CAR) T-cell therapy has exhibited promising clinical outcomes in treating relapsed/refractory (R/R) B-cell hematologic malignancies. Current studies have shown a close correlation between baseline tumor burden and therapeutic response in CAR-T cell therapy. However, the roles of PET/CT metabolic parameters, such as metabolic tumor volume (MTV) and total lesion glycolysis (TLG), remain unclear in this setting. In this study, we retrospectively reviewed 41 R/R NHL patients. 18F-FDG PET/CT was used to measure the average standardized uptake value (SUVavg), MTV, and TLG of the lymphomatous lesions. These patients were divided into two groups according to the optimal cutoff values of respective PET/CT metabolic parameters. The multivariate analysis depicted that early post-therapy SUVavg (HR: 1.418, 95% CI: 1.029, 1.955; p = 0.033) and MTV (HR: 1.001, 95% CI: 1.000, 1.002; p = 0.041) were independent risk factors associated with OS and PFS, respectively. Patients with baseline SUVavg < 4.36 achieved a superior 1-year OS rate than the SUVavg ≥ 4.36 group (100.0% vs. 44.9%, p = 0.019). For the patients with lower values in early post-therapy SUVavg (<2.60) (51.1% vs. 0%, p < 0.001), MTV (<0.55 cm3) (53.6% vs. 0.0%, p = 0.001), and TLG (<1.54) (53.6% vs. 0.0%, p = 0.001), their 1-year PFS rates were higher than the compared groups. Moreover, patients with higher baseline tumor burdens were found to have significantly increased CRS incidence and cytokine levels. In conclusion, the PET/CT metabolic parameters are closely related to OS, PFS, and CRS in R/R NHL patients treated with CAR-T cells. This study may pave the way for building a comprehensive assessment system of tumor burden using 18F-FDG PET/CT, which can optimize therapeutic and supportive approaches in CAR-T cell therapy.

CD19/CD22 Dual-Targeted CAR T-cell Therapy for Relapsed/Refractory Aggressive B-cell Lymphoma: A Safety and Efficacy Study.

Chimeric antigen receptor (CAR) T-cell therapies that target either CD19 or CD22 alone have potent antilymphoma effects. However, antigen escape-mediated relapse often occurs. CAR T cells targeting both CD19 and CD22 may overcome this limitation. In this study, we developed bispecific CAR T cells simultaneously recognizing CD19- and CD22-expressing targets and assessed their safety and efficacy profiles in patients with relapsed/refractory aggressive B-cell lymphoma. Twenty-four patients were screened, and 16 were found eligible for the study. CAR T-cell-associated toxicities were recorded. Responses, overall survival (OS), and progression-free survival (PFS) were assessed. Of the 16 eligible patients, 14 (87.5%) achieved objective response and 10 (62.5%) achieved complete response (CR). The 2-year OS and PFS rates were 77.3% and 40.2%, respectively. Achieving CR (P = 0.046) and the number of prior chemotherapy lines (n = 2; P = 0.047) were independent prognostic factors associated with favorable PFS. The 2-year OS and PFS among patients who achieved CR were higher than among those who did not (P = 0.015 and P < 0.001, respectively). The 2-year PFS among patients who received two prior lines of chemotherapy was higher than that among patients who received more than two lines of chemotherapy (P = 0.049); OS did not differ between the groups. Severe grade 4 cytokine-release syndrome (CRS) was observed in 1 patient; 4 and 11 patients had grades 1 and 2 CRS, respectively. No patients developed neurotoxicity. CD19/CD22 dual-targeted CAR T cells may be a safe, potent antilymphoma cell-based targeted immunotherapy.