Dual epigenetic agents plus rituximab-gemcitabine-oxaliplatin as salvage treatment in relapsed/refractory diffuse large B-cell lymphoma patients failure of salvage chemotherapy.

Refractory/relapsed (R/R) diffuse large B-cell lymphoma (DLBCL) patients' failure of salvage chemotherapy had extremely worse prognoses. Herein, 14 R/R DLBCL patients failed to salvage chemotherapy were exposed to dual epigenetic agents (Chidamide 30 mg biw*2w and Decitabine 10 mg/m2 qd*d1-d5) and sequential R-GemOx (rituximab 375 mg/m2 qd d6; gemcitabine 1 g/m2 d7, d14; and oxaliplatin 100 mg/m2 d7) for further salvage chemotherapy. Finally, 11/14(78.6%) patients achieved overall response with 6/14(42.9%) achieving complete remission and 2-year overall survival (OS)/progression free survival (PFS) rate was 42.7%, extremely higher than reported previously. Further subgroup analysis demonstrated that 2-year OS/PFS rate was significantly higher in patients achieved complete/partial remission or with low international prognosis index (IPI 0-2) than that in patients with steady disease or high IPI (3-5). Common grade 3-4 adverse events were hematological toxicities. All toxicities were transient and reversible. Our report implicates that combination of dual epigenetic agents and R-GemOx is a safe and promising alternative for R/R DLBCL patients.

Trimeric G protein-CARMA1 axis links smoothened, the hedgehog receptor transducer, to NF-κB activation in diffuse large B-cell lymphoma.

Diffuse large B-cell lymphoma (DLBCL) is the most common lymphoid malignancy in adults. Aberrant activation of Hedgehog (Hh) and nuclear factor (NF)-κB pathways is ubiquitously observed and known to mediate tumor growth, survival, and chemoresistance in DLBCL. Here, we find that activation of Hh signaling is positively correlated with NF-κB pathway in DLBCL tumors, and that smoothened (SMO), the signal transducer subunit of Hh pathway, contributes to NF-κB activation through recruiting G protein subunits Gαi and Gα12 to activate PKCß/CARMA1/TRAF6/NEMO signaling axis followed by assembling of the CARMA1/BCL10/MALT1/TRAF6 complex to SMO. Moreover, functional inhibition of SMO enhances the cytotoxic effects of NF-κB inhibitor. Altogether, our study reveals a noncanonical Hh signaling pathway in which SMO activates trimeric G proteins and CARMA1-associated signaling complex, leading to NF-κB activation. This signaling cascade contributes to the survival of DLBCL and may serve as a potential target for combination therapies in DLBCL.

Transcriptional regulation of serine/threonine protein kinase (AKT) genes by glioma-associated oncogene homolog 1.

Aberrant activation of Hedgehog signaling has been described in a growing number of cancers, including malignant lymphomas. Here, we report that canonical Hedgehog signaling modulates the transcriptional expression of AKT genes and that AKT1 is a direct transcriptional target of GLI1. We identified two putative binding sites for GLI1 in the AKT1 promoter region and confirmed their functionality using chromatin immunoprecipitation, luciferase reporter, and site-directed mutagenesis assays. Moreover, we provide evidence that GLI1 contributes to the survival of diffuse large B-cell lymphoma (DLBCL) cells and that this effect occurs in part through promotion of the transcription of AKT genes. This finding is of interest as constitutive activation of AKT has been described in DLBCL, but causative factors that explain AKT expression in this lymphoma type are not completely known. In summary, we demonstrated the existence of a novel cross-talk at the transcriptional level between Hedgehog signaling and AKT with biological significance in DLBCL.

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.

Computer-aided diagnostic system with automated deep learning method based on the AutoGluon framework improved the diagnostic accuracy of early esophageal cancer.

Background: There have been studies on the application of computer-aided diagnosis (CAD) in the endoscopic diagnosis of early esophageal cancer (EEC), but there is still a significant gap from clinical application. We developed an endoscopic CAD system for EEC based on the AutoGluon framework, aiming to explore the feasibility of automatic deep learning (DL) in clinical application. Methods: The endoscopic pictures of normal esophagus, esophagitis, and EEC were collected from The First Affiliated Hospital of Soochow University (September 2015 to December 2021) and the Norwegian HyperKvasir database. All images of non-cancerous esophageal lesions and EEC in this study were pathologically examined. There were three tasks: task A was normal vs. lesion classification under non-magnifying endoscopy (n=932 vs. 1,092); task B was non-cancer lesion vs. EEC classification under non-magnifying endoscopy (n=594 vs. 429); and task C was non-cancer lesion vs. EEC classification under magnifying endoscopy (n=505 vs. 824). In all classification tasks, we took 100 pictures as the verification set, and the rest comprised as the training set. The CAD system was established based on the AutoGluon framework. Diagnostic performance of the model was compared with that of endoscopists grouped according to years of experience (senior >15 years; junior <5 years). Model evaluation indicators included accuracy, recall rate, precision, F1 value, interpretation time, and the area under the receiver operating characteristic (ROC) curve (AUC). Results: In tasks A and B, the accuracies of medium-performance CAD and high-performance CAD were lower than those of junior doctors and senior doctors. In task C, the medium-performance and high-performance CAD accuracies were close to those of junior doctors and senior doctors. The high-performance CAD model outperformed the junior doctors in both task A (0.850 vs. 0.830) and task C (0.840 vs. 0.830) in sensitivity comparison, but there was still a large gap between high-performance CAD models and doctors in sensitivity comparison. In task A, with the aid of CAD pre-interpretation, the accuracy of junior and senior physicians were significantly improved (from 0.880 to 0.915 and from 0.920 to 0.945, respectively); the time spent on film reading was significantly shortened (junior: from 11.3 to 8.7 s; senior: from 6.7 to 5.5 s). In task C, with the aid of CAD pre-interpretation, the accuracy of junior and senior physicians were significantly improved (from 0.850 to 0.865 and from 0.915 to 0.935, respectively); the reading time was significantly shortened (junior: from 9.5 to 7.7 s; senior: from 5.6 to 3.0 s). Conclusions: The CAD system based on the AutoGluon framework can assist doctors to improve the diagnostic accuracy and reading time of EEC under endoscopy. This study reveals that automatic DL methods are promising in clinical application.

Functional inhibition of BCL2 is needed to increase the susceptibility to apoptosis to SMO inhibitors in diffuse large B-cell lymphoma of germinal center subtype.

Previously, we have demonstrated that inhibition of Hedgehog pathway induces predominantly apoptosis in diffuse large B-cell lymphoma (DLBCL) cell lines of activated B-cell (ABC) type but predominantly cell cycle arrest in those of germinal center (GC). Here, we explored the possibility of overcoming the resistance to apoptosis to SMO inhibitors in five DLBCL cells of GC type using the combination of the SMO inhibitor HhAntag (Genentech Inc) with the BH3 mimetic ABT-737 (Abbott Laboratories). As controls we have used two DLBCL of ABC type (OCI-LY10 and OCI-LY3). Combinatorial treatments were performed with increasing concentrations of the HhAntag with low doses (equal or less than the IC20) of ABT-737. MTS assays were used to detect changes in cell viability and Annexin-V and PARP1 cleavage assays were used to detect apoptosis. Combining low doses of ABT-737 with increasing concentrations of HhAntag in GC DLBCL cell lines resulted in significantly increase of apoptosis in comparison to treatments with the SMO inhibitor alone. We concluded that in GC DLBCL cell lines, in contrast to those of ABC type, functional inhibition of BCL2 family members is usually needed to overcome the resistance to apoptosis to SMO inhibitors. These findings provide a rationale to explore the use of SMO and BCL2 inhibitors as adjuvant therapy for treatment of DLBCL of GC type.

Body mass index-associated responses to an ABVD-like regimen in newly-diagnosed patients with Hodgkin lymphoma.

Background: The role of body mass index (BMI) in the treatment outcomes of lymphoma patients is controversial. While investigating the efficacy of ABVD-like regimen in Hodgkin lymphoma (HL) patients, we observed that obese patients had poor responses. To better understand this clinical phenomenon, we evaluated the effect of BMI on responses to ABVD-like chemotherapy in HL patients. Methods: This retrospective cohort study evaluated the clinical outcomes of all 67 patients with confirmed HL who were treated at the First Affiliated Hospital of Soochow University from November 2016 to March 2023 with an ABVD-like regimen as first-line chemotherapy. Baseline patient characteristics and clinical outcomes were compared across different BMI categories. The primary end-point was the overall response rate defined as the proportion of the HL patients who achieved complete response or partial response. The additional end-points included progression-free survival and overall survival. Results: The median age of the HL patients was 31 years old. Of the patients, 10.4% were obese, and 17.9% patients were overweight. Interim and end-term response evaluations revealed overall response rates of 98.5% and 83.6%, respectively. The proportion of patients with potential poor prognostic factors (IPS risk factors) did not differ significantly in the responders versus non-responders. However, non-responders had a higher average BMI when compared with responders (p = 0.002). Poor overall response rates in higher BMI patients indeed manifested with shorter progression free survival (p = 0.013). The minimum relative dose of the ABVD-like regimen in the overweight and obese groups was significantly lower than in the normal weight group (p < 0.001). Conclusion: Our analyses show that >80% of newly-diagnosed HL patients responded to the ABVD-like regimen. We find that being obese or overweight at the time of diagnosis correlated with a poorer overall response rate and that BMI was an independent risk factor in HL patients treated with the ABVD-like regimen. Lower doses of ABVD-like regimen contributed to the discrepant findings of responses in the high BMI groups. These findings indicate that newly-diagnosed, obese HL patients receiving an ABVD-like regimen require personalized treatment.

Efficacy and safety of chimeric antigen receptor T cell therapy in relapsed/refractory diffuse large B-cell lymphoma with different HBV status: a retrospective study from a single center.

Background: Chimeric antigen receptor T cell (CAR-T) therapy is an effective salvage treatment in relapsed or refractory(r/r) diffuse large B-cell lymphoma (DLBCL), but the impact of hepatitis B virus (HBV) infection has not been studied. Methods and results: Here, 51 patients with r/r DLBCL receiving CAR-T therapy were enrolled and analyzed at the First Affiliated Hospital of Soochow University. The overall response rate and the complete remission rate (CR) of CAR-T therapy were 74.5% and 39.2%, respectively. With a median follow-up of 21.1 months after CAR-T, the probabilities of overall survival (OS) and progression-free survival (PFS) at 36 months were 43.4% and 28.7%, respectively. These patients were divided into three cohorts including chronic HBV infection group (n=6), resolved HBV infection group (n=25) and non-HBV infection group (n=20). Bone marrow involvement was significantly higher in the HBV infection group(P<0.001), other basic characteristics before CAR-T therapy were comparable. Subgroup analysis showed that HBV infection status did not affect the efficacy of CAR-T therapy in CR rate, OS or PFS, and there was no significant difference in CAR-T related toxicities between three cohorts. Only one cirrhosis patient with chronic HBV infection experienced HBV reactivation. Conclusions: CAR-T therapy was effective and can be used safely in r/r DLBCL with HBV infection under proper monitoring and antiviral prophylaxis.

Long-term Complete Remission of Decitabine-Primed Tandem CD19/CD22 CAR-T Therapy with PD-1 and BTK Inhibitors Maintenance in a Refractory Primary Central Nervous System Lymphoma Patient.

Primary central nervous system lymphoma (PCNSL) is a rare and aggressive non-Hodgkin's lymphoma that affects the brain, eyes, cerebrospinal fluid, or spinal cord without systemic involvement. The outcome of patients with PCNSL is worse compared to patients with systemic diffuse large B-cell lymphoma. Given potential mortality associated with severe immune effector cell-associated neurotoxicity syndrome (ICANS), patients with PCNSL have been excluded from most clinical trials involving chimeric antigen receptor T-cell (CAR-T) therapy initially. Here, we report for the first time to apply decitabine-primed tandem CD19/CD22 dual-targeted CAR-T therapy with programmed cell death-1 (PD-1) and Bruton's tyrosine kinase (BTK) inhibitors maintenance in one patient with multiline-resistant refractory PCNSL and the patient has maintained complete remission (CR) for a 35-month follow-up period. This case represents the first successful treatment of multiline resistant refractory PCNSL with long-term CR and without inducing ICANS under tandem CD19/CD22 bispecific CAR-T therapy followed by maintenance therapy with PD-1 and BTK inhibitors. This study shows tremendous potential in the treatment of PCNSL and offers a look toward ongoing clinical studies.

Circulating tumor DNA determining hyperprogressive disease after CAR-T therapy alarms in DLBCL: a case report and literature review.

Chimeric antigen receptor T-cell therapy (CAR-T) has been widely applied in the clinical practice of relapse/refractory (R/R) diffuse large B-cell lymphoma (DLBCL) due to its promising effects. Hyperprogressive disease (HPD) has gained attention for rapid tumor progression and has become a therapeutic and prognostic challenge. Here, we present a patient who had suffered from several recurrences previously and controlled well with a very small tumor lesion left was infused with CD19/CD22 bispecific CAR-T, with no immune effector cell-associated neurotoxicity syndrome, or cytokine release syndrome observed. However, rapid deterioration, subsequent imaging examination, circulating tumor DNA, and serum biomarkers detection identified HPD. The patient did not respond to salvage treatment and died 40 days after infusion. To our knowledge, only one case of HPD in DLBCL after CAR-T therapy has been reported. This fatal case alarmed the risk of HPD and the ctDNA profile monitoring we used was performed as a non-invasive method to diagnose HPD, providing far-reaching practical instruction for CAR-T therapy.

Overall survival benefits provided by lenalidomide maintenance after chimeric antigen receptor T cell therapy in patients with refractory/relapsed diffuse large B-cell lymphoma.

Background: Chimeric antigen receptor T cell (CAR-T) therapy has achieved remarkable effects in refractory/relapsed (R/R) diffuse large B-cell lymphoma (DLBCL). However, many patients receiving CAR-T therapy still eventually die of disease recurrence or progression due to target antigen loss or exhaustion of CAR-T cells. Therefore, maintaining the efficacy of CAR-T has become a particular research focus. As lenalidomide can regulate T cell function, we conducted a study to evaluate the efficacy of lenalidomide maintenance after CAR-T therapy in R/R DLBCL patients. Methods: Seven R/R DLBCL patients who received lenalidomide maintenance after CAR-T therapy and nine DLBCL patients that underwent CAR-T treatment alone were included. The clinical data of all subjects were collected to evaluate the efficacy of lenalidomide maintenance. In order to understand the possible mechanisms of lenalidomide in CAR-T therapy, CAR-T copies of peripheral blood were regularly detected by quantitative real-time polymerase chain reaction, and an in vitro test was also conducted. Results: Overall survival (OS) was significantly prolonged in the lenalidomide maintenance group. Furthermore, one case responding to CAR-T therapy initially but suffering a relapse shortly achieved complete remission again after lenalidomide exposure, with an increase in the number of CAR-T copies detected. The in vitro test showed that lenalidomide could delay the exhaustion of CAR-T cells. Conclusions: Lenalidomide maintenance after CAR-T therapy is a safe and effective choice for R/R DLBCL patients. We confirmed that lenalidomide maintenance can improve patients' OS, and the delayed exhaustion of CAR-T cells may contribute to this OS benefit.

Efficacy and toxicity of SEAM (semustine, etoposide, cytarabine, and melphalan) conditioning regimen followed by autologous stem cell transplantation in lymphoma.

OBJECTIVES: The aim of this retrospective study was to evaluate the safety and efficacy of SEAM regimen followed by auto-SCT in lymphoma. PATIENTS AND METHODS: We retrospectively reviewed the records of patients with lymphoma who underwent auto-SCT with SEAM conditioning regimen from January 2010 to June 2018 at our centre. In total, 97 patients were analysed. RESULTS: The median time to neutrophil engraftment and platelet engraftment was 9.5 days (range, 7-15 days) and 12 days (range, 7-25 days), respectively. Grade 3-4 nausea/vomiting, mucositis and diarrhoea were observed in 21.6%, 36.1%, and 11.3% of patients, respectively. Treatment-related mortality at 100 days occurred in 2 patients (2.1%). After a median follow-up time of 53.9 months, the 3-year incidence of disease relapse or progression was 34%. The estimated progression-free survival and overall survival at 3 years were 62% and 75%, respectively. Compared with previous studies using BEAM as the conditioning regimen, this study shows that the SEAM regimen has a comparable efficacy and safety profile. CONCLUSIONS: The SEAM regimen is feasible and might be an ideal alternative to BEAM regimen for lymphoma auto-SCT.

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.

Successful application of PD-1 knockdown CLL-1 CAR-T therapy in two AML patients with post-transplant relapse and failure of anti-CD38 CAR-T cell treatment.

Patients with relapsed/refractory acute myeloid leukemia (R/R AML) often show resistance to chemotherapy and have dismal outcomes. Therefore, it is urgent to develop new treatment strategies to address this problem. With tremendous achievement of chimeric antigen receptor T cells (CAR-T) therapy against B-cell malignancies, many efforts have been devoted to developing CAR-T therapy for R/R AML but with limited success, in part owing to a lack of specific targets. C-type lectin-like molecule-1 (CLL-1) is highly expressed on AML blasts with no expression on normal hematopoietic stem cells, which makes it an ideal target of immunotherapy for AML. Here, we report 2 R/R AML patients who relapsed after allogeneic stem cell transplantation and failed multiline salvage therapies including anti-CD38 CAR-T therapy, but were successfully treated with PD-1 silenced anti-CLL-1 CAR-T therapy. Both patients achieved molecular complete remission with incomplete hematologic recovery at 28 days of evaluation after CLL-1 CAR-T cell infusion. Cytokine release syndrome in cases 1 and 2 were grade 1 and 2, respectively. At the last follow-up, cases 1 and 2 had maintained continuous remission for 8 and 3 months, respectively. Our results demonstrated that CLL-1 CAR-T cells might be an effective and safe salvage therapy for AML patients with posttransplant relapse.

Chimeric antigen receptors containing the OX40 signalling domain enhance the persistence of T cells even under repeated stimulation with multiple myeloma target cells.

Persistence of CAR-T cell function is associated with relapse rate after CAR-T therapy, while co-stimulatory agents are highly concerned with the persistence of CAR-T cells. In this study, we designed and constructed a series of BCMA-targeting second-generation CAR constructs containing CD28, 41BB, and OX40 molecules, respectively, to identify the costimulatory domains most favorable for persistence. The results of routine in vitro studies showed that OX40-CAR-T and 41BB-CAR-T had similar antitumor effects and were superior to CD28-CAR-T in terms of proliferation and cytotoxicity. Although difficult to distinguish by conventional functional assays, OX40-CAR-T cells exhibited greater proliferation and enhanced immune memory than 41BB-CAR-T cells with the repeated stimulation assay by BCMA-expressing target cells. In vivo studies further demonstrated that OX40-CAR-T cells had stronger proliferative activity than 41BB-CAR-T cells, which was highly consistent with the in vitro antitumor activity and proliferation results. Our study provides for the first time a scientific basis for designing OX40-CAR-T cell therapy to improve relapse in patients with MM after CAR-T treatment.

Multiple blood parameters may serve as a warning to immunochemotherapy-related interstitial lung disease in B-cell lymphoma.

BACKGROUND: The main aim of this study was to determine some simple but meaningful parameters that indicate immunochemotherapy-related interstitial lung disease (ILD) early in B-cell lymphoma and provide direction to hematologists. METHODS: The clinical and laboratory characteristics, the treatments and outcomes of 21 B-cell lymphoma patients with ILD who underwent rituximab (RTX) -based immunochemotherapy were collected and retrospectively analyzed. RESULTS: More cycles of immunochemotherapy and higher cumulative doses of RTX and doxorubicin hydrochloride liposome conferred a high risk of ILD. Compared to the baseline, patients had a significantly lower white blood cell count (WBC), absolute lymphocyte count (ALC), and albumin level (4.95×109 vs. 6.32×109, 0.71×109 vs. 1.61×109, 34.1 vs. 40.4 g/L; P<0.05), and higher C-reactive protein (CRP), alpha-hydroxybutyrate dehydrogenase (α-HBDH), and lactate dehydrogenase (LDH) (15.36 vs. 7.00 mg/L, 293.0 vs. 163.1 U/L, 361.8 vs. 231.1 U/L; P<0.05) levels at ILD onset. Further, a positive correlation was found between early glucocorticosteroid intervention and the good prognostication of ILD. In addition, an analysis of the prognoses of 2 cases of patients with pneumocystis pneumonia (PCP) infection indicated that after 3 cycles of treatment, patients, especially unfit patients or those who have received ILD glucocorticoid treatment, may need to receive trimethoprim/sulfamethoxazole (TMP/SMX) to prevent PCP. CONCLUSIONS: There was a relationship between variations of blood parameters and the occurrence of ILD which might serve as a warning for B-cell lymphoma patients with immunochemotherapy-related ILD.

Low-dose decitabine as part of a modified Bu-Cy conditioning regimen improves survival in AML patients with active disease undergoing allogeneic hematopoietic stem cell transplantation.

Relapse is the major cause of mortality in patients with acute myeloid leukemia (AML) after allogeneic hematopoietic stem cell transplantation (allo-HSCT). Effective preventive intervention in high-risk AML may be crucial. In this study, we investigated the clinical efficacy and safety of low dose decitabine (DAC) as part of a modified Busulfan-Cyclophosphamide (Bu-Cy) regimen for high-risk AML patients undergoing allo-HSCT to reduce relapse rate. Fifty-nine patients received DAC (20 mg/m2/d, i.v.) for 5 days, followed by modified Bu-Cy (DAC group). A matched-pair control (CON) group of 177 patients (matched 1:3) received modified Bu-Cy only. The differences were more substantial among patients with active disease: 2-year OS, 80.7% (DAC) versus 43.5% (CON), P = 0.011 and 2-year LFS, 64.9% (DAC) versus 39.2% (CON), P = 0.024. Median time to relapse was 8 months (DAC) versus 5 months (CON) for the entire groups and 6.5 months (DAC) versus 3.5 months (CON) for patients with active disease. In summary, our data indicated that the conditioning regimen containing low dose DAC may confer a survival advantage in high-risk AML patients with active disease undergoing allo-HSCT, and a prospective randomized trial is warranted to confirm these observations.

CD38-directed CAR-T cell therapy: a novel immunotherapy strategy for relapsed acute myeloid leukemia after allogeneic hematopoietic stem cell transplantation.

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is a potentially curative treatment for acute myeloid leukemia (AML). However, most patients experience relapse after allo-HSCT, with a poor prognosis, and treatment options are limited. The lack of an ideal targetable antigen is a major obstacle for treating patients with relapsed AML. CD38 is known to be expressed on most AML and myeloma cells, and its lack of expression on hematopoietic stem cells (HSCs) renders it a potential therapeutic target for relapsed AML. To investigate the clinical therapeutic efficacy and safety of CD38-targeted chimeric antigen receptor T (CAR-T-38) cells, we enrolled 6 AML patients who experienced relapse post-allo-HSCT (clinicaltrials.gov: NCT04351022). Prior to CAR-T-38 treatment, the blasts in the bone marrow of these patients exhibited a median of 95% (92-99%) CD38 positivity. Four weeks after the initial infusion of CAR-T-38 cells, four of six (66.7%) patients achieved complete remission (CR) or CR with incomplete count recovery (CRi); the median CR or CRi time was 191 (range 117-261) days. The cumulative relapse rate at 6 months was 50%. The median overall survival (OS) and leukemia-free survival (LFS) times were 7.9 and 6.4 months, respectively. One case relapsed 117 days after the first CAR-T-38 cell infusion, with remission achieved after the second CAR-T-38 cell infusion. All six patients experienced clinically manageable side effects. In addition, multiparameter flow cytometry (FCM) revealed that CAR-T-38 cells eliminated CD38 positive blasts without off-target effects on monocytes and lymphocytes. Although this prospective study has a limited number of cases and a relatively short follow-up time, our preliminary data highlight the clinical utility and safety of CAR-T-38 cell therapy in treating relapsed AML post-allo-HSCT.