Efficacy of programmed cell death 1 inhibitor maintenance after chimeric antigen receptor T cells in patients with relapsed/refractory B-cell non-Hodgkin-lymphoma.

INTRODUCTION: Chimeric antigen receptor (CAR)-T cells obtained long-term durability in about 30% to 40% of relapsed/refractory (r/r) B-cell non-Hodgkin lymphoma (B-NHL). Maintenance therapy after CAR-T is necessary, and PD1 inhibitor is one of the important maintenance therapy options. METHODS: A total of 173 r/r B-NHL patients treated with PD1 inhibitor maintenance following CD19/22 CAR-T therapy alone or combined with autologous hematopoietic stem cell transplantation (ASCT) from March 2019 to July 2022 were assessed for eligibility for two trials. There were 81 patients on PD1 inhibitor maintenance therapy. RESULTS: In the CD19/22 CAR-T therapy trial, the PD1 inhibitor maintenance group indicated superior objective response rate (ORR) (82.9% vs 60%; P = 0.04) and 2-year progression-free survival (PFS) (59.8% vs 21.3%; P = 0.001) than the non-maintenance group. The estimated 2-year overall survival (OS) was comparable in the two groups (60.1% vs 45.1%; P = 0.112). No difference was observed in the peak expansion levels of CD19 CAR-T and CD22 CAR-T between the two groups. The persistence time of CD19 and CD22 CAR-T in the PD1 inhibitor maintenance group was longer than that in the non-maintenance group. In the CD19/22 CAR-T therapy combined with ASCT trial, no significant differences in ORR (81.4% vs 84.8%; P = 0.67), 2-year PFS (72.3% vs 74.9%; P = 0.73), and 2-year OS (84.1% vs 80.7%; P = 0.79) were observed between non-maintenance and PD1 inhibitor maintenance therapy groups. The peak expansion levels and duration of CD19 and CD22 CAR-T were not statistically different between the two groups. During maintenance treatment with PD1 inhibitor, all adverse events were manageable. In the multivariable analyses, type and R3m were independent predictive factors influencing the OS of r/r B-NHL with PD1 inhibitor maintenance after CAR-T therapy. CONCLUSION: PD1 inhibitor maintenance following CD19/22 CAR-T therapy obtained superior response and survival in r/r B-NHL, but not in the trial of CD19/22 CAR-T cell therapy combined with ASCT.

High-multiplex single-cell imaging analysis reveals tumor immune contexture associated with clinical outcomes after CAR T cell therapy.

Chimeric antigen receptor (CAR) T cell therapy has made great progress in treating lymphoma, yet patient outcomes still vary greatly. The lymphoma microenvironment may be an important factor in the efficacy of CAR T therapy. In this study, we designed a highly multiplexed imaging mass cytometry (IMC) panel to simultaneously quantify 31 biomarkers from 13 patients with relapsed/refractory diffuse large B cell lymphoma (DLBCL) who received CAR19/22 T cell therapy. A total of 20 sections were sampled before CAR T cell infusion or after infusion when relapse occurred. A total of 35 cell clusters were identified, annotated, and subsequently redefined into 10 metaclusters. The CD4+ T cell fraction was positively associated with remission duration. Significantly higher Ki67, CD57, and TIM3 levels and lower CD69 levels in T cells, especially the CD8+/CD4+ Tem and Te cell subsets, were seen in patients with poor outcomes. Cellular neighborhood containing more immune cells was associated with longer remission. Fibroblasts and vascular endothelial cells resided much closer to tumor cells in patients with poor response and short remission after CAR T therapy. Our work comprehensively and systematically dissects the relationship between cell composition, state, and spatial arrangement in the DLBCL microenvironment and the outcomes of CAR T cell therapy, which is beneficial to predict CAR T therapy efficacy.

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.

Hemophagocytic lymphohistiocytosis with a hemizygous PRF1 c.674G>A mutation.

Hemophagocytic lymphohistiocytosis(HLH) is a rare highly-fatal disease presenting with fever, hepatosplenomegaly, and pancytopenia and has a poor prognosis. Homozygous or semi-zygous or complex heterozygous variants can cause familial HLH and heterozygous carriers are frequently seen in secondary HLH. A 42-year-old male patient was admitted to the hospital for persistent fever, fatigue, and splenomegaly. Investigations revealed hypertriglyceridemia, hyperlactatemia dehydrogenaseemia, hyperferritinemia, and elevated levels of soluble cluster of differentiation 25. We found a heterozygous mutation of PRF1: c.674G>A (p.R225Q) through next-generation sequencing technology of hemophagocytic-lymphohistiocytosis-related genes. After a brief remission with dexamethasone and etoposide-based therapy, the disease relapsed quickly, and an allogeneic hematopoietic stem cell transplant was performed to achieve complete remission. To date, the patient's condition was in complete remission. Our study detected a rare missense mutation in the PRF1 gene in a patient with HLH disease and the c.674G>A mutation may be rated as a possible pathogenic variant.

MiR-376a-3p increases cell apoptosis in acute myeloid leukemia by targeting MT1X.

Metallothioneins (MTs) are a group of low-molecular weight cysteine-rich proteins that play vital roles in oxidative stress, metal homeostasis, carcinogenesis and drug resistance. However, few studies have analyzed the roles of MTs in acute myeloid leukemia (AML). In this study, we revealed that the expression of metallothionein1X (MT1X), a main isoform of MTs, was highly expressed and acted as a candidate of prognostic indicator in AML patients. In vitro cell function experiments verified that silencing MT1X inhibited the proliferation of AML cells, sensitized cells to doxorubicin, and increased their apoptosis. We also showed that the downregulation of MT1X expression suppressed nuclear factor-κB (NF-κB) signaling by reducing p65, p-IκB-α, and downstream effectors. Elevated p65 and MT1X levels were indicators in AML. Moreover, we revealed that miR-376a-3p had binding sites with 3'-UTR of MT1X, suggesting that MT1X was negatively regulated by miR-376a-3p. Cell functional assay results indicated that miR-376a-3p overexpression significantly inhibited the proliferation, arrested the AML cells in the G0/G1 phase and induced cell apoptosis. The rescue experiments further confirmed that miR-376a-3p could reverse the promotion of MT1X overexpression on the progress of AML cells. Taken together, our results revealed that elevated MT1X expression might be involved in the mechanism underlying AML progression, indicating that the miR-376a/MT1X axis might serve as a promising novel target for the effective treatment of patients with AML.

Expression pattern of human SERPINE2 in a variety of human tumors.

Serine proteinase inhibitor, clade E member 2 (SERPINE2), also known as protease nexin-1 (PN-1), is a member of the serpin family. Despite several reported roles of SERPINE2 in tumor development the histological distribution of SERPINE2 and its expression levels in a large variety of tumors remains unclear. Through expressed sequence tag database analysis, immunohistochemical staining of tissue microarrays and a literature review, it was revealed that SERPINE2 expression varied according to growth stages and tissue types. SERPINE2 is differentially expressed in a number of tumors and their normal tissue counterparts. SERPINE2 is identified most abundantly in adenocarcinomas. SERPINE2 serves diverse roles in a variety of tumors and therefore may serve as a promising biomarker for tumor diagnosis and prognosis.

Protease nexin 1 induces apoptosis of prostate tumor cells through inhibition of X-chromosome-linked inhibitor of apoptosis protein.

Protease nexin 1 (PN1) is an endogenous serine protease inhibitor (SERPIN), expressed at high levels in the prostate, and capable of inhibiting the proliferation of prostate cancer cells. We previously showed that PN1-uPA complexes inhibited Sonic Hedgehog (SHH) signalling through engagement of the LRP receptor. Here, we describe an alternative anti-proliferative mechanism through which PN1 expression leads to apoptosis. In prostate cancer cells, increased expression of PN1 led to substantial reduction of XIAP levels and apoptosis mediated through the uPAR, but not the LRP receptor. The alterations in XIAP were effected in two ways 1) via alteration in the NF-κB pathway, a pathway known to signal XIAP transcription and 2) by promoting XIAP instability. The AKT pathway is known to phosphorylate XIAP at serine 87 leading to protein stability and PN1 expression is shown to interfere with this process. As a result of both mechanisms, programmed cell death is substantially increased. Consistent with these observations, reduced PN1 protein correlated with elevated p65/XIAP expression and with higher Gleason scores in human prostate tissue arrays. Thus, PN1 expression appears to differentially down-regulate distinct oncogenic pathways depending upon the cell surface receptor engaged by its complexes and demonstrates a novel molecular mechanism by which the protein can promote tumor cell apoptosis.