The ATR inhibitor elimusertib exhibits anti-lymphoma activity and synergizes with the PI3K inhibitor copanlisib.

The DNA damage response (DDR) is the cellular process of preserving an intact genome and is often deregulated in lymphoma cells. The ataxia telangiectasia and Rad3-related (ATR) kinase is a crucial factor of DDR in the response to DNA single-strand breaks. ATR inhibitors are agents that have shown considerable clinical potential in this context. We characterized the activity of the ATR inhibitor elimusertib (BAY 1895344) in a large panel of lymphoma cell lines. Furthermore, we evaluated its activity combined with the clinically approved PI3K inhibitor copanlisib in vitro and in vivo. Elimusertib exhibits potent anti-tumour activity across various lymphoma subtypes, which is associated with the expression of genes related to replication stress, cell cycle regulation and, as also sustained by CRISPR Cas9 experiments, CDKN2A loss. In several tumour models, elimusertib demonstrated widespread anti-tumour activity stronger than ceralasertib, another ATR inhibitor. This activity is present in both DDR-proficient and DDR-deficient lymphoma models. Furthermore, a combination of ATR and PI3K inhibition by treatment with elimusertib and copanlisib has in vitro and in vivo anti-tumour activity, providing a potential new treatment option for lymphoma patients.

Extracellular Vesicle - MDM2-DNA as a Potential Liquid Biopsy Biomarker for Disease Identification in Retroperitoneal Liposarcoma.

OBJECTIVE: We aimed to assess the levels of MDM2-DNA within extracellular vesicles (EVs) isolated from the serum of retroperitoneal liposarcoma (RLS) patients versus healthy donors, as well as within the same patients at the time of surgery versus post-operative surveillance visits. To determine whether EV-MDM2 may serve as a possible first-ever biomarker of liposarcoma recurrence. BACKGROUND: A hallmark of well-differentiated and de-differentiated (WD/DD) retroperitoneal liposarcoma is elevated MDM2 due to genome amplification, with recurrence rates of >50% even after complete resection. Imaging technologies frequently cannot resolve recurrent WD/DD-RLS versus postoperative scarring. Early detection of recurrent lesions, for which biomarkers are lacking, would guide surveillance and treatment decisions. METHODS: WD/DD-RLS serum samples were collected both at the time of surgery and during follow-up visits from 42 patients, along with sera from healthy donors (n=14). EVs were isolated, DNA purified and MDM2-DNA levels determined through q-PCR analysis. Non-parametric tests were employed to compare EV-MDM2 DNA levels from patients versus control group, as well as the time of surgery versus post-surgery conditions. RESULTS: EV-MDM2 levels were significantly higher in WD/DD-RLS than controls (P= 0.00085). Moreover, EV-MDM2 levels were remarkably decreased in WD/DD-RLS patients after resection (P=0.00036), reaching values comparable to control group (P=0.124). During post-operative surveillance, significant increases of EV-MDM2 was observed in some patients, correlating with CT scan evidence of recurrent or persistent post-resection disease. CONCLUSIONS: Serum EV-MDM2 may serve as a potential biomarker of early recurrent or post-operatively persistent WD/DD-RLS, a disease currently lacking such determinants.

Genetic and phenotypic attributes of splenic marginal zone lymphoma.

Splenic marginal zone B-cell lymphoma (SMZL) is a heterogeneous clinico-biological entity. The clinical course is variable, multiple genes are mutated with no unifying mechanism, and essential regulatory pathways and surrounding microenvironments are diverse. We sought to clarify the heterogeneity of SMZL by resolving different subgroups and their underlying genomic abnormalities, pathway signatures, and microenvironment compositions to uncover biomarkers and therapeutic vulnerabilities. We studied 303 SMZL spleen samples collected through the IELSG46 multicenter international study (NCT02945319) by using a multiplatform approach. We carried out genetic and phenotypic analyses, defined self-organized signatures, validated the findings in independent primary tumor metadata and in genetically modified mouse models, and determined correlations with outcome data. We identified 2 prominent genetic clusters in SMZL, termed NNK (58% of cases, harboring NF-κB, NOTCH, and KLF2 modules) and DMT (32% of cases, with DNA-damage response, MAPK, and TLR modules). Genetic aberrations in multiple genes as well as cytogenetic and immunogenetic features distinguished NNK- from DMT-SMZLs. These genetic clusters not only have distinct underpinning biology, as judged by differences in gene-expression signatures, but also different outcomes, with inferior survival in NNK-SMZLs. Digital cytometry and in situ profiling segregated 2 basic types of SMZL immune microenvironments termed immune-suppressive SMZL (50% of cases, associated with inflammatory cells and immune checkpoint activation) and immune-silent SMZL (50% of cases, associated with an immune-excluded phenotype) with distinct mutational and clinical connotations. In summary, we propose a nosology of SMZL that can implement its classification and also aid in the development of rationally targeted treatments.

Targeting CD19-positive lymphomas with the antibody-drug conjugate loncastuximab tesirine: preclinical evidence as single agent and in combination therapy.

Antibody-drug conjugates (ADCs) represent one of the most successful therapeutic approaches introduced in clinical practice in the last few years. Loncastuximab tesirine (ADCT-402) is a CD19 targeting ADC, in which the antibody is conjugated through a protease cleavable dipeptide linker to a pyrrolobenzodiazepine (PBD) dimer warhead (SG3199). Based on the results of a phase 2 study, loncastuximab tesirine was recently approved for adult patients with relapsed/refractory large B-cell lymphoma. We assessed the activity of loncastuximab tesirine using in vitro and in vivo models of lymphomas, correlated its activity with CD19 expression levels, and identified combination partners providing synergy with loncastuximab tesirine. Loncastuximab tesirine was tested across 60 lymphoma cell lines. Loncastuximab tesirine had strong cytotoxic activity in B-cell lymphoma cell lines. The in vitro activity was correlated with CD19 expression level and intrinsic sensitivity of cell lines to the ADC's warhead. Loncastuximab tesirine was more potent than other anti-CD19 ADCs (coltuximab ravtansine, huB4-DGN462), albeit the pattern of activity across cell lines was correlated. Loncastuximab tesirine activity was also largely correlated with cell line sensitivity to R-CHOP. Combinatorial in vitro and in vivo experiments identified the benefit of adding loncastuximab tesirine to other agents, especially BCL2 and PI3K inhibitors. Our data support the further development of loncastuximab tesirine as a single agent and in combination for patients affected by mature B-cell neoplasms. The results also highlight the importance of CD19 expression and the existence of lymphoma populations characterized by resistance to multiple therapies.

A first-in-class Wiskott-Aldrich syndrome protein activator with anti-tumor activity in hematologic cancers.

Hematological cancers are among the most common cancers in adults and children. Despite significant improvements in therapies, many patients still succumb to the disease. Therefore, novel therapies are needed. The Wiskott-Aldrich syndrome protein (WASp) family regulates actin assembly in conjunction with the Arp2/3 complex, a ubiquitous nucleation factor. WASp is expressed exclusively in hematopoietic cells and exists in two allosteric conformations: autoinhibited or activated. Here, we describe the development of EG-011, a first-in-class small molecule activator of the WASp auto-inhibited form. EG-011 possesses in vitro and in vivo anti-tumor activity as a single agent in lymphoma, leukemia, and multiple myeloma, including models of secondary resistance to PI3K, BTK, and proteasome inhibitors. The in vitro activity was confirmed in a lymphoma xenograft. Actin polymerization and WASp binding was demonstrated using multiple techniques. Transcriptome analysis highlighted homology with drugs-inducing actin polymerization.

ETS1 phosphorylation at threonine 38 is associated with the cell of origin of diffuse large B cell lymphoma and sustains the growth of tumour cells.

The transcriptional factor ETS1 is upregulated in 25% of diffuse large B cell lymphoma (DLBCL). Here, we studied the role of ETS1 phosphorylation at threonine 38, a marker for ETS1 activation, in DLBCL cellular models and clinical specimens. p-ETS1 was detected in activated B cell-like DLBCL (ABC), not in germinal centre B-cell-like DLBCL (GCB) cell lines and, accordingly, it was more common in ABC than GCB DLBCL diagnostic biopsies. MEK inhibition decreased both baseline and IgM stimulation-induced p-ETS1 levels. Genetic inhibition of phosphorylation of ETS1 at threonine 38 affected the growth and the BCR-mediated transcriptome program in DLBCL cell lines. Our data demonstrate that ETS1 phosphorylation at threonine 38 is important for the growth of DLBCL cells and its pharmacological inhibition could benefit lymphoma patients.

Characterization of GECPAR, a noncoding RNA that regulates the transcriptional program of diffuse large B-cell lymphoma.

Enhancers are regulatory regions of DNA, which play a key role in cell-type specific differentiation and development. Most active enhancers are transcribed into enhancer RNA (eRNA) that can regulate transcription of target genes by means of in cis as well as in trans action. eRNA stabilize contacts between distal genomic regions and mediate the interaction of DNA with master transcription factors. Here, we characterized an enhancer eRNA, GECPAR (germinal center proliferative adapter RNA), which is specifically transcribed in normal and neoplastic germinal center B cells from the super-enhancer of POU2AF1, a key regulatory gene of the germinal center reaction. Using diffuse large B-cell lymphoma cell line models, we demonstrated the tumor suppressor activity of GECPAR, which is mediated via its transcriptional regulation of proliferation and differentiation genes, particularly MYC and the Wnt pathway.

Resistance to PI3Kδ inhibitors in marginal zone lymphoma can be reverted by targeting the IL-6/PDGFRA axis.

PI3Kδ inhibitors are active in patients with lymphoid neoplasms and a first series of them have been approved for the treatment of multiple types of B-cell lymphoid tumors, including marginal zone lymphoma (MZL). The identification of the mechanisms underlying either primary or secondary resistance is fundamental to optimize the use of novel drugs. Here we present a model of secondary resistance to PI3Kδ inhibitors obtained by prolonged exposure of a splenic MZL cell line to idelalisib. The VL51 cell line was kept under continuous exposure to idelalisib. The study included detailed characterization of the model, pharmacological screens, silencing experiments, and validation experiments on multiple cell lines and on clinical specimens. VL51 developed resistance to idelalisib, copanlisib, duvelisib, and umbralisib. An integrative analysis of transcriptome and methylation data highlighted an enrichment of upregulated transcripts and low-methylated promoters in resistant cells, including IL-6/STAT3- and PDGFRA-related genes and surface CD19 expression, alongside the repression of the let-7 family of miRNA, and miR-125, miR-130, miR-193 and miR-20. The IL-6R blocking antibody tocilizumab, the STAT3 inhibitor stattic, the LIN28 inhibitor LIN1632, the PDGFR inhibitor masitinib and the anti-CD19 antibody drug conjugate loncastuximab tesirine were active compounds in the resistant cells as single agents and/or in combination with PI3Kδ inhibition. Findings were validated on additional in vitro lymphoma models and on clinical specimens. A novel model of resistance obtained from splenic MZL allowed the identification of therapeutic approaches able to improve the antitumor activity of PI3Kδ inhibitors in B-cell lymphoid tumors.

Generation and validation of a PET radiomics model that predicts survival in diffuse large B cell lymphoma treated with R-CHOP14: A SAKK 38/07 trial post-hoc analysis.

Functional parameters from positron emission tomography (PET) seem promising biomarkers in various lymphoma subtypes. This study investigated the prognostic value of PET radiomics in diffuse large B-cell lymphoma (DLBCL) patients treated with R-CHOP given either every 14 (testing set) or 21 days (validation set). Using the PyRadiomics Python package, 107 radiomics features were extracted from baseline PET scans of 133 patients enrolled in the Swiss Group for Clinical Cancer Research 38/07 prospective clinical trial (SAKK 38/07) [ClinicalTrial.gov identifier: NCT00544219]. The international prognostic indices, the main clinical parameters and standard PET metrics, together with 52 radiomics uncorrelated features (selected using the Spearman correlation test) were included in a least absolute shrinkage and selection operator (LASSO) Cox regression to assess their impact on progression-free (PFS), cause-specific (CSS), and overall survival (OS). A linear combination of the resulting parameters generated a prognostic radiomics score (RS) whose area under the curve (AUC) was calculated by receiver operating characteristic analysis. The RS efficacy was validated in an independent cohort of 107 DLBCL patients. LASSO Cox regression identified four radiomics features predicting PFS in SAKK 38/07. The derived RS showed a significant capability to foresee PFS in both testing (AUC, 0.709; p < 0.001) and validation (AUC, 0.706; p < 0.001) sets. RS was significantly associated also with CSS and OS in testing (CSS: AUC, 0.721; p < 0.001; OS: AUC, 0.740; p < 0.001) and validation (CSS: AUC, 0.763; p < 0.0001; OS: AUC, 0.703; p = 0.004) sets. The RS allowed risk classification of patients with significantly different PFS, CSS, and OS in both cohorts showing better predictive accuracy respect to clinical international indices. PET-derived radiomics may improve the prediction of outcome in DLBCL patients.

Revised MALT-IPI: A new predictive model that identifies high-risk patients with extranodal marginal zone lymphoma.

Extranodal marginal zone lymphoma (EMZL) is a heterogeneous disease with a subset of patients exhibiting a more aggressive course. We previously reported that EMZL with multiple mucosal sites (MMS) at diagnosis is characterized by shorter survival. To better recognize patients with different patterns of progression-free survival (PFS) we developed and validated a new prognostic index primarily based on patient's disease characteristics. We derived the "Revised mucosa-associated lymphoid tissue International Prognostic Index" (Revised MALT-IPI) in a large data set (n = 397) by identifying candidate variables that showed highest prognostic association with PFS. The revised MALT-IPI was validated in two independent cohorts, from the University of Iowa/Mayo Clinic (n = 297) and from IELSG-19 study (n = 400). A stepwise Cox regression analysis yielded a model including four independent predictors of shorter PFS. Revised MALT-IPI has scores ranging from 0 to 5, calculated as a sum of one point for each of the following- age >60 years, elevated LDH, and stage III-IV; and two points for MMS. In the training cohort, the Revised MALT-IPI defined four risk groups: low risk (score 0, reference group), low-medium risk (score 1, HR = 1.85, p = .008), medium-high risk (score 2, HR = 3.84, p < .0001), and high risk (score 3+, HR = 8.48, p < .0001). Performance of the Revised MALT-IPI was similar in external validation cohorts. Revised MALT-IPI is a new index centered on disease characteristics that provides robust risk-stratification identifying a group of patients characterized by earlier progression of disease. Revised MALT-IPI can allow a more disease-adjusted management of patients with EMZL in clinical trials and practice.

RNAdetector: a free user-friendly stand-alone and cloud-based system for RNA-Seq data analysis.

BACKGROUND: RNA-Seq is a well-established technology extensively used for transcriptome profiling, allowing the analysis of coding and non-coding RNA molecules. However, this technology produces a vast amount of data requiring sophisticated computational approaches for their analysis than other traditional technologies such as Real-Time PCR or microarrays, strongly discouraging non-expert users. For this reason, dozens of pipelines have been deployed for the analysis of RNA-Seq data. Although interesting, these present several limitations and their usage require a technical background, which may be uncommon in small research laboratories. Therefore, the application of these technologies in such contexts is still limited and causes a clear bottleneck in knowledge advancement. RESULTS: Motivated by these considerations, we have developed RNAdetector, a new free cross-platform and user-friendly RNA-Seq data analysis software that can be used locally or in cloud environments through an easy-to-use Graphical User Interface allowing the analysis of coding and non-coding RNAs from RNA-Seq datasets of any sequenced biological species. CONCLUSIONS: RNAdetector is a new software that fills an essential gap between the needs of biomedical and research labs to process RNA-Seq data and their common lack of technical background in performing such analysis, which usually relies on outsourcing such steps to third party bioinformatics facilities or using expensive commercial software.

Modulation of Biliary Cancer Chemo-Resistance Through MicroRNA-Mediated Rewiring of the Expansion of CD133+ Cells.

BACKGROUND AND AIMS: Changes in single microRNA (miRNA) expression have been associated with chemo-resistance in biliary tract cancers (BTCs). However, a global assessment of the dynamic role of the microRNome has never been performed to identify potential therapeutic targets that are functionally relevant in the BTC cell response to chemotherapy. APPROACH AND RESULTS: High-throughput screening (HTS) of 997 locked nucleic acid miRNA inhibitors was performed in six cholangiocarcinoma cell lines treated with cisplatin and gemcitabine (CG) seeking changes in cell viability. Validation experiments were performed with mirVana probes. MicroRNA and gene expression was assessed by TaqMan assay, RNA-sequencing, and in situ hybridization in four independent cohorts of human BTCs. Knockout of microRNA was achieved by CRISPR-CAS9 in CCLP cells (MIR1249KO) and tested for effects on chemotherapy sensitivity in vitro and in vivo. HTS revealed that MIR1249 inhibition enhanced chemotherapy sensitivity across all cell lines. MIR1249 expression was increased in 41% of cases in human BTCs. In validation experiments, MIR1249 inhibition did not alter cell viability in untreated or dimethyl sulfoxide-treated cells; however, it did increase the CG effect. MIR1249 expression was increased in CD133+ biliary cancer cells freshly isolated from the stem cell niche of human BTCs as well as in CD133+ chemo-resistant CCLP cells. MIR1249 modulated the chemotherapy-induced enrichment of CD133+ cells by controlling their clonal expansion through the Wnt-regulator FZD8. MIR1249KO cells had impaired expansion of the CD133+ subclone and its enrichment after chemotherapy, reduced expression of cancer stem cell markers, and increased chemosensitivity. MIR1249KO xenograft BTC models showed tumor shrinkage after exposure to weekly CG, whereas wild-type models showed only stable disease over treatment. CONCLUSIONS: MIR1249 mediates resistance to CG in BTCs and may be tested as a target for therapeutics.

IDH2 inhibition enhances proteasome inhibitor responsiveness in hematological malignancies.

Proteasome inhibitors (PI) are extensively used for the therapy of multiple myeloma (MM) and mantle cell lymphoma. However, patients continuously relapse or are intrinsically resistant to this class of drugs. Here, to identify targets that synergize with PI, we carried out a functional screening in MM cell lines using a short hairpin RNA library against cancer driver genes. Isocitrate dehydrogenase 2 (IDH2) was identified as a top candidate, showing a synthetic lethal activity with the PI carfilzomib (CFZ). Combinations of US Food and Drug Administration-approved PI with a pharmacological IDH2 inhibitor (AGI-6780) triggered synergistic cytotoxicity in MM, mantle cell lymphoma, and Burkitt lymphoma cell lines. CFZ/AGI-6780 treatment increased death of primary CD138+ cells from MM patients and exhibited a favorable cytotoxicity profile toward peripheral blood mononuclear cells and bone marrow-derived stromal cells. Mechanistically, the CFZ/AGI-6780 combination significantly decreased tricarboxylic acid cycle activity and adenosine triphosphate levels as a consequence of enhanced IDH2 enzymatic inhibition. Specifically, CFZ treatment reduced the expression of nicotinamide phosphoribosyltransferase (NAMPT), thus limiting IDH2 activation through the NAD+-dependent deacetylase SIRT3. Consistently, combination of CFZ with either NAMPT or SIRT3 inhibitors impaired IDH2 activity and increased MM cell death. Finally, inducible IDH2 knockdown enhanced the therapeutic efficacy of CFZ in a subcutaneous xenograft model of MM, resulting in inhibition of tumor progression and extended survival. Taken together, these findings indicate that NAMPT/SIRT3/IDH2 pathway inhibition enhances the therapeutic efficacy of PI, thus providing compelling evidence for treatments with lower and less toxic doses and broadening the application of PI to other malignancies.

Correction: Whole exome sequencing reveals mutations in FAT1 tumor suppressor gene clinically impacting on peripheral T-cell lymphoma not otherwise specified.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Whole exome sequencing reveals mutations in FAT1 tumor suppressor gene clinically impacting on peripheral T-cell lymphoma not otherwise specified.

Peripheral T-cell lymphoma not otherwise specified represents a diagnostic category comprising clinically, histologically, and molecularly heterogeneous neoplasms that are poorly understood. The genetic landscape of peripheral T-cell lymphoma not otherwise specified remains largely undefined, only a few sequencing studies having been conducted so far. In order to improve our understanding of the genetics of this neoplasm, we performed whole exome sequencing along with RNA-sequencing in a discovery set of 21 cases. According to whole exome sequencing results and mutations previously reported in other peripheral T-cell lymphomas, 137 genes were sequenced by a targeted deep approach in 71 tumor samples. In addition to epigenetic modifiers implicated in all subtypes of T-cell neoplasm (TET2, DNMT3A, KMT2D, KMT2C, SETD2), recurrent mutations of the FAT1 tumor suppressor gene were for the first time recorded in 39% of cases. Mutations of the tumor suppressor genes LATS1, STK3, ATM, TP53, and TP63 were also observed, although at a lower frequency. Patients with FAT1 mutations showed inferior overall survival compared to those with wild-type FAT1. Although peripheral T-cell lymphoma not otherwise specified remains a broad category also on molecular grounds, the present study highlights that FAT1 mutations occur in a significant proportion of cases, being provided with both pathogenetic and prognostic impact.

Metabolic heterogeneity on baseline 18FDG-PET/CT scan is a predictor of outcome in primary mediastinal B-cell lymphoma.

An important unmet need in the management of primary mediastinal B-cell lymphoma (PMBCL) is to identify the patients for whom first-line therapy will fail to intervene before the lymphoma becomes refractory. High heterogeneity of intratumoral 18F-fluorodeoxyglucose (18FDG) uptake distribution on positron emission tomography/computed tomography (PET/CT) scans has been suggested as a possible marker of chemoresistance in solid tumors. In the present study, we investigated the prognostic value of metabolic heterogeneity (MH) in 103 patients with PMBCL prospectively enrolled in the International Extranodal Lymphoma Study Group (IELSG) 26 study, aimed at clarifying the role of PET in this lymphoma subtype. MH was estimated using the area under curve of cumulative standardized uptake value-volume histogram (AUC-CSH) method. Progression-free survival at 5 years was 94% vs 73% in low- and high-MH groups, respectively (P = .0001). In a Cox model of progression-free survival including dichotomized MH, metabolic tumor volume, total lesion glycolysis (TLG), international prognostic index, and tumor bulk (mediastinal mass > 10 cm), as well as age as a continuous variable, only TLG (P < .001) and MH (P < .001) retained statistical significance. Using these 2 features to construct a simple prognostic model resulted in early and accurate (positive predictive value, 89%; negative predictive value, ≥90%) identification of patients at high risk for progression at a point that would allow the use of risk-adapted treatments. This may provide an important opportunity for the design of future trials aimed at helping the minority of patients who harbor chemorefractory PMBCL. The study is registered at ClinicalTrials.gov as NCT00944567.

Early progression of disease predicts shorter survival in MALT lymphoma patients receiving systemic treatment.

Early progression of disease (POD) within two years from diagnosis is linked with poor overall survival (OS) in follicular lymphoma but its prognostic role is less clear in extranodal marginal zone B-cell lymphoma (EMZL). We sought to identify prognostic factors associated with early POD and to determine whether is associated with inferior OS. We analyzed the impact of early POD in the IELSG19 clinical trial dataset (training set of 401 patients randomly assigned to chlorambucil or rituximab or chlorambucil plus rituximab). Reproducibility was examined in a validation set of 287 patients who received systemic treatment. In both sets, we excluded from the analysis the patients who, within 24 months from treatment start, died without progression or were lost to follow-up without prior progression. OS was calculated from progression in patients with early POD and from 24 months after start of treatment in those without (reference group). Early POD was observed in 69 of the 384 (18%) evaluable patients of the IELSG19 study. Patients with high-risk MALT-IPI were more likely to have early POD (p=0.006). The 10-year OS rate was 64% in the early POD group and 85% in the reference group (HR= 2.42, 95%CI, 1.35-4.34; log-rank P=0.002). This prognostic impact was confirmed in the validation set, in which early POD was observed in 64 out of 224 (29%) evaluable patients with 10-year OS rate of 48% in the early POD group and 71% in the reference group (HR= 2.15, 95%CI, 1.19-3.90; log-rank P=0.009). In patients with EMZL who received front-line systemic treatment, early POD is associated with poorer survival and may represent a useful endpoint in future prospective clinical trials.

Targeting CD205 with the antibody drug conjugate MEN1309/OBT076 is an active new therapeutic strategy in lymphoma models.

Antibody drug conjugates represent an important class of anti-cancer drugs in both solid tumors and hematological cancers. Here, we report preclinical data on the anti-tumor activity of the first-in-class antibody drug conjugate MEN1309/OBT076 targeting CD205. The study included preclinical in vitro activity screening on a large panel of cell lines, both as single agent and in combination and validation experiments on in vivo models. CD205 was first shown frequently expressed in lymphomas, leukemias and multiple myeloma by immunohistochemistry on tissue microarrays. Anti-tumor activity of MEN1309/OBT076 as single agent was then shown across 42 B-cell lymphoma cell lines with a median IC50 of 200 pM and induction of apoptosis in 25/42 (59.5%) of the cases. The activity appeared highly correlated with its target expression. After in vivo validation as the single agent, the antibody drug conjugate synergized with the BCL2 inhibitor venetoclax, and the anti-CD20 monoclonal antibody rituximab. The first-in-class antibody drug targeting CD205, MEN1309/OBT076, demonstrated strong pre-clinical anti-tumor activity in lymphoma, warranting further investigations as a single agent and in combination.

Prognostic models integrating quantitative parameters from baseline and interim positron emission computed tomography in patients with diffuse large B-cell lymphoma: post-hoc analysis from the SAKK38/07 clinical trial.

Positron emission computed tomography (PET/CT) in patients with diffuse large B-cell lymphoma (DLBCL) enrolled in a prospective clinical trial were reviewed to test the impact of quantitative parameters from interim PET/CT scans on overall (OS) and progression-free (PFS) survival. We centrally reviewed baseline and interim PET/CT scans of 138 patients treated with rituximab plus cyclophosphamide, doxorubicin, vincristine and prednisone given every 14 days (R-CHOP14) in the SAKK38/07 trial (ClinicalTrial.gov identifier: NCT00544219). Cutoff values for maximum standardized uptake value (SUVmax ), metabolic tumor volume (MTV), total lesion glycolysis (TLG) and metabolic heterogeneity (MH) were defined by receiver operating characteristic analysis. Responses were scored using the Deauville scale (DS). Patients with DS 5 at interim PET/CT (defined by uptake >2 times higher than in normal liver) had worse PFS (P = 0.014) and OS (P < 0.0001). A SUVmax reduction (Δ) greater than 66% was associated with longer PFS (P = 0.0027) and OS (P < 0.0001). Elevated SUVmax , MTV, TLG, and MH at interim PET/CT also identified patients with poorer outcome. At multivariable analysis, ΔSUVmax and baseline MTV appeared independent outcome predictors. A prognostic model integrating ΔSUVmax and baseline MTV discriminated three risk groups with significantly (log-rank test for trend, P < 0.0001) different PFS and OS. Moreover, the integration of MH and clinical prognostic indices could further refine the prediction of OS. PET metrics-derived prognostic models perform better than the international indices alone. Integration of baseline and interim PET metrics identified poor-risk DLBCL patients who might benefit from alternative treatments.

Single and combined BTK and PI3Kδ inhibition with acalabrutinib and ACP-319 in pre-clinical models of aggressive lymphomas.

The B-cell receptor and the phosphatidylinositol 3-kinase (PI3K) signalling pathways, together with their downstream partners, represent important therapeutic targets for B-cell lymphomas. Here, we evaluated the activity of acalabrutinib (ACP-196) and ACP-319 (AMG-319), second generation inhibitors of Bruton tyrosine kinase (BTK) and PI3Kδ inhibitor, respectively, in lymphoma pre-clinical models. The two compounds showed activity in activated B-cell-like diffuse large B-cell lymphoma (ABC DLBCL), mantle cell lymphoma and marginal zone lymphoma. Two in vivo experiments with ABC DLBCL and MCL xenografts confirmed the effect of the single agents. Benefit was achieved by exposing the lymphoma cell lines to both acalabrutinib and ACP-319. Two cell lines presented a discordant response to first and second generation BTK inhibitors, probably due to the inhibition by ibrutinib of kinases other than BTK. In conclusion, our data sustain the on-going current trials with acalabrutinib and ACP-319 as single agents and provide the basis for the investigation of their combination as well.