Letter: Presence of progression or absence of response? Alternative trial designs for immunotherapy of advanced hepatocellular carcinoma

This article is linked to Jost‐Brinkmann et al papers. To view these articles, visit https://doi.org/10.1111/apt.17441 and https://doi.org/10.1111/apt.18008

Sfrp1 inhibits lung fibroblast invasion during transition to injury-induced myofibroblasts

BACKGROUND

Fibroblast-to-myofibroblast conversion is a major driver of tissue remodelling in organ fibrosis. Distinct lineages of fibroblasts support homeostatic tissue niche functions, yet their specific activation states and phenotypic trajectories during injury and repair have remained unclear.

METHODS

We combined spatial transcriptomics, multiplexed immunostainings, longitudinal single-cell RNA-sequencing and genetic lineage tracing to study fibroblast fates during mouse lung regeneration. Our findings were validated in idiopathic pulmonary fibrosis patient tissues in situ as well as in cell differentiation and invasion assays using patient lung fibroblasts. Cell differentiation and invasion assays established a function of SFRP1 in regulating human lung fibroblast invasion in response to transforming growth factor (TGF)β1.

MEASUREMENTS AND MAIN RESULTS

We discovered a transitional fibroblast state characterised by high Sfrp1 expression, derived from both Tcf21-Cre lineage positive and negative cells. Sfrp1 + cells appeared early after injury in peribronchiolar, adventitial and alveolar locations and preceded the emergence of myofibroblasts. We identified lineage-specific paracrine signals and inferred converging transcriptional trajectories towards Sfrp1 + transitional fibroblasts and Cthrc1 + myofibroblasts. TGFβ1 downregulated SFRP1 in noninvasive transitional cells and induced their switch to an invasive CTHRC1+ myofibroblast identity. Finally, using loss-of-function studies we showed that SFRP1 modulates TGFβ1-induced fibroblast invasion and RHOA pathway activity.

CONCLUSIONS

Our study reveals the convergence of spatially and transcriptionally distinct fibroblast lineages into transcriptionally uniform myofibroblasts and identifies SFRP1 as a modulator of TGFβ1-driven fibroblast phenotypes in fibrogenesis. These findings are relevant in the context of therapeutic interventions that aim at limiting or reversing fibroblast foci formation.

Independent Validation and Assay Standardization of Improved Metabolic Biomarker Signature to Differentiate Pancreatic Ductal Adenocarcinoma From Chronic Pancreatitis

BACKGROUND & AIMS

Pancreatic ductal adenocarcinoma cancer (PDAC) is a highly lethal malignancy requiring efficient detection when the primary tumor is still resectable. We previously developed the MxPancreasScore comprising 9 analytes and serum carbohydrate antigen 19-9 (CA19-9), achieving an accuracy of 90.6%. The necessity for 5 different analytical platforms and multiple analytical runs, however, hindered clinical applicability. We therefore aimed to develop a simpler single-analytical run, single-platform diagnostic signature.

METHODS

We evaluated 941 patients (PDAC, 356; chronic pancreatitis [CP], 304; nonpancreatic disease, 281) in 3 multicenter independent tests, and identification (ID) and validation cohort 1 (VD1) and 2 (VD2) were evaluated. Targeted quantitative plasma metabolite analysis was performed on a liquid chromatography-tandem mass spectrometry platform. A machine learning-aided algorithm identified an improved (i-Metabolic) and minimalistic metabolic (m-Metabolic) signatures, and compared them for performance.

RESULTS

The i-Metabolic Signature, (12 analytes plus CA19-9) distinguished PDAC from CP with area under the curve (95% confidence interval) of 97.2% (97.1%-97.3%), 93.5% (93.4%-93.7%), and 92.2% (92.1%-92.3%) in the ID, VD1, and VD2 cohorts, respectively. In the VD2 cohort, the m-Metabolic signature (4 analytes plus CA19-9) discriminated PDAC from CP with a sensitivity of 77.3% and specificity of 89.6%, with an overall accuracy of 82.4%. For the subset of 45 patients with PDAC with resectable stages IA-IIB tumors, the sensitivity, specificity, and accuracy were 73.2%, 89.6%, and 82.7%, respectively; for those with detectable CA19-9 >2 U/mL, 81.6%, 88.7%, and 84.5%, respectively; and for those with CA19-9 <37 U/mL, 39.7%, 94.1%, and 76.3%, respectively.

CONCLUSIONS

The single-platform, single-run, m-Metabolic signature of just 4 metabolites used in combination with serum CA19-9 levels is an innovative accurate diagnostic tool for PDAC at the time of clinical presentation, warranting further large-scale evaluation.

Atezolizumab and bevacizumab with transarterial chemoembolization in hepatocellular carcinoma: the DEMAND trial protocol

The combination of the anti-PD-L1 antibody atezolizumab and the anti-VEGF bevacizumab is the first approved immunotherapeutic regimen for first-line therapy in patients with unresectable hepatocellular carcinoma (HCC), currently approved in more than 80 countries. The efficacy and tolerability of this regimen suggest that the use of atezolizumab + bevacizumab could be extended to the treatment of patients with intermediate-stage HCC in combination with transarterial chemoembolization (TACE). The authors describe the rationale and design of the DEMAND study. This investigator-initiated, multicenter, randomized phase II study is the first trial to evaluate the safety and efficacy of atezolizumab + bevacizumab prior to or in combination with TACE in patients with intermediate-stage HCC. The primary end point is the 24-month survival rate; secondary end points include objective response rate, progression-free survival, safety and quality of life. Clinical Trial Registration: NCT04224636 (ClinicalTrials.gov).

Atezolizumab and bevacizumab with transarterial chemoembolization in hepatocellular carcinoma: The DEMAND randomized phase II clinical trial

TPS492

Background: Atezolizumab and bevacizumab is the first approved immunotherapeutic regimen for first-line treatment of patients with advanced hepatocellular carcinoma (HCC). The efficacy and tolerability of this regimen suggests that its use could be extended to the treatment of patients with intermediate-stage HCC in combination with transarterial chemoembolization (TACE). The effect of TACE combined with atezolizumab and bevacizumab could improve response and tumor control as well as prevent disease progression in non-responders to TACE. Response to the early use of immunotherapy could also reduce the number and extent of TACE cycles needed to achieve tumor control, thereby contributing to the prevention of collateral damage to the liver parenchyma and preservation of liver function. Initiating immunotherapy first may also promote the access of circulating lymphocytes into tumor lesions. The DEMAND study investigates the efficacy and ideal sequence of TACE and immunotherapy in intermediate stage HCC. Methods: This investigator-initiated, multi-center, randomized, open-label phase 2 trial is the first study to evaluate the safety and efficacy of atezolizumab and bevacizumab prior to, or in combination with TACE in patients with unresectable HCC. 106 patients (Barcelona Clinic Liver Cancer Stage A not amenable to curative therapy or B, Child-Pugh A or B7, Eastern Cooperative Oncology Group performance status 0 or 1, no prior TACE) will be randomized in a 1:1 ratio to receive either up-front atezolizumab and bevacizumab followed by TACE selectively directed against progressive lesions (Arm A, 53 patients), or TACE and synchronous treatment with atezolizumab and bevacizumab (Arm B, 53 patients). Patients receive study treatment until loss of clinical benefit or unacceptable toxicity for up to 24 months. The use of local ablation is allowed for the treatment of lesions which cannot be targeted sufficiently selectively by TACE, or of de-novo lesions. The primary endpoint is the 24-month survival rate; secondary endpoints include objective response rate, progression-free survival, safety and quality of life. Translational analyses aim at identifying predictive biomarkers and focus on immune cell phenotyping in tumor and peripheral blood, circulating tumor DNA and changes in the diversity of the gut microbiome. Recruitment is ongoing in 15 German centers with 21 of 106 patients randomized. Clinical trial information: NCT04224636.

Plasma Metabolome Profiling Identifies Metabolic Subtypes of Pancreatic Ductal Adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is one of the deadliest cancers. Developing biomarkers for early detection and chemotherapeutic response prediction is crucial to improve the dismal prognosis of PDAC patients. However, molecular cancer signatures based on transcriptome analysis do not reflect intratumoral heterogeneity. To explore a more accurate stratification of PDAC phenotypes in an easily accessible matrix, plasma metabolome analysis using MxP® Global Profiling and MxP® Lipidomics was performed in 361 PDAC patients. We identified three metabolic PDAC subtypes associated with distinct complex lipid patterns. Subtype 1 was associated with reduced ceramide levels and a strong enrichment of triacylglycerols. Subtype 2 demonstrated increased abundance of ceramides, sphingomyelin and other complex sphingolipids, whereas subtype 3 showed decreased levels of sphingolipid metabolites in plasma. Pathway enrichment analysis revealed that sphingolipid-related pathways differ most among subtypes. Weighted correlation network analysis (WGCNA) implied PDAC subtypes differed in their metabolic programs. Interestingly, a reduced expression among related pathway genes in tumor tissue was associated with the lowest survival rate. However, our metabolic PDAC subtypes did not show any correlation to the described molecular PDAC subtypes. Our findings pave the way for further studies investigating sphingolipids metabolisms in PDAC.

Editor's Highlight: Therapeutic Concentrations of Antidepressants Inhibit Pancreatic Beta-Cell Function via Mitochondrial Complex Inhibition

Diabetes mellitus risk is increased by prolonged usage of antidepressants (ADs). Although various mechanisms are suggested for their diabetogenic potential, whether a direct effect of ADs on pancreatic β-cells is involved is unclear. We examined this idea for 3 ADs: paroxetine, clomipramine and, with particular emphasis, fluoxetine, on insulin secretion, mitochondrial function, cellular bioenergetics, KATP channel activity, and caspase activity in murine and human cell-line models of pancreatic β-cells. Metabolic assays showed that these ADs decreased the redox, oxidative respiration, and energetic potential of β-cells in a time and concentration dependent manner, even at a concentration of 100 nM, well within the therapeutic window. These effects were related to inhibition of mitochondrial complex I and III. Consistent with impaired mitochondrial function, lactate output was increased and insulin secretion decreased. Neither fluoxetine, antimycin nor rotenone could reactivate KATP channel activity blocked by glucose unlike the mitochondrial uncoupler, FCCP. Chronic, but not acute, AD increased oxidative stress and activated caspases, 3, 8, and 9. A close agreement was found for the rates of oxidative respiration, lactate output and modulation of KATP channel activity in MIN6 cells with those of primary murine cells; data that supports MIN6 as a valid model to study beta-cell bioenergetics. To conclude, paroxetine, clomipramine and fluoxetine were all cytotoxic at therapeutic concentrations on pancreatic beta-cells; an action suggested to arise by inhibition of mitochondrial bioenergetics, oxidative stress and induction of apoptosis. These actions help explain the diabetogenic potential of these ADs in humans.

The instructive extracellular matrix of the lung: basic composition and alterations in chronic lung disease

The pulmonary extracellular matrix (ECM) determines the tissue architecture of the lung, and provides mechanical stability and elastic recoil, which are essential for physiological lung function. Biochemical and biomechanical signals initiated by the ECM direct cellular function and differentiation, and thus play a decisive role in lung development, tissue remodelling processes and maintenance of adult homeostasis. Recent proteomic studies have demonstrated that at least 150 different ECM proteins, glycosaminoglycans and modifying enzymes are expressed in the lung, and these assemble into intricate composite biomaterials. These highly insoluble assemblies of interacting ECM proteins and their glycan modifications can act as a solid phase-binding interface for hundreds of secreted proteins, which creates an information-rich signalling template for cell function and differentiation. Dynamic changes within the ECM that occur upon injury or with ageing are associated with several chronic lung diseases. In this review, we summarise the available data about the structure and function of the pulmonary ECM, and highlight changes that occur in idiopathic pulmonary fibrosis (IPF), pulmonary arterial hypertension (PAH), chronic obstructive pulmonary disease (COPD), asthma and lung cancer. We discuss potential mechanisms of ECM remodelling and modification, which we believe are relevant for future diagnosis and treatment of chronic lung disease.

Multiplex profiling of cellular invasion in 3D cell culture models

To-date, most invasion or migration assays use a modified Boyden chamber-like design to assess migration as single-cell or scratch assays on coated or uncoated planar plastic surfaces. Here, we describe a 96-well microplate-based, high-content, three-dimensional cell culture assay capable of assessing invasion dynamics and molecular signatures thereof. On applying our invasion assay, we were able to demonstrate significant effects on the invasion capacity of fibroblast cell lines, as well as primary lung fibroblasts. Administration of epidermal growth factor resulted in a substantial increase of cellular invasion, thus making this technique suitable for high-throughput pharmacological screening of novel compounds regulating invasive and migratory pathways of primary cells. Our assay also correlates cellular invasiveness to molecular events. Thus, we argue of having developed a powerful and versatile toolbox for an extensive profiling of invasive cells in a 96-well format. This will have a major impact on research in disease areas like fibrosis, metastatic cancers, or chronic inflammatory states.