Over the last decade, many of the major solid organ cancers have seen improvements in survival due to development of novel therapeutics and corresponding biomarkers that predict treatment efficacy or ...resistance. In contrast, favorable outcomes remain challenging in pancreatic ductal adenocarcinoma (PDAC), in part related to the lack of validated biomarkers for patient and treatment selection and thus optimal clinical decision-making. Increasingly, however, therapeutic development for PDAC is accompanied by bioassays to evaluate response and to study mechanism of actions with a corresponding increase in the number of trials in mid to late stage with integrated biomarkers. In addition, blood-based biomarkers that provide a measure of disease activity and allow for minimally invasive tumor analyses are emerging, including circulating tumor DNA, exosomes, and circulating tumor cells. In this article, we review potential biomarkers for currently approved therapies as well as emerging biomarkers for therapeutics under development.
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Uveal melanoma (UM) is the most common intraocular malignancy and arises from melanocytes in the iris, ciliary body, or choroid. Early diagnosis and local treatment is crucial, as survival correlates ...with primary tumor size. However, approximately 50% of patients will develop metastatic disease with 6-12 months' survival from metastatic diagnosis. Genomic analyses have led to the development of gene-expression profiles that effectively predict metastatic progression; unfortunately, no adjuvant therapy has been shown to prolong survival to date. New insights into the molecular biology of UM have found frequent activating mutations in genes encoding for the G-protein α-subunit,
and
, and improved understanding of the downstream signaling pathways MAPK, PI3K/Akt, and Hippo have afforded an array of new targets for treatment of this disease. Studies are under way with rationally developed regimens targeting these pathways, and novel agents are under development. We review the diagnosis, management, and surveillance of primary UM and the adjuvant therapy trials under way.
Purpose
We evaluated the efficacy and safety of capecitabine and temozolomide (CAPTEM) in patients with metastatic neuroendocrine tumors (NETs) to the liver. This regimen was based on our studies ...with carcinoid cell lines that showed synergistic cytotoxicity with sequence-specific dosing of 5-fluorouracil preceding temozolomide (TMZ).
Methods
A retrospective review was conducted of 18 patients with NETs metastatic to the liver who had failed 60 mg/month of Sandostatin LAR™ (100 %), chemotherapy (61 %), and hepatic chemoembolization (50 %). Patients received capecitabine at 600 mg/m
2
orally twice daily on days 1–14 (maximum 1,000 mg orally twice daily) and TMZ 150–200 mg/m
2
divided into two doses daily on days 10–14 of a 28-day cycle. Imaging was performed every 2 cycles, and serum tumor markers were measured every cycle.
Results
Using RECIST parameters, 1 patient (5.5 %) with midgut carcinoid achieved a surgically proven complete pathological response (CR), 10 patients (55.5 %) achieved a partial response (PR), and 4 patients (22.2 %) had stable disease (SD). Total response rate was 61 %, and clinical benefit (responders and SD) was 83.2 %. Of four carcinoid cases treated with CAPTEM, there was 1 CR, 1 PR, 1 SD, and 1 progressive disease. Median progression-free survival was 14.0 months (11.3–18.0 months). Median overall survival from diagnosis of liver metastases was 83 months (28–140 months). The only grade 3 toxicity was thrombocytopenia (11 %). There were no grade 4 toxicities, hospitalizations, opportunistic infections, febrile neutropenias, or deaths.
Conclusions
CAPTEM is highly active, well tolerated and may prolong survival in patients with well-differentiated, metastatic NET who have progressed on previous therapies.
The synthesis of radioimmunoconjugates via the stochastic attachment of bifunctional chelators to lysines can yield heterogeneous products with suboptimal in vitro and in vivo behavior. In response ...to this, several site-selective approaches to bioconjugation have been developed, yet each has intrinsic drawbacks, such as the need for expensive reagents or the complexity of incorporating unnatural amino acids into IgGs. Herein, we describe the use of a simple and facile approach to lysine-directed site-selective bioconjugation for the generation of radioimmunoconjugates. This strategy relies upon on the selective modification of single lysine residues within each light chain of the monoclonal antibody (mAb) with a branched azide-bearing perfluorophenyl ester (PFP-bisN3) followed by the ligation of dibenzocyclooctyne (DBCO)-bearing payloads to these bioorthogonal handles via the strain-promoted azide–alkyne cycloaddition. This methodology was used to create 89ZrZr-SSKDFO-pertuzumab, a radioimmunoconjugate of the HER2-targeting mAb pertuzumab labeled with desferrioxamine (DFO) and the positron-emitting radiometal zirconium-89 (89Zr). 89ZrZr-SSKDFO-pertuzumab was compared to a pair of analogous probes: one synthesized via random lysine modification (89ZrZr-DFO-pertuzumab) and another via thiol-maleimide chemistry (89ZrZr-malDFO-pertuzumab). The bioconjugation strategy was assessed using ESI mass spectrometry, SDS-PAGE, and autoradiography. All three immunoconjugates demonstrated comparable binding to HER2 via flow cytometry and surface plasmon resonance (SPR), and 89Zr-labeled variants of each were synthesized in >99% radiochemical yield and molar activities of up to ∼55.5 GBq/μmol (10 mCi/mg). Subsequently, the in vivo behavior of this trio of 89Zr-immunoPET probes was interrogated in athymic nude mice bearing subcutaneous HER2-expressing BT-474 human breast cancer xenografts. 89ZrZr-SSKDFO-pertuzumab, 89ZrZr-malDFO-pertuzumab, and 89ZrZr-DFO-pertuzumab produced positron emission tomography (PET) images with high tumoral uptake and high tumor-to-healthy organ activity concentration ratios. A terminal biodistribution study complemented the PET results, revealing tumoral activity concentrations of 126.9 ± 50.3%ID/g, 86.9 ± 53.2%ID/g, and 92.5 ± 27.2%ID/g at 144 h post-injection for 89ZrZr-SSKDFO-pertuzumab, 89ZrZr-malDFO-pertuzumab, and 89ZrZr-DFO-pertuzumab, respectively. Taken together, the data clearly illustrate that this highly modular and facile approach to site-selective bioconjugation produces radioimmunoconjugates that are better-defined and more homogeneous than stochastically modified constructs and also exhibit excellent in vitro and in vivo performance. Furthermore, we contend that this lysine-directed strategy holds several key advantages over extant approaches to site-selective bioconjugation, especially in the context of production for the clinic.
Hepato-pancreatico-biliary (HPB) malignancies are difficult-to-treat and continue to to have a high mortality and significant therapeutic resistance to standard therapies. Immune oncology (IO) ...therapies have demonstrated efficacy in several solid malignancies when combined with chemotherapy, whereas response rates in pancreatic ductal adenocarcinoma (PDA) are poor. While promising in hepatocellular carcinoma (HCC) and cholangiocarcinoma (CCA), there remains an unmet need to fully leverage IO therapies to treat HPB tumors. We therefore defined T cell subsets in the tumor microenvironment of HPB patients utilizing a novel, multiparameter flow cytometry and bioinformatics analysis. Our findings quantify the T cell phenotypic states in relation to checkpoint receptor expression. We demonstrate the presence of CD103
tissue resident memory T cells (T
), CCR7
central memory T cells, and CD57
terminally differentiated effector cells across all HPB cancers, while the anti-tumor function was dampened by expression of multiple co-inhibitory checkpoint receptors. Terminally exhausted T cells lacking co-stimulatory receptors were more prevalent in PDA, whereas partially exhausted T cells expressing both co-inhibitory and co-stimulatory receptors were most prevalent in HCC, especially in early stage. HCC patients had significantly higher T
with a phenotype that could confer restored activation in response to immune checkpoint therapies. Further, we found a lack of robust alteration in T cell activation state or checkpoint expression in response to chemotherapy in PDA patients. These results support that HCC patients might benefit most from combined checkpoint therapies, whereas efforts other than cytotoxic chemotherapy will likely be necessary to increase overall T cell activation in CCA and PDA for future clinical development.
Patient-derived tumor organoids (TOs) are emerging as high-fidelity models to study cancer biology and develop novel precision medicine therapeutics. However, utilizing TOs for systems-biology-based ...approaches has been limited by a lack of scalable and reproducible methods to develop and profile these models. We describe a robust pan-cancer TO platform with chemically defined media optimized on cultures acquired from over 1,000 patients. Crucially, we demonstrate tumor genetic and transcriptomic concordance utilizing this approach and further optimize defined minimal media for organoid initiation and propagation. Additionally, we demonstrate a neural-network-based high-throughput approach for label-free, light-microscopy-based drug assays capable of predicting patient-specific heterogeneity in drug responses with applicability across solid cancers. The pan-cancer platform, molecular data, and neural-network-based drug assay serve as resources to accelerate the broad implementation of organoid models in precision medicine research and personalized therapeutic profiling programs.
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•Tumor organoid cultures from >1,000 patients reveal genomic/transcriptomic fidelity•Establishment of chemically defined minimal medias for each solid tumor type•Pan-cancer neural network predicts drug response from label-free light microscopy
Patient-derived tumor organoids offer promise as tools for precision medicine but require scalable and reproducible methods for wide use. Larsen et al. optimize a pan-cancer platform with tumor organoids from over 1,000 patients. Standards are established for culture conditions, molecular characterization, and therapeutic profiling using deep learning coupled with light microscopy.
Pancreatic ductal adenocarcinoma (PDAC) is the third highest cause of cancer-related deaths in the US, and is projected to be second only to non-small cell lung cancer (NSCLC) by the 2020s. Current ...therapies have a modest impact on survival and median overall survival (mOS) across all stages of disease remains under a year. Over the last decade, however, great strides have been made in the understanding of PDAC pathobiology including the role of the tumor microenvironment (TME), DNA damage repair and mechanism of immunosuppression. Exciting novel therapeutics are in clinical development targeting the TME to increase cytotoxic drug delivery, decrease immunosuppressive cell presence and attack cancer stem cells (CSCs). Immune checkpoint inhibitors, cancer vaccines and other immunotherapies are actively being studied and novel combinations of targeted agents are being pursued. There is a sense of optimism in the oncology community that these scientific advances will translate into improved outcomes for patients with PDAC in the proximate future. In this review, we examine various novel therapeutics under clinical development with a focus on stromal disrupting agents, immunotherapeutics and DNA damage repair strategies.
There is an unmet clinical need for improved tissue and liquid biopsy tools for cancer detection. We investigated the proteomic profile of extracellular vesicles and particles (EVPs) in 426 human ...samples from tissue explants (TEs), plasma, and other bodily fluids. Among traditional exosome markers, CD9, HSPA8, ALIX, and HSP90AB1 represent pan-EVP markers, while ACTB, MSN, and RAP1B are novel pan-EVP markers. To confirm that EVPs are ideal diagnostic tools, we analyzed proteomes of TE- (n = 151) and plasma-derived (n = 120) EVPs. Comparison of TE EVPs identified proteins (e.g., VCAN, TNC, and THBS2) that distinguish tumors from normal tissues with 90% sensitivity/94% specificity. Machine-learning classification of plasma-derived EVP cargo, including immunoglobulins, revealed 95% sensitivity/90% specificity in detecting cancer. Finally, we defined a panel of tumor-type-specific EVP proteins in TEs and plasma, which can classify tumors of unknown primary origin. Thus, EVP proteins can serve as reliable biomarkers for cancer detection and determining cancer type.
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•Proteomic profiles of extracellular vesicles and particles (EVPs) from 426 human samples•Identification of pan-EVP markers•Characterization of tumor-derived EVP markers in human tissues and plasma•EVP proteins can be useful for cancer detection and determining cancer type
A comprehensive proteomic analysis of extracellular vesicles and particles (EVPs) from 426 human samples identifies pan-EVP markers, biomarkers for EVP isolation, for cancer detection and determining cancer type.
Neuroendocrine tumors are uncommon tumors that are histopathologically and biologically heterogeneous and include the multiple endocrine neoplasia (MEN) 1 and 2 syndromes. The morbidity of MEN-1 and ...MEN-2 is often due to the symptomatology of the endocrine hormones produced, and the mortality mainly occurs from hepatic dysfunction incurred by liver metastases. At present, there is essentially no effective cure once the tumor has metastasized to the liver.
We present a patient with progressive, metastatic MEN-1 with the classic '3 P's' triad of neuroendocrine tumor of the pancreas, parathyroid adenoma and a pituitary adenoma.
After progression on high-dose Sandostatin LAR (60 mg/month) and multiple surgeries, the patient had a partial response (40% decrease) to a novel regimen of capecitabine and temozolomide (CAPTEM) and progression-free survival of 18 months. He had minor grade 1 toxicities and no grade 2, 3 or 4 toxicities.
The history and treatment options for MEN-1/2 cancers are reviewed, as well as the data behind our novel regimen, CAPTEM.
The CAPTEM regimen is a tolerable, safe, easy to administer oral regimen with possible efficacy for MEN-1 tumors.
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