Multiplexed Evaluation of Microdosed Antineoplastic Agents In Situ in the Tumor Microenvironment of Patients with Soft Tissue Sarcoma.

PURPOSE: A persistent issue in cancer drug development is the discordance between robust antitumor drug activity observed in laboratory models and the limited benefit frequently observed when patients are treated with the same agents in clinical trials. Difficulties in accurately modeling the complexities of human tumors may underlie this problem. To address this issue, we developed Comparative In Vivo Oncology (CIVO), which enables in situ investigation of multiple microdosed drugs simultaneously in a patient's tumor. This study was designed to test CIVO's safety and feasibility in patients with soft tissue sarcoma (STS). PATIENTS AND METHODS: We conducted a single arm, prospective, 13-patient pilot study. Patients scheduled for incisional biopsy or tumor resection were CIVO-injected 1 to 3 days prior to surgery. Saline or microdoses of anticancer agents were percutaneously injected into the tumor in a columnar fashion through each of eight needles. Following excision, drug responses were evaluated in the injected tissue. RESULTS: The primary objective was met, establishing CIVO's feasibility and safety. Device-related adverse events were limited to transient grade 1 nonserious events. In addition, biomarker evaluation of localized tumor response to CIVO microinjected drugs by IHC or with NanoString GeoMx Digital Spatial Profiler demonstrated consistency with known mechanisms of action of each drug, impact on the tumor microenvironment, and historic clinical activity. CONCLUSIONS: These results are an advance toward use of CIVO as a translational research tool for early evaluation of investigational agents and drug combinations in a novel approach to phase 0 trials.See related commentary by Sleijfer and Lolkema, p. 3897.

Voruciclib, a clinical stage oral CDK9 inhibitor, represses MCL-1 and sensitizes high-risk Diffuse Large B-cell Lymphoma to BCL2 inhibition.

Aberrant regulation of BCL-2 family members enables evasion of apoptosis and tumor resistance to chemotherapy. BCL-2 and functionally redundant counterpart, MCL-1, are frequently over-expressed in high-risk diffuse large B-cell lymphoma (DLBCL). While clinical inhibition of BCL-2 has been achieved with the BH3 mimetic venetoclax, anti-tumor efficacy is limited by compensatory induction of MCL-1. Voruciclib, an orally bioavailable clinical stage CDK-selective inhibitor, potently blocks CDK9, the transcriptional regulator of MCL-1. Here, we demonstrate that voruciclib represses MCL-1 protein expression in preclinical models of DLBCL. When combined with venetoclax in vivo, voruciclib leads to model-dependent tumor cell apoptosis and tumor growth inhibition. Strongest responses were observed in two models representing high-risk activated B-cell (ABC) DLBCL, while no response was observed in a third ABC model, and intermediate responses were observed in two models of germinal center B-cell like (GCB) DLBCL. Given the range of responses, we show that CIVO, a multiplexed tumor micro-dosing technology, represents a viable functional precision medicine approach for differentiating responders from non-responders to BCL-2/MCL-1 targeted therapy. These findings suggest that the combination of voruciclib and venetoclax holds promise as a novel, exclusively oral combination therapy for a subset of high-risk DLBCL patients.

Multidrug Analyses in Patients Distinguish Efficacious Cancer Agents Based on Both Tumor Cell Killing and Immunomodulation.

The vision of a precision medicine-guided approach to novel cancer drug development is challenged by high intratumor heterogeneity and interpatient diversity. This complexity is rarely modeled accurately during preclinical drug development, hampering predictions of clinical drug efficacy. To address this issue, we developed Comparative In Vivo Oncology (CIVO) arrayed microinjection technology to test tumor responsiveness to simultaneous microdoses of multiple drugs directly in a patient's tumor. Here, in a study of 18 canine patients with soft tissue sarcoma (STS), CIVO captured complex, patient-specific tumor responses encompassing both cancer cells and multiple immune infiltrates following localized exposure to different chemotherapy agents. CIVO also classified patient-specific tumor resistance to the most effective agent, doxorubicin, and further enabled assessment of a preclinical autophagy inhibitor, PS-1001, to reverse doxorubicin resistance. In a CIVO-identified subset of doxorubicin-resistant tumors, PS-1001 resulted in enhanced antitumor activity, increased infiltration of macrophages, and skewed this infiltrate toward M1 polarization. The ability to evaluate and cross-compare multiple drugs and drug combinations simultaneously in living tumors and across a diverse immunocompetent patient population may provide a foundation from which to make informed drug development decisions. This method also represents a viable functional approach to complement current precision oncology strategies. Cancer Res; 77(11); 2869-80. ©2017 AACR.

A Platform for Rapid, Quantitative Assessment of Multiple Drug Combinations Simultaneously in Solid Tumors In Vivo.

While advances in high-throughput screening have resulted in increased ability to identify synergistic anti-cancer drug combinations, validation of drug synergy in the in vivo setting and prioritization of combinations for clinical development remain low-throughput and resource intensive. Furthermore, there is currently no viable method for prospectively assessing drug synergy directly in human patients in order to potentially tailor therapies. To address these issues we have employed the previously described CIVO platform and developed a quantitative approach for investigating multiple combination hypotheses simultaneously in single living tumors. This platform provides a rapid, quantitative and cost effective approach to compare and prioritize drug combinations based on evidence of synergistic tumor cell killing in the live tumor context. Using a gemcitabine resistant model of pancreatic cancer, we efficiently investigated nine rationally selected Abraxane-based combinations employing only 19 xenografted mice. Among the drugs tested, the BCL2/BCLxL inhibitor ABT-263 was identified as the one agent that synergized with Abraxane® to enhance acute induction of localized apoptosis in this model of human pancreatic cancer. Importantly, results obtained with CIVO accurately predicted the outcome of systemic dosing studies in the same model where superior tumor regression induced by the Abraxane/ABT-263 combination was observed compared to that induced by either single agent. This supports expanded use of CIVO as an in vivo platform for expedited in vivo drug combination validation and sets the stage for performing toxicity-sparing drug combination studies directly in cancer patients with solid malignancies.

Minimally invasive in tumor multidrug comparative analysis with contrast-enhanced MRI in mice.

PURPOSE: To facilitate decision making in the oncology clinic, technologies have recently been developed to independently inject and assess multiple anticancer agents directly in a patient's tumor. To increase the flexibility of this approach beyond histological readouts of response, contrast-enhanced MRI was evaluated for the detection of cell death in living tumors after injection. METHODS: A six-needle arrayed microinjection device designed to provide head-to-head comparisons of chemotherapy responses in living tumors was used. Xenografted non-Hodgkin lymphoma tumors in athymic Nude-Foxn1(nu) mice were injected either with different doses of vincristine or with one needle each of vincristine, doxorubicin, bendamustine, prednisolone, mafosfamide, and a vehicle control. To assess drug responses, measurements of enhancement by T1-weighted contrast-enhanced MRI were made for individual sites at 24, 48, and 72 h after injection. For comparison, histological evaluations of cell death were obtained after tumor resection. RESULTS: Measurements of MRI enhancement at injection sites showed a significant (P < 0.001) positive regression slope as a function of vincristine dose. Average MRI measurements were closely correlated with cell death by hematoxylin and eosin staining (R = 0.81; P = 0.001). CONCLUSION: Contrast-enhanced MRI has the potential to replace or augment histological analyses of tumor responses to microinjected doses of chemotherapy agents with potential application in selecting optimal chemotherapy regimens. Magn Reson Med 76:946-952, 2016. © 2015 Wiley Periodicals, Inc.

A technology platform to assess multiple cancer agents simultaneously within a patient's tumor.

A fundamental problem in cancer drug development is that antitumor efficacy in preclinical cancer models does not translate faithfully to patient outcomes. Much of early cancer drug discovery is performed under in vitro conditions in cell-based models that poorly represent actual malignancies. To address this inconsistency, we have developed a technology platform called CIVO, which enables simultaneous assessment of up to eight drugs or drug combinations within a single solid tumor in vivo. The platform is currently designed for use in animal models of cancer and patients with superficial tumors but can be modified for investigation of deeper-seated malignancies. In xenograft lymphoma models, CIVO microinjection of well-characterized anticancer agents (vincristine, doxorubicin, mafosfamide, and prednisolone) induced spatially defined cellular changes around sites of drug exposure, specific to the known mechanisms of action of each drug. The observed localized responses predicted responses to systemically delivered drugs in animals. In pair-matched lymphoma models, CIVO correctly demonstrated tumor resistance to doxorubicin and vincristine and an unexpected enhanced sensitivity to mafosfamide in multidrug-resistant lymphomas compared with chemotherapy-naïve lymphomas. A CIVO-enabled in vivo screen of 97 approved oncology agents revealed a novel mTOR (mammalian target of rapamycin) pathway inhibitor that exhibits significantly increased tumor-killing activity in the drug-resistant setting compared with chemotherapy-naïve tumors. Finally, feasibility studies to assess the use of CIVO in human and canine patients demonstrated that microinjection of drugs is toxicity-sparing while inducing robust, easily tracked, drug-specific responses in autochthonous tumors, setting the stage for further application of this technology in clinical trials.

EGFR/Ras/MAPK signaling mediates adult midgut epithelial homeostasis and regeneration in Drosophila.

Many tissues in higher animals undergo dynamic homeostatic growth, wherein damaged or aged cells are replaced by the progeny of resident stem cells. To maintain homeostasis, stem cells must respond to tissue needs. Here we show that in response to damage or stress in the intestinal (midgut) epithelium of adult Drosophila, multiple EGFR ligands and rhomboids (intramembrane proteases that activate some EGFR ligands) are induced, leading to the activation of EGFR signaling in intestinal stem cells (ISCs). Activation of EGFR signaling promotes ISC division and midgut epithelium regeneration, thereby maintaining tissue homeostasis. ISCs defective in EGFR signaling cannot grow or divide, are poorly maintained, and cannot support midgut epithelium regeneration after enteric infection by the bacterium Pseudomonas entomophila. Furthermore, ISC proliferation induced by Jak/Stat signaling is dependent upon EGFR signaling. Thus the EGFR/Ras/MAPK signaling pathway plays central, essential roles in ISC maintenance and the feedback system that mediates intestinal homeostasis.

Cytokine/Jak/Stat signaling mediates regeneration and homeostasis in the Drosophila midgut.

Cells in intestinal epithelia turn over rapidly due to damage from digestion and toxins produced by the enteric microbiota. Gut homeostasis is maintained by intestinal stem cells (ISCs) that divide to replenish the intestinal epithelium, but little is known about how ISC division and differentiation are coordinated with epithelial cell loss. We show here that when enterocytes (ECs) in the Drosophila midgut are subjected to apoptosis, enteric infection, or JNK-mediated stress signaling, they produce cytokines (Upd, Upd2, and Upd3) that activate Jak/Stat signaling in ISCs, promoting their rapid division. Upd/Jak/Stat activity also promotes progenitor cell differentiation, in part by stimulating Delta/Notch signaling, and is required for differentiation in both normal and regenerating midguts. Hence, cytokine-mediated feedback enables stem cells to replace spent progeny as they are lost, thereby establishing gut homeostasis.