Targeting MDSC-HTR2B to Improve Immune Checkpoint Inhibitors in Breast to Brain Metastasis.

Myeloid Derived Suppressor Cells (MDSCs) support breast cancer growth via immune suppression and non-immunological mechanisms. Although 15% of patients with breast cancer will develop brain metastasis, there is scant understanding of MDSCs' contribution within the breast-to-brain metastatic microenvironment. Utilizing co-culture models mimicking a tumor-neuron-immune microenvironment and patient tissue arrays, we identified serotonergic receptor, HTR2B, on MDSCs to upregulate pNF-κB and suppress T cell proliferation, resulting in enhanced tumor growth. In vivo murine models of metastatic and intracranial breast tumors treated with FDA-approved, anti-psychotic HTR2B antagonist, clozapine, combined with immunotherapy anti-PD-1 demonstrated a significant increase in survival and increased T cell infiltration. Collectively, these findings reveal a previously unknown role of MDSC-HTR2B in breast-to-brain metastasis, suggesting a novel and immediate therapeutic approach using neurological drugs to treat patients with metastatic breast cancer.

Baseline weight recovery and mortality risk in head and neck cancer.

BACKGROUND: As a surrogate of malnutrition, degree of weight loss and recovery from head and neck cancer (HNC) treatment is understudied. The influence of modifiable factors that affect weight, including speech/language pathology (SLP) and nutrition counseling, is also poorly defined. We characterize weight loss trends, baseline weight recovery (BWR), and the impact of interdisciplinary care on oncologic outcomes. METHODS: Retrospective cohort study assessing 266 newly diagnosed patients with HNC who completed curative-intent radiation (definitive or adjuvant) between January 2016 to January 2022. Relevant treatment factors were analyzed using multivariable Cox regression models. RESULTS: Altogether, 266 patients completed full-course radiation therapy (RT), encompassing definitive chemoRT (53.0%), surgery with chemoRT (18.4%), surgery with RT (17.7%), and RT alone (10.9%). Patient weight reached a nadir at median 3.0 months (IQR 3.0-11.3) after radiation, with a median weight loss of 12.6% (IQR 7.9-18.7). Notably, only 47.4% exhibited BWR. For those who recovered, median time to BWR was 10.5 months (IQR 3.0-24.0). On multivariable analysis, BWR by 6 months was significantly associated with overall survival (HR 0.28 [95% CI 0.10-0.76], p = 0.013), as was SLP consultation (HR 0.40 [95% CI 0.17-0.92], p = 0.031) and nutrition consultation (HR 0.34 [95% CI 0.13-0.89], p = 0.028). CONCLUSION: A high proportion of patients with HNC fail to recover baseline weight after treatment; those that do can take longer than expected to return. Failure to recover baseline weight is associated with a notable decrease in survival. Similarly, SLP and nutrition consultation are independent, modifiable determinants correlated with outcomes, supporting the emphasis on multidisciplinary management. Measures to promote BWR may reduce mortality.

Patient perceptions underlying ctDNA molecular surveillance for HPV(+) oropharyngeal squamous cell carcinoma.

OBJECTIVE: Circulating tumor DNA assays have robust potential as molecular surveillance tools. They may also exacerbate patient distress without improving outcomes. We investigate patient acceptability of a validated ctHPVDNA assay (NavDx) during cancer surveillance for HPV(+) oropharyngeal cancer (OPC). METHODS: Consented HPV(+) OPC participants completed the NCCN Distress Thermometer, the Hospital Anxiety Depression Scale (HADS), and the Functional Assessment of Cancer Therapy-General (FACT-G) scale both (1) before NavDx blood draw, and (2) after results were provided. Patients then completed a series of focused questions related to their perceptions of the assay. RESULTS: Overall, 55 patients completed the study, with 98.2 % showing no recurrence. For the NCCN Distress Thermometer, median patient distress decreased (2.0 (IQR 1-5) vs. 1.0 (IQR 0-3)) (p < 0.001) in association with NavDx. Using scores ≥ 4 as a cutoff point to define clinically elevated distress, scores also improved (36.4 % vs. 18.2 %, p = 0.031). For HADS, anxiety significantly improved (5.0 (IQR 2.0-7.0) vs. 3.0 (IQR 1.0-6.5)) (p = 0.037), but not depression (3.0 (IQR 1.0-7.0) vs. 3.0 (IQR 1.0-6.5)) (p = 0.870). FACT-G scores showed no substantial differences. On survey questionnaires, 95.5 % of patients believed the test to be helpful, and 100 % felt "somewhat" or "extremely" confident in the assay as a monitoring tool. While 59.1 % felt that it reduced anxiety, 88.4 % concordantly felt that it did not introduce anxiety. CONCLUSION: ctHPVDNA as a molecular surveillance tool reduced distress levels in HPV(+) OPC patients, with notably high patient confidence in the approach. Further investigation is warranted to judiciously incorporate this emerging modality in surveillance guidelines.

A new Neu-a syngeneic model of spontaneously metastatic HER2-positive breast cancer.

Metastatic disease results from the dissemination of tumor cells beyond their organ of origin to grow in distant organs and is the primary cause of death in patients with advanced breast cancer. Preclinical murine models in which primary tumors spontaneously metastasize are valuable tools for studying metastatic progression and novel cancer treatment combinations. Here, we characterize a novel syngeneic murine breast tumor cell line that provides a model of spontaneously metastatic neu-expressing breast cancer with quicker onset of widespread metastases after orthotopic mammary implantation in immune-competent NeuN mice. The NT2.5-lung metastasis (-LM) cell line was derived from serial passaging of tumor cells that were macro-dissected from spontaneous lung metastases after orthotopic mammary implantation of parental NT2.5 cells. Within one week of NT2.5-LM implantation, metastases are observed in the lungs. Within four weeks, metastases are also observed in the bones, spleen, colon, and liver. We demonstrate that NT2.5-LM metastases are positive for NeuN-the murine equivalent of human epidermal growth factor 2 (HER2). We further demonstrate altered expression of markers of epithelial-to-mesenchymal transition (EMT), suggestive of their enhanced metastatic potential. Genomic analyses support these findings and reveal enrichment in EMT-regulating pathways. In addition, the metastases are rapidly growing, proliferative, and responsive to HER2-directed therapy. The new NT2.5-LM model provides certain advantages over the parental NT2/NT2.5 model, given its more rapid and spontaneous development of metastases. Besides investigating mechanisms of metastatic progression, this new model may be used for the rationalized development of novel therapeutic interventions and assessment of therapeutic responses.

Mimicking the breast metastatic microenvironment: characterization of a novel syngeneic model of HER2+ breast cancer.

Preclinical murine models in which primary tumors spontaneously metastasize to distant organs are valuable tools to study metastatic progression and novel cancer treatment combinations. Here, we characterize a novel syngeneic murine breast tumor cell line, NT2.5-lung metastasis (-LM), that provides a model of spontaneously metastatic neu-expressing breast cancer with quicker onset of widespread metastases after orthotopic mammary implantation in immune-competent NeuN mice. Within one week of orthotopic implantation of NT2.5-LM in NeuN mice, distant metastases can be observed in the lungs. Within four weeks, metastases are also observed in the bones, spleen, colon, and liver. Metastases are rapidly growing, proliferative, and responsive to HER2-directed therapy. We demonstrate altered expression of markers of epithelial-to-mesenchymal transition (EMT) and enrichment in EMT-regulating pathways, suggestive of their enhanced metastatic potential. The new NT2.5-LM model provides more rapid and spontaneous development of widespread metastases. Besides investigating mechanisms of metastatic progression, this new model may be used for the rationalized development of novel therapeutic interventions and assessment of therapeutic responses targeting distant visceral metastases.

Comparative impact of grade on mortality across salivary cancers: A novel, unifying staging system.

BACKGROUND: The comparative impact of histologic variants and grade has not been well described. METHODS: Salivary cancer histologies were profiled using hospital and population-based cancer registries. Multivariable models were employed to assess relationships between histology, grade, and survival. RESULTS: On univariate analysis, histologic variants exhibited a wide spectrum of mortality risk (5-year overall survival (OS): 86% (acinic cell carcinoma), 78% (mucoepidermoid carcinoma), 72% (adenoid cystic carcinoma), 64% (carcinoma ex-pleomorphic adenoma), 52% (adenocarcinoma NOS), and 47% (salivary duct carcinoma) (p < 0.001). However, on multivariable analysis these differences largely vanished. Worsening grade corresponded with deteriorating survival (5-year OS: 89% [low-grade], 81% [intermediate-grade], 45% [high-grade]; p < 0.001), which was upheld on multivariable analysis and propensity score matching. Recursive partitioning analysis generated TNM + G schema (c-index 0.75) superior to the existing system (c-index 0.73). CONCLUSION: Grade represents a primary determinant of salivary cancer prognosis. Integrating grade into stage strengthens current staging systems.

Knowledge and Understanding of Radiation Therapy Among Patients With Breast Cancer From Culturally Diverse Backgrounds at a Safety-Net Hospital.

INTRODUCTION: Comprehensive understanding of oncologic treatment is essential for shared decision-making. However, comprehension of information in radiation oncology consults is poorly understood, particularly among Spanish-speaking patients at safetynet hospitals. The purpose of this pilot study was to examine post-consultation radiation oncology knowledge and health literacy among breast cancer patients from culturally diverse backgrounds. METHODS: After consultation for curative post-operative breast radiotherapy (cT1-4N1-3M0), the Radiation Oncology Knowledge Assessment Survey (ROKAS) was administered to Spanish- and English-speaking patients ≥ 18 years old, from January 2021 to January 2022 at a safety-net hospital. Radiation knowledge was assessed using the ROKAS which included eight radiation-specific multiple-choice questions and two separate questions regarding short- and long-term side effects. Additional independent variables included validated questionnaires related to health literacy, health numeracy, acculturation, primary language, and sociodemographic factors. Bivariate Pearson correlations and T-test analyses were conducted to examine the relationship between the independent variables and post-consultation radiation knowledge. RESULTS: Fifty ROKAS were obtained from 25 English- and 25 Spanish-speaking breast cancer patients (median age 57 [IQR 49.75-62.25]). When compared to Englishspeaking patients, Spanish-speaking patients had lower health literacy, health numeracy, and acculturation. There was no difference in the multiple-choice ROKAS score between English- and Spanish-speakers, or correlation with the other independent factors. Higher health numeracy correlated with a higher accuracy for identifying short-term side effects. Lower accuracy of identifying long-term side effects was seen in patients with lower education levels, health literacy, health numeracy, and acculturation, with the most missed long-term side effects being arm swelling, skin toxicity, and heart toxicity. CONCLUSIONS: Patients with low health literacy, health numeracy, acculturation, and education levels as well as Spanish-speaking patients were associated with poor understanding of radiotherapy long-term side effects. Determining barriers to radiation knowledge is crucial to improve shared decision-making between patients and providers in a culturally diverse population.

Deletion of monoamine oxidase A in a prostate cancer model enhances anti-tumor immunity through reduced immune suppression.

We have previously shown that monoamine oxidase A (MAO A) mediates prostate cancer growth and metastasis. Further, MAO A/Pten double knockout (DKO) mice were generated and demonstrated that the deletion of MAO A delayed prostate tumor development in the Pten knockout mouse model of prostate adenocarcinoma. Here, we investigated its effect on immune cells in the tumor microenvironment in MAO A/Pten DKO mouse model. Our results shows that Paraffin embedded prostate tissues from MAO A/Pten DKO mice had elevated markers of immune stimulation (CD8+ cytotoxic T cells, granzyme B, and IFNγ) and decreased expression of markers of immune suppression (FoxP3, CD11b, HIF-1-alpha, and arginase 1) compared to parental Pten knockouts (MAO A wildtype). CD11b+ myeloid derived suppressor cells (MDSC) were the primary immunosuppressive cell types in these tumors. The data suggest that deletion of MAO A reduces immune suppression in prostate tumors to enhance antitumor immunity in prostate cancer. Thus, MAO A inhibitor may alleviate immune suppression, increase the antitumor immune response and be used for cancer immunotherapy.

Patterns of Use of Stereotactic Body Radiation Therapy Compared With Surgery for Definitive Treatment of Primary Early-stage Non-small Cell Lung Cancer.

OBJECTIVE: As stereotactic body radiation therapy (SBRT) becomes widely available for early-stage non-small cell lung cancer (NSCLC), there may be concerns in the surgical community that SBRT is being offered for patients with operable tumors, even though surgery is standard of care. We evaluated the trends in SBRT and surgery over time for patients with NSCLC. MATERIALS AND METHODS: The National Cancer Database was queried for patients with node-negative NSCLC ≤5 cm from 2004 to 2016. The relationships between definitive local treatment modalities and year were analyzed using a multinomial regression model while controlling for other covariates. RESULTS: Among the 202,367 patients who met the inclusion criteria, there was a steady decrease in mean tumor size in all treatment modalities, from 2.44 cm (SD=1.08) to 2.25 cm (SD=1.00) over the study period. In the multinomial model, the probability of receiving lobectomy demonstrated a slight decline from 58% (2004) to 53% (2016). The use of SBRT increased from 1% to 20%, while patients receiving no therapy declined from 27% to 16%. The likelihood of SBRT increased with year of diagnosis (P<0.0001) and decreasing tumor size (P<0.0001), compared with lobectomy. Age, race, income, facility, and Charlson-Deyo score were also associated with treatment modality. CONCLUSIONS: The mean tumor size of early-stage NSCLC decreased over the study period for all treatment modalities. SBRT use has increased, mostly among older patients with smaller tumors and Charlson-Deyo scores ≥3. The increase in SBRT contributed to the significant decline in patients who had no therapy.

Entinostat Decreases Immune Suppression to Promote Antitumor Responses in a HER2+ Breast Tumor Microenvironment.

Therapeutic combinations to alter immunosuppressive, solid tumor microenvironments (TME), such as in breast cancer, are essential to improve responses to immune checkpoint inhibitors (ICI). Entinostat, an oral histone deacetylase inhibitor, has been shown to improve responses to ICIs in various tumor models with immunosuppressive TMEs. The precise and comprehensive alterations to the TME induced by entinostat remain unknown. Here, we employed single-cell RNA sequencing on HER2-overexpressing breast tumors from mice treated with entinostat and ICIs to fully characterize changes across multiple cell types within the TME. This analysis demonstrates that treatment with entinostat induced a shift from a protumor to an antitumor TME signature, characterized predominantly by changes in myeloid cells. We confirmed myeloid-derived suppressor cells (MDSC) within entinostat-treated tumors associated with a less suppressive granulocytic (G)-MDSC phenotype and exhibited altered suppressive signaling that involved the NFκB and STAT3 pathways. In addition to MDSCs, tumor-associated macrophages were epigenetically reprogrammed from a protumor M2-like phenotype toward an antitumor M1-like phenotype, which may be contributing to a more sensitized TME. Overall, our in-depth analysis suggests that entinostat-induced changes on multiple myeloid cell types reduce immunosuppression and increase antitumor responses, which, in turn, improve sensitivity to ICIs. Sensitization of the TME by entinostat could ultimately broaden the population of patients with breast cancer who could benefit from ICIs.

Radiation Therapy for Brain Metastases: A Systematic Review.

PURPOSE: This evidence report synthesizes the available evidence on radiation therapy for brain metastases. METHODS AND MATERIALS: The literature search included PubMed, EMBASE, Web of Science, Scopus, CINAHL, clinicaltrials.gov, and published guidelines in July 2020; independently submitted data, expert consultation, and contacting authors. Included studies were randomized controlled trials (RCTs) and large observational studies (for safety assessments), evaluating whole brain radiation therapy (WBRT) and stereotactic radiosurgery (SRS) alone or in combination, as initial or postoperative treatment, with or without systemic therapy for adults with brain metastases due to lung cancer, breast cancer, or melanoma. RESULTS: Ninety-seven studies reported in 189 publications were identified, but the number of analyses was limited owing to different intervention and comparator combinations as well as insufficient reporting of outcome data. Risk of bias varied, and 25 trials were terminated early, predominantly owing to poor accrual. The combination of SRS plus WBRT compared with SRS alone or WBRT alone showed no statistically significant difference in overall survival (hazard ratio [HR], 1.09; 95% confidence interval [CI], 0.69%-1.73%; 4 RCTs) or death owing to brain metastases (relative risk [RR], 0.93; 95% CI, 0.48%-1.81%; 3 RCTs). Radiation therapy after surgery did not improve overall survival compared with surgery alone (HR, 0.98; 95% CI, 0.76%-1.26%; 5 RCTs). Data for quality of life, functional status, and cognitive effects were insufficient to determine effects of WBRT, SRS, or postsurgery interventions. We did not find systematic differences across interventions in serious adverse events, number of adverse events, radiation necrosis, fatigue, or seizures. WBRT plus systemic therapy (RR 1.44; 95% CI, 1.03%-2.00%; 14 studies) was associated with increased risks for vomiting compared with WBRT alone. CONCLUSIONS: Despite the substantial research literature on radiation therapy, comparative effectiveness information is limited. There is a need for more data on patient-relevant outcomes such as quality of life, functional status, and cognitive effects.

Acute Respiratory Events and Dosimetry of Total Body Irradiation Patients Using In Vivo Lung Dose Monitoring and Custom Lung Block Adaptation.

PURPOSE: Most myeloablative regimens before stem cell transplant involved total body irradiation (TBI). Pulmonary complications from TBI contribute to treatment-related mortality and toxicity. We report the rate of acute respiratory complications after TBI at our institution. In an exploratory analysis, we investigated differences in dosimetry between patients who did and did not experience respiratory complications. METHODS AND MATERIALS: In this single institution retrospective study, 49 patients received TBI from 2016 to 2018 and had dosimetry data available for analysis. Patients were prescribed 1200 cGy to be delivered over 6 fractions. Lung doses were limited using custom lung blocks. Clinical lung complications (eg, coughing and shortness of breath) were reviewed for the hospitalization period during transplant, at 4 months after transplant, and at 1 year after transplant. Supplemental oxygen use during the hospitalization period was also reported. Median anterior-posterior diameter at the umbilicus, body mass index, and lung doses were compared between patients with and without respiratory complications using a Mann-Whitney U test. RESULTS: During the hospitalization period, 14% (n = 7) of patients used supplemental oxygen administered by nasal canula and 16% (n = 8) experienced respiratory symptoms. At the 4-month follow-up, 16% (n = 8) of patients had documented respiratory symptoms. Respiratory symptoms were grade 1 to 2 except for one grade 3 attributed to infection during the hospitalization period and another grade 3 due to infection during the 4-month follow-up. At 1-year post-TBI, 4% (n = 2) of patients reported grade 1 to 2 chronic cough. Patients with respiratory complications at the 4-month follow-up had a larger umbilical anterior-posterior diameter (31.5 cm vs 26.5 cm, P = .01) and body mass index (34.5 kg/m2 vs 29.7 kg/m2, P = .02) than patients without respiratory complication. Respiratory complications were not associated with higher lung doses. CONCLUSIONS: There was no respiratory-related mortality using the individualized planning technique described here. Acute and chronic respiratory complications were minor, with the most significant intervention requiring antibiotics for respiratory infection.

Correction to: A Radiation Oncologist's Guide to Axillary Management in Breast Cancer: A Walk Through the Trials.

[This corrects the article PMC7093898.].

Novel Microbial-Based Immunotherapy Approach for Crohn's Disease.

Background: Current Crohn's disease (CD) therapies focus on suppressing immune function and come with consequent risk, such as infection and cancer. Notwithstanding, most CD patients still experience disease progression. There is a need for new CD treatment strategies that offer better health outcomes for patients. Aims: To assess safety, efficacy, and tolerability of a novel microbial-derived immunotherapy, QBECO, that aims to restore rather than suppress immune function in CD. Methods: A randomized, double-blind, placebo-controlled trial was conducted in 68 patients with moderate-to-severe CD. Primary endpoints: safety and Week 8 clinical improvement. Secondary endpoints: Week 8 clinical response and remission. Week 8 responders continued blinded treatment through Week 16; non-responders received open-label QBECO from Weeks 9-16. Exploratory analyses included immune biomarker and genotype assessments. Results: QBECO was well-tolerated. Mean reduction in Crohn's Disease Activity Index (CDAI) score was -68 for QBECO vs. -31 for placebo at Week 8. Improvement with QBECO continued through Week 16 (-130 CDAI reduction). Week 8 QBECO clinical response, improvement and remission rates were 41.2%, 32.4%, 29.4% vs. 26.5%, 23.5%, 23.5% for placebo. TNFα inhibitor-naïve subjects achieved higher response rates at Week 8 with QBECO (64%) vs. placebo (26%). Specific immune biomarkers were identified that linked to QBECO response. Conclusion: This proof-of-concept study supports further investigation for the use of QBECO as a novel immunotherapy approach for CD. Biomarker analyses suggests it may be feasible to personalize CD treatment with QBECO. Larger trials are now needed to confirm clinical improvement and the unique biological findings. Clinical Trial Number: NCT01809275 (https://clinicaltrials.gov/ct2/show/NCT01809275).

A Radiation Oncologist's Guide to Axillary Management in Breast Cancer: A Walk Through the Trials.

PURPOSE OF REVIEW: The axilla is the most common site for breast cancer nodal metastases. Aggressive management includes axillary lymph node dissection (ALND), radiotherapy, and systemic therapy, but carries the risks of lymphedema and "overtreatment". We review the clinical trials that led to de-escalation of axillary management and their nuances that are often overlooked. RECENT FINDINGS: With the rise of sentinel lymph node biopsy, several trials conclude that ALND can be omitted in specific populations. However, the subtleties in those trials, such as the role of chemotherapy and radiotherapy, have yet to be clarified. These discussions carry forward into the era of neoadjuvant chemotherapy, where ongoing trials investigate who needs ALND and/or radiation. SUMMARY: This review examines the clinical trials that form the standard of care, and highlights why axillary management is individualized today.

Targetable vulnerabilities in T- and NK-cell lymphomas identified through preclinical models.

T- and NK-cell lymphomas (TCL) are a heterogenous group of lymphoid malignancies with poor prognosis. In contrast to B-cell and myeloid malignancies, there are few preclinical models of TCLs, which has hampered the development of effective therapeutics. Here we establish and characterize preclinical models of TCL. We identify multiple vulnerabilities that are targetable with currently available agents (e.g., inhibitors of JAK2 or IKZF1) and demonstrate proof-of-principle for biomarker-driven therapies using patient-derived xenografts (PDXs). We show that MDM2 and MDMX are targetable vulnerabilities within TP53-wild-type TCLs. ALRN-6924, a stapled peptide that blocks interactions between p53 and both MDM2 and MDMX has potent in vitro activity and superior in vivo activity across 8 different PDX models compared to the standard-of-care agent romidepsin. ALRN-6924 induced a complete remission in a patient with TP53-wild-type angioimmunoblastic T-cell lymphoma, demonstrating the potential for rapid translation of discoveries from subtype-specific preclinical models.

Redefining Health: The Evolution of Health Ideas from Antiquity to the Era of Value-Based Care.

The current healthcare system in the United States (US) is characterized by high costs and poor patient outcomes. A value-based healthcare system, centered on providing the highest quality of care for the lowest cost, is the country's chosen solution for its healthcare crisis. As the US transitions to a value-based model, a new definition of health is necessary to clearly define what constitutes a healthy state. However, such a definition is impossible to develop without a proper understanding of what "health" actually means. To truly understand its meaning, one must have a thorough historical understanding of the changes in the concept of health and how it has evolved to reflect the beliefs and scientific understanding of each time period. Thus, this review summarizes the changes in the definition of health over time in order to provide a context for the definition needed today. We then propose a new definition of health that is specifically tailored to providers working in the era of value-based care.

Systemic delivery of chTNT-3/CpG immunoconjugates for immunotherapy in murine solid tumor models.

CpG oligodeoxynucleotides (CpG) potently activate the immune system by mimicking microbial DNA. Conjugation of CpG to chTNT-3, an antibody targeting the necrotic centers of tumors, enabled CpG to accumulate in tumors after systemic delivery, where it can activate the immune system in the presence of tumor antigens. CpG chemically conjugated to chTNT-3 (chTNT-3/CpG) were compared to free CpG in their ability to stimulate the immune system in vitro and reduce tumor burden in vivo. In subcutaneous Colon 26 adenocarcinoma and B16-F10 melanoma models in BALB/c and C57BL/6 mice, respectively, chTNT-3/CpG, free CpG, or several different control constructs were administered systemically. Intraperitoneal injections of chTNT-3/CpG delayed tumor growth and improved survival and were comparable to intratumorally administered CpG. Compared to saline-treated mice, chTNT-3/CpG-treated mice had smaller average tumor volumes by as much as 72% in Colon 26-bearing mice and 79% in B16-bearing mice. Systemically delivered free CpG and CpG conjugated to an isotype control antibody did not reduce tumor burden or improve survival. In this study, chTNT-3/CpG retained immunostimulatory activity of the CpG moiety and enabled delivery to tumors. Because systemically administered CpG rapidly clear the body and do not accumulate into tumors, chTNT-3/CpG provide a solution to the limitations observed in preclinical and clinical trials.

Herpes simplex virus downregulation of secretory leukocyte protease inhibitor enhances human papillomavirus type 16 infection.

Herpes simplex virus (HSV) was originally implicated in the aetiology of cervical cancer, and although high-risk human papillomavirus (HPV) is now the accepted causative agent, the epidemiological link between HSV and HPV-associated cancers persists. The annexin A2 heterotetramer (A2t) has been shown to mediate infectious HPV type 16 (HPV16) uptake by human keratinocytes, and secretory leukocyte protease inhibitor (SLPI), an endogenous A2t ligand, inhibits HPV16 uptake and infection. Interestingly, HSV infection induces a sustained downregulation of SLPI in epithelial cells, which we hypothesized promotes HPV16 infection through A2t. Here, we show that in vitro infection of human keratinocytes with HSV-1 or HSV-2, but not with an HSV-1 ICP4 deletion mutant that does not downregulate SLPI, leads to a >70% reduction of SLPI mRNA and a >60% decrease in secreted SLPI protein. Consequently, we observed a significant increase in the uptake of HPV16 virus-like particles and gene transduction by HPV16 pseudovirions (two- and 2.5-fold, respectively) in HSV-1- and HSV-2-infected human keratinocyte cell cultures compared with uninfected cells, whereas exogenously added SLPI reversed this effect. Using a SiMPull (single-molecule pulldown) assay, we demonstrated that endogenously secreted SLPI interacts with A2t on epithelial cells in an autocrine/paracrine manner. These results suggested that ongoing HSV infection and resultant downregulation of local levels of SLPI may impart a greater susceptibility for keratinocytes to HPV16 infection through the host cell receptor A2t, providing a mechanism that may, in part, provide an explanation for the aetiological link between HSV and HPV-associated cancers.

Phase 1 Dose-Escalation Study with LEC/chTNT-3 and Toceranib Phosphate (Palladia®) in Dogs with Spontaneous Malignancies.

OBJECTIVES: LEC chemokine promotes TH1 responses and recruits immune cells to inflammatory sites. By linking LEC to an antibody targeting tumor necrosis, LEC/chTNT-3 can be used for the immunotherapeutic treatment of tumors. The primary objective of this study was to determine the safety profile of LEC/chTNT-3 and toceranib phosphate (Palladia®) combination therapy in dogs with spontaneous malignancies. Secondary purpose was to determine objective responses to treatment. METHODS: Twenty-three dogs with cancer were enrolled, covering nine different malignancies. In this dose escalation study, dogs received LEC/chTNT-3 for five days, and toceranib every 48 hours for the remainder of the study. Dogs received physical exams, chemistry panel, urinalysis, and complete blood counts on days 0, 10, 28 of the study, and every 6-8 weeks thereafter. RESULTS: Lethargy was noted in 13% dogs. There were no statistical differences in the prevalence of anorexia, diarrhea, thrombocytopenia, renal toxicity, or hepatic toxicity before or during the study. There were trends in increases in the prevalence of vomiting, lymphopenia, and neutropenia (all grade 2 or lower, p=0.07) over the initial 28 days of the study. By day 28, 10% of dogs had partial responses, 58% had stable disease, and 32% had progressive disease. CONCLUSIONS: LEC/chTNT-3 and toceranib were well tolerated. This combination therapy showed some biological activity against a variety of cancers at a low dose and short duration of LEC/chTNT-3 administration.