Reaching adults who smoke cigarettes in rural Appalachia: Rationale, design & analysis plan for a mixed-methods study disseminating pharmacy-delivered cessation treatment

INTRODUCTION

Unlike other U.S. geographical regions, cigarette smoking prevalence remains stagnant in rural Appalachia. One avenue for reaching rural residents with evidence-based smoking cessation treatments could be utilizing community pharmacists. This paper describes the design, rationale, and analysis plan for a mixed-method study that will determine combinations of cessation treatment components that can be integrated within community pharmacies in rural Appalachia. The aim is to quantify the individual and synergistic effects of five highly disseminable and sustainable cessation components in a factorial experiment.

METHODS

This sequential, mixed-method research design, based on the RE-AIM (Reach, Effectiveness, Adoption, Implementation, and Maintenance) framework, will use a randomized controlled trial with a 25 fully crossed factorial design (32 treatment combinations) to test, alone and in combination, the most effective evidence-based cessation components: (1) QuitAid (yes vs. no) (2) tobacco quit line (yes vs. no) (3) SmokefreeTXT (yes vs. no) (4) combination NRT lozenge + NRT patch (vs. NRT patch alone), and (5) eight weeks of NRT (vs. standard four weeks).

RESULTS

Logistic regression will model abstinence at six-months, including indicators for the five treatment factors and all two-way interactions between the treatment factors. Demographic and smoking history variables will be considered to assess potential effect modification. Poisson regression will model quit attempts and percent of adherence to treatment components as secondary outcomes.

CONCLUSION

This study will provide foundational evidence on how community pharmacies in medically underserved, rural regions can be leveraged to increase utilization of existing evidence-based tobacco cessation resources for treating tobacco dependence.

CLINICAL TRIALS

NCT05660525.

Secondary Analysis of RRx-001 on the Incidence of Related Toxicities in Patients Treated with Concomitant Chemoradiation for Locally Advanced Head and Neck Cancer

PURPOSE/OBJECTIVE(S)

The results of an open-labeled Phase 2a trial (PREVLAR) suggested that infusion of RRx-001 (bromonitrozidine), a nitrogen-containing NLRP3 inhibitor and Nrf2 activator, attenuated the course and severity of severe oral mucositis (SOM) associated CRT (cisplatin/IMRT) in cancers of the mouth or OPC without impeding tumor response.1 Given its mechanism of action and the shared biology of radiation injury pathogenesis among other exposed tissues, we investigated the potential halo effect of RRx-001 on other regimen-related toxicities.

MATERIALS/METHODS

PREVLAR was a multi-center, open-label randomized trial in which patients (n = 46) having locally advanced, histologically confirmed SCC of the OC or OPC were centrally randomized to one of four arms. Arms 1-3 received 2 weekly doses of RRx-001 (4 mg/dose) beginning 2 weeks before the start of CRT. Arm 2 (n = 11) received 2 additional RRx-001 infusions during weeks 2 and 5 and patients in Arm 3 (n = 13) received weekly RRx-001 for the first 6 weeks of CRT. 10 mg of dexamethasone was administered before RRx-001 infusions. Arm 4 (n = 10), the control, received CRT only. Adverse events (AEs) were assessed using CTCAE v5. All patients received standard regimens of IMRT (daily fractions of 2-2.2 Gy/minimum cumulative dose of 55 Gy) plus either weekly or tri-weekly cisplatin.

RESULTS

Consistent with the observation that RRx-001 was most efficacious in attenuating the course of SOM when administered only prior to CRT (Arm 1) or prior to CRT with additional dosing on weeks 2 and 5 (Arm 2), compared to Arm 3 or control, the same dosing schedule appeared to be impactful on signs and symptoms of radiation-associated damage with tissues such as salivary glands and skin (Table 1). In particular, compared to control patients, patients in Arms 1 and 2 had a lower incidence of dry mouth (none vs. 60%), dysphagia (none vs. 70%), salivary duct inflammation (none vs. 30%), candida infection (9.1% vs 40%), radiation associated skin injury (Arm 1 none, Arm 2 18.2%, control 70%) and weight loss (none vs. 50%) as examples.

CONCLUSION

In this small proof of concept trial, RRx-001 infusion resulted in a reduction of multiple, biologically-related, side effects associated with a standard chemoradiation regimen used to the treatment of head and neck cancers. KEVLAR, a larger Phase 2b trial is planned to begin enrollment in Q4 of 2023 at about thirty sites in North America.

A Local and Abscopal Effect Observed with Liposomal Encapsulation of Intratumorally Injected Oncolytic Adenoviral Therapy

This study evaluated the in vivo therapeutic efficacy of oncolytic serotype 5 adenovirus TAV255 in CAR-deficient tumors. In vitro experiments were performed with cell lines that expressed different levels of CAR (HEK293, A549, CT26, 4T1, and MCF-7). Low CAR cells, such as CT26, were poorly transduced by Ad in vitro unless the adenovirus was encapsulated in liposomes. However, the CT26 tumor in an immune-competent mouse model responded to the unencapsulated TAV255; 33% of the tumors were induced into complete remission, and mice with complete remission rejected the rechallenge with cancer cell injection. Encapsulation of TAV255 improves its therapeutic efficacy by transducing more CT26 cells, as expected from in vitro results. In a bilateral tumor model, nonencapsulated TAV255 reduced the growth rate of the locally treated tumors but had no effect on the growth rate of the distant tumor site. Conversely, encapsulated TAV255-infected CT26 induced a delayed growth rate of both the primary injected tumor and the distant tumor, consistent with a robust immune response. In vivo, intratumorally injected unencapsulated adenoviruses infect CAR-negative cells with only limited efficiency. However, unencapsulated adenoviruses robustly inhibit the growth of CAR-deficient tumors, an effect that constitutes an 'in situ vaccination' by stimulating cytotoxic T cells.

A multicenter, phase 1, dose escalation clinical trial (G-FORCE-1) of XRT, RRx-001 and temozolomide followed by temozolomide +/- RRx-001 in newly diagnosed glioblastoma

Introduction

The current standard of care for newly diagnosed glioblastoma (GBM) is maximum surgical resection followed by concurrent treatment with temozolomide (TMZ) and radiotherapy (RT) and then six to twelve cycles of maintenance TMZ. RRx-001, an NLRP3 inhibitor and nitric oxide (NO) donor with chemoradiosensitizing, vascular normalizing and macrophage repolarizing properties, is currently in a Phase III trial for small cell lung cancer (SCLC). The purpose of this non-randomized trial was to establish the safety and look for a signal of clinical activity of RRx-001 as an add-on to RT and TMZ in patients with newly diagnosed glioblastoma.

Methods

In this non-randomized, open-label, two part trial called G-FORCE-1 (NCT02871843), the first four cohorts of adult patients with histologically confirmed high grade gliomas received fractionated radiotherapy (60 Gy in 30 fractions over 6 weeks), daily 75 mg/m2 temozolomide and escalating doses of once weekly RRx-001 from 0.5 mg to 4 mg according to a 3+3 design followed by a 6 week no treatment interval and then standard maintenance TMZ (150 mg/m2 Cycle 1 and 200 mg/m2 in subsequent cycles) until disease progression. The second two cohorts of patients received fractionated radiotherapy (60 Gy in 30 fractions over 6 weeks), daily 75 mg/m2 temozolomide and once weekly RRx-001 4 mg followed by a 6 week no treatment interval and then two different maintenance schedules until disease progression according to the same 3+ 3 design: 1. 0.5 mg RRx-001 once weekly + 100 mg/m2 TMZ 5 days/week for up to 6 cycles of therapy; 2. 4 mg RRx-001 once weekly + 100 mg/m2 TMZ 5 days/week for up to 6 cycles of therapyThe primary endpoint was the recommended dose/maximally tolerated dose of the combination of RRx-001, TMZ and RT. Secondary endpoints were overall survival, progression free survival, objective response rate, duration of response and clinical benefit response.

Results

A total of 16 newly diagnosed glioblastoma patients were enrolled. No dose limiting toxicities were observed and no MTD was reached. The recommended dose is 4 mg. After 24 months of follow up the median OS was 21.9 months (95% CI: 11.7 - NA). PFS median was 8 months (95% CI: 5 - NA). The overall response rate was 18.8% (3 PR out of 16) and the disease control rate was 68.8% (3 PR, 8 SD out of 16).

Conclusions

The addition of RRx-001 to TMZ and RT and to TMZ during maintenance was safe and well-tolerated and deserves further study.

RRx-001: a chimeric triple action NLRP3 inhibitor, Nrf2 inducer, and nitric oxide superagonist

RRx-001 is a shape shifting small molecule with Fast Track designation for the prevention/amelioration of chemoradiation-induced severe oral mucositis (SOM) in newly diagnosed Head and Neck cancer. It has been intentionally developed or "engineered" as a chimeric single molecular entity that targets multiple redox-based mechanisms. Like an antibody drug conjugate (ADC), RRx-001 contains, at one end a "targeting" moiety, which binds to the NLRP3 inflammasome and inhibits it as well as Kelch-like ECH-associated protein 1 (KEAP1), the negative regulator of Nrf2, and, at the other end, a conformationally constrained, dinitro containing 4 membered ring, which fragments under conditions of hypoxia and reduction to release therapeutically active metabolites i.e., the payload. This "payload", which is delivered specifically to hypoperfused and inflamed areas, includes nitric oxide, nitric oxide related species and carbon-centered radicals. As observed with ADCs, RRx-001 contains a backbone amide "linker" attached to a binding site, which correlates with the F_ab region of an antibody, and to the dinitroazetidine payload, which is microenvironmentally activated. However, unlike ADCs, whose large size impacts their pharmacokinetic properties, RRx-001 is a nonpolar small molecule that easily crosses cell membranes and the blood brain barrier (BBB) and distributes systemically. This short review is organized around the de novo design and in vivo pro-oxidant/pro-inflammatory and antioxidant/anti-inflammatory activity of RRx-001, which, in turn, depends on the reduced to oxidized glutathione ratio and the oxygenation status of tissues.

Abstract P3-07-20: Treatment of 4T1 Breast Cancer with Liposome-Encapsulated AdAPT-001, a TGF-beta Trap Encoded Oncolytic Adenovirus Currently in a Phase 1/2 Anticancer Trial

Adenoviral vectors have been used extensively for gene therapy. However, efficient infection of cells requires expression of the coxsackie-adenoviral receptor (CAR). Many tumor cells lack adequate expression of CAR and, hence, are not good targets for adenoviral based vectors. We have developed a unique nanoparticle (Epi-039) that can be used to efficiently introduce adenoviral vectors into tumor cells that have low or no CAR expression. We used the CAR-negative 4T1 mammary carcinoma model system, which represents a typical triple-negative breast cancer cell line (ER−, PR−, HER2−) and which is refractory to adenoviral infection to demonstrate effective transduction of an encapsulated oncolytic adenovirus. The adenovirus that was used is called AdAPT-001. This armed oncolytic virus, which is currently in a phase I/II clinical trial called BETA PRIME for the treatment of refractory cancers, expresses a TGFb receptor trap to neutralize the immunosuppressive cytokine, TGF beta. Overexpression of TGF-beta positively correlates with metastasis in breast carcinoma and thus confers a poorer prognosis. In this study, the unique Epi-039 nanoparticle carrying AdAPT-001 not only significantly enhanced the transduction efficiency of AdAPT-001 but also protected it from neutralization by natural antibodies in human whole blood. Accordingly, we demonstrate a significant increase (P value= 0.0029) in the expression of green fluorescent protein (GFP) in CAR-negative 4T1 cells infected with the encapsulated AdAPT-001 adenovirus but not the unencapsulated AdAPT-001 adenovirus. Additional in vivo studies using nanoparticle encapsulated adenoviral vectors including AdAPT-001 to treat breast cancer are underway for rapid translation to the clinic.

Citation Format: Tony Reid, Andrew Kummel, Scott Caroen, Jaimin Shah, Bryan Oronsky, Christopher Larson. Treatment of 4T1 Breast Cancer with Liposome-Encapsulated AdAPT-001, a TGF-beta Trap Encoded Oncolytic Adenovirus Currently in a Phase 1/2 Anticancer Trial [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P3-07-20.

PREVLAR: Phase 2a Randomized Trial to Assess the Safety and Efficacy of RRx-001 in the Attenuation of Oral Mucositis in Patients Receiving Head and Neck Chemoradiotherapy

PURPOSE

No Food and Drug Administration-approved intervention exists for oral mucositis (OM) from chemoradiotherapy (CRT) used to treat head and neck cancers. RRx-001 is a hypoxia-activated, cysteine-directed molecule that affects key pathways involved in OM pathogenesis. This phase 2a, multi-institutional trial was designed to assess the safety and feasibility of 3 schedules of a fixed concentration of RRx-001; a standard-of-care arm was included to identify potential signals of efficacy for further study.

METHODS AND MATERIALS

This study enrolled patients with oral cavity and oropharynx squamous cell carcinoma receiving definitive or postoperative cisplatin-based CRT. Patients were randomized into 4 cohorts. In arms 1 to 3, RRx-001 was coinfused with patients' blood at differing intervals. Arm 4 was a control cohort of patients treated with CRT alone. Trained evaluators assessed OM using a standardized data collection instrument twice weekly during treatment and then until resolution. OM severity was scored centrally using World Health Organization criteria. Safety outcomes were assessed using National Cancer Institute - Common Terminology Criteriav4 benchmarks. Long-term tumor response was defined by Response evaluation criteria in solid tumors v1.1 criteria.

RESULTS

Fifty-three patients were enrolled, with 46 and 45 individuals contributing safety and efficacy data, respectively. There were no severe adverse events attributed to the study drug. Across all 3 active arms, the study drug was infused fully per protocol in 86% of patients. All 3 RRx-001 treatment cohorts appeared to demonstrate a similar or lower OM duration relative to control; arm 1 had the lowest median duration of severe oral mucositis (SOM), 8.5 days versus 24 days in controls among patients who developed at least 1 day of SOM. There were no locoregional failures in any patient.

CONCLUSIONS

Our results support the safety and feasibility of RRx-001 as an intervention to mitigate SOM. Additional studies are planned to confirm its efficacy.

Patent and Marketing Exclusivities 101 for Drug Developers

Despite an ever-increasing need for newer, safer, more effective, and more affordable therapies to treat a multitude of diseases and conditions, drug development takes too long, costs too much, and is too uncertain to be undertaken without the conferment of exclusionary rights or entry barriers to motivate and sustain investment in it. These entry barriers take the form of patents that protect intellectual property and marketing exclusivity provisions that are provided by statute. This review focuses on the basic ins and outs of regulatory and patent exclusivities for which new chemical entities (NCEs), referring to never-before approved drugs with an entirely new active ingredient, are eligible and uses RRx-001, a small molecule aerospace-derived NCE in development for the treatment of cancer, radiation toxicity, and diseases of the NLR family pyrin domain containing 3 (NLRP3) inflammasome, as a "real world" example. This is intended as a '101-type' of primer; its aim is to help developers of original pharmaceuticals navigate the maze of patents, other IP regulations, and statutory exclusivities in major markets so that they can make proper use of them.

Investigating chemical and microbial functional indicators of nutrient retention capacity in greenhouse stormwater retention ponds in southwestern Ontario, Canada

The tributaries flowing through Leamington, Ontario are unique in the Canadian Lake Erie watershed due to the broad spatial extent of greenhouse operations, which more than doubled in size and density from 2011 to 2022. These greenhouse operations are considered to be potential nutrient point sources with respect to observed nutrient concentrations in tributaries adjacent to greenhouse stormwater retention ponds (GSWPs). Identifying causal factors of nutrient release, whether this be chemical or biological, within these ponds may be critical for mitigating their impact on the watershed and ultimately the receiving waters of Lake Erie. Specifically, phosphorus and nitrogen accumulation in freshwater ponds can contribute to environmental damage proximal to adjacent streams, serving as a potential catalyst for algal blooms and eutrophication. This study compared correlations between the water column N:P stoichiometry, sediment nutrient retention capacity, and drivers of microbial metabolism within GSWP sediments. Correlations between water column TN:TP ratios and sediment nutrient retention capacity were observed, suggesting an interplay between N and P in terms of nutrient limitation. Further, clear shifts were observed in the bacterial metabolic pathways analyzed through metatranscriptomics. Specifically, genes related to nitrogen fixation, nitrification and denitrification, and other metabolic processes involving sulfur and methane showed differential expression depending on the condition of the respective pond (i.e., naturalized wetland vs. dredged, eutrophic pond). Collectively, this research serves to highlight the interconnected role of chemical-biological processes particularly as they relate to significant ecosystem processes such as nutrient loading and retention dynamics in impaired freshwater systems.

Case Report of AdAPT-001-Mediated Sensitization to a Previously Failed Checkpoint Inhibitor in a Metastatic Chordoma Patient

Chordoma is a rare, but aggressive bone tumor with a high recurrence rate that primarily arises at the cranial and caudal ends of the axial skeleton. Systemic chemotherapies are not effective against the tumor, and outside of surgical resection and radiation, no approved options are available. Prognosis depends on the extent of surgical resection, with the more the better, and adjuvant radiotherapy. Herein is presented the first-ever case of a recurrent chordoma patient that responded to the combination of one dose of an experimental TGF-beta trap carrying oncolytic adenovirus, known as AdAPT-001, followed by immune checkpoint inhibitor therapy, despite prior progression on an anti-PD-1. This case report highlights the potential of AdAPT-001 as a treatment modality in combination with checkpoint inhibition for recurrent chordoma.

Phase 1 pilot study of RRx-001 + nivolumab in patients with advanced metastatic cancer (PRIMETIME)

Background

Bromonitrozidine (RRx-001) is a minimally toxic, NLRP3 inhibitor that has been observed, in experimental systems, to also downregulate CD47, repolarize tumor associated macrophages (TAMs) and normalize aberrant tumor perfusion. This phase 1 pilot study was undertaken to determine the safety and feasibility of RRx-001 and nivolumab in patients with advanced cancer and no standard options.

Methods

This single arm, single site, open-label pilot study (NCT02518958) called PRIMETIME was designed to evaluate the safety profile of RRx-001 and nivolumab in patients with advanced malignancies and no other standard therapeutic options. A 3 + 3 trial design was used to establish safety of the combination at each dose level and guide the decision to escalate dose. RRx-001 is infused once weekly while nivolumab is given at 3mg/kg once every 2 weeks. The RRx-001 starting dose was 2 mg IV weekly with 4 dose level escalations up to 16 mg IV weekly. From January 2015 to November 2015, twelve patients received treatment for only 4 cycles (total 12 weeks) with the combination due to unavailability of nivolumab, which was not supplied to the Sponsor. Treatment-emergent (all cause, TEAEs) and treatment-related (TRAEs) adverse events that occurred within 16 weeks of the first dose of RRx-001 and nivolumab were characterized according to CTCAE v4.03.

Results

Twelve patients received ≥1 dose of RRx-001 and nivolumab. One discontinuation occurred due to pneumonitis and one to voluntary withdrawal after a post-procedural infection. There were no DLTs. The main adverse event related to RRx-001 was infusion reaction (33.3%). The main adverse event related to the combination was pseudoprogression manifested by larger tumors in patients that were symptomatically improved (25%). The most common immune-related treatment-emergent AEs were pneumonitis (8.3%), and hypothyroidism (8.3%). The objective response rate at 12 weeks was 25% and the disease control rate (DCR) consisting of ≥SD was 67% by Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1. 25% of the patients progressed on the combination.

Conclusions

The combination of RRx-001 and nivolumab was safe and well-tolerated with preliminary evidence of anti-cancer activity. Further clinical trials with RRx-001 and nivolumab are warranted.

Clinical trial registration

ClinicalTrials.gov identifier, NCT02518958.

Full Remission of CAR-Deficient Tumors by DOTAP-Folate Liposome Encapsulation of Adenovirus

Adenovirus (Ad)-based vectors have shown considerable promise for gene therapy. However, Ad requires the coxsackievirus and adenovirus receptor (CAR) to enter cells efficiently and low CAR expression is found in many human cancers, which hinder adenoviral gene therapies. Here, cationic 1,2-dioleoyl-3-trimethylammonium-propane (DOTAP)-folate liposomes (Df) encapsulating replication-deficient Ad were synthesized, which showed improved transfection efficiency in various CAR-deficient cell lines, including epithelial and hematopoietic cell types. When encapsulating replication-competent oncolytic Ad (TAV255) in DOTAP-folate liposome (TAV255-Df), the adenoviral structural protein, hexon, was readily produced in CAR-deficient cells, and the tumor cell killing ability was 5× higher than that of the non-encapsulated Ad. In CAR-deficient CT26 colon carcinoma murine models, replication-competent TAV255-Df treatment of subcutaneous tumors by intratumoral injection resulted in 67% full tumor remission, prolonged survival, and anti-cancer immunity when mice were rechallenged with cancer cells with no further treatment. The preclinical data shows that DOTAP-folate liposomes could significantly enhance the transfection efficiency of Ad in CAR-deficient cells and, therefore, could be a feasible strategy for applications in cancer treatment.

What Exactly Is Inflammation (and What Is It Not?)

In medicine, inflammation is a fuzzy, overused word first coined by the Romans, the intended meaning and precise definition of which varies according to the person and the clinical context. It tends to carry a negative connotation as a response gone awry, like a raging, out-of-control wildfire that requires immediate control and containment lest it destroy all in its path; however, frequently overlooked or lost in the shuffle is the primordial importance of inflammation to health and survival. The precise definition of inflammation matters for several reasons, not least because of the over-liberal use of anti-inflammatory drugs to inhibit inflammation, which may, contrary to prevailing dogma that all inflammation is harmful, act counterproductively to prevent restitutio ad integrum. Using fire as a central analogy, this overview attempts to define inflammation, the better to determine how to manage it, i.e., whether to fan its flames, let it burn out, or suppress it entirely.

Oncolytic Adenoviruses: The Cold War against Cancer Finally Turns Hot

Oncolytic viruses, colloquially referred to as "living drugs", amplify themselves and the therapeutic transgenes that they carry to stimulate an immune response both locally and systemically. Remarkable exceptions aside, such as the recent 14-patient trial with the PD-1 inhibitor, dostarlimab, in mismatch repair (MMR) deficient rectal cancer, where the complete response rate was 100%, checkpoint inhibitors are not cure-alls, which suggests the need for a combination partner like oncolytic viruses to prime and augment their activity. This review focuses on adenoviruses, the most clinically investigated of all the oncolytic viruses. It covers specific design features of clinical adenoviral candidates and highlights their potential both alone and in combination with checkpoint inhibitors in clinical trials to turn immunologically "cold" and unresponsive tumors into "hotter" and more responsive ones through a domino effect. Finally, a "mix-and-match" combination of therapies based on the paradigm of the cancer-immunity cycle is proposed to augment the immune responses of oncolytic adenoviruses.

Nucleocapsid as a next-generation COVID-19 vaccine candidate

Multiple new variants of the SARS-CoV-2 virus have emerged globally, due to viral mutation. The majority of COVID-19 vaccines contain SARS-CoV-2 spike protein, which is susceptible to mutation. It is known that protection against COVID-19 after two doses of mRNA vaccine continuously wanes over time. If viral variants contain mutated spike protein, current vaccines may not provide robust protection. This perspective suggests the inclusion of SARS-CoV-2 nucleocapsid protein in future COVID-19 vaccines and boosters, as nucleocapsid is much less vulnerable to mutation and may provide stronger immunity to novel viral variants.

BETA PRIME: Phase I study of AdAPT-001 as monotherapy and combined with a checkpoint inhibitor in superficially accessible, treatment-refractory solid tumors

AdAPT-001 is an investigational therapy consisting of a replicative type 5 adenovirus armed with a TGF-β receptor-immunoglobulin Fc fusion trap, designed to neutralize isoforms 1 and 3 of the profibrotic and immunosuppressive cytokine, TGF-β. In preclinical studies with an immunocompetent mouse model, AdAPT-001 eradicated directly treated 'cold' tumors as well as distant untreated tumors, and, from its induction of systemic CD8+ T cell-mediated antitumor immunity, protected the mice from rechallenge with tumor cells. AdAPT-001 also sensitized resistant tumors to checkpoint blockade. This manuscript describes the rationale and design of the first-in-human phase I, dose-escalation and dose-expansion study of AdAPT-001 alone and in combination with a checkpoint inhibitor in adults with treatment-refractory superficially accessible solid tumors.

A 2022 Update on Extensive Stage Small-Cell Lung Cancer (SCLC)

For close to 40 years small-cell lung cancer (SCLC) was adrift, as listless, and as idle as a painted ship on a painted ocean, with nary a breeze to blow in the direction of clinical progress or change. The preferred decades-old first line regimen was etoposide-platinum, to which ≥50% of patients respond, followed by decades-old, tired topotecan in second line for platinum sensitive patients, full stop, because there were no approved therapeutic options (nor generally any compelling experimental ones) in third line or beyond. In 2012 SCLC was designated by the U.S. Congress as a “recalcitrant” tumor type and for good reason: because most patients relapse, after the generally favorable response in first line, respond poorly, if at all to subsequent therapies, and rarely survive beyond 1 year.

A significant sea change occurred in 2018 with the approval of nivolumab followed by pembrolizumab and atezolizumab in 2019, durvalumab in 2020, accelerated approval for lurbinectedin in 2020 and trilaciclib in 2021 for myelosuppression. In 2021, the US indications for nivolumab and pembrolizumab were withdrawn. Suddenly, a tumor type, whose name was virtually synonymous with stalled progress and movement, and which was much less well studied and funded than its more prevalent cousin, non-small cell lung cancer (NSCLC), finds itself in the eye of the storm, that is, at the epicenter of an intense flurry and ferment of activity, not all of it positive. This review surveys approved drugs and select up-and-coming ones in development for extensive stage SCLC.

AdAPT-001, an oncolytic adenovirus armed with a TGF-β trap, overcomes in vivo resistance to PD-L1-immunotherapy

Monoclonal antibodies targeting the programmed cell death protein-1/programmed cell death-ligand 1 (PD-1/PD-L1) and cytotoxic T lymphocyte-associated protein-4 (CTLA-4) axes have permanently changed the therapeutic landscape for multiple tumor types previously associated with a dismal prognosis such as melanoma, non-small cell lung cancer, renal cell carcinoma, bladder cancer, head and neck squamous cell carcinoma, MSI-high colorectal carcinoma, Merkel cell carcinoma, and Hodgkin lymphoma. However, only a subset of patients initially benefits from these inhibitors, and increasing clinical experience indicates that in a substantial proportion of initial responders, lethal secondary resistance ultimately develops months or years later. In this paper we evaluated combination therapy with a Phase 1 oncolytic adenovirus called AdAPT-001, armed with a TGF-β "trap" that binds to and neutralizes the immunosuppressive cytokine, TGF-β, and a checkpoint inhibitor, anti-PD-L1, in PD-L1 resistant tumors. The study, which was performed in an immunocompetent syngeneic ADS-12 mouse model, demonstrated that the combination of AdAPT-001 with PD-L1 blockade reversed PD-L1 resistance, potentially representing a future paradigm shift for patients that are primarily or secondarily resistant to checkpoint inhibitors.

The small molecule NLRP3 inhibitor RRx-001 potentiates regorafenib activity and attenuates regorafenib-induced toxicity in mice bearing human colorectal cancer xenografts

The multi-kinase inhibitor Regorafenib, approved for the treatment of metastatic colorectal cancer, is poorly tolerated with a Grade 3/4 drug related adverse event rate of 54% resulting in frequent dose reductions and discontinuations. RRx-001 is a minimally toxic NLRP3 inhibitor small molecule with macrophage-repolarizing properties in Phase 3 clinical trials. Studies have demonstrated the inhibitory impact of M2 macrophages on the activity of tyrosine kinases, suggesting that the repolarization of macrophages by RRx-001 may enhance the activity of TKIs. The purpose of these experiments was to determine whether RRx-001 demonstrated in vitro and in vivo synergy with regorafenib in colorectal cancer and whether RRx-001 attenuated the toxicity of regorafenib. Tumor-bearing mice were randomized into four cohorts: RRx-001 alone, regorafenib alone, RRx-001 + regorafenib and control. RRx-001 demonstrated in vitro and in vivo synergy with regorafenib with attenuation of toxicity in colorectal cancer cell lines. These results provide a rationale to treat colorectal cancer with RRx-001 plus another tyrosine kinase inhibitor like regorafenib.

248 Urethral Self-Insertion of a USB Cable as Sexual Experimentation: A Case Report

Introduction

The insertion of a foreign body in the urethra is an uncommon urological emergency. A wide variety of inserted objects have been described, presenting either asymptomatically or with lower abdominal discomfort and lower urinary tract symptoms. Sexual experimentation and gratification as well as mental disorders are considered the main underlying causes. The aim of this report is to present the case of a USB wire self-insertion and its challenging urological management.

Case Presentation

A 15-year-old male patient presented to his local Accident and Emergency department with gross haematuria following self-insertion of the knotted cable of a USB wire into his urethra in the context of sexual experimentation. Endoscopic approach via rigid cystoscopy and optical urethrotomy was not effective. A suprapubic catheter was inserted, and the patient was urgently transferred to our hospital for tertiary management.

Following radiological assessment to confirm the position of the wire, a longitudinal peno-scrotal incision over the palpable foreign body was made. Urethrotomy revealed the knotted cable in the proximal aspect of the penile urethra, which was cut and removed. Urethra was subsequently closed over a urethral catheter. Postoperative recovery was uneventful, and patient was discharged home with oral antibiotics. Urethral catheter was removed following normal fluoroscopic assessment of the urethra two weeks later.

Conclusions

The management of a foreign urethral body can be challenging and usually requires tertiary expertise to achieve optimal outcomes. Poor initial management could potentially lead to devastating long-term complications such as urethral strictures and fistulas.

Superficial Venous-Associated Inflammation from Direct IV Administration of RRx-001 in Rats

RRx-001 is a small molecule NLRP3 inflammasome inhibitor with anti-CD47 and antiangiogenic/vascular normalization properties in a Phase 3 clinical trial that has been designated as a drug-device combination by the FDA. In the Phase 1 first-in-man dose escalation clinical trial, where RRx-001 was given by direct intravenous (IV) infusion, the main adverse event was a sterile painful infusion phlebitis (IP). Less pain was experienced when RRx-001 was infused at a slower rate over multiple hours which was impractical on an outpatient basis. In Phase 2, for reasons of convenience and safety, RRx-001 was co-administered with an aliquot of autologous blood from an ex-vivo device called the eLOOP on the premise that RRx-001 binds to hemoglobin on red blood cells (RBCs), making it unavailable to directly interact with venous nociceptors. Phlebitis has the potential to progress to deep venous thrombosis or septic thrombophlebitis or post-thrombotic syndrome in hypercoagulable and immunosuppressed cancer patients. In this 13-week toxicology study of once weekly IV RRx-001 administration to Wistar Han rats followed by a recovery period of 28 days. The main observed toxicity was a significant inflammatory response in the vein wall, consistent with superficial venous thrombosis observed in man. Due to this development, direct IV infusion of RRx-001 is relatively contraindicated in favor of co-administration with autologous blood.

Vascular priming with RRx-001 to increase the uptake and accumulation of temozolomide and irinotecan in orthotopically implanted gliomas

Vascular normalisation refers to a 'remodeling' of the dysfunctional tumour capillary network, which regresses under the influence of anti-VEGF treatment, resulting in improved blood flow and oxygenation. RRx-001 is an anti-CD47-SIRPα small molecule with vascular normalising properties under investigation in clinical trials for the treatment of glioblastoma, brain metastases, lung cancer and colorectal cancer, with FDA Orphan Drug Designation in glioblastoma and other tumour types. This study investigated whether the improved oxygenation and perfusion that has been previously observed with RRx-001 both preclinically and clinically in the context of a brain metastasis trial was correlated with increased penetration and accumulation of the cytotoxic chemotherapies, irinotecan and temozolomide, in orthotopically implanted gliomas, priming tumours for improved response. The experiments demonstrate that administration of RRx-001 prior to temozolomide or irinotecan results in significantly increased uptake of irinotecan and temozolomide in orthotopic glioma tumours. Since the success of chemotherapy in the brain (and outside of it) is limited by subtherapeutic tumoral drug concentrations, vascular normalisation-enhanced delivery of standard cytotoxics as demonstrated with RRx-001 may mitigate or reverse clinical drug resistance and thereby improve the outcome of cancer therapy, particularly in the brain.

COVID-19 and cancer: A guide with suggested COVID-19 rule-out criteria to support clinical decision-making

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a highly contagious zoonotic pathogen that has exacted heavy public health, social and economic tolls. In February 2020, the World Health Organization acronymed the disease caused by SARS-CoV-2 as COVID-19, for coronavirus disease 2019. The number of confirmed COVID-19 infections, which has been detected in at least 103 countries, has reached 1,970,225 worldwide as of April 14, 2020 with 124,544 deaths, according to the U.S. Centers for Disease Control and Prevention (CDC). Many cases of COVID-19 resolve quickly. However, the disease, which, like other respiratory pathogens that cause common cold symptoms is believed to be transmitted through respiratory droplets. Infection with COVID-19 can also lead to significant morbidity and death; this is particularly the case for cancer patients. Moreover, because the signs and symptoms of COVID-19 are easily misattributed to the sequelae of cancer itself, such as pulmonary embolism, or its treatment, such as nausea and diarrhea, diagnosis may be delayed or missed. Potential COVID-19 rule out criteria, based on the Wells' criteria for pulmonary embolism, another protean disease entity, are provided as a decision-making aid. This review summarizes the current understanding of the transmission, clinical presentation, diagnosis and differential diagnosis, pathogenesis, rationale to treat the cancer or not, treatment and prevention of COVID-19 with an emphasis on implications in cancer.

Just eat it: A review of CD47 and SIRP-α antagonism

The mammalian immune system consists of two distinct arms, nonspecific innate and more specific adaptive, with the innate immune response as the first line of defense and protection, which primes and amplifies subsequent adaptive responses. On the basis of this binary immune interplay, stimulation of T cells through checkpoint inhibitors (CIs), which bypasses innate involvement, seems likely to engender suboptimal or incomplete anticancer immunity, given that the successful induction of effect or responses depends on two-way innate/adaptive coordination. Indeed, the majority of patients-70%-80%, do not respond to CIs, which is potentially problematic if access to more optimal standard therapies is withheld or delayed in favor of ineffective or only marginally effective anti-PD-1/PD-L1 treatment. Therefore, stimulation of the innate immune response in combination with CIs (or other inducers of T cell cytotoxicity) has the potential to make the immune system "whole" and thereby to enhance and broaden the anti-tumor activity of PD-1/PD-L1 inhibitors for example, in relatively nonimmunogenic or "cold" tumor types. A critical innate macrophage immune checkpoint and druggable target is the antiphagocytic and "marker of self" CD47-SIRPα pathway, which is co-opted by cancer cells to mediate escape from immune-mediated clearance and checkpoint inhibition. This review summarizes the status of key CD47 antagonists in clinical trials, including the biologics, Hu5F9-G4 (5F9), TTI-621, and ALX148, as well as the small molecule, RRx-001, now in a Phase 3 clinical trial, which has not been previously included in CD47-SIRPα reviews focused on biologics. Hu5F9-G4 (5F9), TTI-621, ALX148, and RRx-001 are chosen as compounds with potentially promising data that have advanced the farthest in clinical development.

Locally advanced rectal cancer: The past, present, and future

From a series of clinical trials in the last several decades, current treatment paradigms for locally advanced rectal cancer include: (1) preoperative long-course radiotherapy (RT) combined with radiosensitizing chemotherapy; (2) preoperative short-course RT alone followed by adjuvant postoperative chemotherapy; and (3) total neoadjuvant therapy with induction chemotherapy followed by chemoradiotherapy. Other strategies under active investigation in both institutional and cooperative trials include neoadjuvant chemotherapy alone without RT in select patients, total neoadjuvant therapy, watchful waiting after a clinical complete response as an alternative to surgical resection, and the use of different chemotherapeutic and targeted agents. The focus of this review is on established and novel therapeutic strategies for locally advanced rectal cancer.

Profiling and predicting help-seeking behaviour among trauma-exposed UK firefighters

Background: Firefighters often do not avail of psychological support services within fire services. Hence, investigating help-seeking behaviour is crucial to determine viable support options. Objective: This study attempted to characterize help-seeking behaviour among UK firefighters by profiling and identifying patterns of help-seeking. Methods: An online survey was administered to 1282 UK firefighters who were asked which help-seeking options they availed of within and outside professional settings. The analysis was conducted in two linked phases. First, latent class analysis was used to identify the fewest profiles that most accurately described help-seeking behaviour. Second, multinomial logistic regression analysis was employed to describe class composition using demographic and years in service variables, while ANOVA was employed to identify variation in alcohol consumption and openness to discussing emotions across help-seeking classes. Results: Five distinct help-seeking classes were identified. Class 1 (9.2%) represented firefighters who availed of all forms of support. Class 2, the smallest class (6.9%) represented firefighters who independently sought External Professional Psychological Support. Class 3 (12.2%) represented those who mainly sought Friends Support. Class 4, the largest class (48.7%) represented those who mainly sought Spousal Support. Class 5 (23%) represented firefighters who sought all avenues of Social Support. Regression analyses indicated that the External Psychological Support class was more likely to be single with fewer years in service. Firefighters longest in service were less likely to seek Social Support, and those who relied on Spousal support had the lowest alcohol consumption. Conclusion: Variations in help-seeking behaviour among UK firefighters were found. Firefighters who sought spousal support had the lowest alcohol consumption rates, indicating a protected profile. Firefighters who only sought friends and informal colleagues' support had the highest alcohol consumption rates and the most difficulty in discussing feelings, indicating a potential at-risk profile. Recognizing these differences in help-seeking patterns is important for targeting interventions.

Tracking functional bacterial biomarkers in response to a gradient of contaminant exposure within a river continuum

Within all aquatic environments, aside from the physical dispersal of dissolved and/or particulate phase contaminants, alteration from both biological and chemical processes are shown to change the chemistry of the parent compounds. Often these alterations can lead to secondary influences because of cooperative microbial processes (i.e. coupled respiratory pathways and/or energy and biodegradation cycles), complicating our understanding of the biological impact that these mobile compounds impose on ecosystem health. The McMurray Formation (MF) (the formation constituting the minable bituminous oil sands) is a natural, ongoing source of hydrocarbon-bound sediments to river ecosystems in the region (via terrestrial and aquatic erosion), providing a natural "mesocosm" to track and characterize the effects of these compounds on regional aquatic primary productivity. Here we characterize the natural, in-situ microbial response to increasing hydrocarbon exposure along a river continuum in the downstream direction. Using the Steepbank River (STB), suspended and bed sediment samples were collected at 3 sites from upstream to downstream, as the water flows into and through the MF. Samples were then analyzed for the active, in-situ gene expression of the microbial communities. Results from both suspended and bed sediments show clear and significant shifts in the microbial metabolic processes within each respective compartment, in response to the elevated polycyclic aromatic compound (PAC) concentrations. Specific genes likely responsible for hydrocarbon breakdown (Alkane Monooxygenase, Benzoyl-CoA Reductase etc.) experience elevated expression levels, while certain energy metabolism genes (nitrogen, sulfur, methane) reveal fundamental shifts in their pathway specificity, indicating an adaptation response in their basic energy metabolism. Expression from suspended sediments reveal subtle yet delayed metabolic response further downstream compared to bed sediments, indicative of the erosion and transport dynamics within a lotic system. These results provide insight into the use of novel clusters of gene biomarkers to track the active, in-situ microbial response of both emerging and legacy contaminants. Such information will be important in determining the best management strategies for the monitoring and assessment of aquatic health in both natural and contaminated ecosystems.

Validation of Three Rapid Screening Methods for Detection of Verotoxin-Producing Escherichia coli in Foods: Interlaboratory Study

An interlaboratory study was conducted for the validation of 3 methods for the detection of all verotoxin-producing Escherichia coli (VTEC) in foods. The methods were a multi-analyte 1-step lateral flow immunoassay (LFIA) for detection of E. coli O157 and verotoxin (VT); an enzyme-linked immunosorbent assay targeted against VT1, VT2, and VT2c (VT-ELISA); and a polymerase chain reaction (PCR) method for detection of VT genes (VT-PCR). Aliquots (25 g or 25 mL) of 4 food types (raw minced [ground] beef, unpasteurized milk, unpasteurized apple juice [cider], and salami) were individually inoculated with low numbers (<9 to 375 cells/25 g) of 6 test strains of E. coli (serogroups O26, O103, O111, O145, and O157) with differing VT-producing capabilities. Five replicates for each test strain and 5 uninoculated samples were prepared for each food type. Fourteen participating laboratories analyzed samples using the LFIA, 9 analyzed the samples by ELISA, and 9 by PCR. The LFIA for O157 and VT had a specificity (correct identification of negative samples) of 92 and 94%, respectively, and a sensitivity (correct identification of positive samples) of 94 and 55%, respectively. The VT-ELISA and VT-PCR

Microbial metatranscriptomic investigations across contaminant gradients of the Detroit River

Microbial community function in freshwater sediments is influenced by the presence and persistence of anthropogenic pollutants, yet simultaneously imposes significant control on their transformation. Thus, microbes provide valuable ecosystem services in terms of biodegradation and bioindicators of compromised habitats. From a remediation perspective it is valuable to leverage the suite of microbial genes at the transcriptional level that are active in either natural versus stressed environments to provide insight into the cycling and fate of contaminants. Metatranscriptomic analysis of total bacterial and archaeal messenger RNA (mRNA) is a useful tool in this facet and was applied to sediments sampled from the Detroit River; a binational Area of Concern (AOC) in the Great Lakes. Previously established sediment surveys and modelling delineated the river into contaminant gradients based on concentrations of polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), and metals. Differential expression analysis through DESeq2 revealed that microbial transcripts associated with nitrate reduction, methanogenesis, and beta-oxidation were significant in legacy polluted sediments and linked with energetic pathways key in the generation of cellular currencies (acetyl-CoA, succinyl-CoA). Gluconeogenesis and polyester synthesis also showed high abundance in contaminated regions, along with increased expression of stress response genes and transposons, despite decreases in community α-diversity. Aromatic cleavage genes were detected, but in low abundance across the contaminant gradient. These results suggest that microbial communities within the Detroit River exploit unique anabolic and catabolic pathways to derive and store energy from legacy organic contaminants while simultaneously recruiting stress-response and gene transfer mechanisms to cope with xenobiotic pressures. By coupling well-resolved chemical datasets with metatranscriptomics, this study adds to the spatial understanding of in-situ microbial activities in pristine and perturbed freshwater sediments.

Results from a Phase IIb, Randomized, Multicenter Study of GVAX Pancreas and CRS-207 Compared with Chemotherapy in Adults with Previously Treated Metastatic Pancreatic Adenocarcinoma (ECLIPSE Study)

PURPOSE

Limited options exist for patients with advanced pancreatic cancer progressing after 1 or more lines of therapy. A phase II study in patients with previously treated metastatic pancreatic cancer showed that combining GVAX pancreas (granulocyte-macrophage colony-stimulating factor-secreting allogeneic pancreatic tumor cells) with cyclophosphamide (Cy) and CRS-207 (live, attenuated Listeria monocytogenes expressing mesothelin) resulted in median overall survival (OS) of 6.1 months, which compares favorably with historical OS achieved with chemotherapy. In the current study, we compared Cy/GVAX + CRS-207, CRS-207 alone, and standard chemotherapy in a three-arm, randomized, controlled phase IIb trial.

PATIENTS AND METHODS

Patients with previously treated metastatic pancreatic adenocarcinoma were randomized 1:1:1 to receive Cy/GVAX + CRS-207 (arm A), CRS-207 (arm B), or physician's choice of single-agent chemotherapy (arm C). The primary cohort included patients who had failed ≥2 prior lines of therapy, including gemcitabine. The primary objective compared OS between arms A and C in the primary cohort. The second-line cohort included patients who had received 1 prior line of therapy. Additional objectives included OS between all treatment arms, safety, and tumor responses.

RESULTS

The study did not meet its primary efficacy endpoint. At the final study analysis, median OS [95% confidence interval (CI)] in the primary cohort (N = 213) was 3.7 (2.9-5.3), 5.4 (4.2-6.4), and 4.6 (4.2-5.7) months in arms A, B, and C, respectively, showing no significant difference between arm A and arm C [P = not significant (NS), HR = 1.17; 95% CI, 0.84-1.64]. The most frequently reported adverse events in all treatment groups were chills, pyrexia, fatigue, and nausea. No treatment-related deaths occurred.

CONCLUSIONS

The combination of Cy/GVAX + CRS-207 did not improve survival over chemotherapy. (ClinicalTrials.gov ID: NCT02004262)See related commentary by Salas-Benito et al., p. 5435.

Late life revision surgery for dilated colonic conduit in long gap oesophageal atresia

Long gap oesophageal atresia presents a surgical challenge as there is insufficient length of the oesophagus to restore continuity. Oesophageal replacement is generally achieved using a conduit, taken from the stomach, jejunum or colon. Preferences of approach vary between and within surgical centres. Specific to colonic interposition, the continued growth and dilation of the interposed segment may lead to redundancy. Revision surgery in these cases is challenging and has been sparsely described in adult patients. We present two patients who had colonic interposition for long gap oesophageal atresia in infancy and who then underwent successful revision surgery in their fifth decade.

Journey towards universal viral load monitoring in Maputo, Mozambique: many gaps, but encouraging signs

Introduction

Viral load (VL) monitoring for people on antiretroviral therapy (ART) is extremely challenging in resource-limited settings. We assessed the VL testing scale-up in six Médecins Sans Frontières supported health centres in Maputo, Mozambique, during 2014–15.

Methods

In a retrospective cohort study, routine programme data were used to describe VL testing uptake and results, and multi-variate logistical regression to estimate predictors of VL testing uptake and suppression.

Results

Uptake of a first VL test was 40% (17 236/43 579). Uptake of a follow-up VL test for patients with a high first VL result was 35% (1095/3100). Factors associated with a higher uptake included: age below 15 years, longer time on ART and attending tailored service delivery platforms. Virological suppression was higher in pregnant/breastfeeding women and in community ART Group members. Patients with a high first VL result (18%; 3100/17 236) were mostly younger, had been on ART longer or had tuberculosis. Out of 1095 attending for a follow-up VL test, 678 (62%) had virological failure. Of those, less than one-third had started second line ART.

Conclusion

This was the first study describing the uptake and results of VL testing scale-up in Mozambique. Identified gaps show patient and programmatic challenges. Where service delivery was customized to patient needs, VL monitoring was more successful.

Childhood tuberculosis in Mauritania, 2010-2015: diagnosis and outcomes in Nouakchott and the rest of the country

Setting: The National Tuberculosis Programme, Mauritania. Objective: To compare the diagnosis and treatment outcomes of childhood tuberculosis (TB) cases (aged <15 years) registered between 2010 and 2015 inside and outside Nouakchott, the capital city. Design: This was a retrospective comparative cohort study. Results: A total of 948 children with TB were registered. The registration rate was 10 times higher in Nouakchott. The proportion of children among all TB cases was higher inside than outside Nouakchott (7.5% vs. 4.6%, P < 0.01). Under-fives represented 225 (24%) of all childhood TB cases, of whom 204 (91%) were registered in Nouakchott. Extra-pulmonary TB was more common in Nouakchott, while smear-negative TB was less common. Treatment success was similar inside and outside Nouakchott (national rate 61%). The principal unsuccessful outcomes were loss to follow-up outside Nouakchott (21% vs. 11%, P < 0.01) while transfers out were more common in the city (25% vs. 14%, P = 0.01). Being aged <5 years (OR 1.2, 95%CI 1.1-1.5) was associated with an unsuccessful outcome. Conclusion: This study indicates problems in the diagnosis and treatment of childhood TB in Mauritania, especially outside the city of Nouakchott. We suggest strengthening clinical diagnosis and management, improving communications between TB treatment centres and health services and pressing the TB world to develop more accurate and easy-to-use diagnostic tools for children.

The macrophage stimulating anti-cancer agent, RRx-001, protects against ischemia-reperfusion injury

BACKGROUND

RRx-001, a clinical macrophage-stimulating anti-cancer agent that also produces nitric oxide (NO) was studied in a model of ischemia-reperfusion injury.

METHODS

The production of NO is dependent on the oxygen tension because nitric oxide synthases convert l-arginine to NO and l-citrulline in the presence of O₂. Since the P450 enzymes, which metabolize nitrate esters such as nitroglycerin are dependent on oxygen, the generation of 'exogenous' NO is also sensitive to alterations in tissue PO₂. I/R injury was studied in a hamster chamber window, with compression of the periphery of the window for 1 h to induce ischemia. Animals received RRx-001 (5 mg/kg) 24 h before ischemia and sodium nitrite (10 nmols/kg) was supplemented 10 min after the start of reperfusion. Vessel diameter, blood flow, adherent leukocytes, and functional capillary density were assessed by intravital microscopy at 0.5, 2, and 24 h following the release of the ischemia.

RESULTS

The results demonstrated that, compared to control, RRx-001 preconditioning increased blood flow and functional capillary density, and preserved tissue viability in the absence of side effects over a sustained time period.

CONCLUSION

Thus, RRx-001 may serve as a long-lived protective agent during postsurgical restoration of flow and other ischemia-reperfusion associated conditions, increasing blood flow and functional capillary density as well as preserving tissue viability in the absence of side effects.

The symbiotic relationship of sediment and biofilm dynamics at the sediment water interface of oil sands industrial tailings ponds

Within the oil sands industry, tailings ponds are used as a means of retaining tailings until a reclamation technology such as end pit lakes (EPLs) can be developed and optimized to remediate such tailings with a water cap (although dry-land strategies for tailing reclamation are also being developed). EPLs have proven successful for other mining ventures (e.g. metal rock mines) in eventually mitigating contaminant loads to receiving waters once biochemical remediation has taken place (although the duration for this to occur may be decades). While the biological interactions at the sediment water interface of tailings ponds or EPLs have been shown to control biogeochemical processes (i.e. chemical fluxes and redox profiles), these have often been limited to static microcosm conditions. Results from such experiments may not tell the whole story given that the sediment water interface often represents a dynamic environment where erosion and deposition may be occurring in association with microbial growth and decay. Mobilization of sediments and associated contaminants may therefore have a profound effect on remediation rates and, as such, may decrease the effectiveness of EPLs as viable reclamation strategies for mining industries. Using a novel core erosion system (U-GEMS), this paper examines how the microbial community can influence sediment water interface stability and how the biofilm community may change with tailings age and after disturbance (biofilm reestablishment). Shear strength, eroded mass measurements, density gradients, high-resolution microscopy, and microbial community analyses were made on 2 different aged tailings (fresh and ∼38 years) under biotic and abiotic conditions. The same experiments were repeated as duplicates with both sets of experiments having consolidation/biostabilization periods of 21 days. Results suggest that the stability of the tailings varies between types and conditions with the fresh biotic tailings experiencing up to 75% more biostabilization than the same abiotic tailings. Further, greater microbial diversity in the aged pond could be a contributing factor to the overall increase in stability of this material over the fresh tailings source.

An enhanced temperature index model for debris-covered glaciers accounting for thickness effect

Debris-covered glaciers are increasingly studied because it is assumed that debris cover extent and thickness could increase in a warming climate, with more regular rockfalls from the surrounding slopes and more englacial melt-out material. Debris energy-balance models have been developed to account for the melt rate enhancement/reduction due to a thin/thick debris layer, respectively. However, such models require a large amount of input data that are not often available, especially in remote mountain areas such as the Himalaya, and can be difficult to extrapolate. Due to their lower data requirements, empirical models have been used extensively in clean glacier melt modelling. For debris-covered glaciers, however, they generally simplify the debris effect by using a single melt-reduction factor which does not account for the influence of varying debris thickness on melt and prescribe a constant reduction for the entire melt across a glacier. In this paper, we present a new temperature-index model that accounts for debris thickness in the computation of melt rates at the debris-ice interface. The model empirical parameters are optimized at the point scale for varying debris thicknesses against melt rates simulated by a physically-based debris energy balance model. The latter is validated against ablation stake readings and surface temperature measurements. Each parameter is then related to a plausible set of debris thickness values to provide a general and transferable parameterization. We develop the model on Miage Glacier, Italy, and then test its transferability on Haut Glacier d'Arolla, Switzerland. The performance of the new debris temperature-index (DETI) model in simulating the glacier melt rate at the point scale is comparable to the one of the physically based approach, and the definition of model parameters as a function of debris thickness allows the simulation of the nonlinear relationship of melt rate to debris thickness, summarised by the Østrem curve. Its large number of parameters might be a limitation, but we show that the model is transferable in time and space to a second glacier with little loss of performance. We thus suggest that the new DETI model can be included in continuous mass balance models of debris-covered glaciers, because of its limited data requirements. As such, we expect its application to lead to an improvement in simulations of the debris-covered glacier response to climate in comparison with models that simply recalibrate empirical parameters to prescribe a constant across glacier reduction in melt.

A look inside the mechanistic black box: Are red blood cells the critical effectors of RRx-001 cytotoxicity?

The therapeutic potential of epi-immunotherapeutic anticancer agent RRx-001 in cancer has been validated with preclinical and clinical studies, since RRx-001 has successfully completed a phase 1 trial and multiple single-agent and combination phase 2 trials with preliminary evidence of promising activity are underway. Previous experimental work has implicated diverse anticancer mechanisms such as oxidative stress, ATP and NADPH depletion, anti-angiogenesis and epigenetic modulation in the overall antitumor effect of RRx-001. The hypothesis of this study was that the RRx-001 red blood cells are the essential and de facto intermediaries responsible for the reprograming of tumor behavior via transfer of their intracellular and membrane contents. To test this hypothesis, and thereby resolve the "black box" incompleteness in the continuity of the mechanism, the fate of red blood cells incubated with RRx-001 was explored in vitro and in vivo both in healthy animals and in tumor-bearing mice. The collective results establish that RRx-001-derivatized red blood cells are the critical "missing links" to explain the specificity and anticancer activity of RRx-001, including its immunomodulatory effects on tumor-associated macrophages. These experimental results delineate a novel erythrocyte-based mechanism without precedent in the annals of oncology and open the door to rational combination strategies with RRx-001 both in cancer therapy and beyond, particularly in disease states that affect red blood cell and vascular function such as malaria, leishmaniasis, sickle-cell disease and hemorrhagic shock.