Characterization of the responses of brain macrophages to focused ultrasound-mediated blood-brain barrier opening.

The opening of the blood-brain barrier (BBB) by focused ultrasound (FUS) coupled with intravenously injected microbubbles can be leveraged as a form of immunotherapy for the treatment of neurodegenerative disorders. However, how FUS BBB opening affects brain macrophages is not well understood. Here by using single-cell sequencing to characterize the distinct responses of microglia and central nervous system-associated macrophages (CAMs) to FUS-mediated BBB opening in mice, we show that the treatment remodels the immune landscape via the recruitment of CAMs and the proliferation of microglia and via population size increases in disease-associated microglia. Both microglia and CAMs showed early and late increases in population sizes, yet only the proliferation of microglia increased at both timepoints. The population of disease-associated microglia also increased, accompanied by the upregulation of genes associated with gliogenesis and phagocytosis, with the depletion of brain macrophages significantly decreasing the duration of BBB opening.

Getting ahead of Alzheimer's disease: early intervention with focused ultrasound.

The amyloid-ß (Aß) hypothesis implicates Aß protein accumulation in Alzheimer's disease (AD) onset and progression. However, therapies targeting Aß have proven insufficient in achieving disease reversal, prompting a shift to focus on early intervention and alternative therapeutic targets. Focused ultrasound (FUS) paired with systemically-introduced microbubbles (µB) is a non-invasive technique for targeted and transient blood-brain barrier opening (BBBO), which has demonstrated Aß and tau reduction, as well as memory improvement in models of late-stage AD. However, similar to drug treatments for AD, this approach is not sufficient for complete reversal of advanced, symptomatic AD. Here we aim to determine whether early intervention with FUS-BBBO in asymptomatic AD could delay disease onset. Thus, the objective of this study is to measure the protective effects of FUS-BBBO on anxiety, memory and AD-associated protein levels in female and male triple transgenic (3xTg) AD mice treated at an early age and disease state. Here we show that early, repeated intervention with FUS-BBBO decreased anxiety-associated behaviors in the open field test by 463.02 and 37.42% in male and female cohorts, respectively. FUS-BBBO preserved female aptitude for learning in the active place avoidance paradigm, reducing the shock quadrant time by 30.03 and 31.01% in the final long-term and reversal learning trials, respectively. Finally, FUS-BBBO reduced hippocampal accumulation of Aß40, Aß42, and total tau in females by 12.54, 13.05, and 3.57%, respectively, and reduced total tau in males by 18.98%. This demonstration of both cognitive and pathological protection could offer a solution for carriers of AD-associated mutations as a safe, non-invasive technique to delay the onset of the cognitive and pathological effects of AD.

Using a novel rapid alternating steering angles pulse sequence to evaluate the impact of theranostic ultrasound-mediated ultra-short pulse length on blood-brain barrier opening volume and closure, cavitation mapping, drug delivery feasibility, and safety.

Background: Focused ultrasound (FUS)-mediated blood-brain barrier (BBB) opening is a noninvasive, safe and reversible technique for targeted drug delivery to the brain. Most preclinical systems developed to perform and monitor BBB opening are comprised of a separate geometrically focused transducer and passive cavitation detector (PCD) or imaging array. This study builds upon previous work from our group developing a single imaging phased array configuration for simultaneous BBB opening and monitoring called theranostic ultrasound (ThUS), leveraging ultra-short pulse lengths (USPLs) and a novel rapid alternating steering angles (RASTA) pulse sequence design for simultaneous bilateral sonications with target-specific USPL. The RASTA sequence was further employed to evaluate the impact of USPL on BBB opening volume, power cavitation imaging (PCI) pixel intensity, BBB closing timeline, drug delivery efficiency, and safety. Methods: A P4-1 phased array transducer driven by a Verasonics Vantage ultrasound system was operated using a custom script to run the RASTA sequence which consisted of interleaved steered, focused transmits and passive imaging. Contrast-enhanced magnetic resonance imaging (MRI) confirmed initial opening volume and closure of the BBB by longitudinal imaging through 72 hours post-BBB opening. For drug delivery experiments, mice were systemically administered a 70 kDa fluorescent dextran or adeno-associated virus serotype 9 (AAV9) for fluorescence microscopy or enzyme-linked immunosorbent assay (ELISA) to evaluate ThUS-mediated molecular therapeutic delivery. Additional brain sections were also H&E-stained to evaluate histological damage, and IBA1- and GFAP-stained to elucidate the effects of ThUS-mediated BBB opening on stimulation of key cell types involved in the neuro-immune response, microglia and astrocytes. Results: The ThUS RASTA sequence induced distinct BBB openings simultaneously in the same mouse where volume, PCI pixel intensity, level of dextran delivery, and AAV reporter transgene expression were correlated with brain hemisphere-specific USPL, consistent with statistically significant differences between 1.5, 5, and 10-cycle USPL groups. BBB closure after ThUS required 2-48 hours depending on USPL. The potential for acute damage and neuro-immune activation increased with USPL, but such observable damage was nearly reversed 96 hours post-ThUS. Conclusion: ThUS is a versatile single-array technique which exhibits the potential for investigating a variety of non-invasive therapeutic delivery applications in the brain.

Non-invasive optogenetics with ultrasound-mediated gene delivery and red-light excitation.

Optogenetics has revolutionized the capability of controlling genetically modified neurons in vitro and in vivo and has become an indispensable neuroscience tool. Using light as a probe for selective neuronal activation or inhibition and as a means to read out neural activity has dramatically enhanced our understanding of complex neural circuits. However, a common limitation of optogenetic studies to date is their invasiveness and spatiotemporal range. Direct viral injections into the brain tissue along with implantation of optical fibers and recording electrodes can disrupt the neuronal circuitry and cause significant damage. Conventional approaches are spatially limited around the site of the direct injection and insufficient in examining large networks throughout the brain. Lastly, optogenetics is currently not easily scalable to large animals or humans. Here, we demonstrate that optogenetic excitation can be achieved entirely non-invasively through the intact skull in mice. Using a needle-free combination of focused ultrasound-mediated viral delivery and extracorporeal illumination with red light, we achieved selective neuronal activation at depths up to 4 mm in the murine brain, confirmed through cFos expression and electrophysiology measurements within the treated areas. Ultrasound treatment significantly reduced freezing time during recall in fear conditioning experiments, but remote light exposure had a moderate effect on the freezing behavior of mice treated with viral vectors. The proposed method has the potential to open new avenues of studying, but also stimulating, neuronal networks, in an effort to elucidate normal or dysfunctional brain activity and treat neurological diseases. Finally, the same non-invasive methodology could be combined with gene therapy and applied to other organs, such as the eye and the heart.

Transcranial Theranostic Ultrasound for Pre-Planning and Blood-Brain Barrier Opening: A Feasibility Study Using an Imaging Phased Array In Vitro and In Vivo.

Focused ultrasound (FUS) for blood-brain barrier (BBB) opening is a safe, reversible and non-invasive strategy for targeted drug delivery to the brain, however extensive pre-planning strategies are necessary for successful FUS-mediated BBB opening through the structurally complex primate skull. OBJECTIVE: This study aims to demonstrate a pre-planning pipeline consisting of transcranial simulations and in vitro experimentation used to inform synchronous BBB opening and power cavitation imaging (PCI) with a single theranostic ultrasound (TUS) phased array. METHODS: Acoustic wave propagation simulation findings of pressure attenuation and focal shift through clinical-CT and micro-CT-based primate skull models were compared, while the latter were used to determine the impact of beam steering angle on focal shift and pressure attenuation. In vitro experimentation with a channel phantom enabled characterization of skull-induced receive focal shift (RFS), while in vivo BBB opening and PCI using in silico and in vitro pre-planning information was conducted using a custom Verasonics/MATLAB script. RESULTS: Simulations confirmed steering angle dependent transcranial focal shift and pressure attenuation, while in vitro experiments revealed minimal (0.30-1.50 mm) skull-induced RFS. In vivo rodent experiments with overlaid primate skull fragments demonstrated successful TUS-mediated BBB opening and spatially correlated power cavitation images (PCI) with regions of BBB opening on T1-weighted magnetic resonance images (MRI). CONCLUSION: We demonstrated the feasibility for TUS-mediated BBB opening in vivo using in silico and in vitro pre-planning information. SIGNIFICANCE: TUS as an ultrasound-guided modality for BBB opening could serve as a promising alternative to current FUS-mediated BBB opening configurations in the clinic.

Effective Partnering in Conducting Benefit-Risk Patient Preference Studies: Perspectives From a Patient Advocacy Organization, a Pharmaceutical Company, and Academic Stated-Preference Researchers.

BACKGROUND: Formal incorporation of patients' perspectives is becoming increasingly important in medical product development and decision making. This article shares practical advice regarding how patient advocacy organizations, the pharmaceutical industry, and academic experts in stated-preference research can effectively partner on benefit-risk patient preference studies. METHODS: The authors partnered on a benefit-risk patient preference study related to the treatment of psoriasis. The authors from Duke Clinical Research Institute also share their experiences in collaborating with numerous other organizations in conducting benefit-risk patient preference studies. RESULTS: Upon initiation of the study partnership with appropriate experts, training is important to ensure all collaborators have a common understanding of the methodology, what objectives stated-preference methods can support, and expectations for the project. To the extent possible, partners should align on and document relevant clinical and logistical details prior to study implementation. During study implementation, partners should use good communication practices and document and maintain a record of any changes to the original plan. Presentation of the study results should be tailored to the particular audience, with the appropriate partner leading the presentation based on its format and audience. CONCLUSION: Partners from patient advocacy organizations, the pharmaceutical industry, and academia can effectively collaborate on benefit-risk patient preference studies with sufficient planning and ongoing communication. This article is a call for action for other organizations to engage in sharing of experiences regarding effective partnering in quantifying patient preferences in medical product development.

What is clearance worth? Patients' stated risk tolerance for psoriasis treatments.

PURPOSE: The purpose of this study was to provide quantitative evidence of patients' tolerance for therapeutic risks associated with psoriasis treatments that could offer psoriasis improvements beyond the PASI 75 benchmark. MATERIALS AND METHODS: We used a discrete-choice experiment in which respondents chose between competing psoriasis treatments characterized by benefits (i.e. reduced plaque severity, reduced plaque area), risks (i.e. 10-year risk of tuberculosis, 10-year risk of death from infection), and treatment regimen. We analyzed choice data using random-parameters logit models for psoriasis affecting the body, face, or hands. RESULTS: Of 927 eligible members of the National Psoriasis Foundation who completed the survey, 28% were unwilling to accept any greater risk of treatment-related infection mortality. Among the remaining 72%, respondents were willing to accept higher risks of infection-related mortality associated with treatment to completely remove plaques covering only 1% of the body, compared to reducing lesions from 10 to 1% of the affected area. This finding was more pronounced for lesions on the face. CONCLUSIONS: Most patients placed greater value on eliminating even very small plaques compared to avoiding treatment-related risks. The perceived importance of complete versus near-complete clearance was stronger than previously documented.

Recommendations for benefit-risk assessment methodologies and visual representations.

PURPOSE: The purpose of this study is to draw on the practical experience from the PROTECT BR case studies and make recommendations regarding the application of a number of methodologies and visual representations for benefit-risk assessment. METHODS: Eight case studies based on the benefit-risk balance of real medicines were used to test various methodologies that had been identified from the literature as having potential applications in benefit-risk assessment. Recommendations were drawn up based on the results of the case studies. RESULTS: A general pathway through the case studies was evident, with various classes of methodologies having roles to play at different stages. Descriptive and quantitative frameworks were widely used throughout to structure problems, with other methods such as metrics, estimation techniques and elicitation techniques providing ways to incorporate technical or numerical data from various sources. Similarly, tree diagrams and effects tables were universally adopted, with other visualisations available to suit specific methodologies or tasks as required. Every assessment was found to follow five broad stages: (i) Planning, (ii) Evidence gathering and data preparation, (iii) Analysis, (iv) Exploration and (v) Conclusion and dissemination. CONCLUSIONS: Adopting formal, structured approaches to benefit-risk assessment was feasible in real-world problems and facilitated clear, transparent decision-making. Prior to this work, no extensive practical application and appraisal of methodologies had been conducted using real-world case examples, leaving users with limited knowledge of their usefulness in the real world. The practical guidance provided here takes us one step closer to a harmonised approach to benefit-risk assessment from multiple perspectives.

Literature review of visual representation of the results of benefit-risk assessments of medicinal products.

BACKGROUND: The PROTECT Benefit-Risk group is dedicated to research in methods for continuous benefit-risk monitoring of medicines, including the presentation of the results, with a particular emphasis on graphical methods. METHODS: A comprehensive review was performed to identify visuals used for medical risk and benefit-risk communication. The identified visual displays were grouped into visual types, and each visual type was appraised based on five criteria: intended audience, intended message, knowledge required to understand the visual, unintentional messages that may be derived from the visual and missing information that may be needed to understand the visual. RESULTS: Sixty-six examples of visual formats were identified from the literature and classified into 14 visual types. We found that there is not one single visual format that is consistently superior to others for the communication of benefit-risk information. In addition, we found that most of the drawbacks found in the visual formats could be considered general to visual communication, although some appear more relevant to specific formats and should be considered when creating visuals for different audiences depending on the exact message to be communicated. CONCLUSION: We have arrived at recommendations for the use of visual displays for benefit-risk communication. The recommendation refers to the creation of visuals. We outline four criteria to determine audience-visual compatibility and consider these to be a key task in creating any visual. Next we propose specific visual formats of interest, to be explored further for their ability to address nine different types of benefit-risk analysis information.

Implementing Benefit-Risk Assessment for the Periodic Benefit-Risk Evaluation Report.

BACKGROUND: In 2012, the International Conference on Harmonisation (ICH) E2C (R1) guideline for periodic safety update reporting (PSUR) for medicines was revised. Several new concepts that expanded the scope of the report were added, including a new section focused on benefits and an additional section focused on integrated benefit-risk (B-R) assessment. These changes are reflected in the new title of the report, namely, the Periodic Benefit-Risk Evaluation Report (PBRER). Recently, structured frameworks have been developed by the pharmaceutical industry and regulatory agencies to facilitate B-R analysis for medicines. METHODS: This manuscript provides suggestions for incorporating the elements of a structured B-R assessment into the PBRER and also includes practical approaches for implementing the ICH guidelines for the B-R analysis section. RESULTS: The main components of a B-R assessment for the PBRER include decision context; key benefits and key risks; strengths, limitations, and uncertainties of the evidence; risk management; and the overall B-R conclusions. CONCLUSIONS: A structured, systematic approach to defining a medicine's B-R profile will help ensure compliance with this ICH objective for the PBRER.

Implementation of Structured Benefit-Risk Assessments in Marketing Authorization Applications: Lessons Learned.

BACKGROUND: A recent publication from Eli Lilly and Company provided guidance on incorporation of a structured benefit-risk assessment framework into Section 2.5.6 of the Clinical Overview of marketing authorization applications. Because a template alone cannot deliver a judicious benefit-risk evaluation, the purpose of this manuscript is to present lessons learned and practical approaches that pharmaceutical companies (sponsors) can apply in developing holistic benefit risk assessments of medicinal products for their marketing authorization applications. METHODS: Benefit-risk scientists at Eli Lilly and Company facilitated use of a structured benefit-risk assessment in Section 2.5.6 of the Clinical Overview for a number of marketing authorization applications submitted to regulators between 2013 and the 2016. Based on our experiences in implementing the approach described in the publication by Wolka et al, we have identified commonalities that contributed to successful implementation. RESULTS: The 3 key learnings from the authors' experience are to (1) use a cross-functional team approach; (2) employ a process that lends to the objectivity and efficiency of benefit-risk assessments; and (3) leverage data visualizations for clear and concise communication of benefit-risk information. CONCLUSIONS: Sponsors can apply these approaches to incorporate benefit-risk assessments into their marketing authorization applications. Further shared learnings and benchmarking among the pharmaceutical industry will be necessary to further advance the science and practice of benefit-risk assessment.

Patient Engagement at a Tipping Point-The Need for Cultural Change Across Patient, Sponsor, and Regulator Stakeholders: Insights From the DIA Conference, "Patient Engagement in Benefit Risk Assessment Throughout the Life Cycle of Medical Products".

Benefit-risk assessment is the foundation for decision making throughout the life cycle of medical products. Because patients are the beneficiaries of the efficacy of medical treatments and also bear their possible risks, their perspectives and judgments about value and the relative importance of benefits and risks should be at the heart of the medical decision-making process. Patient engagement is now at a tipping point; there have been a growing number of patient engagement initiatives over the past several years, but there remains the need for a common language, alignment on engagement approaches and best practices, and a shared vision regarding a desired future state. This article discusses insights gleaned from the DIA conference, "Patient Engagement in Benefit-Risk Assessment throughout the Life Cycle of Medical Products" (September 2015). It highlights the changes that will need to occur within the patient, medical-product sponsor, and regulatory cultures in order for patient engagement to become integrated into the medical-product development process and life cycle maintenance. Furthermore, it emphasizes that reaching the desired future state will require a conscious commitment from all stakeholders to work collaboratively to develop shared solutions and to map a common path forward.

Incorporation of a Benefit-Risk Assessment Framework Into the Clinical Overview of Marketing Authorization Applications.

BACKGROUND: The main responsibility of regulators and industry is to ensure the benefit-risk balance of pharmaceutical products is positive for the intended patient populations. In recent decades, regulators and industry have taken steps to systematize benefit-risk decision making related to marketing authorization applications through the use of structured benefit-risk assessment. METHODS: This manuscript presents an outline for a structured benefit-risk assessment that can be incorporated into Section 2.5.6 of the Clinical Overview to provide the basis for approval of pharmaceutical products in these regulatory submissions. RESULTS: The structured format presents the benefits and risks of a pharmaceutical product in the context of the medical need in the disease state, the benefits and risks of available pharmacologic and nonpharmacologic therapies, and the approach for mitigating the risks of the product under review. CONCLUSIONS: Ultimately, such an approach that lends further support to quality decision making would be beneficial to patients who would be treated with new pharmaceutical products.

Upregulated TRPC3 and Downregulated TRPC1 Channel Expression during Hypertension is Associated with Increased Vascular Contractility in Rat.

Transient receptor potential (TRP) C1 and C3 (TRPC1 and TRPC3) are expressed in vascular smooth muscle cells and are thought to be involved in vascular contractility. In the present study, we determined the effect of systemic hypertension on TRPC1/TRPC3 channel expression and vascular contractility in rat carotid artery (CA). CA were studied from male spontaneously hypertensive rats (SHR), Wistar-Kyoto (WKY), and Long Evans (LE) rats. TRPC1/3 expression was determined by RT-PCR and Western blot. TRP channel function was evaluated by whole-cell patch clamp, using UTP (60 µM) to stimulate TRPC1/3 channels. Contractions of endothelium-denuded CA segments to UTP (1-300 µM) and phenylephrine (Phe; 0.1 nM-10 µM) were measured in an isometric tension bath. TRPC1 and TRPC3 mRNA was present in CA of both WKY and SHR. Western blot demonstrated 3.1 ± 1.2 times greater TRPC3 expression and 0.5 ± 0.2 times TRPC1 in SHR versus WKY CA. Isolated CA showed potentiated contraction to UTP in the SHR versus WKY. Activation of voltage-dependent Ca(2+) channels (VDCC) in UTP-mediated constriction only occurred in SHR CA. Contraction to Phe was unaltered between WKY and SHR CA and involved equal significant VDCC activation in both groups. Patch clamp demonstrated that the UTP-stimulated current (I(utp)) was greater in SHR compared to the normotensive WKY and LE rats with peak I(utp) (at -110 mV) of -63 ± 24 pA compared to -25 ± 4 pA, respectively. We demonstrate that UTP-mediated but not Phe-mediated constrictions are potentiated in the CA during hypertension. Expression of TRPC1 is decreased whereas TRPC3 is increased in SHR CA. Interestingly, VDCC activation only contributes to UTP-mediated contraction of SHR CAs whereas it contributes substantially and equally in Phe-mediated contraction. We speculate that the alteration of TRPC channel expression in hypertension leads to greater smooth muscle depolarization, VDCC activation, and vascular contractility in the UTP (but not Phe) signaling pathway.

Increased risk of acute pancreatitis and biliary disease observed in patients with type 2 diabetes: a retrospective cohort study.

OBJECTIVE: The objective of this study was to assess the risk of acute pancreatitis in patients with type 2 diabetes compared with that in patients without diabetes. We also examined the risk of biliary disease (defined as occurrence of cholelithiasis, acute cholecystitis, or cholecystectomy), which is a major cause of pancreatitis. RESEARCH DESIGN AND METHODS: We conducted a retrospective cohort study using a large, geographically diverse U.S. health care claims database. Eligible patients (>or=18 years) were enrolled for at least 12 continuous months (1999-2005), with no incident events of pancreatitis or biliary disease during that 1 year baseline period. ICD-9 codes and prescription data were used to identify patients with type 2 diabetes; ICD-9 codes were also used to identify cases of pancreatitis and biliary disease. Overall, 337,067 patients with type 2 diabetes were matched on age and sex with 337,067 patients without diabetes. Incidence rates of disease and 95% CI were calculated per 100,000 person-years of exposure. RESULTS: The type 2 diabetic cohort had a 2.83-fold (95% CI 2.61-3.06) greater risk of pancreatitis and 1.91-fold (1.84-1.99) greater risk of biliary disease compared with the nondiabetic cohort. Relative to patients of corresponding age without diabetes, younger type 2 diabetic patients had the highest risk of pancreatitis (<45 years: incidence rate ratio [IRR] 5.26 [95% CI 4.31-6.42]; >or=45 years: 2.44 [2.23-2.66]). CONCLUSIONS: These data suggest that patients with type 2 diabetes may have an increased risk of acute pancreatitis and biliary disease.

A multiattribute model for evaluating the benefit-risk profiles of treatment alternatives.

The assessment of the benefits and risks associated with a medicine's use requires careful consideration of a wealth of information of varying format and quality, ranging from efficacy and safety data derived from randomized clinical trials to statistical results from health outcomes studies to spontaneously reported adverse events. Contrary to the expectations of patients, physicians, and regulators, the literature offers little guidance as to how to strike an appropriate balance between benefit and risk. Although a qualitative listing of a medicine's benefits and risks is useful, much could be gained from a systematic and transparent process to evaluate a medicine's pre- and postmarketing performance. The authors propose a representational model based on multicriteria decision analysis that can incorporate both evaluative judgments from different perspectives (e.g., physician, patient) and quantitative data to inform tradeoffs between multiple benefit and multiple risk elements in a logically consistent and transparent manner. The model is designed to highlight the relative merits and deficits of treatment alternatives in well-defined and specific contexts. It is intended to serve as a common platform to facilitate focused benefit-risk tradeoff discussions between scientists, physicians, regulatory authorities, and pharmaceutical companies, and to assist in the communication of clear and consistent messages regarding those tradeoffs.