Improved Diffusion Interaction Parameter Measurement to Predict the Viscosity of Concentrated mAb Solutions.

During the developability assessment of therapeutic monoclonal antibody (mAb) candidates, utilization of robust high-throughput predictive assays enables rapid selection of top candidates with low risks for late-stage development. Predicting the viscosities of highly concentrated mAbs using limited materials is an important aspect of developability assessment because high viscosity can complicate manufacturability, stability, and administration. Here, we report a high-throughput assay measuring protein-protein interactions to predict mAb viscosity. The diffusion interaction parameter (kD) measures colloidal self-association in dilute solutions and has been reported to be predictive of the mAb viscosity at high concentrations. However, kD of Amgen early stage IgG1 mAb candidates measured in 10 mM acetate at pH 5.2 containing sucrose and polysorbate (denoted A52SuT) shows only weak correlation to their viscosities at 140 mg/mL in A52SuT. We hypothesize that kD measured in A52SuT reflects primarily long-range electrostatic repulsions because most of these mAb candidates carry strong net positive charges in this low ionic strength formulation with pH (5.2) well below pI values of mAb candidates. However, the viscosities of high concentration mAbs depend heavily on short-range molecular interactions. We propose an improved kD method in which salt is added to suppress charge repulsions and to allow for detection of key short-range interactions in dilute solutions. Salt types and salt concentrations were screened, and an optimal salt condition was identified. This optimized method was further validated using two test mAb sets. Overall, the method improves the Pearson R2 between kD and viscosity (6-230 cP) from 0.24 to 0.80 for a data set consisting of 37 mAbs.

Glycemic outcomes of Advanced Hybrid Closed Loop system in children and adolescents with Type 1 Diabetes, previously treated with Multiple Daily Injections (MiniMed 780G system in T1D individuals, previously treated with MDI).

BACKGROUND: The objective of this study was to evaluate the glycemic outcomes in children and adolescents with Type 1 Diabetes (T1D) previously treated with Multiple Daily Injections (MDI) using a structured initiation protocol for the Advanced Hybrid Closed Loop (AHCL) Minimed 780G insulin pump system. METHODS: In this prospective open label single-arm, single-center, clinical investigation, we recruited children and adolescents (aged 7-17 years) with T1D on MDI therapy and HbA1c below 12.5%. All participants followed a 10-day structured initiation protocol which included 4 steps: step 1: AHCL system assessment; step 2: AHCL system training; step 3: Sensor augmented pump therapy (SAP) for 3 days; step 4: AHCL system use for 12 weeks, successfully completing the training from MDI to AHCL in 10 days. The primary outcome of the study was the change in the time spent in the target in range (TIR) of 70-180 mg/dl and HbA1c from baseline (MDI + CGM, 1 week) to study phase (AHCL, 12 weeks). The paired student t-test was used for statistical analysis and a value < 0.05 was considered statistically significant. RESULTS: Thirty-four participants were recruited and all completed the 12 weeks study. TIR increased from 42.1 ± 18.7% at baseline to 78.8 ± 6.1% in the study phase (p < 0.001). HbA1c decreased from 8.6 ± 1.7% (70 ± 18.6 mmol/mol) at baseline, to 6.5 ± 0.7% (48 ± 7.7 mmol/mol) at the end of the study (p = 0.001). No episodes of severe hypoglycemia or DKA were reported. CONCLUSION: Children and adolescents with T1D on MDI therapy who initiated the AHCL system following a 10-days structured protocol achieved the internationally recommended goals of glycemic control with TIR > 70% and a HbA1c of < 7%.

Synthesis of Zwitterionic and Trehalose Polymers with Variable Degradation Rates and Stabilization of Insulin.

Polymers that stabilize biomolecules are important as excipients in protein formulation. Herein, we describe a class of degradable polymers that have tunable degradation rates depending on the polymer backbone and can stabilize proteins to aggregation. Specifically, zwitterion- and trehalose-substituted polycaprolactone, polyvalerolactone, polycarbonate, and polylactide were prepared and characterized with regards to their hydrolytic degradation and ability to stabilize insulin to mechanical agitation during heat. Ring-opening polymerization (ROP) of allyl-substituted monomers was performed by using organocatalysis, resulting in well-defined alkene-substituted polymers with good control over molecular weight and dispersity. The polymers were then modified by using photocatalyzed thiol-ene reactions to install protein-stabilizing carboxybetaine and trehalose side chains. The resulting polymers were water-soluble and exhibited a wide range of half-lives, from 12 h to more than 3 months. The polymers maintained the ability to stabilize the therapeutic protein insulin from activity loss due to aggregation, demonstrating their potential as degradable excipients for protein formulation.

Hepatitis C elimination among people who inject drugs: Challenges and recommendations for action within a health systems framework.

The burden of hepatitis C infection is considerable among people who inject drugs (PWID), with an estimated prevalence of 39%, representing an estimated 6.1 million people who have recently injected drugs living with hepatitis C infection. As such, PWID are a priority population for enhancing prevention, testing, linkage to care, treatment and follow-up care in order to meet World Health Organization (WHO) hepatitis C elimination goals by 2030. There are many barriers to enhancing hepatitis C prevention and care among PWID including poor global coverage of harm reduction services, restrictive drug policies and criminalization of drug use, poor access to health services, low hepatitis C testing, linkage to care and treatment, restrictions for accessing DAA therapy, and the lack of national strategies and government investment to support WHO elimination goals. On 5 September 2017, the International Network of Hepatitis in Substance Users (INHSU) held a roundtable panel of international experts to discuss remaining challenges and future priorities for action from a health systems perspective. The WHO health systems framework comprises six core components: service delivery, health workforce, health information systems, medical procurement, health systems financing, and leadership and governance. Communication has been proposed as a seventh key element which promotes the central role of affected community engagement. This review paper presents recommended strategies for eliminating hepatitis C as a major public health threat among PWID and outlines future priorities for action within a health systems framework.

PEG Analogs Synthesized by Ring-Opening Metathesis Polymerization for Reversible Bioconjugation.

Poly(ethylene glycols) (PEGs) with protein-reactive end-groups are widely utilized in bioconjugation reactions. Herein, we describe the use of ring-opening metathesis polymerization (ROMP) to synthesize unsaturated protein-reactive PEG analogs. These ROMP PEGs (rPEGs) contained terminal aldehyde functionality and ranged in molecular weight from 6 to 20 kDa. The polymers were readily conjugated to free amines on the protein hen egg-white lysozyme (Lyz). Biocompatibility of the unsaturated PEGs was assessed in vitro, revealing the polymers to be nontoxic up to concentrations of at least 1 mg/mL in human dermal fibroblasts (HDFs). The resulting unsaturated rPEG-lysozyme conjugates underwent metathesis-based depolymerization, resulting in decreased molecular weight of the conjugate.

"We just follow the patients' lead": Healthcare professional perspectives on the involvement of teenagers with cancer in decision making.

PURPOSE: We report on an in-depth interview and participant observation study that uses data from multiple sources to determine how the involvement of teenagers with leukaemia is understood and enacted in healthcare. In this article, we investigate healthcare professionals' (HCP) views of teenagers' involvement in decisions about their care and treatment for leukaemia. METHODS: We conducted participant observation at 98 multi-disciplinary meetings and 95 open-ended, semi-structured interviews and informal conversations with clinical teenage cancer teams at one UK tertiary referral centre. Data were collected over a 9-month period, audio-recorded, transcribed verbatim and analysed using principles of grounded theory. RESULTS: HCP revealed principles relating to the involvement of teenagers with leukaemia in decision making: (1) do the 'right thing', (2) act on the care and treatment preferences of the teenager and (3) openly disclose information about the teenagers' condition. These principles were prioritised and utilised uniquely in each situation, reliant on three mediating factors: (1) family communication styles, (2) stage of illness and (3) nature of the disease. CONCLUSIONS: Specialist haematology teams are aware of the individual, and shifting and situational preferences of teenagers. They follow the lead which teenagers give them with regard to these preferences. If actual practice with regard to the involvement of teenagers is found to be wanting, this study refutes that this should be ascribed to insensitivity on the part of HCP about teenagers informational and decisional role preferences.

Synthesis and Biological Evaluation of a Degradable Trehalose Glycopolymer Prepared by RAFT Polymerization.

There is a significant need for new biodegradable protein stabilizing polymers. Herein, the synthesis of a polymer with trehalose side chains and hydrolytically degradable backbone esters and its evaluation for protein stabilization and cytotoxicity are described. Specifically, an alkene-containing parent polymer is synthesized by reversible addition-fragmentation chain transfer polymerization, and thiolated trehalose is installed using a radical-initiated thiol-ene reaction. The stabilizing properties of the polymer are investigated by thermally stressing granulocyte colony-stimulating factor (G-CSF), which is expressed and purified using a custom-designed G-CSF fusion protein with a polyhistidine-tagged maltose binding protein. The degradable polymer is shown to stabilize G-CSF to 66% after heating at 40 °C. Poly(5,6-benzo-2-methylene-1,3-dioxepane (BMDO)-co-butyl methacrylate-trehalose) is degraded and its cellular compatibility is investigated. While the polymer is noncytotoxic, cytotoxic effects are observed from the degraded products in fibroblasts and murine myeloblasts. These data provide important information for future use of BMDO-containing trehalose glycopolymers for biomedical applications.

Substituted Polyesters by Thiol-Ene Modification: Rapid Diversification for Therapeutic Protein Stabilization.

Many proteins, especially those used as therapeutics, are unstable to storage and shipping temperatures, leading to increased costs in research and industry. Therefore, the design and synthesis of novel stabilizers is an important area of investigation. Herein we report new degradable polymers that stabilize proteins to environmental stressors such as refrigeration and elevated temperature. Specifically, polycaprolactones with different pendant groups were synthesized and surveyed for their ability to stabilize an important therapeutic protein to storage and shipping conditions. Ring-opening polymerization (ROP) of an allyl-substituted caprolactone monomer was carried out using the organocatalyst 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD) to yield a well-defined, alkene-substituted degradable polymer, which was used as a common backbone to control for the degree of polymerization. Relevant side chains such as trehalose, lactose, glucose, carboxybetaine, and oligo(ethylene glycol) were installed via postpolymerization thiol-ene reactions. These degradable polymers were then employed as excipients for the stabilization of the therapeutic protein granulocyte colony-stimulating factor (G-CSF) against storage at 4 °C and shipping temperatures of 60 °C. The best stabilization was observed using the trehalose- and zwitterion- substituted polyesters. Both the trehalose- and carboxybetaine-substituted pCL were further investigated with regard to molecular weight dependence, and it was found that the molecular weight was minimally important for stabilization to refrigeration, but critical for G-CSF stabilization at elevated temperatures. Both high performing zwitterionic and trehalose polyesters were also degraded, and the polymers and degradation products were shown to be noncytotoxic. This work provides potential biocompatible polymers for stabilization of the important therapeutic G-CSF, as well as a general platform for the future discovery of new polymeric protein stabilizers.

Controlled Radical Polymerization as an Enabling Approach for the Next Generation of Protein-Polymer Conjugates.

Protein-polymer conjugates are unique constructs that combine the chemical properties of a synthetic polymer chain with the biological properties of a biomacromolecule. This often leads to improved stabilities, solubilities, and in vivo half-lives of the resulting conjugates, and expands the range of applications for the proteins. However, early chemical methods for protein-polymer conjugation often required multiple polymer modifications, which were tedious and low yielding. To solve these issues, work in our laboratory has focused on the development of controlled radical polymerization (CRP) techniques to improve synthesis of protein-polymer conjugates. Initial efforts focused on the one-step syntheses of protein-reactive polymers through the use of functionalized initiators and chain transfer agents. A variety of functional groups such as maleimide and pyridyl disulfide could be installed with high end-group retention, which could then react with protein functional groups through mild and biocompatible chemistries. While this grafting to method represented a significant advance in conjugation technique, purification and steric hindrance between large biomacromolecules and polymer chains often led to low conjugation yields. Therefore, a grafting from approach was developed, wherein a polymer chain is grown from an initiating site on a functionalized protein. These conjugates have demonstrated improved homogeneity, characterization, and easier purification, while maintaining protein activity. Much of this early work utilizing CRP techniques focused on polymers made up of biocompatible but nonfunctional monomer units, often containing oligoethylene glycol meth(acrylate) or N-isopropylacrylamide. These branched polymers have significant advantages compared to the historically used linear poly(ethylene glycols) including decreased viscosities and thermally responsive behavior, respectively. Recently, we were motivated to use CRP techniques to develop polymers with rationally designed and functional biological properties for conjugate preparation. Specifically, two families of saccharide-inspired polymers were developed for stabilization and activation of therapeutic biomolecules. A series of polymers with trehalose side-chains and vinyl backbones were prepared and used to stabilize proteins against heat and lyophilization stress as both conjugates and additives. These materials, which combine properties of osmolytes with nonionic surfactants, have significant potential for in vivo therapeutic use. Additionally, polymers that mimic the structure of the naturally occurring polysaccharide heparin were prepared. These polymers contained negatively charged sulfonate groups and imparted stabilization to a heparin-binding growth factor after conjugation. A screen of other sulfonated polymers led to the development of a polymer with improved heparin mimesis, enhancing both stability and activity of the protein to which it was attached. Chemical improvements over the past decade have enabled the preparation of a diverse set of protein-polymer conjugates by controlled polymerization techniques. Now, the field should thoroughly explore and expand both the range of polymer structures and also the applications available to protein-polymer conjugates. As we move beyond medicine toward broader applications, increased collaboration and interdisciplinary work will result in the further development of this exciting field.

Current understanding of decision-making in adolescents with cancer: A narrative systematic review.

BACKGROUND: Policy guidance and bioethical literature urge the involvement of adolescents in decisions about their healthcare. It is uncertain how roles and expectations of adolescents, parents and healthcare professionals influence decision-making and to what extent this is considered in guidance. AIMS: To identify recent empirical research on decision-making regarding care and treatment in adolescent cancer: (1) to synthesise evidence to define the role of adolescents, parents and healthcare professionals in the decision-making process and (2) to identify gaps in research. DESIGN: A narrative systematic review of qualitative, quantitative and mixed-methods research. We adopted a textual approach to synthesis, using a theoretical framework of interactionism to interpret findings. DATA SOURCES: The databases MEDLINE, PsycINFO, SCOPUS, EMBASE and CINHAL were searched from 2001 through May 2015 for publications on decision-making for adolescents (13-19 years) with cancer. RESULTS: Twenty-eight articles were identified. Adolescents and parents initially find it difficult to participate in decision-making due to a lack of options in the face of protocol-driven care. Parent and adolescent preferences for information and response to loss of control vary between individuals and over time. No studies indicate parental or adolescent preference for a high degree of independence in decision-making. CONCLUSION: Striving to make parents and adolescents fully informed or urge them towards more independence than they prefer may add to distress and confusion. This may interfere with their ability to participate in their preferred way in decisions about care and treatment. Future research should include analysis of on-ground interactions among parents, adolescents and clinicians across the trajectory.

Therapeutic protein-polymer conjugates: advancing beyond PEGylation.

Protein-polymer conjugates are widely used as therapeutics. All Food and Drug Administration (FDA)-approved protein conjugates are covalently linked to poly(ethylene glycol) (PEG). These PEGylated drugs have longer half-lives in the bloodstream, leading to less frequent dosing, which is a significant advantage for patients. However, there are some potential drawbacks to PEG that are driving the development of alternatives. Polymers that display enhanced pharmacokinetic properties along with additional advantages such as improved stability or degradability will be important to advance the field of protein therapeutics. This perspective presents a summary of protein-PEG conjugates for therapeutic use and alternative technologies in various stages of development as well as suggestions for future directions. Established methods of producing protein-PEG conjugates and new approaches utilizing controlled radical polymerization are also covered.

Reduction of monoclonal antibody viscosity using interpretable machine learning.

Early identification of antibody candidates with drug-like properties is essential for simplifying the development of safe and effective antibody therapeutics. For subcutaneous administration, it is important to identify candidates with low self-association to enable their formulation at high concentration while maintaining low viscosity, opalescence, and aggregation. Here, we report an interpretable machine learning model for predicting antibody (IgG1) variants with low viscosity using only the sequences of their variable (Fv) regions. Our model was trained on antibody viscosity data (>100 mg/mL mAb concentration) obtained at a common formulation pH (pH 5.2), and it identifies three key Fv features of antibodies linked to viscosity, namely their isoelectric points, hydrophobic patch sizes, and numbers of negatively charged patches. Of the three features, most predicted antibodies at risk for high viscosity, including antibodies with diverse antibody germlines in our study (79 mAbs) as well as clinical-stage IgG1s (94 mAbs), are those with low Fv isoelectric points (Fv pIs < 6.3). Our model identifies viscous antibodies with relatively high accuracy not only in our training and test sets, but also for previously reported data. Importantly, we show that the interpretable nature of the model enables the design of mutations that significantly reduce antibody viscosity, which we confirmed experimentally. We expect that this approach can be readily integrated into the drug development process to reduce the need for experimental viscosity screening and improve the identification of antibody candidates with drug-like properties.

Simplified Meal Announcement Versus Precise Carbohydrate Counting in Adolescents With Type 1 Diabetes Using the MiniMed 780G Advanced Hybrid Closed Loop System: A Randomized Controlled Trial Comparing Glucose Control.

OBJECTIVE: We aimed to compare glucose control in adolescents with type 1 diabetes (T1D) using the MiniMed 780G system who used simplified meal announcement with those who used precise carbohydrate counting. RESEARCH DESIGN AND METHODS: This randomized controlled trial included 34 participants (age 12-18 years) with T1D who were on multiple daily injections or insulin pump and were scheduled to start using the MiniMed 780G system at Sidra Medicine in Qatar. After a 7-day run-in period, participants were randomly assigned to the fix group (simplified meal announcement by preset of three personalized fixed carbohydrate amounts) or the flex group (precise carbohydrate counting) and followed for 12 weeks. Between-group difference in time in range (TIR) was the primary end point. Secondary end points included HbA1c and other glycometrics. RESULTS: During the 12-week study phase, TIR was 73.5 ± 6.7% in the fix and 80.3 ± 7.4% in the flex group, with a between-group difference of 6.8% in favor of flex (P = 0.043). Time >250 mg/dL was better in the flex group (P = 0.012), whereas HbA1c (P = 0.168), time below range (P = 0.283), and time between 180 and 250 mg/dL (P = 0.114) did not differ. CONCLUSIONS: Adolescents using the MiniMed 780G system with a preset of three personalized fixed carbohydrate amounts can reach international targets of glycemic control. Therefore, it may be a valuable alternative to precise carbohydrate counting in users who are challenged by precise carbohydrate counting. Because carbohydrate counting further improves outcomes, these skills remain important for MiniMed 780G users.

Microfluidic viscometer by acoustic streaming transducers.

Measurement of fluid viscosity represents a huge need for many biomedical and materials processing applications. Sample fluids containing DNA, antibodies, protein-based drugs, and even cells have become important therapeutic options. The physical properties, including viscosity, of these biologics are critical factors in the optimization of the biomanufacturing processes and delivery of therapeutics to patients. Here we demonstrate an acoustic microstreaming platform termed as microfluidic viscometer by acoustic streaming transducers (µVAST) that induces fluid transport from second-order microstreaming to measure viscosity. Validation of our platform is achieved with different glycerol content mixtures to reflect different viscosities and shows that viscosity can be estimated based on the maximum speed of the second-order acoustic microstreaming. The µVAST platform requires only a small volume of fluid sample (∼1.2 µL), which is 16-30 times smaller than that of commercial viscometers. In addition, µVAST can be scaled up for ultra-high throughput measurements of viscosity. Here we demonstrate 16 samples within 3 seconds, which is an attractive feature for automating the process flows in drug development and materials manufacturing and production.

Prediction of Antibody Viscosity from Dilute Solution Measurements.

The high antibody doses required to achieve a therapeutic effect often necessitate high-concentration products that can lead to challenging viscosity issues in production and delivery. Predicting antibody viscosity in early development can play a pivotal role in reducing late-stage development costs. In recent years, numerous efforts have been made to predict antibody viscosity through dilute solution measurements. A key finding is that the entanglement of long, flexible complexes contributes to the sharp rise in antibody viscosity at the required dosing. This entanglement model establishes a connection between the two-body binding affinity and the many-body viscosity. Exploiting this insight, this study connects dilute solution measurements of self-association to high-concentration viscosity profiles to quantify the relationship between these regimes. The resulting model has exhibited success in predicting viscosity at high concentrations (around 150 mg/mL) from dilute solution measurements, with only a few outliers remaining. Our physics-based approach provides an understanding of fundamental physics, interpretable connections to experimental data, the potential to extrapolate beyond training conditions, and the capacity to effectively explain the physical mechanics behind these outliers. Conducting hypothesis-driven experiments that specifically target the viscosity and relaxation mechanisms of outlier molecules may allow us to unravel the intricacies of their behavior and, in turn, enhance the performance of our model.

Development of in silico models to predict viscosity and mouse clearance using a comprehensive analytical data set collected on 83 scaffold-consistent monoclonal antibodies.

Biologic drug discovery pipelines are designed to deliver protein therapeutics that have exquisite functional potency and selectivity while also manifesting biophysical characteristics suitable for manufacturing, storage, and convenient administration to patients. The ability to use computational methods to predict biophysical properties from protein sequence, potentially in combination with high throughput assays, could decrease timelines and increase the success rates for therapeutic developability engineering by eliminating lengthy and expensive cycles of recombinant protein production and testing. To support development of high-quality predictive models for antibody developability, we designed a sequence-diverse panel of 83 effector functionless IgG1 antibodies displaying a range of biophysical properties, produced and formulated each protein under standard platform conditions, and collected a comprehensive package of analytical data, including in vitro assays and in vivo mouse pharmacokinetics. We used this robust training data set to build machine learning classifier models that can predict complex protein behavior from these data and features derived from predicted and/or experimental structures. Our models predict with 87% accuracy whether viscosity at 150 mg/mL is above or below a threshold of 15 centipoise (cP) and with 75% accuracy whether the area under the plasma drug concentration-time curve (AUC0-672 h) in normal mouse is above or below a threshold of 3.9 × 106 h x ng/mL.

High-Throughput Mass Spectrometry for Biopharma: A Universal Modality and Target Independent Analytical Method for Accurate Biomolecule Characterization.

Reversed-phase liquid chromatographic mass spectrometry (rpLC-MS) is a universal, platformed, and essential analytical technique within pharmaceutical and biopharmaceutical research. Typical rpLC method gradient times can range from 5 to 20 min. As monoclonal antibody (mAb) therapies continue to evolve and bispecific antibodies (BsAbs) become more established, research stage engineering panels will clearly evolve in size. Therefore, high-throughput (HT) MS and automated deconvolution methods are key for success. Additionally, newer therapeutics such as bispecific T-cell engagers and nucleic acid-based modalities will also require MS characterization. Herein, we present a modality and target agnostic HT solid-phase extraction (SPE) MS method that affords the analysis of a 96-well plate in 41.4 min, compared to the traditional rpLC-MS method that would typically take 14.4 h. The described method can accurately determine the molecular weights for monodispersed and highly polydispersed biotherapeutic species and membrane proteins; determine levels of glycosylation, glycation, and formylation; detect levels of chain mispairing; and determine accurate drug-to-antibody ratio values.

The effect of advanced hybrid closed loop system on glycated hemoglobin (HbA1c) in a young male with type 1 diabetes mellitus and growth hormone treatment: A case report.

The advanced hybrid closed loop system MiniMed 780G can be an effective tool to improve glycemic control and decrease the health burden in a young male with type 1 diabetes and short stature.

Priorities and recommended actions for how researchers, practitioners, policy makers, and the affected community can work together to improve access to hepatitis C care for people who use drugs.

It is estimated that 6.1 million people with recent injecting drug use (PWID) are living with hepatitis C virus (HCV). Although HCV-related morbidity and mortality among PWID continues to increase, the advent of direct acting antiviral (DAA) HCV regimens with cure rates >95% provides an opportunity to reverse the rising burden of disease. Additionally, given evidence that opioid substitution therapy and high-coverage needle and syringe programs can reduce HCV incidence by up to 80%, there is an opportunity to reduce HCV transmission with increased coverage of harm reduction services. However, there are significant patient, provider, health system, structural, and societal barriers that impede access to HCV prevention and care for PWID. The International Network on Hepatitis in Substance Users (INHSU), in collaboration with the Australasian Society for HIV, Viral Hepatitis, Sexual Health Medicine (ASHM), Harm Reduction International, the Canadian Network on Hepatitis C, Canadian Research Initiative in Substance Misuse, the National Viral Hepatitis Roundtable, Médecins du Monde and CATIE, held a roundtable discussion prior to the Harm Reduction Conference in Montreal, Canada on 13th May 2017 to discuss how to improve HCV prevention and care for PWID. Over 100 international researchers, practitioners, policy makers, advocates, and affected community members came together to discuss shared priorities for action, develop actionable next steps and to create partnerships to enable application of priorities. This paper highlights the key priority areas identified by participants including: enhancing global coverage of harm reduction services; addressing punitive drug policies; ensuring access to affordable HCV diagnostics and treatment; improving the evidence-base for HCV prevention, testing, linkage to care and treatment; implementing integrated HCV programs; advancing peer-based models of HCV care; and tackling social determinants of health inequalities for PWID. This paper also highlights the recommended actions for each priority identified by the participants from this roundtable.