Development of a cost-effective ovine antibody-based therapy against SARS-CoV-2 infection and contribution of antibodies specific to the spike subunit proteins.

Antibodies against SARS-CoV-2 are important to generate protective immunity, with convalescent plasma one of the first therapies approved. An alternative source of polyclonal antibodies suitable for upscaling would be more amendable to regulatory approval and widespread use. In this study, sheep were immunised with SARS-CoV-2 whole spike protein or one of the subunit proteins: S1 and S2. Once substantial antibody titres were generated, plasma was collected and samples pooled for each antigen. Non-specific antibodies were removed via affinity-purification to yield candidate products for testing in a hamster model of SARS-CoV-2 infection. Affinity-purified polyclonal antibodies to whole spike, S1 and S2 proteins were evaluated for in vitro for neutralising activity against SARS-CoV-2 Wuhan-like virus (Australia/VIC01/2020) and a recent variant of concern, B.1.1.529 BA.1 (Omicron), antibody-binding, complement fixation and phagocytosis assays were also performed. All antibody preparations demonstrated an effect against SARS-CoV-2 disease in the hamster model of challenge, with those raised against the S2 subunit providing the most promise. A rapid, cost-effective therapy for COVID-19 was developed which provides a source of highly active immunoglobulin specific to SARS-CoV-2 with multi-functional activity.

COVID-19 et anticorps neutralisant le SARS-CoV-2: (23 décembre 2021) / COVID-19 and SARS-CoV-2 neutralizing antibodies: (December 23, 2021)

CONTEXTE: Le présent document ainsi que les constats qu'il énonce ont été rédigés en réponse à une interpellation du ministère de la Santé et des Services sociaux dans le contexte de la crise sanitaire liée à la maladie à coronavirus (COVID-19) au Québec. L'objectif est de réaliser une recension des données publiées et de mobiliser les savoirs clés afin d'informer les décideurs publics et les professionnels de la santé et des services sociaux. Bien que les constats reposent sur un repérage exhaustif des données scientifiques publiées, sur l'évaluation de la qualité méthodologique des études et sur une appréciation du niveau de preuve scientifique par paramètre clinique d'intérêt ainsi que sur la consultation de cliniciens avec différentes spécialités et expertises, le processus ne repose pas entièrement sur les normes habituelles à l'INESSS. Dans les circonstances d'une telle crise de santé publique, l'INESSS reste à l'affût de tout

Opportunities and challenges to the use of neutralizing monoclonal antibody therapies for COVID-19.

The coronavirus disease 2019 (COVID-19) pandemic has resulted in a substantial global public healthcare crisis, leading to the urgent need for effective therapeutic strategies. Neutralizing antibodies (nAbs) are a potential treatment for COVID-19. This article provides a brief overview of the targets and development of nAbs against COVID-19, and it examines the efficacy of nAbs as part of both outpatient and inpatient treatments based on emerging clinical trial data. Assessment of several promising candidates in clinical trials highlights the potential of nAbs to be an effective therapeutic to treat COVID-19 in outpatient settings. Nevertheless, the efficacy of nAbs treatment for hospitalized patients varies. In addition, this review identifies challenges to ending the COVID-19 pandemic, including concerns over nAbs development and clinical use. Resistant variants significantly threaten the availability of nAb-based therapeutics. This review also discusses other approaches that may improve the clinical benefit of neutralizing mAbs.

Inmunoterapia pasiva con anticuerpos policlonales equinos (suero equino hiperinmune) para el tratamiento de pacientes con COVID-19 / Passive immunotherapy with equine polyclonal antibodies (hyperimmune equine serum) for the treatment of patients with COVID-19

INTRODUCIÓN: El presente informe es producto del trabajo colaborativo de la Comisión Nacional de Evaluación de Tecnologías de Salud (CONETEC), dependiente del Ministerio de Salud de la Nación y creada por RM N° 623/2018. La CONETEC realiza evaluaciones y emite recomendaciones a la autoridad sanitaria sobre la incorporación, forma de uso, financiamiento y políticas de cobertura de las tecnologías sanitarias desde una perspectiva global del sistema de salud argentino. En sus evaluaciones y recomendaciones, la CONETEC tiene en cuenta criterios de calidad, seguridad, efectividad, eficiencia y equidad, evaluados bajo dimensiones éticas, médicas, económicas y sociales. Sus resultados son consensuados mediante discusiones públicas y ponderados a través de un marco de valor explícito, con la participación de todos los actores involucrados en el proceso de toma de decisiones en salud. Los informes y recomendaciones de esta comisión surgen de este proceso público, transparente y colaborativo, siendo de libre consulta y acceso para toda la sociedad. El objetivo del presente informe es evaluar parámetros de eficacia, seguridad y conveniencia de anticuerpos policlonales equinos (suero equino hiperinmune) para el tratamiento de pacientes con COVID-19. OBJETIVO El objetivo del presente informe es evaluar parámetros de eficacia, seguridad y conveniencia de anticuerpos policlonales equinos (suero equino hiperinmune) para el tratamiento de pacientes con COVID-19. METODOLOGÍA: Realizamos una evaluación "viva" (con un proceso de actualización continua) de una tecnología sanitaria, basada en evidencia proveniente de revisiones sistemáticas "vivas" de referencia y guías de práctica clínica de alta calidad metodológica para brindar parámetros actualizados y balanceados que sean de utilidad para la toma de decisiones en los diferentes niveles de gestión. RESULTADOS: Se identificó una revisión sistemática que cumple con los criterios de inclusión del presente informe. Adicionalmente se identificaron otras dos revisiones sistemáticas con adecuado proceso de desarrollo pero ninguna contestó la pregunta pertinente al presente informe. La revisión sistemática identificada incluyó un estudio aleatorizado con un total de 243 pacientes aleatorizados a suero equino hiperinmune o placebo. Se realizaron múltiples análisis de subgrupo incluyendo uno que comparó pacientes según su severidad al comienzo del estudio. Ninguno de estos análisis mostró resultados que sugieran un efecto diferencial en los subgrupos comparados. CONCLUSIONES: El cuerpo de evidencia disponible hasta el momento muestra que existe incertidumbre en el efecto de los anticuerpos policlonales equinos (suero equino hiperinmune) sobre la mortalidad y el ingreso en ventilación mecánica. El uso de anticuerpos policlonales equinos (suero equino hiperinmune) podría impactar positivamente en el tiempo de mejoría clínica, pero podría no incrementar la proporción de pacientes que alcanzan la recuperación clínica que lleva al alta hospitalaria. Los anticuerpos policlonales equinos (suero equino hiperinmune) podrían no asociarse a afectos adversos severos. La incertidumbre sobre el efecto de la tecnología evaluada sobre los desenlaces críticos para pacientes hospitalizados con COVI-19 (mortalidad y requerimiento de ventilación invasiva) determina que la certeza en los efectos de suero equino sobre la salud de pacientes con COVID-19 sea muy baja. A pesar que la tecnología se produce en Argentina lo que facilitaría su acceso, encontramos barreras relacionadas con una amplia población objetivo y elevado costo comparativo de esta intervención que podrían acarrear problemas de producción y afectar la distribución equitativa en situaciones de alta demanda. No identificamos recomendaciones con el rigor metodológico apropiado para ser incluidas en el informe.

Neutralising antibody escape of SARS-CoV-2 spike protein: Risk assessment for antibody-based Covid-19 therapeutics and vaccines.

The Spike protein is the target of both antibody-based therapeutics (convalescent plasma, polyclonal serum, monoclonal antibodies) and vaccines. Mutations in Spike could affect efficacy of those treatments. Hence, monitoring of mutations is necessary to forecast and readapt the inventory of therapeutics. Different phylogenetic nomenclatures have been used for the currently circulating SARS-CoV-2 clades. The Spike protein has different hotspots of mutation and deletion, the most dangerous for immune escape being the ones within the receptor binding domain (RBD), such as K417N/T, N439K, L452R, Y453F, S477N, E484K, and N501Y. Convergent evolution has led to different combinations of mutations among different clades. In this review we focus on the main variants of concern, that is, the so-called UK (B.1.1.7), South African (B.1.351) and Brazilian (P.1) strains.

Possible treatment and strategies for COVID-19: review and assessment.

The coronavirus disease 2019 (COVID-19) is declared as an international emergency in 2020. Its prevalence and fatality rate are rapidly increasing but the medication options are still limited for this perilous disease. The emergent outbreak of COVID-19 triggered by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) keeps propagating globally. The present scenario has emphasized the requirement for therapeutic opportunities to relive and overcome this latest pandemic. Despite the fact, the deteriorating developments of COVID-19, there is no drug certified to have considerable effects in the medical treatment for COVID-19 patients. The COVID-19 pandemic requests for the rapid testing of new treatment approaches. Based on the evidence, hydroxychloroquine is the first medicine opted for the treatment of disease. Umifenovir, remdesivir, and fevipiravir are deemed the most hopeful antiviral agent by improving the health of infected patients. The dexamethasone is a first known steroid medicine that can save the lives of seriously ill patients, and it is shown in a randomized clinical trial by the United Kingdom that it reduced the death rate in COVID-19 patients. The current review recapitulates the existing evidence of possible therapeutic drugs, peptides, humanized antibodies, convulsant plasma, and vaccination that has revealed potential in fighting COVID-19 infections. Many randomized and controlled clinical trials are taking place to further validate these agent's safety and effectiveness in curing COVID-19.

Informe diário de evidências COVID-19: busca realizada em 11 de agosto de 2020 / COVID-19 daily evidence report: search conducted on August 11, 2020

O Informe Diário de Evidências é uma produção do Ministério da Saúde que tem como objetivo acompanhar diariamente as publicações científicas sobre tratamento farmacológico e vacinas para a COVID-19. Dessa forma, são realizadas buscas estruturadas em bases de dados biomédicas, referentes ao dia anterior desse informe. Não são incluídos estudos pré-clínicos (in vitro, in vivo, in silico). A frequência dos estudos é demonstrada de acordo com a sua classificação metodológica (revisões sistemáticas, ensaios clínicos randomizados, coortes, entre outros). Para cada estudo é apresentado um resumo com avaliação da qualidade metodológica. Essa avaliação tem por finalidade identificar o grau de certeza/confiança ou o risco de viés de cada estudo. Para tal, são utilizadas ferramentas já validadas e consagradas na literatura científica, na área de saúde baseada em evidências. Cabe ressaltar que o documento tem caráter informativo e não representa uma recomendação oficial do Ministério da Saúde sobre a temática. Foram encontrados 14 artigos e 5 protocolos.

Neutralizing Antibodies against SARS-CoV-2 and Other Human Coronaviruses.

Coronavirus (CoV) disease 2019 (COVID-19) caused by severe acute respiratory syndrome (SARS)-CoV-2 (also known as 2019-nCoV) is threatening global public health, social stability, and economic development. To meet this challenge, this article discusses advances in the research and development of neutralizing antibodies (nAbs) for the prevention and treatment of infection by SARS-CoV-2 and other human CoVs.

Cost-effectiveness of three different strategies for the treatment of first recurrent Clostridium difficile infection diagnosed in a community setting.

OBJECTIVE: A significant portion of patients with Clostridium difficile infections (CDI) experience recurrence, and there is little consensus on its treatment. With the availability of newer agents for CDI and the added burdens of recurrent disease, a cost-effectiveness analysis may provide insight on the most efficient use of resources. DESIGN: A decision-tree analysis was created to compare the cost-effectiveness of 3 possible treatments for patients with first CDI recurrence: oral vancomycin, fidaxomicin, or bezlotoxumab plus vancomycin. The model was performed from a payer's perspective with direct cost inputs and a timeline of 1 year. A systematic review of literature was performed to identify clinical, utility, and cost data. Quality-adjusted life years (QALY) and incremental cost-effectiveness ratios were calculated. The willingness-to-pay (WTP) threshold was set at $100,000 per QALY gained. The robustness of the model was tested using one-way sensitivity analyses and probabilistic sensitivity analysis. RESULTS: Vancomycin had the lowest cost ($15,692) and was associated with a QALY gain of 0.8019 years. Bezlotoxumab plus vancomycin was a dominated strategy. Fidaxomicin led to a higher QALY compared to vancomycin, at an incremental cost of $500,975 per QALY gained. Based on our WTP threshold, vancomycin alone was the most cost-effective regimen for treating the first recurrence of CDI. Sensitivity analyses demonstrated the model's robustness. CONCLUSIONS: Vancomycin alone appears to be the most cost-effective regimen for the treatment of first recurrence of CDI. Fidaxomicin alone led to the highest QALY gained, but at a cost beyond what is considered cost-effective.

Cost-effectiveness of Bezlotoxumab Compared With Placebo for the Prevention of Recurrent Clostridium difficile Infection.

Background: Clostridium difficile infection (CDI) is the most commonly recognized cause of recurrent diarrhea. Bezlotoxumab, administered concurrently with antibiotics directed against C. difficile (standard of care [SoC]), has been shown to reduce the recurrence of CDI, compared with SoC alone. This study aimed to assess the cost-effectiveness of bezlotoxumab administered concurrently with SoC, compared with SoC alone, in subgroups of patients at risk of recurrence of CDI. Methods: A computer-based Markov health state transition model was designed to track the natural history of patients infected with CDI. A cohort of patients entered the model with either a mild/moderate or severe CDI episode, and were treated with SoC antibiotics together with either bezlotoxumab or placebo. The cohort was followed over a lifetime horizon, and costs and utilities for the various health states were used to estimate incremental cost-effectiveness ratios (ICERs). Both deterministic and probabilistic sensitivity analyses were used to test the robustness of the results. Results: The cost-effectiveness model showed that, compared with placebo, bezlotoxumab was associated with 0.12 quality-adjusted life-years (QALYs) gained and was cost-effective in preventing CDI recurrences in the entire trial population, with an ICER of $19824/QALY gained. Compared with placebo, bezlotoxumab was also cost-effective in the subgroups of patients aged ≥65 years (ICER of $15298/QALY), immunocompromised patients (ICER of $12597/QALY), and patients with severe CDI (ICER of $21430/QALY). Conclusions: Model-based results demonstrated that bezlotoxumab was cost-effective in the prevention of recurrent CDI compared with placebo, among patients receiving SoC antibiotics for treatment of CDI.

Clostridium difficile infection in the elderly: an update on management.

The burden of Clostridium difficile infection (CDI) is profound and growing. CDI now represents a common cause of health care-associated diarrhea, and is associated with significant morbidity, mortality, and health care costs. CDI disproportionally affects the elderly, possibly explained by the following risk factors: age-related impairment of the immune system, increasing antibiotic utilization, and frequent health care exposure. In the USA, recent epidemiological studies estimate that two out of every three health care-associated CDIs occur in patients 65 years or older. Additionally, the elderly are at higher risk for recurrent CDI. Existing therapeutic options include metronidazole, oral vancomycin, and fidaxomicin. Choice of agent depends on disease severity, history of recurrence, and, increasingly, the drug cost. Bezlotoxumab, a recently approved monoclonal antibody targeting C. difficile toxin B, offers an exciting advancement into immunologic therapies. Similarly, fecal microbiota transplantation is gaining popularity as an effective option mainly for recurrent CDI. The challenge of decreasing CDI burden in the elderly involves adopting preventative strategies, optimizing initial treatment, and decreasing the risk of recurrence. Expanded strategies are certainly needed to improve outcomes in this high-risk population. This review considers available data from prospective and retrospective studies as well as case reports to illustrate the merits and gaps in care related to the management of CDI in the elderly.

Bezlotoxumab: anti-toxin B monoclonal antibody to prevent recurrence of Clostridium difficile infection.

INTRODUCTION: Clostridium difficile infection (CDI) is the most common nosocomial infection in the U.S. 25% of CDI patients go on to develop recurrent CDI (rCDI) following current standard of care (SOC) therapy, leading to morbidity, mortality and economic loss. The first passive immunotherapy drug targeting C.difficile toxin B (bezlotoxumab) has been approved recently by the FDA and EMA for prevention of rCDI. Areas covered: A body of key studies was selected and reviewed by the authors. The unmet needs in CDI care were ascertained with emphasis in rCDI, including the epidemiology, pathophysiology and current management. The current knowledge about the immune response to C. difficile toxins and how this knowledge led to the development and the clinical use of bezlotoxumab is described. Current and potential future competitors to the drug were examined. Expert commentary: A single 10 mg/kg intravenous infusion of bezlotoxumab has been shown to decrease rCDI by ~40% (absolute reduction ~10%) in patients being treated for primary CDI or rCDI with SOC antibiotics. Targeting C.difficile toxins by passive immunotherapy is a novel mechanism for prevention of C.difficile infection. Bezlotoxumab will be a valuable adjunctive therapy to reduce the burden of CDI.

"Hep C, where art thou": What are the remaining (fundable) questions in hepatitis C virus research?

Hepatitis C virus (HCV) has dominated the field of hepatology for the past 25 years, and its cure in the majority of treated patients is one of the greatest achievements in all of medicine. However, the latter has led to the belief by some that HCV research should be shelved for other, more pressing areas. The mission for HCV eradication is far from accomplished. As a historical reference, we should consider that disease elimination has required vaccination with all previously controlled infections including smallpox and polio and that simple, effective treatment is not sufficient in most infections to lead to substantial control. Syphilis is the best example, for which a single dose of penicillin (which literally costs pennies and that we have had since 1945) is curative in early stages. Not only have we not eradicated syphilis, rates of infection have increased in many places within the United States in recent years. Most HCV-infected subjects are unaware of their infection, remaining at risk for transmission to others and disease progression, including cirrhosis and hepatocellular carcinoma. In the era of highly effective direct-acting antivirals (DAAs), many questions pertaining to HCV remain, but they are more complex and difficult to answer. Here, I provide my perspective on some of these salient issues: the residual risk for disease progression after sustained virologic response, the optimal approach to current DAA failures, the impact of targeting people who inject drugs with DAAs, vaccine prospects, and application of neutralizing HCV glycoprotein antibodies. (Hepatology 2017;65:341-349).

Pathogen-reduced Ebola virus convalescent plasma: first steps towards standardization of manufacturing and quality control including assessment of Ebola-specific neutralizing antibodies.

BACKGROUND: Ebola virus disease is a public health emergency of international concern, and enormous efforts are being made in the development of vaccines and therapies. Ebola virus convalescent plasma is a promising anti-infective treatment of Ebola virus disease. Therefore, we developed and implemented a pathogen-reduced Ebola virus convalescent plasma concept in accordance with national, European and global regulatory framework. MATERIALS AND METHODS: Ebola virus convalescent plasma manufacture and distribution was managed by a collection centre, two medical centres and an expert group from the European Blood Alliance. Ebola virus convalescent plasma was collected twice with an interval of 61 days from a donor recovering from Ebola virus disease in Germany. After pathogen reduction, the plasma was analysed for Ebola virus-specific immunoglobulin G (IgG) antibodies and its Ebola virus neutralizing activity. RESULTS: Convalescent plasma could be collected without adverse events. Anti-Ebola virus IgG titres and Ebola-specific neutralizing antibodies in convalescent plasma were only slightly reduced after pathogen reduction treatment with S59 amotosalen/UVA. A patient in Italy with Ebola virus disease was treated with convalescent plasma without apparent adverse effects. DISCUSSION: As proof of principle, we describe a concept and practical implementation of pathogen-reduced Ebola virus convalescent plasma manufacture, quality control and its clinical application to an Ebola virus disease patient.

Prophylactic and therapeutic testing of Nicotiana-derived RSV-neutralizing human monoclonal antibodies in the cotton rat model.

Severe lower respiratory tract infection in infants and small children is commonly caused by respiratory syncytial virus (RSV). Palivizumab (Synagis(®)), a humanized IgG1 monoclonal antibody (mAb) approved for RSV immunoprophylaxis in at-risk neonates, is highly effective, but pharmacoeconomic analyses suggest its use may not be cost-effective. Previously described potent RSV neutralizers (human Fab R19 and F2-5; human IgG RF-1 and RF-2) were produced in IgG format in a rapid and inexpensive Nicotiana-based manufacturing system for comparison with palivizumab. Both plant-derived (palivizumab-N) and commercial palivizumab, which is produced in a mouse myeloma cell line, showed protection in prophylactic (p < 0.001 for both mAbs) and therapeutic protocols (p < 0.001 and p < 0.05 respectively). The additional plant-derived human mAbs directed against alternative epitopes displayed neutralizing activity, but conferred less protection in vivo than palivizumab-N or palivizumab. Palivizumab remains one of the most efficacious RSV mAbs described to date. Production in plants may reduce manufacturing costs and improve the pharmacoeconomics of RSV immunoprophylaxis and therapy.