Publication Date: 17 January 2020 TOUCH MEDICAL MEDIA 17 Review Airway and Lung Infection Immunomodulation Therapy – Clinical Relevance of Bacterial Lysates OM-85 Giovanni A Rossi, 1 Susanna Esposito, 2 Wojciech Feleszko, 3 Giovanni Melioli, 4 Dario Olivieri, 5 Giorgio Piacentini, 6 Francesco Scaglione 7 and Donata Vercelli 8 1. Giannina Gaslini Institute, Genoa, Italy; 2. Pediatric Clinic, Department of Surgical and Biomedical Sciences, University of Perugia, Perugia, Italy; 3. Medical University of Warsaw, Warsaw, Poland; 4. Humanitas University, Milan, Italy; 5. University of Parma, Parma, Italy; 6. University of Verona, Verona, Italy; 7. University of Milan, Milan, Italy; 8. University of Arizona, Tucson, AZ, US R espiratory tract infections (RTIs) affect children and adults with chronic respiratory conditions throughout the world. As RTIs can often recur, they confer a significant morbidity and mortality burden and represent an important unmet medical need. Studies have shown that the bacterial lysates OM-85 can activate both innate and adaptive immune responses via maturation of gut mucosal dendritic cells, resulting in the homing of immune cells to lymphoid tissue in the lungs and subsequent antibody production. In line with these mechanistic properties, OM-85 has demonstrated clinical efficacy in preventing RTIs in several clinical studies, as well as exacerbations of various respiratory conditions such as asthma, chronic bronchitis, chronic obstructive pulmonary disease and chronic rhinosinusitis. In addition, clinical study and pharmacovigilance data show that OM-85 is not only well tolerated in both adult and paediatric populations, but also can be used in combination with vaccines to provide additional benefits with a manageable risk profile. As such, OM-85 represents a valuable addition to the therapeutic landscape for recurrent or chronic respiratory conditions. Keywords Bacterial lysates, immunomodulation therapy, OM-85 Disclosures: Giovanni A Rossi has received honoraria for his scientifc support from AbbVie Inc, Chiesi Farmaceutici, Lusofarmaco and OM Pharma (a Vifor Pharma Group company). Susanna Esposito has received research grants from DMG, GlaxoSmithKline, Sanof, OM Pharma (a Vifor Pharma Group company) and honoraria for her scientifc support from AstraZeneca, MSD, Sanof and Vifor Pharma. Wojciech Feleszko has worked as a speaker for Angellini, Bayer AG, GlaxoSmithKline, Mylan, Nutricia, Sandoz and OM Pharma (a Vifor Pharma Group company), and has received research grants from Phillips and Biomed. Giovanni Melioli is an advisor to Bruschettini SRL, Lallemand Pharma SAS, Eltek SPA and DASIT Spa and has received honoraria for scientifc support from OM Pharma (a Vifor Pharma Group company) and OM Pharma (a Vifor Pharma Group company in Asia). Giorgio Piacentini has received honoraria for scientifc support from Chiesi, Merck Sharp & Dhome, Vifor Pharma, and Pediatrica. Donata Vercelli has received research grants from The National Institutes of Health, OM Pharma (a Vifor Pharma Group company), and Johnson & Johnson. Dario Olivieri and Francesco Scaglione have no conficts of interest to declare. Acknowledgements: Editorial assistance was provided by Stuart Wakelin of Touch Medical Communications and funded by OM Pharma, a Vifor Pharma Group company. Review Process: Double-blind peer review. Compliance with Ethics: This article expresses the opinions of the authors based on the results of a review of the literature and did not involve any studies with human or animal subjects performed by any of the authors. Authorship: All named authors meet the International Committee of Medical Journal Editors (ICMJE) criteria for authorship of this manuscript, take responsibility for the integrity of the work as a whole, and have given fnal approval to the version to be published. Received: 13 February 2019 Accepted: 24 June 2019 Citation: European Respiratory & Pulmonary Diseases. 2019;5(1):17–23 Corresponding Author: Giovanni A Rossi, G Gaslini Hospital, Largo G Gaslini 4, 16147 Genoa, Italy. E: giovannirossi@gaslini.org Support: This article was drafted using content from an Advisory Board meeting organised by OM Pharma, a Vifor Pharma Group company. The publication of this article was supported by OM Pharma, a Vifor Pharma Group company. The views and opinions expressed are those of the authors. Acute respiratory tract infections (RTIs) affect children and adults with chronic respiratory conditions throughout the world, and are associated with significant morbidity and mortality. 1 Acute RTIs are one of the leading causes of mortality in both children and adults, with an estimated 3.5–4 million deaths per year attributed to both acute upper and lower RTIs. 2,3 Recurrent RTIs are especially common in young children, affecting up to 25% of children <1 year of age and 18% of children 1–4 years of age. 1 Paediatric RTIs also incur substantial healthcare costs; they frequently cause complications that necessitate multiple medical visits, accounting for nearly half of all paediatric consultations in developed countries, and are among the leading causes of paediatric hospital admissions in the USA. 1 Furthermore, although many RTIs have viral aetiology, they are still a leading cause of antibiotic prescriptions, thereby contributing to the development of antibiotic resistance and further increasing healthcare costs. 1,4 Overall, despite the availability of healthcare in developed countries, RTIs still exert a substantial clinical and economic burden and represent a clear unmet medical need. 1 Prevention of RTIs can be difficult, as the risk factors are many and varied, including sociodemographic (partial immunisation, overcrowding), nutritional (malnutrition) and environmental aspects, as well as clinical risk factors, such as minor immunodeficiencies. 5–7 However, the use of immunostimulants or immunomodulator therapies may provide an alternative therapeutic option that is complementary to vaccination. 8 Bacterial lysates, such as OM-85, are produced by chemical or mechanical lysis of specific bacterial cultures. As such, they contain conserved pathogen-associated molecular patterns (PAMPs) for these bacteria, which have the potential to activate the cellular constituents of innate and adaptive non-specific loco-regional immune responses. 9–12 This can lead to the induction of not only specific, but also non-specific loco-regional immune responses, with polyclonal production of immunoglobulins. 10–13 Therefore, lysates of bacteria from the respiratory tract may provide clinical benefit in patients with recurrent RTIs, regardless of the viral or bacterial aetiology, in different DOI: https://doi.org/10.17925/ERPD.2019.5.1.17