AIT Bioscience ImmunXperts are now Nexelis

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Nexelis is your partner for assay and biomarker development, advanced bioanalytical and laboratory testing, and translational immunology. As the leading specialty laboratory, we have unrivaled expertise in immunology, specifically in the areas of infectious diseases, vaccine development, metabolic diseases, and immuno-oncology. Vast experience, scientific discipline, and operational agility make Nexelis the partner to advance your molecule to market faster.

Our deep bench of scientists, advanced technology platforms, and international network of laboratories provide the biopharmaceutical industry with translational solutions from discovery through late stage clinical development. Nexelis is instrumental in the development and large-scale sample testing for new modalities. These future therapies include blockbuster vaccines and biologics, antiviral drugs, immunotherapies, and gene and cell therapy products.

When you need a partner to navigate therapeutic development, advance programs, and consistently generate high-quality data, choose Nexelis.

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for what’s next in immunology

infectious diseases

With our roots in infectious diseases, Nexelis has an extensive track record and expertise across the spectrum of drug development and testing. Having emerged from a leading pharma company, we understand our customers’ point of view. Dedicated to immunology and vaccines, we continue to expand and excel in the space through acquisitions and partnerships. Recent acquisitions include the GSK clinical laboratory in Marburg, Germany, bioanalytical laboratory, AIT Bioscience in Indianapolis, Indiana, and previously Pacific Biomarkers, a biomarker-focused laboratory in Seattle, Washington. We worked with a broad range of infectious agents from flu, COVID-19, pneumonia, meningitis, and pathogenic bacteria.


Combining cutting-edge technology platforms and state-of-the-art laboratories with over 20 years of vaccine testing experience, Nexelis is the immunology partner of choice to support your candidate selection and assay development. Take advantage of our five vaccine platforms, our in-house custom in vivo services, and our protein sciences capabilities – including molecular biology, protein expression, purification, and characterization. To adapt to your specific needs, we can rapidly produce custom antigen and pseudoparticle reagents in-house, as we have in our COVID-19 work. In addition, our team in Belgium can support vaccine-candidate selection via in vitro assays using primary human immune cells.

Partner with Nexelis for the development, qualification, and validation of immunological assays and sample testing to support your vaccine development from lead selection through late stage clinical trials. With renowned specialists on the forefront of COVID-19 assay development and having worked with the leading large pharma and biotech companies, we are well-equipped to take on your next vaccine project.


Functional profiling and evaluation of immunogenicity of candidate therapeutics with in vitro bioassays is a critical step in documenting mode of action and prioritizing candidate selection for immunotherapies. Under the leadership of industry-recognized expert Sofie Pattijn, CTO and founder of Nexelis company ImmunXperts, our team delivers flexible, customized services for immuno-oncology therapies, from investigative preclinical through exploratory clinical endpoints.

Our custom and off-the-shelf in vitro assays, such as immune checkpoint inhibitor screening, use high-quality human primary immune cells to help you select the candidates most likely to become life-saving therapies. Find greater value in ex vivo models as a way to simulate the human tumor environment and overcome certain limitations of animal studies.

In clinical immuno-oncology studies, guided by Dr. Paul Trampont, we apply more than three decades of biomarker expertise to support the next generation of therapeutics. Whether you need standard or custom solutions, the team at our CAP/CLIA-certified biomarker facility will partner with you from feasibility to validation, reducing your costs and timelines. Nexelis also supports exploratory flow cytometry work in translational immuno-science, allowing you to expand your clinical trial to investigate secondary readouts and elucidate unknowns, offering evidence to expand your understanding of patient selection and the disease process itself.


Biologics can induce an antidrug antibody (ADA) response causing allergic reactions, reduced efficacy, or induced autoimmunity. Our team has more than 15 years of experience developing and validating single and multiplex immunochemistry assays for a wide variety of molecules.

For immunogenicity services from preclinical evaluation and screening of candidate therapeutics through clinical immunogenicity monitoring, you can rely on our expert bioanalysis support. Whether you need in silico immunogenicity assessment with epitope prediction or advanced clinical laboratory testing for therapeutic protein products via neutralizing antibody assays and ADA-isotyping, Nexelis delivers. Our flexible, customized programs help you mitigate risk while saving time and expense.

metabolic diseases

Nexelis has a 30-year history in the metabolic field, drawing on expertise from heritage biomarker company Pacific Biomarkers and bioanalytical CRO AIT Bioscience, now Nexelis companies. Our team of renal pathway experts helped support the development of an AKI multiplex biomarker panel, the first approved by the FDA to aid in the detection of kidney tubular injury in Phase I trials. We also offer a broad range of biomarkers for other indications including end-stage liver disease, metabolic syndrome, diabetes, cardiovascular disease, and lipotoxicity.

Committed to continued investment and development in the metabolic field, such as biomarkers and bioanalytical methods for NASH and NAFL/NAFLD, Nexelis maintains a “fit-for-purpose” assay development and validation philosophy. We expedite your program from feasibility to full validations including novel biomarkers, proprietary technology transfers, and comprehensive bioanalytical services for both large and small molecules.

forefront of COVID-19

Nexelis initiated work on SARS-CoV-2 in January 2020 to rapidly support the global pandemic response. In partnership with Public Health England and Nexelis’ leading scientists, we developed in vivo models; expressed, purified, and characterized viral proteins; designed viral and surrogate pseudovirion neutralization assays. Our team produced assays measuring humoral and cellular response to SARS-CoV-2 and its variants to evaluate vaccines and antivirals in all preclinical and clinical phases.

Throughout the pandemic, Nexelis has been recognized by leaders in the COVID-19 field as the reference assay development company for vaccines, from lead optimization through large-scale, advanced clinical.

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  • Bill and Melinda Gates Foundation reference lab for all grantees
  • CEPI referral lab for humoral and cellular testing
  • World Health Organization (WHO) public statement signatory for collaboration on COVID-19
  • Public Health England strategic partner
  • Coronavirus Immunotherapy Consortium for Antibody-Based Therapies (CoVIC) partner
  • BARDA/Operation Warp Speed COVID-19 Medical Countermeasure Support Service Partner for high-throughput SARS-COV-2 assay development and testing

CEPI establishes global network of laboratories to centralise assessment of COVID-19 vaccine candidates

02 Oct 2020 | Press Release

Porton Down to accelerate testing for Covid-19 vaccine

21st Oct 2020

Trans-Hit Biomarkers Announces Today a Partnership With Nexelis, Supporting Sample Procurement Activities for a Number of Strategic Projects Including COVID-19 Vaccines and Immuno-oncology Development Initiatives.

22 Oct 2020


Sofie Pattijn

Sofie Pattijn

Sofie Pattijn, Chief Technology Officer and Founder of ImmunXperts, has over 20 years of experience in the field of immunogenicity assessment (vaccines and biotherapeutics) and in vitro assay development with a focus on functional assays for immunogenicity, immuno-oncology, and cell and gene therapy products. She has extensive hands-on lab experience and has managed and coached several in vitro teams over the last decade. From 2008 to 2013, Sofie was head of the in vitro immunogenicity group at AlgoNomics (Ghent, Belgium) and Lonza Applied Protein Services (Cambridge, UK). Prior to that, she worked at Innogenetics in Belgium for over 15 years.

Luc Gagnon

Luc Gagnon

Luc Gagnon, Vice President of Vaccine Sciences, leads scientific operations at Nexelis to support vaccines and biologics throughout the different phases of clinical trials. Luc brings over 20 years of experience in several biotech, CRO, and pharmaceutical companies to his role, including extensive expertise in ligand binding and microbiology/virology functional assay development, qualification, and validation.

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