Antibody discovery typically requires 9-12 months in animal models. EXIS™ reduces discovery time of fully human antibody leads to 16 days.

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Our proprietary algorithm leverages the nature of whole tissue development of B cells into high affinity clonal pools.

EXIS Advantage


Antibody discovery typically requires 9-12 months in animal models. EXIS™ reduces discovery time of therapeutic-quality fully human antibodies to 16 days. Single cell sorting of B cells from a large population of people infected with SARS-CoV-2 have allowed for screening of circulating B cells from a human infected with a pathogen. However, screening of infected patients is limited and low through-put relative to ultrafast development in lymph node organoids. Furthermore, single cell sorting lacks tissue-resident B cell information such as clonality and the ability to characterize the quality of the human immune response. 

Synthetic human lymph nodes and the EXIS platform were developed by Prellis founder and CEO, Melanie Matheu, PhD.

Dr. Matheu has over 15 years of research experience in Immunology and thousands of citations of her peer reviewed work characterizing cell-cell interactions in living tissues during immune responses. Prellis Biologics, Inc. holds exclusive rights and all intellectual property related to the EXIS platform. (US Patent Issued, December 2019)

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Marburg Hemorrhagic Fever

Prellis has isolated 62 potentially neutralizing human antibodies against the Marburg Hemorrhagic Fever, a cousin of the Ebola virus. Marburg is a high lethality (up to 88% death rate) virus that has the potential to become a pandemic virus. There are currently no known therapeutics that are effective against Marburg Hemorrhagic Fever. Prellis is working closely with a partner to finalize the neutralizing antibodies for clinical development.


Influenza A causes up to 80,000 deaths annually in the US. Often, a novel influenza strain threatens to develop pandemic potential. Prellis generated a library of 300,000 unique antibodies that are active against either the H1, H3, or both H1 and H3 of 2020 predicted Influenza A strains. Currently Prellis is screening 30 antibodies for in vivo efficacy. In addition, we are investigating a set of promising antibodies that bind to H1, H3, H5, and H7 as part of a discovery effort for a pan-neutralizing antibody.



Since the advent of the COVID19 pandemic, Prellis has isolated over 730 unique human antibodies that are active against the SARS-CoV-2 spike protein. Similar to antibodies isolated from infected donors, Prellis antibodies demonstrated convergence on known neutralizing CDRs. Prellis is currently moving top antibody candidates with low-nanomolar binding affinities through IND enabling studies.

Rapid Human Antibody Discovery

EXIS Timeline

EXIS™ in vitro Human Antibody Discovery

The EXIS™ human antibody discovery platform mimics the human lymph node. Prellis generates lymph node organoids (LNO™) from healthy human lymphocytes. LNOs can be challenged with a variety of target antigens in different formats and produce fully human antibody libraries ready for lead selection. This platform allows for selection from the ‘best’ human B cells that have undergone clonal expansion.

EXIS™ Externalized Immune System platform

EXIS™ Platform Process