Cortalix is a clinical-stage biopharmaceuticals company developing PET-imaging diagnostics, targeted radiotherapeutics and immunotherapeutics for novel targets based on its proprietary singled domain antibody platforms in close partnerships with pharmaceutical companies.

Our Mission

To work with modern, affordable and animal-free synthetic single domain antibody library technology for the development of next-generation diagnostics, therapeutics and bio-analytical tools.

Our Vision

To be among the leading drivers in the development of innovative single domain antibodies for immuno-molecular imaging, targeted radiotherapy and immuno-therapies for patients worldwide


A single domain antibody is an antibody fragment consisting of a single monomeric variable antibody domain. They have been shown to be as specific as regular antibodies, but they offer many more attractive benefits.

At Cortalix we have many years of experience with immune libraries, which has laid the foundation for our synthetic single domain antibody libraries. These offer great opportunities to make completely animal-free new single domain antibody selections and to develop them into clinical products.

Internal Programs

Cortalix has currently developed a pipeline of radiopharmaceuticals targeting fibrogenesis-related membrane receptors and proteins present in early-stage fibrotic diseases such as pulmonary fibrosis, cardiac fibrosis, liver fibrosis, renal fibrosis and various solid cancers with fibrotic stroma, with a special focus on colon cancer.
We have single domain antibodies in development for myofibroblast-specific membrane proteins and receptors, including PDGFRA (CD140a), PDGFRB (CD140b), EGFR, IGF-2R (CD222) and FAP. These single domian antibodies also contain a NOTA chelator that can bind 68-Ga that is suitable for immunoPET imaging. Ultimately, the platform enables a theranostic approach to cancer using the same single domain antibody for patient identification, targeted therapy (e.g. 177-Lu) and disease monitoring.

Partner Programs

Cortalix collaborates with other (radio)pharmaceutical companies and academic institutions in Partner Programs to select and develop new single domain antibodies for attractive (radio)pharmaceutical targets. We are good at that, we understand the characteristics of this field and we will continue to build on that in the future. We select candidate single domain antibodies, we can further improve them with additional cloning steps, modify linkers and spacers, conjugate functional (radionuclide-binding) groups and adjust the kinetics with other functional groups.


In addition to collaborations in Partner Programs, we also want to leverage our platform technology and development expertise into a suite of services that we can deliver as an orderly series of steps, ensuring precision and effectiveness in developing single domain antibodies tailored to your specific needs.

executive team

CEO, founder

Herman Steen holds a PhD in pharmacology from the University of Groningen in 1992. He worked at Byk Gulden (Altana Pharma/Nycomed/Takeda) and in 1998 he founded PharmaScope, a clinical contract research and pharma recruitment organization. Following the sale of PharmaScope to Quintiles Transnational Corp. in 2005, the internationally operating orphan drug CRO PSR Group was established and eventually sold to Ergomed plc in 2017. Dr. Steen has extensive experience in the organization of clinical research and as a serial entrepreneur in the field of pharma biotech, he is closely involved in commercialization and bridging preclinical research to the clinic. He co-founded BiOrion and led that company for many years as CEO. Early 2023, BiOrion’s assets were purchased by Cortalix, where he is acting as CEO again.


Guus van Scharrenburg obtained his PhD (cum laude) at the University of Utrecht on the structure-function relationship of lipolytic enzymes. He has over more than 30 years of experience in the pharmaceutical industry (Solvay, Abbott) with responsibility for programs and projects in all R&D phases. During his career he was responsible for R&D alliances with big Pharma partners as well as smaller innovative biotechs. He was Head of Biotechnology of Solvay in Weesp (NL) and Global Project Director of the Solvay -Bristol-Myers Squibb alliance for development of CB1 antagonists. In addition, he was involved in neurology research programs, responsible for phase II and III development projects for cardio-metabolic and neurology indications, respectively. After working many years for BiOrion as COO, he joined Cortalix in a similar position.

VP Discovery & Innovation

Amanda van Tilburg obtained a PhD degree in molecular biology at the University of Groningen in 2021. During her PhD research, she became an expert in genetic engineering of bacteria and heterologous protein expression, which led to various publications in peer-reviewed journals. The focus of Amanda her research at Cortalix is to discover, engineer and produce novel single domain antibodies against several attractive targets. 

VP Product Development

Joost Caumanns obtained his PhD in molecular and medical biology from the University of Groningen in 2019. As a translational scientist, he investigated kinase and synthetic lethality targeting strategies for the treatment of ovarian cancer. His postdoctoral research at the University of Toronto focused on the use of CRISPR-Cas9-mediated whole-genome knockout screening to unravel genetic dependencies on immunotherapy resistance in cancer. He then gained experience as a project manager for bioanalytical services at Ardena, in Assen, the Netherlands. At Cortalix, Joost is responsible for the development of products and services based on synthetic single-domain antibody libraries.

Director Conjugation Chemistry

Roxana Postolache obtained a PhD in organic chemistry from the University of Groningen in 2023. She has an extensive background in synthetic organic chemistry. During her PhD research, she became an expert in mechanistic strategies that led to useful synthetic building blocks that are widely used in industry. She was closely involved in the synthesis, purification and characterization of reaction substrates, products and metal complexes. Roxana’s focus at Cortalix is on engineering, conjugating, producing and optimizing functional groups into unique nanobodies against selected targets.