Protein Engineering Leadership + Deep Understanding of Molecular Drivers of Disease = Novel Local-acting Therapies

Anticalin proteins are small, stable, modular, and inhalable molecules derived from human lipocalins – proteins that naturally transport molecules throughout the body. These stable, modular proteins can be linked to other therapeutic modalities or each other to create multispecific and multifunctional drug candidates with a broad range of therapeutic applications. At Pieris, our expansive libraries contain more than 100 billion different Anticalin proteins, ensuring a candidate for almost any therapeutic target.

Advantages of Anticalin® Proteins

Anticalin proteins' stable structure, small size, and human origin make them a potentially safer, more convenient and more efficacious treatment option to existing alternatives.



Anticalin proteins are comprised of a four-loop variable region and a rigidly conserved beta-barrel backbone, which together, form a pliable cup-like binding pocket.

Stable and Monovalent

Stable and Monovalent

Anticalin proteins contain rationally diversified amino acids while maintaining the integrity of the lipocalin structure, providing a coveted specificity and affinity against a broad spectrum of targets and durability that allows for flexibility of formulation and delivery.

Bi- and Multispecific Approaches

Bi- and Multispecific Approaches

Anticalin proteins can be genetically fused to other proteins, including other Anticalin proteins and antibodies, to create bi- and multispecific drug candidates.

Broad Target Space

Anticalin proteins’ cup-shaped structure with variable loops allows them to bind to molecules considered too small to bind to other drug classes, such as antibodies. They can accommodate a range of ligands, including hapten-like molecules, proteins, and even toxins or other drugs.

Flexible Formatting

Anticalin proteins can bind end-to-end with other proteins, without affecting the ligand-binding regions. Linked Anticalin proteins can form bi- or multispecific drugs and antibody-Anticalin fusions, allowing therapies to bind multiple targets or be tuned for a specific half-life.


Anticalin proteins’ monovalent, monomeric structure prevents unwanted agonist receptor cross-linking.


Anticalin proteins’ small size and stable structure enable both inhalable delivery and localized, sustained-release depot formulations.


Anticalin proteins are derived from human lipocalins, which naturally bind and transport ligands. They offer both dual and multi-specific approaches with single gene expression. Anticalin proteins have been demonstrated to be well-tolerated in multiple clinical trials to date.

Speed & Low Costs

Anticalin proteins are produced by bacterial expression technology, allowing for lower production costs and faster development timelines than traditional protein refolding technologies.

Advancing the Possibilities Together

Our partners are industry-leading biotechnology and pharmaceutical firms that share our commitment to innovation.

Meet Our Partners

A Broad Spectrum of Therapeutic Potential

Our pipeline includes preclinical and clinical-stage programs that demonstrate Anticalin proteins’ potential to treat diseases as diverse as asthma and cancer.

Explore Our Pipeline

Research Underlies All that We Do

Read about how we are working to advance our next-generation protein technology.

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Expert Advisors Guide Our Innovation

We engage outside experts to help us navigate the world of cutting-edge protein engineering.

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