Swedish proteomics and biotherapy firm Affibody AB raised US$28 million in third-round funding from an international investor consortium led by Schroder Ventures Life Sciences, HealthCap and Investor Growth Capital.

This boosts Affibody¿s total funding to around SEK350 million (US$35 million), CEO Torben Jorgensen told BioWorld International, and it enables the Stockholm-based company to embark on therapeutic development programs.

¿What we¿re aiming at first is proof of concept,¿ he said.

The company is rapidly ramping up headcount in areas such as pharmacology, preclinical development and clinical development. It aims to double its payroll to 70 people over the next month, and already has received 800 applications for an initial 30 positions, Jorgensen said.

Affibody¿s core technology platform is based on high-affinity protein ligands ¿ also called Affibodies ¿ that mimic the binding properties of antibodies. These are generated by making single amino acid substitutions at one of 13 positions at the binding site of a Staphylococcus aureus Protein A domain, which comprises 58 amino acids in total. The company can obtain protein signatures from entire genomes by expressing randomly generated libraries of Affibodies in phage-display systems. Each clone selectively binds a target molecule with high specificity.

¿It¿s like a bait on a fishing rod,¿ said Affibody Chief Scientific Officer Stefan Stahl.

Before Affibody can embark on clinical development of candidate therapeutics, it must first examine any potential immunogenicity effects associated with the technology. ¿That is the question: What does it do with your immune system?¿ Jorgensen said. Initial preclinical studies have been promising, he said, but the company needs to amass more data.

It plans to target oncology initially. It will then investigate disease areas in which monoclonal antibodies are currently used as therapy, with a view to developing a replacement strategy.

¿Ours is only 4 percent of the size of a monoclonal antibody, which means first of all it¿s much cheaper to produce,¿ Jorgensen said. Affibodies also display greater binding efficiency than antibodies, he said, and the area is not affected by the legal disputes that have had an impact on aspects of monoclonal antibody development.

The Affibody platform has broad application, outside of clinical development. The company has an alliance in the area of protein purification with Amersham Pharmacia Biotech AB, of Uppsala, Sweden. This already resulted in the development of two products, Jorgensen said, although neither has yet reached the market. It is developing high-throughput CD-based protein microarrays with Gyros AB, also of Uppsala, and it is engaged in a gene therapy collaboration with Got-A-Gene AB, of Gothenburg, Sweden.

Affibody was established in 1998 by a team of scientists from the Royal Institute of Technology and the Karolinska Institute. Jorgensen is a former president of one of Sweden¿s flagship biotechnology firms, Karo Bio AB, also of Stockholm. He joined Affibody in August.