BioWorld International Correspondent
Molecular Partners AG raised CHF18.5 million (US$15.3 million) in a heavily oversubscribed Series A round to progress its preclinical portfolio of Designed Ankyrin Repeat Proteins (DARPins), which have multiple therapeutic and diagnostic applications.
Since there were "dozens" of potential investors, closing the round took longer than originally anticipated, Molecular Partners CEO Christian Zahnd said. "We had quite a number of term sheets on the table."
The recent spate of acquisition activity in the field sparked the interest, Zahnd said, referring to the acquisitions of Domantis Ltd. and Avidia Inc. by GlaxoSmithKline plc and Amgen Inc., respectively. Other firms, among them Ablynx N.V. and Adnexus Therapeutics Corp. have entered large-scale partnering deals with big pharma companies.
"The area is very hot," Zahnd said.
In addition, Schlieren, Switzerland-based Molecular Partners has some auspicious history on its side.
The company was spun out of the lab of Andreas Plückthun at the University of Zurich, who is a well-recognized pioneer in antibody development and the founder of the profitable antibody firm Morphosys AG, of Martinsried, Germany.
Molecular Partners eventually agreed to terms with a syndicate of four investors, led by Geneva, Switzerland-based Index Ventures. The other participants included BB Biotech Ventures, Johnson & Johnson Development Corp. and Endeavour Vision, of Geneva.
The agreement includes an option for additional funding. "It's a significant tranche we can get without additional fundraising," Zahnd said.
The current cash will fund the company's activities until the end of 2009, Zahnd said, by which time it aims to have its first drug candidate in the clinic. "We have a lead program. It's not public what exactly it is," Zahnd said. "We are a few months before the final selection of a lead [compound]." Several other earlier-stage programs also are under way.
Molecular Partners' DARPin protein format is based on the ubiquitous ankyrin repeat, which mediates protein-protein interactions among numerous protein families. It engineers diversity into the 33-amino-acid scaffold by randomizing up to seven amino acid residues.
DARPins, along with other novel protein formats, are attempting to overcome the disadvantages associated with monoclonal antibodies. They are considerably smaller in size - with a molecular weight of 15 to 20 kiloDaltons - and can be produced at very high efficiencies in bacterial expression systems. They have high-binding affinities, high-tissue penetration, are resistant to high temperatures and, Zahnd said, appear to be nonimmunogenic in mice and rabbits.
He attributes this to their stability - they tend not to aggregate into large complexes. Because of their small size, they are expelled quickly via the kidney, but their serum half-life easily can be extended using a variety of tools, he said.