BioWorld International Correspondent
Molecular Partners AG entered a research collaboration with F. Hoffmann-La Roche Ltd. under which it will investigate the potential of its DRP technology against targets provided by Roche.
Molecular Partners, of Zurich, Switzerland, will select DARPins to undisclosed Roche targets. DARPins are a class of binding proteins from the company's designed repeat protein technology.
Terms of the transaction were not disclosed, but the deal highlights the growing interest on the part of large pharmaceutical firms in both antibody fragments and in novel protein recognition molecules based on non-antibody scaffolds, which are smaller, less complex and easier to manufacture than full-sized monoclonal antibodies.
Last week, New York-based Bristol-Myers Squibb Co. entered a pact in oncology - potentially worth more than $1.2 billion - with Waltham, Mass.-based Adnexus Therapeutics Corp., involving the latter firm's adnectins, which are based on a domain of the human protein fibronectin. A nanobody platform developed by Ghent, Belgium-based Ablynx NV recently attracted deals worth up to $265 million and $212.5 million, respectively, with Ingelheim, Germany-based Boehringer Ingelheim and Madison, N.J.-based Wyeth. And Thousand Oaks, Calif.-based Amgen Inc. acquired Mountain View, Calif.-based Avidia Inc. last fall in a cash deal valued at up to $450 million. That gave Amgen access to Avidia's Avimer technology, which is based on domains derived from cell surface receptors.
Molecular Partners was spun out of the Department of Biochemistry at the University of Zurich in 2004 to commercialize several classes of repeat binding proteins developed in the lab of Andreas Plückthun. The most advanced of these are called DARPins. Those protein-recognition molecules are based on repeat structures found in ankyrins, which are ubiquitously expressed intracellular membrane adaptor proteins that link proteins involved in several functions to the cell's cytoskeleton.
Molecular Partners is developing the agents as potential drug candidates and as a means of targeting other therapies more precisely than can be done at present. It engineers diversity into the scaffold by making several amino acid substitutions in each subunit. "We randomize up to seven positions per repeat," CEO Christian Zahnd told BioWorld International.
A functioning DARPins comprises several such repeats but still has a molecular weight of just 15 to 20 kilodaltons, about one-tenth of an antibody. They can be expressed in E. coli and have a very high melting point, typically above 60 degrees Celsius, said Chief Business Officer Patrick Amstutz. "It's just one single brick. That's what makes it so stable," he said.
Working with a fermentation partner, the company has obtained manufacturing yields of 10 grams per liter. "It's one of the best-expressed proteins of all," Amstutz said.
Roche is a "dream customer" for the company, Zahnd said, because of its strong position in biologic drugs. "It's a very broad set of applications that they are thinking of," he said.
In November, Molecular Partners entered a similar collaboration, focused on oncology and diagnostic applications, with Schering AG, now part of Berlin-based Bayer Schering Pharma AG.
The company also has several internal development programs under way, the first of which could reach the clinic by the end of 2009, Zahnd said. The company is currently in the process of closing a Series A funding round, he said.