Beyond Antibodies: The DARPin Drug Platform.

The DARPin drug platform was established with a vision to expand the medical use of biologics beyond what was possible with monoclonal antibodies. It is based on naturally occurring ankyrin repeat domains that are typically building blocks of multifunctional human proteins. The platform allows for the generation of diverse, well-behaved, multifunctional drug candidates. Recent clinical data illustrate the favorable safety profile of the first DARPin molecules tested in patients. With the positive phase III results of the most advanced DARPin drug candidate, abicipar, the DARPin drug platform is potentially about to achieve its first marketing approval. This review highlights some of the key milestones and decisions encountered when transforming the DARPin platform from an academic concept to a biotech drug pipeline engine.