Invasion of the Nanobodies
Can they crack a $15-billion global market?
September 11, 2006 Print Issue
Although monoclonal antibodies (MAbs) are among the most effective means to treat complex diseases such as cancer, these big-molecule drugs come with a long list of caveats. They must be administered through injection, have a short shelf life, and must be stored at near-freezing temperatures.
Side effects are also plentiful and treatments expensive.
Finding a way around these shortcomings has been the goal of Belgian biotech firm Ablynx. The Ghent-based company’s technology is based on the serendipitous discovery that camels and llamas have antibodies in their bloodstream that are much smaller and more stable than those in other animals. The therapeutic proteins that Ablynx has derived from dromedary donors are called “nanobodies”—and they’re approximately one-tenth the size of MAbs.
Over the last several years, Ablynx has developed nanobodies that work against more than 20 different disease targets including rheumatoid arthritis, Alzheimer’s disease, and some cancers. In addition to obtaining positive in vivo efficacy data in advanced primate studies, the company has yet to detect any deleterious immune response.
While nanobodies have yet to be tested in humans, investors are very excited about their human potential. On August 23, Ablynx raised $51 million in financing from a syndicate of investors, including Belgium’s leading bank, KBC, and the venture capital arm of GlaxoSmithKline, SR One.
Unlike conventional MAbs, nanobodies can penetrate the Blood Brain Barrier and other tissues. Nanobodies can also engage with targets that cannot be addressed by MAbs available today, according to a company source.
Ablynx is not alone in the race to produce a more efficient type of therapeutic antibody. In the United Kingdom, Cambridge-based Domantis, also privately held, is developing treatments based on human Domain Antibodies (dAbs). The company has so far raised over $83 million from investors, including Novo Nordisk and MC (Mitsubishi Corporation) Life Science Ventures.
Domantis CEO Robert Connelly notes that dAbs, which are similar in size to nanobodies, are fully human in nature, completely mimicking the human structure, while nanobodies are derived from camelids. “dAbs are extraordinarily rugged and can be frozen, boiled, formulated in powder or solution with no loss of biological activity,” Mr. Connelly adds.
Will the littlest antibodies win the day? There’s a lot of money betting on it. But only human trials, expected to begin for both companies in 2007, will tell. |
