GHENT, Belgium–Antibody specialist Ablynx recently announced an R&D and licensing deal with the National Research Council of Canada's Institute for Biological Sciences (NRC-IBS), based in Ottawa. Under the terms of the agreement, the two groups will cooperate on the development of Nanobodies, novel therapeutics proteins derived from single-chain antibodies, which both groups had previously studied independently.
The R&D component of the agreement will see Ablynx fund further study of two Nanobodies generated by the NRC-IBS that are capable of efficiently crossing the blood-brain barrier (BBB), a physiological construct that normally prevents circulating compounds from reaching the brain. The licensing component gives Ablynx access to any subsequent intellectual property generated by the BBB-crossing Nanobodies.
According to Dr. Mark Vaeck, Ablynx CEO, a Nanobody is a functional single antigen-binding domain–also called the "VH domain"–derived from an antibody heavy chain.
"All Nanobodies contain the unique structural features of the antigen-binding domain of a naturally occurring antibody that functions without a light chain," he says. "This means that Nanobodies are a novel class of therapeutic proteins that combine the beneficial features of conventional antibodies with desirable properties of small-molecule drugs."
"The goal of the collaboration is to create bi-specific antibodies that target Alzheimer's disease and brain tumors," says Dr. Danica Stanimirovic, director of the Neurobiology Program at NRC-IBS. "A Nanobody isolated by the Belgium group that 'attacks' beta-amyloid found in amyloid plaques in the brain of Alzheimer's disease patients will be 'fused' with the second Nanobody isolated by NRC-IBS researchers that can cross the BBB and, thus, deliver the 'therapeutic Nanobody' into the brain.
"A similar approach will be applied with another Nanobody that 'targets' a receptor expressed by deadly brain tumors called glioblastomas. Animal studies will then be conducted to assess success of these bi-specific Nanobodies in reaching the brain targets."
As potential therapeutics, Nanobodies seem to combine the best of both worlds. They offer researchers the binding affinity and specificity of antibodies, with the small size, stability, and pharmacokinetics of small molecules. Similarly, according to Vaeck, Nanobodies do not present the toxicity issues that many small molecules do and so their development time is shorter and less risky.
"Nanobodies can be developed for all diseases that are currently addressed by conventional antibodies," he says. "However, due to their small size and unique properties, they will also be able to address disease targets that are inaccessible to conventional antibodies."
Given the researchers' abilities to develop Nanobodies that target a wide range of molecules, Stanimirovic believes that they can be broadly applied both in human and animal health as diagnostics and therapeutics.