Belgium drug developer Ablynx and UK-based Spirogen have entered into a research collaboration to discover and develop novel anticancer drug conjugates combining Spirogen's proprietary cytotoxic drugs, pyrrolobenzodiazepines (PBDs), and the company's associated linker technology, with nanobodies generated using Ablynx's proprietary technology platform.

Under the terms of the collaboration, Ablynx will provide access to its novel nanobodies against a specific undisclosed cancer target and Spirogen will provide access to its proprietary PBDs and conjugation technologies. The collaboration is expected to last for up to one year initially. Both companies have agreed to contribute their resources towards the collaboration.

Once this feasibility phase is completed, Ablynx will have the option to either in-license Spirogen's technology or, in collaboration with Spirogen, move development forward with a third party. No further terms have been disclosed.

"We are very pleased to be working with Spirogen to discover and develop novel cancer therapeutics based on both companies' proprietary technologies. Our nanobodies have the potential to selectively and efficiently deliver Spirogen's PBD drugs to the site of the tumour. We are very excited about combining our unique and powerful technology with Spirogen's novel cytotoxic agents to search for breakthrough opportunities in oncology," Dr Andreas Menrad, Chief Scientific Officer of Ablynx, said in a press statement.

"The collaboration with Ablynx is designed to evaluate the potential of a Nanobody to act as the targeting molecule for the PBD warhead, which is released once it is inside the cancer cell. These warheads have the potential to be extremely potent without distorting the DNA helix thus avoiding mechanisms that lead to tumours becoming resistant to other anti-cancer drugs," commented Dr Chris Martin, Chief Executive Officer of Spirogen in the same statement.

Ablynx's nanobody platform consists of antibody-derived therapeutic proteins that have unique structural and functional properties of naturally-occurring heavy-chain antibodies. The nanobody technology was originally developed after it was discovered that camelidae (camels and llamas) possess fully functional antibodies despite the lack of light chains. These heavy-chain antibodies contain a single variable domain (VHH) and two constant domains (CH2 and CH3). The VHH domain can be cloned and isolated to form a perfectly stable polypeptide harbouring the full antigen-binding capacity of the original heavy-chain antibody.

Antibody drug conjugates are highly targeted drug constructs with monoclonal antibodies specific to particular types of tumour cells attached to potent cytotoxic agents. These antibodies bind to specific receptors or antigens present on the surface of the tumor cells where the cytotoxic agent is then released. This selective killing of tumor cells minimizes the impact on normal, healthy tissues and significantly reduces the side effects associated with chemotherapy treatments. The principle can also be applied beyond antibodies, with the possibility of linking anticancer agents to antibody fragments, peptides, vitamins and hormones.