BioWorld International Correspondent

Pepscan Systems BV and Cytos Biotechnology AG entered a research and license option agreement in which the companies will combine their expertise in epitope mapping and immune response induction in the development of a therapeutic vaccine candidate against an undisclosed cytokine target.

Cytos has options to in-license products and technologies for further commercial development. Financial terms were not revealed, but the companies will shortly disclose another agreement involving a second target, said Pepscan's chief commercial officer, Peter van Dijken.

In the first project, Pepscan, of Lelystad, the Netherlands, will employ its Chemically Linked Peptides on Scaffolds (CLIPS) platform to map and then reconstruct the cytokine's 3-dimensional receptor interaction site, which will be the target of a Cytos Immunodrug. The latter platform comprises a virus-like particle that induces neutralizing antibody or T-cell responses by presenting antigenic epitopes to the immune system in highly repetitive arrays. Cytos, of Zurich, Switzerland, will be responsible for preclinical and clinical development of whatever vaccine candidates emerge from the collaboration.

Efforts to develop vaccines based on linear peptide sequences have had limited success to date, van Dijken said. Pepscan's CLIPS platform enables it to generate constructs comprising one or more defined peptides linked to a chemical template that retain their biologically active 3-dimensional loop configuration.

The approach can bypass the problems associated with epitope mapping of highly hydrophobic membrane proteins. It also can be cheaper than working with full recombinant proteins. Even when they are available, he said, they might not induce the optimum immune response.

"It's not always perfect to use a whole protein," he said.

Most of Pepscan's external agreements to date have been fee-for-service assignments. The Cytos deal arose, he said, because of the fit between the companies' respective platforms. It has disclosed just one other collaborative agreement so far: UK firm PowderJect Pharmaceuticals licensed a preclinical prostate cancer vaccine candidate. That program survived PowderJect's acquisition by Emeryville, Calif.-based Chiron Corp.

"That was very encouraging for us," van Dijken said. The program is about to enter the clinic. "In the next couple of months we will probably start recruiting patients for the combined Phase I and Phase II study."

No Comments