Cyclacel Obtains Worldwide Rights to Penetratin®

DUNDEE - 9 July 1998 - Cyclacel Limited ("Cyclacel"), the cancer therapeutics company, has obtained worldwide commercial rights to Penetratin®, a proprietary peptide with unique drug carrier properties, from the Centre National de Recherche Scientifique (CNRS) of Paris, France. In addition to exploitation for its own programmes, Cyclacel has been approached by several companies seeking sub-licences.

The exclusive licence covers cancer (in cancers of the central nervous system the licence is co-exclusive) and other therapeutic applications, including auto-immune, cardiovascular, dermatological and inflammatory diseases. Under the terms of the agreement, Cyclacel will pay CNRS an upfront fee, milestone payments and royalties on future sales. Specific financial terms were not disclosed.

Spiro Rombotis, Chief Executive of Cyclacel, said: "Obtaining rights to Penetratin is our first in-licensing deal and an important addition to Cyclacel's portfolio. David Lane, Cyclacel's Chief Scientific Officer, was one of the first to recognise the potential of this technology during a collaboration with Dr Alain Prochiantz, the French researcher who discovered Penetratin. After initially obtaining rights in the cancer field, we quickly realised Penetratin's versatility and expanded our license to cover a number of other applications where we believe we can add value."

Dr Alain Prochiantz, CNRS, said: "I was pleased that David Lane collaborated with me on the unusual potential of this exciting technology. I am delighted that Cyclacel are taking it forward." Initially Cyclacel plans to use this technology in conjunction with its Pimetic™ drug candidates (cell cycle control peptide mimics) which require an efficient delivery system. Penetratin is widely used for research purposes by many academic and industrial groups some of whom have approached Cyclacel seeking to sub-license rights. Penetratin is protected by one issued patent (and foreign equivalents) and certain pending applications.

Penetratin Nuclear Transport Protein
Penetratin is a short, 16 aminoacid, component of the Antennapaedia homeodomain protein first identified in the Drosophila species. Although its mechanism of action is not completely understood, it is proposed that its ability of rapidly penetrating into live cells and of being targetted to the cell cytoplasm and nucleus is not based on chiral recognition by a classical receptor. Many groups seeking low toxicity, high labelling efficiency, cytoplasmic and nuclear transport of peptides and other cargos have published encouraging results with Penetratin. Penetratin's performance advantage over other carrier systems appears to lie in its rapid clearance from serum and very efficient labelling of over 90% of target cells. This efficiency and the absence of particular tissue specificity make Penetratin an attractive vehicle for delivering cancer therapeutics addressing metatastic disease. In tests so far, Penetratin has demonstrated a benign profile with regard to immunogenicity or other toxicities. The size of molecule that can be carried by Penetratin as cargo has been demonstrated to exceed Penetratin's own size by several orders of magnitude. Its resilient thermodynamic stability suggests many intriguing possibilities for exploiting Penetratin's properties as a small molecule drug carrier.