DNA Therapeutics announces highly significant efficacy against xenografted tumors in animals thanks to its molecule Dbait, in association with standard radiotherapy EVRY (France), November 7, 2006. DNA Therapeutics S.A. announced today that an abstract of its presentation at the 18th EORTC-NCI-AACR Symposium "Molecular Targets and Cancer Therapeutics" (Prague) is now on line (www.fecs.be/emc.asp?pageId=1321). The presentation itself will be available from November 10 onwards at (www.dna-therapeutics.com/content.php?idcontent=events&lg=en). Xenografted nude mice proof of concept: Kaplan Meier median survival for nude mice grafted with human tumor cell lines (head & neck squamous cell cancer, melanoma), treated by intra-tumoral Dbait, in association with radiotherapy, at nil, 1, 3 and 6 nanomoles, is dose dependent and respectively of 61, 93, 129 and > 150 days. Hazard ratios, compared to the nil group, are 0.42 (p<0.01), 0.28 (p<0.0004), 0.18 (p<0.000004). MRI follow-up of mice shows therapy induced necrosis of the tumor with Dbait superior to radiotherapy alone. How does Dbait work: Cancer therapies induce DNA double strand breaks (DSBs), but unfortunately cells possess DNA repair complexes which are attracted to these breaks, and repair them. Dbait is a short inhibiting DNA (siDNA) which mimicks DSBs, diverting them from their primary objective, and allows cancer cells to be killed. Physico-chemical facts: The Dbait used is a 32-bp double stranded modified DNA molecule. Its activity is length/structure dependent (mimicking a break) and not linked to the nature of its sequence. Biological facts: Before going into nude mice, DNA Therapeutics demonstrated that in vitro Dbait inhibits religation of DNA fragments, and traps one of the first elements of the repair complexes: the Ku70/Ku80 heterodimer. From then on the repair system is completely disorganized: DNA-PKcs is activated, and histone H2AX is phosphorylated, but they fail in their repair task. Commercial potential: J.S. Sun, CEO of DNA Therapeutics said: "we have already had a first meeting with regulatory authorities. We expect to initiate clinical trials by 4Q07/1Q08. In view of the breadth of indications open to us, and of course if we continue to meet with success, peak sales are expected beyond the $ 1 billion range". DNA Therapeutics S.A.: DNA Therapeutics S.A., founded in May 2006, as a spinoff from the Curie Institute, the CNRS, the INSERM (French NIH) and the Museum National d’Histoire Naturelle, is the premier corporation developing DNA baits to trap and inhibit enzyme complexes involved in DNA repair. It is headquartered in the Genopole Science Park (Evry, France). GENOPOLE Premier bioparc français dédié à la recherche en génétique et aux biotechnologies, Genopole® rassemble sur un même site de 90 000 m2, des laboratoires de recherche privés et publics, des entreprises de biotechnologies ainsi que des formations universitaires (Université d’Evry Val d’Essonne). Avec 23 laboratoires de recherche sur le campus et un portefeuille de plus de 60 entreprises de biotechnologies, l’innovation à visée thérapeutique est au cœur des préoccupations des acteurs de Genopole®. Son objectif : Favoriser le développement de la recherche en génomique, post-génomique et sciences associées et le transfert de technologies vers le secteur industriel, développer des enseignements de haut niveau dans ces domaines, créer et soutenir des entreprises de biotechnologies. www.genopole.fr Contacts DNA Therapeutics: Pr.Jian Sheng Sun, Ph.D. Chairman and CEO +33 624 753 239 [email protected] www.dna-therapeutics.com Contact Genopole Communication: Bénédicte Robert, 01 60 87 83 10 – [email protected] Tony Marcel, MD, PhD Vice-Chairman of the Board +33 147 556 195, cell +33 609 165 382 [email protected]