Press Release

Cellectis S.A. announces the publication of a Current Gene Therapy article on Meganucleases and its Perspectives for Gene Therapy.

Romainville, France - March the 19^th, 2007 - Cellectis S.A., a biotechnology company specialized in genome engineering and developing a new range of products for the custom rewriting of DNA sequences for the research, healthcare and industrial fields, announced today the publication of a paper entitled "Meganucleases and DNA Double-Strand Break-Induced Recombination: Perspectives for Gene Therapy" in the Current Gene Therapy journal (http://www.bentham-direct.org) Volume 7, Issue 1, February 2007.

This article describes the recent development of artificial endonucleases with tailored specificities: custom designed endonucleases cleaving chosen sequences could be used to correct mutated genes or introduce transgenes in chosen loci. These results open the door to a wide range of new applications, including therapeutic ones. Such "targeted" approaches markedly differ from current gene therapy strategies based on the random insertion of a complementing virus-borne transgene. As a consequence, this new technology could offer a safer alternative as it should bypass the odds of random insertion. After a brief description of the origin of the technology, current systems based on redesigned endonucleases are presented, with a special emphasis on the recent advances in homing endonuclease engineering

About Cellectis S.A.

Cellectis S.A. is a biotech company developing innovative, proprietary technologies for genome engineering: a new class of "molecular scissors" - Meganuclease™ enzymes - capable of recognizing, binding and cutting DNA with extremely high specificity. The company is developing and commercializing Meganuclease Recombination Systems (MRSs) which combine these molecular scissors with a DNA matrix for targeting and modifying a gene of interest in vivo (and without affecting the rest of the genome) via the action of the cell's natural maintenance and repair system. By developing this first-in-class technology on the industrial scale, Cellectis has opened the way to rational genome engineering, which seeks to accurately and reliability insert, modify, modulate or correct genes in any living organism - without the addition of foreign genes, which are often imprecise and poorly tolerated. Cellectis now holds a portfolio of 8 MRSs in development, of which 5 have a therapeutic focus.
Founded in 2000 by André Choulika and David Sourdive, Cellectis is a spin-off from Institut Pasteur in Paris, which has granted the company exclusive rights to a portfolio of patents. The company holds a portfolio of 27 granted patents and 69 pending applications. Since its creation, Cellectis has raised 42 millions euros, including 24,4 million euros raised during the company's IPO on Alternext, in February 2007 (Alternext Paris: FR0010425595 - ALCLS), and 17,5 million euros in seed financing and VC rounds (in 2000 and 2002). The company's principal shareholders are AGF Private Equity, BankInvest Biomedical Venture, Edmond de Rothschild Investment Partners, Kaminvest Holding and Odyssée Venture; Institut Pasteur; as well as founders, employees and directors.
To date, Cellectis has signed 45 collaboration agreements and alliances worldwide with pharma companies (including AstraZeneca, Merck & Co., Wyeth and Shire), agrochemical groups (including Bayer, DuPont and BASF) and biotech companies (including Genentech, Regeneron and Lexicon Genetics) worldwide. Cellectis' corporate headquarters are located on the Biocitech biopark at Romainville near Paris. It currently has 40 staff, including 16 PhDs.
For more information on Cellectis, visit our web site: www.cellectis.com.