Exhibit 99.1

Cellectis Announces Presentation at the 34th Annual J.P. Morgan Healthcare Conference in San Francisco, January 11 - 14, 2016

NEW YORK--(BUSINESS WIRE)--December 21, 2015--Regulatory News:

Cellectis (Paris:ALCLS) (NASDAQ:CLLS) (Alternext: ALCLS – Nasdaq: CLLS), a biopharmaceutical company focused on developing immunotherapies based on gene edited CAR-T cells (UCART), today announced that it will be presenting at the 34th Annual J.P. Morgan Healthcare Conference.

The Cellectis presentation will take place on Thursday, January 14, 2016, at 10:30AM Pacific Time, followed by a Q&A session at 11:00AM Pacific Time, at the Westin St. Francis Hotel, San Francisco, California.

About Cellectis

Cellectis is a biopharmaceutical company focused on developing immunotherapies based on gene edited engineered CAR-T cells (UCART). The company’s mission is to develop a new generation of cancer therapies based on engineered T-cells. Cellectis capitalizes on its 15 years of expertise in genome engineering - based on its flagship TALEN® products and meganucleases and pioneering electroporation PulseAgile technology - to create a new generation of immunotherapies. CAR technologies are designed to target surface antigens expressed on cells. Using its life-science-focused, pioneering genome-engineering technologies, Cellectis’ goal is to create innovative products in multiple fields and with various target markets. Cellectis S.A. is listed on the Nasdaq Global Market (ticker: CLLS) and on the NYSE Alternext market (ticker: ALCLS). To find out more about us, visit our website: www.cellectis.com

Talking about gene editing? We do it.
TALEN® is a registered trademark owned by the Cellectis Group.

Disclaimer

This press release and the information contained herein do not constitute an offer to sell or subscribe, or a solicitation of an offer to buy or subscribe, for shares in Cellectis in any country. This press release contains forward-looking statements that relate to the Company’s objectives based on the current expectations and assumptions of the Company’s management only and involve risk and uncertainties that could cause the Company to fail to achieve the objectives expressed by the forward-looking statements above.

CONTACT:
For further information:
Cellectis
Jennifer Moore, 917-580-1088
VP Communications
media@cellectis.com
or
KCSA Strategic Communications
Caitlin Kasunich, 212-896-1241
ckasunich@kcsa.com
or
Simon Harnest, 646-385-9008
VP Finance and Investor Relations
simon.harnest@cellectis.com