Cytheris SA is a privately held company founded in January 1999 with the financial support of the founder and several angel investors. In April 1999, the company signed an exclusive worldwide in-licensing agreement with sanofi-aventis on the basic patents protecting Interleukin-7 (IL-7).

In July 2002 Cytheris raised €7 million (US$10.4 million) in a Series B round of venture financing led by Bioam Gestion of Paris and including two Canadian funds, GestionT2C2/Bio and CDP Capital Technology Ventures (a subsidiary of Caisse de Dépôt et Placement du Québec), and two French funds, AXA Private Equity and Crédit Agricole Private Equity.

In 2003, Cytheris established a US subsidiary in Rockville, Maryland, and was granted its first Phase I IND by the US Food and Drug Administration for its recombinant Interleukin-7 (rIL-7). Since then, additional clinical studies have been launched in various indications in Europe and in the US in immuno-deficit settings.

The Company’s first Phase I study in oncology was completed early in 2005 in collaboration with the US National Cancer Institute.

In October 2006, Cytheris raised new venture financing of more than €24 million (US$30 million) in a Series C round led by CDC Innovation (France) and including ABN AMRO Capital Life Sciences (now: Forbion Capital Partners, Netherlands) as a new investor, together with all five previous investors.

In February 2007, Cytheris completed a full set of five clinical Phase I studies of its recombinant IL-7, confirming good product tolerance and a broad spectrum of lymphopoietic activities in cancer and HIV infected patients.  The company has since launched Phase I/IIa studies in HIV, HBV and HCV, and continues to investigate IL-7 in a variety of indications.

In June of 2010, Cytheris raised additional venture financing in a Series D round of €12 million (US$15 million). In this most recent round, new investor, CDC Entreprises (France), acting for the Strategic Investment Fund (FSI), participated in the round along with existing investors Bioam Gestion, Caisse de Dépôt et Placement du Québec, CDC Innovation, Crédit Agricole Private Equity, and Forbion Capital Partners.