Portfolio Overview

IL-7 -- The lead compound, a recombinant Interleukin-7 (rIL-7) -- the EPO of the immune system -- is a pivotal growth factor with unique features to rebuild the immune system and enhance global and specific immune response. Acquired in 1999 under a worldwide exclusive license from sanofi-aventis, IL-7 is a non-redundant and pleiotropic growth factor for T-cell homeostasis and plays an important role at various stages of T cell development, from T cell precursors in the bone marrow to mature T cells in the periphery. The homeostatic effect of IL-7 is characterized by the expansion of T cells (CD4 and CD8) through thymopoiesis stimulation and peripheral T cell expansion.

IL-7 is also known to enhance antigen specific T cell responses and is key to the activation and proliferation of effector T cells. Recent publications show that this antigen-specific effect is favored by the generation and maintenance of memory T cells which are critical to triggering an efficient and sustained immune response.

IL-7 is now entering a second round of more extensive Phase I/II clinical studies in the US and Europe. Further therapeutic indications will include immuno-deficit settings (such as HIV infection and post bond marrow transplant) as well as situations where specific immune response with existing therapies needs to be enhanced (hepatitis C, cancer, and HIV).

NKT Ligands -- The second family of products being developed by Cytheris consists of NKT ligands in-licensed from New York University, the Aaron Diamond AIDS Research Center and the City University of New York. This family consists of highly potent and specific ligands that activate NKT and dendritic cells.

NKT cells, considered a critical hinge between the innate and adaptive arms of the immune system, play a pivotal role in prompting many infection- and disease-fighting immune cells to act against pathogens and cancer. Dendritic cells are at the heart of the immune system's activities, processing and presenting antigens to the immune system.

The interaction of NKT cells with dendritic cells results in the production of many immune-enhancing cytokines acting on immune system cells so that they can expand or differentiate, or develop into, helpers or killers focused on removing an antigen. These new ligands specifically trigger the local release of gamma-Interferon and IL-12, two potent Th-1 inducing cytokines.

These ligands are being investigated for their potential as a stand-alone therapeutic agent and as therapeutic or prophylactic vaccine adjuvants. Proof of concept has been validated in various animal models, confirming high potency at very low doses together with the high specificity of those products.