BioWorld International Correspondent

PARIS - Immutep SA initiated a Phase I trial of its lead compound, ImmuFact IMP321, in the indication of metastatic melanoma.

The product is being tested in a novel protocol combining adoptive T-cell transfer after transient lymphodepletion associated with peptide association.

ImmuFact IMP321 is a natural human T-cell immunostimulatory factor that amplifies the T-cell immune response in therapeutic vaccines through the activation of dendritic cells and more efficient antigen presentation to T cells. It can be used either as an immunopotentiator in therapeutic vaccines, or alone at higher doses as a monotherapy, or in combination with chemotherapy.

Immutep has carried out five earlier Phase I trials of IMP321, including one in metastatic renal cell carcinoma, which was completed in June 2006, and one in metastatic breast carcinoma, which was completed earlier this year. The last trial was the first in which chemoimmunotherapy - chemotherapy followed by immune stimulation - was used to treat metastatic breast cancer.

The melanoma trial is being conducted by the Fondation du Centre Pluridisciplinaire d'Oncologie in association with the Ludwig Institute for Cancer Research, both based in Lausanne, Switzerland. The protocol involves depleting the patient's lymphocytes using chemotherapy and then reinjecting autologous peripheral mononuclear cells including tumor-specific CD8 T cells. In addition, to further amplify the anti-tumor immune response during homeostatic proliferation in the immune reconstitution period, the patient also will receive a therapeutic cancer vaccine containing a peptide melanoma antigen (Melan-A/MARTI) and IMP321, as well as incomplete Freud's adjuvant.

Immutep is developing therapeutic vaccines for the treatment of cancer, infectious diseases and allergies based on the use of LAG-3, an immunomodulatory protein expressed on the surface of activated T cells. ImmuFact is one of three LAG-3-based product platforms it has developed, the other two being ImmuCcine, which is designed to produce immunostimulatory vaccines, and ImmuTune, which uses LAG-3 specific antibodies to control signaling of the membrane-bound LAG-3 molecule into activated effector T cells or regulatory T cells to modulate the T cell response.

Immutep, which was founded in 2001, has completed two €2.5 million (US$3.4 million) funding rounds, the second of which dates back to January 2005. In summer 2006, the company indicated that it was engaged in a third funding round in which it hoped to raise up to €13 million, but closure has taken longer than expected.